JP2005043381A

JP2005043381A - Thermal infrared detector and method for manufacturing the same

Info

Publication number: JP2005043381A
Application number: JP2004303313A
Authority: JP
Inventors: Naoki Oda; 直樹小田
Original assignee: NEC Corp
Current assignee: NEC Corp
Priority date: 2004-10-18
Filing date: 2004-10-18
Publication date: 2005-02-17

Abstract

【課題】熱型赤外線検出器の開口率を高め、熱時定数を殆ど増加させずに感度を高くする。
【解決手段】コンタクトパッドを有するシリコン基板１に赤外線反射膜２と第１の絶縁保護膜３が積層され、赤外線受光部５が支持部６によって、第１の絶縁保護膜３の表面から空洞部４を隔てて支持されている。赤外線受光部５は、温度検出部（サーミスターボロメータ薄膜７）と、それを覆う第１の赤外線吸収部（絶縁保護膜８）と、電極部１３とからなる。絶縁保護膜８の表面から第２の赤外線吸収部（庇部１２）が突出し、赤外線受光部５の縁部または電極部１３の内側から赤外線受光部５の外側に向けて延び、電極部１３、支持部６、コンタクトパッドを覆っている。絶縁保護膜８の中央部は庇部１２の中央開口を介して赤外線の入射方向に露出しており、絶縁保護膜８と庇部１２の赤外線入射可能な総面積は、絶縁保護膜８の基板１と反対側の面積よりも大きい。
【選択図】図２
PROBLEM TO BE SOLVED: To increase the aperture ratio of a thermal infrared detector and increase the sensitivity without substantially increasing the thermal time constant.
An infrared reflecting film 2 and a first insulating protective film 3 are laminated on a silicon substrate 1 having a contact pad, and an infrared light receiving part 5 is supported by a support part 6 from a surface of the first insulating protective film 3 to a cavity part. 4 is supported. The infrared light receiving unit 5 includes a temperature detection unit (thermistor bolometer thin film 7), a first infrared absorption unit (insulating protective film 8) covering the temperature detection unit (thermistor bolometer thin film 7), and an electrode unit 13. A second infrared ray absorbing portion (protrusion portion 12) protrudes from the surface of the insulating protective film 8, and extends from the edge of the infrared ray receiving portion 5 or the inside of the electrode portion 13 toward the outside of the infrared ray receiving portion 5, The support 6 and the contact pad are covered. The central portion of the insulating protective film 8 is exposed in the infrared incident direction through the central opening of the flange portion 12, and the total area of the insulating protective film 8 and the flange portion 12 that can receive infrared rays is the substrate of the insulating protective film 8. It is larger than the area opposite to 1.
[Selection] Figure 2

Description

本発明は、赤外線を受ける受光部が梁等によって基板から空間を隔てて支持された構造、いわゆる熱分離構造を有する高開口率の熱型赤外線検出器およびその製造方法に関する。 The present invention relates to a high-aperture-rate thermal infrared detector having a structure in which a light receiving portion receiving infrared rays is supported by a beam or the like with a space from a substrate, a so-called thermal separation structure, and a method for manufacturing the same.

熱分離構造を有する熱型赤外線検出器の開口率（フィルファクター）を向上させるために、特許文献１に記載された赤外線固体撮像素子の構造や、非特許文献１に記載された熱型赤外線検出器アレイの構造等が提案されている。図２１は、熱分離構造を有する従来の熱型赤外線検出器として、特許文献１に記載された二次元赤外線固体撮像素子を示す断面図である。図２１には、二次元赤外線固体撮像素子の１個の画素における電流経路に沿った断面が示されている。図２２は、図２１に示した二次元赤外線固体撮像素子の１個の画素における赤外線吸収部を除いた部分の平面図である。図２３は、特許文献１に記載された二次元赤外線固体撮像素子の別の例を示す断面図である。また、図２４は、熱分離構造を有する従来の熱型赤外線検出器として、非特許文献１に記載された熱型赤外線検出器アレイを示す断面図である。 In order to improve the aperture ratio (fill factor) of a thermal infrared detector having a thermal separation structure, the structure of an infrared solid-state imaging device described in Patent Document 1 or the thermal infrared detection described in Non-Patent Document 1 A structure of a container array has been proposed. FIG. 21 is a cross-sectional view showing a two-dimensional infrared solid-state imaging device described in Patent Document 1 as a conventional thermal infrared detector having a thermal separation structure. FIG. 21 shows a cross section along a current path in one pixel of the two-dimensional infrared solid-state imaging device. FIG. 22 is a plan view of a portion excluding the infrared absorbing portion in one pixel of the two-dimensional infrared solid-state imaging device shown in FIG. FIG. 23 is a cross-sectional view showing another example of the two-dimensional infrared solid-state imaging device described in Patent Document 1. FIG. 24 is a cross-sectional view showing a thermal infrared detector array described in Non-Patent Document 1 as a conventional thermal infrared detector having a thermal separation structure.

まず、図２１および図２２に示される従来の熱型赤外線検出器について説明する。図２１に示すようにシリコン基板１００の表面には、空洞部１０４となる凹部が形成されている。シリコン基板１００に形成された空洞部１０４の上に、シリコン基板１００の表面に積層された絶縁膜１０８，１０９等から成る梁１０２，１０３がある。絶縁膜１０８，１０９のそれぞれの厚さは数百ｎｍであり、梁１０２，１０３の厚さ、すなわちシリコン基板１００上の絶縁膜の厚さの合計が１μｍ程度となっている。梁１０２，１０３のそれぞれの幅は１〜３μｍ程度となっている。 First, the conventional thermal infrared detector shown in FIGS. 21 and 22 will be described. As shown in FIG. 21, a recess that becomes the cavity 104 is formed on the surface of the silicon substrate 100. On the cavity 104 formed in the silicon substrate 100, there are beams 102 and 103 made of insulating films 108 and 109 and the like laminated on the surface of the silicon substrate 100. The thickness of each of the insulating films 108 and 109 is several hundred nm, and the total thickness of the beams 102 and 103, that is, the thickness of the insulating film on the silicon substrate 100 is about 1 μm. The width of each of the beams 102 and 103 is about 1 to 3 μm.

梁１０２，１０３はそれぞれ、サーミスターボロメータ薄膜１０１を含む温度検出部１０５を空洞部１０４の上で浮かして支持している。これらの絶縁膜１０８，１０９はそれぞれ、温度検出部１０５からシリコン基板１００への熱の流出を制御する熱抵抗の大きい材料であるシリコン窒化膜またはシリコン酸化膜等から成る。これら２つの絶縁膜１０８，１０９は、梁１０２，１０３および温度検出部１０５の機械的構造を形成して温度検出部１０５を支えている。 Each of the beams 102 and 103 floats and supports the temperature detection unit 105 including the thermistor bolometer thin film 101 on the cavity 104. These insulating films 108 and 109 are each made of a silicon nitride film or a silicon oxide film, which is a material having a high thermal resistance for controlling the outflow of heat from the temperature detection unit 105 to the silicon substrate 100. These two insulating films 108 and 109 form a mechanical structure of the beams 102 and 103 and the temperature detection unit 105 to support the temperature detection unit 105.

絶縁膜１０８と１０９との間には金属配線１０６，１０７が形成されている。金属配線１０６，１０７のそれぞれの一端がサーミスターボロメータ薄膜１０１に接続されている。金属配線１０６の他端は、絶縁膜１０９に形成されたコンタクト部１１０を介して、図２２に示されるようにシリコン基板１００上に設けられた信号線２０２と電気的に接続されている。図２１では、シリコン基板１００上に設けられた信号線２０２が省略されている。金属配線１０７の他端は、絶縁膜１０９に形成されたコンタクト部１１１を介して信号読出回路２０１と電気的に接続されている。すなわち、サーミスターボロメータ薄膜１０１が、金属配線１０６，１０７およびコンタクト部１１０，１１１を介して信号読出回路２０１と電気的に接続されている。図２１では、シリコン基板１００上に設けられた信号読出回路２０１が省略されている。 Metal wirings 106 and 107 are formed between the insulating films 108 and 109. One end of each of the metal wirings 106 and 107 is connected to the thermistor bolometer thin film 101. The other end of the metal wiring 106 is electrically connected to a signal line 202 provided on the silicon substrate 100 through a contact portion 110 formed in the insulating film 109 as shown in FIG. In FIG. 21, the signal line 202 provided on the silicon substrate 100 is omitted. The other end of the metal wiring 107 is electrically connected to the signal readout circuit 201 through a contact portion 111 formed in the insulating film 109. That is, the thermistor bolometer thin film 101 is electrically connected to the signal readout circuit 201 via the metal wirings 106 and 107 and the contact portions 110 and 111. In FIG. 21, the signal readout circuit 201 provided on the silicon substrate 100 is omitted.

一方、温度検出部１０５の、空洞部１０４側と反対側の面には、接合柱１１３を介して赤外線吸収部１１２が接合されている。赤外線吸収部１１２は、赤外線を吸収して熱に変換する部分であり、シリコン窒化膜またはシリコン酸化膜、あるいはそれらの積層膜等により構成されている。接合柱１１３は、赤外線吸収部１１２を温度検出部１０５から離して保持すると共に赤外線吸収部１１２と温度検出部１０５とを熱的に結合している。接合柱１１３も赤外線吸収部１１２と同様に、シリコン窒化膜またはシリコン酸化膜、あるいはそれらの積層膜等により構成されている。接合柱１１３の寸法としては、太さが数μｍで、長さが１〜２μｍであることが好ましく、接合柱１１３の形状は任意である。 On the other hand, an infrared absorption unit 112 is bonded to the surface of the temperature detection unit 105 opposite to the cavity 104 side via a bonding column 113. The infrared absorbing portion 112 is a portion that absorbs infrared rays and converts the infrared rays into heat, and is constituted by a silicon nitride film, a silicon oxide film, or a laminated film thereof. The joining column 113 holds the infrared absorption unit 112 apart from the temperature detection unit 105 and thermally couples the infrared absorption unit 112 and the temperature detection unit 105. Similar to the infrared absorption portion 112, the bonding pillar 113 is also composed of a silicon nitride film, a silicon oxide film, or a laminated film thereof. The dimensions of the joining column 113 are preferably several μm in thickness and 1 to 2 μm in length, and the shape of the joining column 113 is arbitrary.

熱型赤外線検出器では、赤外線吸収部に赤外線が照射されると、赤外線吸収部に赤外線が吸収されて、その赤外線吸収部の温度が上昇する。そして、赤外線吸収部の温度変化を検出することによって、赤外線吸収部に照射された赤外線が検出される。従って、図２１および図２２に示した従来の熱型赤外線検出器は、主に赤外線吸収部１１２と温度検出部１０５とから構成されている。この熱型赤外線検出器では、赤外線吸収部１１２に入射した赤外線によって赤外線吸収部１１２に生じる温度変化が、接合柱１１３を介して温度検出部１０５へと伝えられる。そして、温度変化による温度検出部１０５の特性変化、具体的には図２１および図２２に示されるサーミスターボロメータ薄膜１０１の電気抵抗の変化を検出することによって、赤外線吸収部１１２の温度変化を検出する。 In the thermal infrared detector, when infrared rays are irradiated on the infrared absorbing portion, the infrared rays are absorbed by the infrared absorbing portion, and the temperature of the infrared absorbing portion rises. And the infrared rays irradiated to the infrared absorption part are detected by detecting the temperature change of the infrared absorption part. Therefore, the conventional thermal infrared detector shown in FIG. 21 and FIG. 22 mainly includes an infrared absorber 112 and a temperature detector 105. In this thermal infrared detector, a temperature change generated in the infrared absorption unit 112 due to infrared rays incident on the infrared absorption unit 112 is transmitted to the temperature detection unit 105 via the joining column 113. Then, the temperature change of the infrared absorption unit 112 is detected by detecting the characteristic change of the temperature detection unit 105 due to the temperature change, specifically, the change of the electrical resistance of the thermistor bolometer thin film 101 shown in FIGS. To do.

図２２には、１個の画素２００の全体と、その１個の画素２００における信号読出回路２０１の一部が示されている。画素２００に設置された信号読出回路２０１は、ＭＯＳトランジスタやダイオード等から構成されている。この信号読出回路２０１にはコンタクト部２０５が形成されている。そのコンタクト部２０５が金属配線２０４を介して、制御クロックバスライン２０３に形成されたコンタクト部２０６と接続されている。制御クロックバスライン２０３は信号読出回路２０１を制御するためのものである。一方、金属配線１０６は、コンタクト部１１０を介して信号線２０２と接続されている。信号線２０２は、温度検出部１０５からの信号を読み出すためのものである。 FIG. 22 shows the entire pixel 200 and a part of the signal readout circuit 201 in the pixel 200. The signal readout circuit 201 installed in the pixel 200 is composed of a MOS transistor, a diode, or the like. A contact portion 205 is formed in the signal readout circuit 201. The contact portion 205 is connected to a contact portion 206 formed on the control clock bus line 203 via a metal wiring 204. The control clock bus line 203 is for controlling the signal readout circuit 201. On the other hand, the metal wiring 106 is connected to the signal line 202 via the contact portion 110. The signal line 202 is for reading a signal from the temperature detection unit 105.

図２３に示される別の熱型赤外線検出器、すなわち特許文献１に示される別の例では、シリコン基板３００の上に空洞部３０２を隔てて温度検出部３０１が配置されている。温度検出部３０１にはサーミスターボロメータ薄膜３０３が備えられており、サーミスターボロメータ薄膜３０３が絶縁保護膜３０４，３０５で取り囲まれている。温度検出部３０１は、梁３０６，３０７によりシリコン基板３００から浮かせて持ち上げられている。 In another thermal infrared detector shown in FIG. 23, ie, another example shown in Patent Document 1, a temperature detector 301 is arranged on a silicon substrate 300 with a cavity 302 therebetween. The temperature detector 301 is provided with a thermistor bolometer thin film 303, and the thermistor bolometer thin film 303 is surrounded by insulating protective films 304 and 305. The temperature detection unit 301 is lifted from the silicon substrate 300 by beams 306 and 307.

サーミスターボロメータ薄膜３０３は、それに電流を流すための金属配線３０８，３０９と、絶縁膜３０５，３１０に形成されたコンタクト部３１１，３１２とにより、シリコン基板３００内の信号読出回路（不図示）に接続されている。金属配線３０８，３０９はそれぞれ、絶縁膜３０４，３０５で取り囲まれている。温度検出部３０１の、シリコン基板３００側と反対側の面には、金属反射膜３１３と金属赤外線吸収膜３１６との間に赤外線吸収部３１５が挟まれて成るものが接合柱３１４を介して接合されている。接合柱３１４は金属反射膜３１３と一体になっており、金属反射膜３１３の、接合柱３１４側と反対側の面に、赤外線吸収部３１５および金属赤外線吸収膜３１６がこの順番で積層されている。このように金属反射膜３１３、赤外線吸収部３１５および金属赤外線吸収膜３１６によって、３層構造の光学的共振構造が構成されている。 The thermistor bolometer thin film 303 is connected to a signal readout circuit (not shown) in the silicon substrate 300 by means of metal wirings 308 and 309 for flowing current thereto and contact portions 311 and 312 formed in the insulating films 305 and 310. It is connected. The metal wirings 308 and 309 are surrounded by insulating films 304 and 305, respectively. On the surface of the temperature detection unit 301 opposite to the silicon substrate 300 side, an infrared absorption unit 315 sandwiched between a metal reflection film 313 and a metal infrared absorption film 316 is bonded via a bonding column 314. Has been. The joining column 314 is integrated with the metal reflecting film 313, and the infrared absorbing portion 315 and the metallic infrared absorbing film 316 are laminated in this order on the surface of the metallic reflecting film 313 opposite to the joining column 314 side. . As described above, the metal reflection film 313, the infrared absorption portion 315, and the metal infrared absorption film 316 form an optical resonance structure having a three-layer structure.

熱型赤外線検出器によって検出したい赤外線の波長をλとし、赤外線吸収部３１５の屈折率をｎとすると、赤外線吸収部３１５の厚みは、λ／（４ｎ）と表される。金属反射膜３１３における赤外線の反射率は１００％であることが好ましく、金属赤外線吸収膜３１６のシート抵抗は３７７Ω程度であることが望ましい。これらの条件を満たすことで、図２３に示されるような光学的共振構造によって波長λの赤外線が効率良く吸収されて熱に変換される。変換された熱は、接合柱３１４を通してサーミスターボロメータ薄膜３０３に伝えられ、これによりサーミスターボロメータ薄膜３０３の抵抗値が変化する。サーミスターボロメータ薄膜３０３の抵抗値の変化は、シリコン基板３００の信号読出回路によって電圧変化に変換されて電気信号として出力され、その電気信号が外部回路によって画像化される。 When the wavelength of the infrared ray desired to be detected by the thermal infrared detector is λ and the refractive index of the infrared absorbing portion 315 is n, the thickness of the infrared absorbing portion 315 is expressed as λ / (4n). The infrared reflectance of the metal reflection film 313 is preferably 100%, and the sheet resistance of the metal infrared absorption film 316 is preferably about 377Ω. By satisfying these conditions, the infrared light having the wavelength λ is efficiently absorbed and converted into heat by the optical resonance structure as shown in FIG. The converted heat is transferred to the thermistor bolometer thin film 303 through the joining column 314, whereby the resistance value of the thermistor bolometer thin film 303 changes. The change in resistance value of the thermistor bolometer thin film 303 is converted into a voltage change by the signal readout circuit of the silicon substrate 300 and output as an electrical signal, and the electrical signal is imaged by an external circuit.

図２４に示されるように、非特許文献１に記載された熱型赤外線検出器アレイでは、ＳＯＩ（Silicon on insulator）シリコン基板４００の表面に、空洞部４０２となる凹部が形成されている。その空洞部４０２の上に温度検出部４０１が配置されている。温度検出部４０１は梁４０５によって、空洞部４０２の底面から空洞部４０２の空間を隔てて、すなわちＳＯＩシリコン基板４００から隔てられて支持されている。温度検出部４０１の埋め込み酸化膜４１３上にはシリコンダイオード４０３が直列に形成され、シリコンダイオード４０３が絶縁保護膜４０４で取り囲まれている。ここで、ＳＯＩシリコン基板４００には埋め込み酸化膜４１３が存在している。シリコンダイオード４０３は、それに電流を流すために梁４０５内に形成された金属配線４０６により、ＳＯＩシリコン基板４００上の信号線４０７と、ＳＯＩシリコン基板４００内の信号読出回路（不図示）とに接続されている。金属配線４０６は絶縁膜４０８で取り囲まれている。 As shown in FIG. 24, in the thermal infrared detector array described in Non-Patent Document 1, a recess serving as a cavity 402 is formed on the surface of an SOI (Silicon on insulator) silicon substrate 400. A temperature detector 401 is disposed on the cavity 402. The temperature detection unit 401 is supported by a beam 405 so as to separate the space of the cavity 402 from the bottom surface of the cavity 402, that is, separated from the SOI silicon substrate 400. A silicon diode 403 is formed in series on the buried oxide film 413 of the temperature detection unit 401, and the silicon diode 403 is surrounded by an insulating protective film 404. Here, a buried oxide film 413 is present on the SOI silicon substrate 400. The silicon diode 403 is connected to a signal line 407 on the SOI silicon substrate 400 and a signal readout circuit (not shown) in the SOI silicon substrate 400 by a metal wiring 406 formed in the beam 405 so that a current flows therethrough. Has been. The metal wiring 406 is surrounded by an insulating film 408.

温度検出部４０１の、ＳＯＩシリコン基板４００側と反側の面には、赤外線反射膜４０９、絶縁膜４１１、および赤外線吸収膜４１２がこの順番で積層された積層体が接合されている。赤外線反射膜４０９、絶縁膜４１１、および赤外線吸収膜４１２の積層体の、温度検出部４０１との接合部分は、温度検出部４０１側に向かって突出する接合柱４１０となっている。接合柱４１０の絶縁膜４１１側の面が温度検出部４０１に接している。これらの赤外線反射膜４０９、絶縁膜４１１、および赤外線吸収膜４１２から、３層構造の光学的共振構造が構成されている。 A laminated body in which an infrared reflection film 409, an insulating film 411, and an infrared absorption film 412 are laminated in this order is bonded to the surface of the temperature detection unit 401 opposite to the SOI silicon substrate 400 side. A joining portion of the laminated body of the infrared reflecting film 409, the insulating film 411, and the infrared absorbing film 412 with the temperature detecting unit 401 is a joining column 410 protruding toward the temperature detecting unit 401 side. The surface on the insulating film 411 side of the bonding column 410 is in contact with the temperature detection unit 401. The infrared reflection film 409, the insulating film 411, and the infrared absorption film 412 constitute an optical resonance structure having a three-layer structure.

熱型赤外線検出器によって検出したい赤外線の波長をλ（具体的には８〜１２μｍ帯）とし、絶縁膜４１１の屈折率をｎとすると、絶縁膜４１１の厚さは、λ／（４ｎ）と表される。絶縁膜４１１はシリコン酸化膜とシリコン窒化膜で構成されている。赤外線反射膜４０９の赤外反射率は１００％であることが好ましく、赤外線吸収膜４１２のシート抵抗は３７７Ω程度であることが望ましい。これらの条件を満たすことで、図２４に示されるような光学的共振構造によって波長λの赤外線が効率良く吸収されて熱に変換される。変換された熱は、接合柱４１０を通してシリコンダイオード４０３に伝えられ、伝えられた熱によってシリコンダイオード４０３における電流−電圧特性が変化する。シリコンダイオード４０３における電流−電圧特性の変化は、信号読出回路によって電圧変化に変換されて電気信号として出力され、その電気信号が外部回路によって画像化される。熱型赤外線検出器の感度は、温度検出部と基板との間の熱分離が大きいほど高くなる。非特許文献１に記載された赤外線検出器の場合、熱コンダクタンスが８．２×１０^-8Ｗ／Ｋと小さく、高い感度を得られることが予想される。 When the wavelength of infrared rays to be detected by the thermal infrared detector is λ (specifically, 8 to 12 μm band) and the refractive index of the insulating film 411 is n, the thickness of the insulating film 411 is λ / (4n). expressed. The insulating film 411 is composed of a silicon oxide film and a silicon nitride film. The infrared reflectance of the infrared reflection film 409 is preferably 100%, and the sheet resistance of the infrared absorption film 412 is preferably about 377Ω. By satisfying these conditions, the infrared light having the wavelength λ is efficiently absorbed and converted into heat by the optical resonance structure as shown in FIG. The converted heat is transferred to the silicon diode 403 through the junction pillar 410, and the current-voltage characteristic in the silicon diode 403 is changed by the transferred heat. The change in the current-voltage characteristic in the silicon diode 403 is converted into a voltage change by the signal readout circuit and output as an electrical signal, and the electrical signal is imaged by an external circuit. The sensitivity of the thermal infrared detector increases as the thermal separation between the temperature detector and the substrate increases. In the case of the infrared detector described in Non-Patent Document 1, it is expected that the thermal conductance is as small as 8.2 × 10 ⁻⁸ W / K and high sensitivity can be obtained.

図２５は、特許文献１に記載された熱型赤外線センサを示す斜視図であり、図２６は、図２５に示される熱型赤外線センサのＡ−Ａ’線断面図である。図２５および図２６に示される熱型赤外線検出器では、赤外線受光部５１０が、２つの梁５０１、第１の柱部５０２および第２の柱部５０３によって半導体基板５０４から浮かせられて支持されている。赤外線受光部５１０には、図２６に示されるように、ｐｎ接合サーミスターである多結晶シリコン膜５１１が形成されている。赤外線受光部５１０は、入射した赤外線のエネルギーを吸収する赤外線吸収層と、その赤外線エネルギーの吸収に起因する温度上昇による物性値（例えば抵抗値）の変化を電気的に検知するセンサ部として機能する熱電変換層とによって構成されている。 25 is a perspective view showing a thermal infrared sensor described in Patent Document 1, and FIG. 26 is a cross-sectional view taken along the line A-A ′ of the thermal infrared sensor shown in FIG. 25. In the thermal infrared detector shown in FIGS. 25 and 26, the infrared light receiving unit 510 is supported by being floated from the semiconductor substrate 504 by the two beams 501, the first column unit 502 and the second column unit 503. Yes. As shown in FIG. 26, a polycrystalline silicon film 511 that is a pn junction thermistor is formed in the infrared light receiving portion 510. The infrared light receiving unit 510 functions as an infrared absorption layer that absorbs incident infrared energy and a sensor unit that electrically detects a change in a physical property value (for example, resistance value) due to a temperature rise caused by the absorption of the infrared energy. And a thermoelectric conversion layer.

２つの梁５０１はそれぞれ、平面形状がＬ字型の板状に形成されていて、赤外線受光部５１０と半導体基板５０４との間に配置されている。半導体基板５０４の表層に部分的に形成された不純物拡散層５０４ａと、梁５０１の一端部とが第１の柱部５０２によって接続され、梁５０１の他端部と赤外線受光部５１０とが第２の柱部５０３によって接続されている。これら梁５０１、第１の柱部５０２および第２の柱部５０３によって支持部が構成されている。そして、この支持部によって、赤外線受光部５１０が、図２６に示される所定の高さｈの空隙Ｍを介して半導体基板５０４上で支持されている。従って、梁５０１、第１の柱部５０２および第２の柱部５０３はそれぞれ、赤外線受光部５１０の下方に配置されている。 Each of the two beams 501 is formed in a plate shape having an L shape in plan view, and is disposed between the infrared light receiving unit 510 and the semiconductor substrate 504. The impurity diffusion layer 504a partially formed on the surface layer of the semiconductor substrate 504 and one end of the beam 501 are connected by the first pillar 502, and the other end of the beam 501 and the infrared light receiving unit 510 are second. The column portions 503 are connected. The beam 501, the first pillar portion 502 and the second pillar portion 503 constitute a support portion. Then, the infrared light receiving portion 510 is supported by the support portion on the semiconductor substrate 504 via a gap M having a predetermined height h shown in FIG. Accordingly, the beam 501, the first pillar portion 502, and the second pillar portion 503 are each disposed below the infrared light receiving portion 510.

図２６に示されるように、赤外線受光部５１０は、多結晶シリコン膜５１１と、多結晶シリコン膜５１１の表面を被覆する窒化シリコン膜５１２，５１３，５１４とによって構成されている。窒化シリコンは、赤外線を吸収し易い材質であるため、多結晶シリコン膜５１１の上面に形成された窒化シリコン膜５１３，５１４が赤外線受光部５１０における赤外線吸収層の実質的な大きさ（面積）を決定することになる。 As shown in FIG. 26, the infrared light receiving unit 510 includes a polycrystalline silicon film 511 and silicon nitride films 512, 513, and 514 that cover the surface of the polycrystalline silicon film 511. Since silicon nitride is a material that easily absorbs infrared rays, the silicon nitride films 513 and 514 formed on the upper surface of the polycrystalline silicon film 511 have a substantial size (area) of the infrared absorption layer in the infrared light receiving portion 510. Will be determined.

多結晶シリコン膜５１１には、ｎ形拡散層およびｐ形拡散層が形成され、これらのｎ形拡散層およびｐ形拡散層によってｐｎ接合型サーミスターが構成されている。また、赤外線受光部５１０の所定の位置にはスルーホール５２４が設けられており、スルーホール５２４を囲むように、高濃度不純物拡散層（導電部）５１１ａが形成されている。この高濃度不純物拡散層５１１ａは前記ｐｎ接合型サーミスターに電気的に接続されている。 In the polycrystalline silicon film 511, an n-type diffusion layer and a p-type diffusion layer are formed, and the n-type diffusion layer and the p-type diffusion layer constitute a pn junction type thermistor. Further, a through hole 524 is provided at a predetermined position of the infrared light receiving portion 510, and a high concentration impurity diffusion layer (conductive portion) 511a is formed so as to surround the through hole 524. The high concentration impurity diffusion layer 511a is electrically connected to the pn junction type thermistor.

２つの梁５０１はそれぞれ、図２６に示すようにチタン膜５１５、およびチタン膜５１５を覆う窒化シリコン膜５１６，５１７により構成されている。これらの膜のうちチタン膜５１５の一端部５１５ａは、半導体基板５０４に形成された不純物拡散層５０４ａに電気的に接続されている。また、チタン膜５１５を覆う窒化シリコン膜５１７には開口５１７ａが設けられ、この開口５１７ａにおいてチタン膜５１５の他端部５１５ｂがアルミニウム膜５１８を介して、多結晶シリコン膜５１１に形成された高濃度不純物拡散層（導電部）５１１ａに電気的に接続される。従って、赤外線受光部５１０の導体部（若しくは半導体部）と半導体基板５０４の不純物拡散層５０４ａとが、チタン膜５１５およびアルミニウム膜５１８を介して電気的に接続されている。 Each of the two beams 501 includes a titanium film 515 and silicon nitride films 516 and 517 covering the titanium film 515 as shown in FIG. Of these films, one end 515 a of the titanium film 515 is electrically connected to an impurity diffusion layer 504 a formed on the semiconductor substrate 504. The silicon nitride film 517 covering the titanium film 515 is provided with an opening 517a, and the other end 515b of the titanium film 515 is formed in the polycrystalline silicon film 511 through the aluminum film 518 in the opening 517a. The impurity diffusion layer (conductive portion) 511a is electrically connected. Therefore, the conductor part (or semiconductor part) of the infrared light receiving part 510 and the impurity diffusion layer 504a of the semiconductor substrate 504 are electrically connected via the titanium film 515 and the aluminum film 518.

チタン膜５１５の一端部５１５ａが第１の柱部５０２（および導電部）として機能し、アルミニウム膜５１８が第２の柱部５０３（および導電部）として機能している。アルミニウム膜５１８は、スルーホール５２４において高濃度不純物拡散層５１１ａに接するようにスルーホール５２４の内壁に形成されている。アルミニウム膜５１８の外周面および内周面は各々、保護膜としての窒化シリコン膜５１４，５１３で覆われている。 One end portion 515a of the titanium film 515 functions as the first column portion 502 (and the conductive portion), and the aluminum film 518 functions as the second column portion 503 (and the conductive portion). The aluminum film 518 is formed on the inner wall of the through hole 524 so as to be in contact with the high-concentration impurity diffusion layer 511a in the through hole 524. The outer peripheral surface and inner peripheral surface of the aluminum film 518 are respectively covered with silicon nitride films 514 and 513 as protective films.

このような熱型赤外線検出器では、赤外線が赤外線受光部５１０に入射すると、入射した赤外線が赤外線受光部５１０の赤外線吸収部に吸収されて熱に変換される。そして、変換された熱量に応じて赤外線受光部５１０のセンサ部の物性値（例えば抵抗値）が変化する。上述したように梁５０１は、赤外線受光部５１０とほぼ平行に赤外線受光部５１０の下方に配置されている。また、梁５０１と共に支持部を構成する第１の柱部５０２および第２の柱部５０３も、赤外線受光部５１０の下方に配置されている。よって、赤外線が入射する側（図２６の上方）から見たとき、梁５０１と第１の柱部５０２と第２の柱部５０３とから成る支持部が赤外線受光部５１０で覆われている。これにより、赤外線受光部５１０が占める面積の割合（開口率）を高めることができ、温度分解能を向上させることができる。
特開平１０−２０９４１８号公報特表平７−５０９０５７号公報特開平１０−１８５６８１号公報特開平１１−３３００５１号公報イシカワ（Ishikawa）等著、「ローコスト３２０×２４０アンクールドＩＲＦＰＡユージングコンベンショナルシリコンＩＣプロセス（Low-cost 320 x 240 uncooled IRFPA using conventional silicon IC process）」ＳＰＩＥｖｏｌ．３６９８、１９９９年、ｐ５５６−５６４ギブン・Ｗ・クリーク（Given W. Cleek）著、「ジオプティカルコンスタンツオブサムオキサイドグラスィズインザストロングアブソープションリジョン（The Optical Constants of Some Oxide Glasses in the Strong Absorption Region）」アプライドオプティクス（Applied Optics）ｖｏｌ．５Ｎｏ．５、１９６６年、ｐ７７１ヘンリー・バルテス（Henry Baltes）、オリバー・ポール（Oliver Paul）著、「サーマルセンサーズファブリケイテッドバイＣＭＯＳアンドマイクロマシニング（Thermal Sensors Fabricated by CMOS and Micromachining）」センサーアンドマテリアルズ（Sensors and Materials）ｖｏｌ．８、１９９６年、ｐ４０９−４２１Ｒ・Ａ・ウッド（R. A. Wood）著、「モノリシックシリコンマイクロボロメータアレイズ（Monolithic Silicon Microbolometer Arrays）」「アンクールドインフレイテッドイメージングアレイズアンドシステムズ（Uncooled Infrared Imaging Arrays and Systems）」セミコンダクターズアンドセミメタルズ（Semiconductors and Semimetals）ｖｏｌ．４７、ポール・Ｗ・クルーズ（Paul W. Kruse）、デイビッド・Ｄ・スカトラッド（David D. Skatrud）編、アカデミックプレス（Academic Press）、１９９７年、ｐ９９ In such a thermal infrared detector, when infrared light enters the infrared light receiving unit 510, the incident infrared light is absorbed by the infrared absorption unit of the infrared light receiving unit 510 and converted into heat. And the physical property value (for example, resistance value) of the sensor part of the infrared light-receiving part 510 changes according to the converted heat quantity. As described above, the beam 501 is disposed below the infrared light receiving unit 510 so as to be substantially parallel to the infrared light receiving unit 510. In addition, the first pillar portion 502 and the second pillar portion 503 that constitute the support portion together with the beam 501 are also disposed below the infrared light receiving portion 510. Therefore, when viewed from the side on which infrared rays are incident (upper side in FIG. 26), the support portion including the beam 501, the first column portion 502, and the second column portion 503 is covered with the infrared light receiving unit 510. Thereby, the ratio (aperture ratio) of the area occupied by the infrared light receiving unit 510 can be increased, and the temperature resolution can be improved.
Japanese Patent Laid-Open No. 10-209418 Japanese translation of PCT publication No. 7-509057 Japanese Patent Laid-Open No. 10-185681 JP-A-11-330051 Ishikawa et al., “Low-cost 320 × 240 uncooled IRFPA using conventional silicon IC process” SPIE vol. 3698, 1999, p556-564 "Given W. Cleek", "The Optical Constants of Some Oxide Glasses in the Strong Absorption Region", Applied Optics, vol. . 5 No. 5, 1966, p771 Henry Baltes, Oliver Paul, “Thermal Sensors Fabricated by CMOS and Micromachining” Sensors and Materials vol. 8, 1996, p409-421 RA Wood, "Monolithic Silicon Microbolometer Arrays""Uncooled Infrared Imaging Arrays and Systems" Semiconductors and Semimetals vol. 47. Paul W. Kruse, edited by David D. Skatrud, Academic Press, 1997, p99.

特許文献１や非特許文献１に記載された熱型赤外線検出器は、小さい熱コンダクタンスと高い開口率（フィルファクター）を有しているため感度が高いと予想される。熱型赤外線検出器アレイを用いて実時間画像（３０Ｈｚ以上のフレームレート）を得るためには、熱時定数が３０ｍsecより十分小さいことが要求される。熱時定数（τ_th）は、図２１〜図２６に示したそれぞれの熱型赤外線検出器において、次の式（１）のように温度検出部および赤外線吸収部の熱容量（Ｈ）と、熱分離構造の熱コンダクタンス（Ｇ_th）との比で表わされる。 The thermal infrared detectors described in Patent Document 1 and Non-Patent Document 1 are expected to have high sensitivity because they have a small thermal conductance and a high aperture ratio (fill factor). In order to obtain a real-time image (a frame rate of 30 Hz or more) using a thermal infrared detector array, the thermal time constant is required to be sufficiently smaller than 30 msec. The thermal time constant (τ _th ) is the thermal capacity (H) of the temperature detection unit and the infrared absorption unit as shown in the following equation (1) in each thermal infrared detector shown in FIGS. It is expressed as a ratio to the thermal conductance (G _th ) of the separation structure.

τ_th＝Ｈ／Ｇ_th （１）
前述した従来のそれぞれの熱型赤外線検出器は、次に説明するように、熱時定数が３０ｍsecよりかなり大きいことが予想され、実時間画像化において残像が大きな問題になると考えられる。 τ _th = H / G _th (1)
As described below, each of the conventional thermal infrared detectors described above is expected to have a thermal time constant considerably larger than 30 msec, and it is considered that an afterimage becomes a big problem in real-time imaging.

非特許文献１に記載された熱型赤外線検出器の場合、熱コンダクタンスの値が８．２×１０^-8Ｗ／Ｋと記述されているが、熱容量に関する記載が一切ない。但し、温度検出部の大きさは、その文献中のＳＥＭ写真より約１７×２３μｍであることが分かる。非特許文献１の著者と同じグループである発明者の特許文献１には、熱コンダクタンスに関する記述はないが、温度検出部の厚さは梁の厚さから約１μｍと推測でき、その温度検出部の熱容量を計算することができる。また、赤外線吸収部の熱容量については、非特許文献１の光学的共振構造に対して、波長８〜１２μｍ帯でのシリコン酸化膜とシリコン窒化膜の屈折率の値および両材料の定積比熱から計算される。波長８〜１２μｍ帯の赤外線に対するシリコン酸化膜の屈折率は、非特許文献２に記載されているように０．５１〜３．３８の範囲にあり、波長９．５μｍに特異な吸収があるため、同波長帯での代表的な屈折率を決めることは容易ではない。しかし、ここでは非特許文献２の７７４頁に記載された図７を参考にして、波長８〜１２μｍ帯の赤外線に対するシリコン酸化膜の屈折率として１．５を用いることにする。波長８〜１２μｍ帯でのシリコン窒化膜の屈折率は、特許文献２の図７に示されているシリコン窒化膜の反射率のデータから１．９と計算される。シリコン酸化膜の定積比熱は成膜方法に依存していて、１．０５Ｊ／ｃｍ³・Ｋ（非特許文献３参照）から２．２７Ｊ／ｃｍ³・Ｋ（非特許文献４参照）の範囲にある。シリコン窒化膜の定積比熱についてはデータが見当たらない。そこで両材料に対して１．７Ｊ／ｃｍ³・Ｋという値を用いて熱容量を計算する。 In the case of the thermal infrared detector described in Non-Patent Document 1, the value of thermal conductance is described as 8.2 × 10 ⁻⁸ W / K, but there is no description regarding the heat capacity. However, the size of the temperature detection part is found to be about 17 × 23 μm from the SEM photographs in that document. Patent Document 1 of the inventor, which is the same group as the author of Non-Patent Document 1, has no description regarding thermal conductance, but the thickness of the temperature detection unit can be estimated to be about 1 μm from the thickness of the beam. The heat capacity of can be calculated. Regarding the heat capacity of the infrared absorption part, compared to the optical resonant structure of Non-Patent Document 1, the refractive index values of the silicon oxide film and the silicon nitride film in the wavelength band of 8 to 12 μm and the constant volume specific heat of both materials are used. Calculated. Since the refractive index of the silicon oxide film with respect to infrared rays in the wavelength band of 8 to 12 μm is in the range of 0.51 to 3.38 as described in Non-Patent Document 2, there is specific absorption at the wavelength of 9.5 μm. It is not easy to determine a typical refractive index in the same wavelength band. However, referring to FIG. 7 described on page 774 of Non-Patent Document 2, 1.5 is used as the refractive index of the silicon oxide film with respect to infrared rays having a wavelength of 8 to 12 μm. The refractive index of the silicon nitride film in the wavelength band of 8 to 12 μm is calculated as 1.9 from the reflectance data of the silicon nitride film shown in FIG. Specific heat at constant volume of a silicon oxide film is dependent on the film formation method, the range of 1.05J / cm ³ · K (see Non-Patent Document 3) of 2.27J / cm ³ · K (see Non-Patent Document 4) It is in. There is no data on the specific volume heat of silicon nitride film. Therefore, the heat capacity is calculated using a value of 1.7 J / cm ³ · K for both materials.

まず、波長８〜１２μｍ帯でのシリコン酸化膜とシリコン窒化膜の屈折率の値から赤外線吸収部の絶縁膜４１１の厚みは１．３〜１．７μｍと推測され、非特許文献１の熱型赤外線検出器アレイの開口率が９０％であることを考慮すると、温度検出部４０１と赤外線吸収部（４０９，４１１，４１２）の熱容量は各々、６．６×１０^-10Ｊ／Ｋ、（３．２〜４．２）×１０^-9Ｊ／Ｋであり、熱容量の合計は（３．９〜４．８）×１０^-9Ｊ／Ｋとなる。この値と熱コンダクタンスの値８．２×１０^-8Ｗ／Ｋより、特許文献１および非特許文献１の熱型赤外線検出器アレイの熱時定数は、４７〜５８ｍsecと予想され、実時間画像化において残像等が大きな問題になると判断される。 First, the thickness of the insulating film 411 in the infrared absorbing portion is estimated to be 1.3 to 1.7 μm from the refractive index values of the silicon oxide film and the silicon nitride film in the wavelength band of 8 to 12 μm. Considering that the aperture ratio of the infrared detector array is 90%, the heat capacities of the temperature detector 401 and the infrared absorbers (409, 411, 412) are 6.6 × 10 ⁻¹⁰ J / K, (3 0.2 to 4.2) × 10 ⁻⁹ J / K, and the total heat capacity is (3.9 to 4.8) × 10 ⁻⁹ J / K. From this value and the thermal conductance value of 8.2 × 10 ⁻⁸ W / K, the thermal time constant of the thermal infrared detector array of Patent Document 1 and Non-Patent Document 1 is expected to be 47 to 58 msec, and a real-time image is obtained. It is judged that afterimages and the like become a big problem in conversion.

次に、赤外線吸収部が、厚さ５００ｎｍのシリコン窒化膜から成る絶縁膜４１１と、厚さ１５０ｎｍのＴｉ膜から成る赤外線反射膜４０９とだけで構成されている場合、赤外線吸収部の熱容量が１．７×１０^-9Ｊ／Ｋとなり、熱時定数は３０ｍsecと計算される。しかし、依然としてテレビのフレームレート３０Ｈｚ（時間で３３ｍsec）とあまり変わらず、やはり残像等が問題になると判断される。 Next, in the case where the infrared absorption part is composed only of the insulating film 411 made of a silicon nitride film having a thickness of 500 nm and the infrared reflection film 409 made of a Ti film having a thickness of 150 nm, the heat capacity of the infrared absorption part is 1 7 × 10 ⁻⁹ J / K, and the thermal time constant is calculated as 30 msec. However, it is still not much different from the television frame rate of 30 Hz (33 msec in time), and it is determined that afterimages are also a problem.

特許文献３の熱型赤外線検出器の場合、赤外線受光部５１０、梁５０１、および半導体基板５０４の三階建て構造のため、第１の柱部５０２および第２の柱部５０３が必要になる。よって、導電材料の接触不良が発生しやすいという問題点がある。また、第２の柱部５０３の直上部とその近傍はサーミスターの電極として機能するため、その分、開口率が小さくなるという問題点がある。 In the case of the thermal infrared detector disclosed in Patent Document 3, the first pillar portion 502 and the second pillar portion 503 are required because of the three-story structure of the infrared light receiving portion 510, the beam 501, and the semiconductor substrate 504. Therefore, there is a problem that poor contact of the conductive material is likely to occur. In addition, since the portion directly above the second column portion 503 and its vicinity function as electrodes of the thermistor, there is a problem that the aperture ratio is reduced accordingly.

本発明の目的は、開口率を高めると同時に、熱時定数を殆ど増加させることなく、感度をより高くすることが可能な熱型赤外線検出器およびその製造方法を提供することにある。 An object of the present invention is to provide a thermal infrared detector capable of increasing the aperture ratio and at the same time increasing sensitivity without increasing the thermal time constant, and a method for manufacturing the same.

上記目的を達成するために、本発明の第１の熱型赤外線検出器は、
コンタクトパッドを備えた基板と、
赤外線を吸収すると赤外線により加熱される第１の赤外線吸収部、第１の赤外線吸収部から伝えられる熱による温度変化を検出する温度検出部、および温度検出部と電気的に接続された電極部を備え、基板のコンタクトパッド形成面の上方に間隔をあけて配置された赤外線受光部と、
基板上で赤外線受光部を基板のコンタクトパッド形成面から浮かせて支持し、基板のコンタクトパッドに赤外線受光部の電極部を電気的に接続する配線を構成するように少なくとも一部が導電性材料により形成された支持部と、
赤外線受光部の第１の赤外線吸収部から突出し、赤外線受光部の縁部から、および／または電極部の内側に位置する根元から赤外線受光部の外側に向けて延び、電極部との間に空間を隔てて、電極部の、基板側と反対側の面を覆う庇部からなり、赤外線を吸収すると赤外線により加熱されその熱を第１の赤外線吸収部を介して温度検出部に伝える第２の赤外線吸収部とを有し、
第２の赤外線吸収部は、隣接する画素の第２の赤外線吸収部と物理的に分離されており、
第１の赤外線吸収部の中央部は、第２の赤外線吸収部に設けられた中央開口を介して、赤外線が入射してくる方向に向けて露出しており、
第１の赤外線吸収部および第２の赤外線吸収部の赤外線入射可能な面の総面積は、第１の赤外線吸収部の、基板側と反対側の面の面積よりも大きい。 In order to achieve the above object, the first thermal infrared detector of the present invention comprises:
A substrate with contact pads;
A first infrared absorbing portion that is heated by infrared when absorbing infrared rays, a temperature detecting portion that detects a temperature change due to heat transmitted from the first infrared absorbing portion, and an electrode portion that is electrically connected to the temperature detecting portion An infrared light receiving unit disposed at a distance above the contact pad forming surface of the substrate;
The infrared light receiving unit is supported on the substrate by floating from the contact pad forming surface of the substrate, and at least part of the substrate is made of a conductive material so as to constitute a wiring that electrically connects the electrode part of the infrared light receiving unit to the contact pad of the substrate. A formed support, and
Projects from the first infrared absorbing part of the infrared light receiving part, extends from the edge of the infrared light receiving part and / or from the root located inside the electrode part toward the outside of the infrared light receiving part, and is spaced from the electrode part A second part that covers the surface of the electrode part opposite to the substrate side with a gap therebetween, is heated by infrared rays when infrared rays are absorbed, and the heat is transmitted to the temperature detection unit via the first infrared absorption unit. An infrared absorption part,
The second infrared absorbing portion is physically separated from the second infrared absorbing portion of the adjacent pixel,
The central portion of the first infrared absorbing portion is exposed toward the direction in which the infrared rays enter through the central opening provided in the second infrared absorbing portion,
The total area of the first infrared absorbing section and the second infrared absorbing section where the infrared rays can be incident is larger than the area of the first infrared absorbing section on the side opposite to the substrate side.

この構成によると、赤外線受光部の第１の赤外線吸収部と、第１の赤外線吸収部から突出した庇部からなる第２の赤外線吸収部とに赤外線が入射すると、入射した赤外線の少なくとも一部を第１および第２の赤外線吸収部が吸収して加熱される。第１の赤外線吸収部の熱は温度検出部に伝わり、第２の赤外線吸収部の熱も第１の赤外線吸収部を通して温度検出部に伝わり、温度検出部の温度が変化する。温度検出部の温度変化は、温度検出部と電気的に接続された電極部、支持部の配線、および基板のコンタクトパッドを通る信号として、例えば信号読出回路に伝えられて、その信号読出回路によって電気信号に変換される。そして、その電気信号を基に温度検出部の温度変化が外部回路などによって赤外画像化される。 According to this configuration, when infrared rays are incident on the first infrared absorbing portion of the infrared light receiving portion and the second infrared absorbing portion including the flange protruding from the first infrared absorbing portion, at least part of the incident infrared rays Are absorbed by the first and second infrared absorbing portions and heated. The heat of the first infrared absorption unit is transmitted to the temperature detection unit, the heat of the second infrared absorption unit is also transmitted to the temperature detection unit through the first infrared absorption unit, and the temperature of the temperature detection unit changes. The temperature change of the temperature detection unit is transmitted to the signal readout circuit, for example, as a signal passing through the electrode unit electrically connected to the temperature detection unit, the wiring of the support unit, and the contact pad of the substrate. It is converted into an electrical signal. Based on the electrical signal, the temperature change of the temperature detection unit is converted into an infrared image by an external circuit or the like.

ここで、前記したように赤外線受光部の第１の赤外線吸収部から第２の赤外線吸収部（庇部）を突出させて、その第２の赤外線吸収部によって、電極部との間に空間を隔てて電極部の、基板側と反対側の面を覆うことにより、熱型赤外線検出器の各画素の開口率を増加させて、赤外線をより多く吸収することができる。その結果、熱型赤外線検出器の感度を高くすることができる。また、第２の赤外線吸収部の根元を赤外線受光部の縁部近傍に配置させることにより、熱容量も殆ど増えず、熱時定数もテレビのフレームレートに対応する時間３３ｍsecより十分小さくすることができる。 Here, as described above, the second infrared ray absorbing portion (protrusion portion) is protruded from the first infrared ray absorbing portion of the infrared ray receiving portion, and a space is formed between the electrode portion and the second infrared ray absorbing portion. By covering the surface of the electrode portion opposite to the substrate side at a distance, the aperture ratio of each pixel of the thermal infrared detector can be increased and more infrared rays can be absorbed. As a result, the sensitivity of the thermal infrared detector can be increased. Further, by arranging the base of the second infrared absorbing portion in the vicinity of the edge of the infrared light receiving portion, the heat capacity hardly increases, and the thermal time constant can be made sufficiently smaller than the time 33 msec corresponding to the television frame rate. .

第２の赤外線吸収部が、支持部との間に空間を隔てて、支持部の、基板側と反対側の面を覆うとともに、基板のコンタクトパッドとの間に空間を隔ててコンタクトパッドを覆うものであることが好ましい。このように、第２の赤外線吸収部がコンタクトパッドおよび支持部を覆うことにより、熱型赤外線検出器における各画素の開口率をより増加させて、赤外線をより多く吸収することができる。 The second infrared absorbing part covers the surface of the support part opposite to the substrate side with a space between the support part and the contact pad with a space between the contact pad of the substrate. It is preferable. As described above, the second infrared absorbing portion covers the contact pad and the support portion, whereby the aperture ratio of each pixel in the thermal infrared detector can be further increased and more infrared rays can be absorbed.

第２の赤外線吸収部は、第１の赤外線吸収部の、電極部に対応する部分を除く部分から突出し、赤外線受光部の縁部に位置する根元から赤外線受光部の外側に向けて延びていてもよい。 The second infrared absorbing portion protrudes from a portion of the first infrared absorbing portion excluding the portion corresponding to the electrode portion, and extends from the root located at the edge of the infrared receiving portion toward the outside of the infrared receiving portion. Also good.

本発明の第２の熱型赤外線検出器は、
コンタクトパッドを備えた基板と、
赤外線を吸収すると赤外線により加熱される第１の赤外線吸収部、第１の赤外線吸収部から伝えられる熱による温度変化を検出する温度検出部、および温度検出部と電気的に接続された電極部を備え、基板のコンタクトパッド形成面の上方に間隔をあけて配置された赤外線受光部と、
基板上で赤外線受光部を基板のコンタクトパッド形成面から浮かせて支持し、基板のコンタクトパッドに赤外線受光部の電極部を電気的に接続する配線を構成するように少なくとも一部が導電性材料により形成された支持部と、
赤外線受光部の第１の赤外線吸収部の、電極部に対応する部分を除く部分からから突出し、赤外線受光部の縁部に位置する根元から赤外線受光部の外側に向けて延び、支持部との間に空間を隔てて、支持部の、基板側と反対側の面を覆い、かつ基板のコンタクトパッドとの間に空間を隔ててコンタクトパッドを覆う庇部からなり、赤外線を吸収すると赤外線により加熱されその熱を第１の赤外線吸収部を介して温度検出部に伝える第２の赤外線吸収部とを有し、
第２の赤外線吸収部は、隣接する画素の第２の赤外線吸収部と物理的に分離されており、
第１の赤外線吸収部の中央部は、第２の赤外線吸収部に設けられた中央開口を介して、赤外線が入射してくる方向に向けて露出しており、
第１の赤外線吸収部および第２の赤外線吸収部の赤外線入射可能な面の総面積は、第１の赤外線吸収部の、基板側と反対側の面の面積よりも大きい。 The second thermal infrared detector of the present invention is
A substrate with contact pads;
A first infrared absorbing portion that is heated by infrared when absorbing infrared rays, a temperature detecting portion that detects a temperature change due to heat transmitted from the first infrared absorbing portion, and an electrode portion that is electrically connected to the temperature detecting portion An infrared light receiving unit disposed at a distance above the contact pad forming surface of the substrate;
The infrared light receiving unit is supported on the substrate by floating from the contact pad forming surface of the substrate, and at least part of the substrate is made of a conductive material so as to constitute a wiring that electrically connects the electrode part of the infrared light receiving unit to the contact pad of the substrate A formed support, and
The first infrared absorption part of the infrared light receiving part protrudes from the part excluding the part corresponding to the electrode part, extends from the root located at the edge of the infrared light receiving part toward the outside of the infrared light receiving part, and It consists of a ridge that covers the surface of the support part opposite to the board side with a space in between and covers the contact pad with a space between it and the contact pad of the board. And a second infrared absorber that transmits the heat to the temperature detector via the first infrared absorber,
The second infrared absorbing portion is physically separated from the second infrared absorbing portion of the adjacent pixel,
The central portion of the first infrared absorbing portion is exposed toward the direction in which the infrared rays enter through the central opening provided in the second infrared absorbing portion,
The total area of the first infrared absorbing section and the second infrared absorbing section where the infrared rays can be incident is larger than the area of the first infrared absorbing section on the side opposite to the substrate side.

この構成によると、赤外線受光部の第１の赤外線吸収部の、電極部に対応する部分を除く部分から第２の赤外線吸収部（庇部）を突出させて、その第２の赤外線吸収部によって支持部および基板のコンタクトパッドを覆うことにより、熱型赤外線検出器の各画素の開口率を増加させて、赤外線をより多く吸収することができる。ここで、第１の赤外線吸収部の、電極部に対応する部分を除く部分から第２の赤外線吸収部が突出していることにより、第２の赤外線吸収部の熱が、電極部および支持部の配線を伝わって基板に逃げることが防止される。その結果、熱型赤外線検出器の感度が悪化することが防止される。 According to this configuration, the second infrared absorbing portion (protrusion portion) is protruded from the portion of the first infrared absorbing portion of the infrared receiving portion except the portion corresponding to the electrode portion, and the second infrared absorbing portion By covering the support portion and the contact pads of the substrate, the aperture ratio of each pixel of the thermal infrared detector can be increased, and more infrared rays can be absorbed. Here, since the second infrared absorbing portion protrudes from the portion of the first infrared absorbing portion excluding the portion corresponding to the electrode portion, the heat of the second infrared absorbing portion is increased between the electrode portion and the support portion. Escape to the board through the wiring is prevented. As a result, the sensitivity of the thermal infrared detector is prevented from deteriorating.

基板の赤外線受光部側の表面であるコンタクトパッド形成面に形成された赤外線反射膜と、赤外線反射膜を覆うように赤外線反射膜の表面に形成された第１の絶縁保護膜とをさらに有し、赤外線受光部が、第１の絶縁保護膜の上方に支持部によって浮かせられて支持されていることが好ましい。このように、赤外線反射膜および第１の絶縁保護膜が形成されていることにより、赤外線受光部を透過した赤外線が基板上の赤外線反射膜によって赤外線受光部に向けて反射される。反射された赤外線は、第１の赤外線吸収部や第２の赤外線吸収部に再度入射して、それらに吸収される。よって、このように基板のコンタクトパッド形成面に赤外線反射膜が形成されていることにより、より多くの赤外線を赤外線吸収部や庇部に吸収させることができる。 An infrared reflection film formed on a contact pad forming surface which is a surface on the infrared light receiving portion side of the substrate; and a first insulating protective film formed on the surface of the infrared reflection film so as to cover the infrared reflection film The infrared light receiving part is preferably supported by being floated and supported by the support part above the first insulating protective film. Thus, by forming the infrared reflective film and the first insulating protective film, the infrared light transmitted through the infrared light receiving part is reflected toward the infrared light receiving part by the infrared reflective film on the substrate. The reflected infrared rays are incident again on the first infrared absorbing portion and the second infrared absorbing portion and absorbed by them. Therefore, by forming the infrared reflecting film on the contact pad forming surface of the substrate in this way, more infrared rays can be absorbed by the infrared absorbing portion and the collar portion.

さらに、温度検出部の、基板側と反対側の面に第１の赤外線吸収部が設けられており、第１の赤外線吸収部の、基板側と反対側の表面と、第２の赤外線吸収部の、基板側と反対側の表面に、金属薄膜が形成されていてもよい。 Further, a first infrared absorption unit is provided on a surface of the temperature detection unit opposite to the substrate side, a surface of the first infrared absorption unit opposite to the substrate side, and a second infrared absorption unit. A metal thin film may be formed on the surface opposite to the substrate side.

このように、第１および第２の赤外線吸収部の、基板側と反対側の表面に金属薄膜を形成することにより、その金属薄膜で赤外線同士を干渉させて金属薄膜を加熱するように熱型赤外線検出器を構成することができる。そのような熱型赤外線検出器における具体的な動作としては、まず、第１および第２の赤外線吸収部の上の金属薄膜に赤外線が入射すると、入射した赤外線の一部が金属薄膜により反射されようとする。一方、金属薄膜に入射した赤外線の残りの部分は、金属薄膜を通過して基板に向かって進行する。金属薄膜を通過した赤外線は、基板上の赤外線反射膜やコンタクトパッド等により金属薄膜に向けて反射されて、金属薄膜に再び入射する。ここで、金属薄膜に再び入射する赤外線は、金属薄膜により反射されようとする赤外線と打ち消し合う干渉を起こし、干渉を起こした赤外線同士が金属薄膜内の自由電子により吸収されて熱になる。その結果、金属薄膜が加熱されてその温度が上昇し、金属薄膜の熱は第１および第２の赤外線吸収部を介して温度検出部に伝わる。ここで、第１および第２の赤外線吸収部の上に形成された金属薄膜によって、第１および第２の赤外線吸収部の熱が温度検出部に速く伝わるようになっている。 In this way, by forming a metal thin film on the surface opposite to the substrate side of the first and second infrared absorbing parts, the metal thin film causes the infrared rays to interfere with each other to heat the metal thin film. An infrared detector can be constructed. As a specific operation in such a thermal infrared detector, first, when infrared rays are incident on the metal thin film on the first and second infrared absorbers, a part of the incident infrared rays is reflected by the metal thin film. Try to. On the other hand, the remaining part of the infrared light incident on the metal thin film travels toward the substrate through the metal thin film. Infrared light that has passed through the metal thin film is reflected toward the metal thin film by an infrared reflecting film, a contact pad, or the like on the substrate, and is incident on the metal thin film again. Here, the infrared rays that are incident again on the metal thin film cause interference that cancels the infrared rays that are to be reflected by the metal thin film, and the infrared rays that caused the interference are absorbed by free electrons in the metal thin film and become heat. As a result, the metal thin film is heated and its temperature rises, and the heat of the metal thin film is transmitted to the temperature detection unit via the first and second infrared absorption units. Here, the metal thin film formed on the first and second infrared absorbing portions allows the heat of the first and second infrared absorbing portions to be quickly transmitted to the temperature detecting portion.

さらに、基板のコンタクトパッドと電気的に接続され、温度検出部により検出された温度変化を電気信号に変換するとともに、電気信号を読み出すことができる読出回路を基板が有していることが好ましい。 Further, it is preferable that the substrate has a reading circuit that is electrically connected to the contact pad of the substrate, converts a temperature change detected by the temperature detection unit into an electric signal, and can read out the electric signal.

さらに、支持部が、基板のコンタクトパッドに電極部を電気的に接続するための配線を構成する導電性材料と、導電性材料を覆う第２の絶縁保護膜とから成るものであることが好ましい。 Furthermore, it is preferable that the support portion is composed of a conductive material that forms wiring for electrically connecting the electrode portion to the contact pad of the substrate, and a second insulating protective film that covers the conductive material. .

本発明の第３の熱型赤外線検出器は、
赤外線が照射される表面層として金属薄膜が形成されている絶縁膜からなる第１の赤外線吸収部、第１の赤外線吸収部から伝えられる熱による温度変化を検出する温度検出部、および温度検出部と電気的に接続された電極部を備えた赤外線受光部と、
電極部と電気的に接続されるコンタクトパッドを備えた基板と、
基板のコンタクトパッド側の面に形成され、金属薄膜に照射された赤外線のうち金属薄膜を透過した赤外線を金属薄膜に向けて反射することで、金属薄膜内にて赤外線同士の干渉を生じさせて金属薄膜を加熱するための赤外線反射膜と、
赤外線反射膜を覆うように赤外線反射膜の表面に形成された第１の絶縁保護膜と、
コンタクトパッドに電極部を電気的に接続する配線を構成する導電性材料、および導電性材料を覆う第２の絶縁保護膜から成り、第１の絶縁保護膜の上方に赤外線受光部を浮かせて支持する支持部と、
赤外線受光部の絶縁膜から突出し、赤外線受光部の縁部から、および／または電極部の内側に位置する根元から赤外線受光部の外側に向けて延び、電極部との間に空間を隔てて、電極部の、基板側と反対側の面を覆い、支持部との間に空間を隔てて、支持部の、基板側と反対側の面を覆い、かつ基板のコンタクトパッドとの間に空間を隔ててコンタクトパッドを覆う庇部からなり、赤外線を吸収すると赤外線により加熱されその熱を第１の赤外線吸収部を介して温度検出部に伝える第２の赤外線吸収部とを有し、
第２の赤外線吸収部には赤外線が照射される表面層として金属薄膜が形成されており、第１の赤外線吸収部の表面層である金属薄膜と第２の赤外線吸収部の表面層である金属薄膜は、互いに連続するように一体的に形成されたものであり、
第２の赤外線吸収部は、隣接する画素の第２の赤外線吸収部と物理的に分離されており、
第１の赤外線吸収部の中央部は、第２の赤外線吸収部に設けられた中央開口を介して、赤外線が入射してくる方向に向けて露出しており、
第１の赤外線吸収部および第２の赤外線吸収部の赤外線入射可能な面の総面積は、第１の赤外線吸収部の、基板側と反対側の面の面積よりも大きい。 The third thermal infrared detector of the present invention is
A first infrared absorbing portion made of an insulating film on which a metal thin film is formed as a surface layer irradiated with infrared rays, a temperature detecting portion for detecting a temperature change due to heat transmitted from the first infrared absorbing portion, and a temperature detecting portion An infrared light receiving portion including an electrode portion electrically connected to the
A substrate having a contact pad electrically connected to the electrode portion;
It is formed on the contact pad side surface of the substrate, and by reflecting the infrared rays transmitted through the metal thin film to the metal thin film among the infrared rays irradiated to the metal thin film, interference between infrared rays is caused in the metal thin film. An infrared reflective film for heating the metal thin film;
A first insulating protective film formed on the surface of the infrared reflective film so as to cover the infrared reflective film;
Consists of a conductive material that constitutes a wiring that electrically connects the electrode portion to the contact pad, and a second insulating protective film that covers the conductive material, and supports the infrared light receiving unit by floating above the first insulating protective film A supporting part to
Projecting from the insulating film of the infrared light receiving part, extending from the edge of the infrared light receiving part and / or from the root located inside the electrode part toward the outside of the infrared light receiving part, with a space between the electrode part, Cover the surface of the electrode part on the opposite side of the substrate side with a space between it and the support part, cover the surface of the support part on the opposite side of the substrate side, and leave a space between the contact pad of the board. It has a second infrared absorbing portion that is formed of a collar portion that covers the contact pad and is heated by infrared rays when infrared rays are absorbed, and transmits the heat to the temperature detecting portion via the first infrared absorbing portion,
A metal thin film is formed on the second infrared absorbing portion as a surface layer irradiated with infrared rays, and a metal thin film that is a surface layer of the first infrared absorbing portion and a metal that is a surface layer of the second infrared absorbing portion. The thin film is integrally formed to be continuous with each other,
The second infrared absorbing portion is physically separated from the second infrared absorbing portion of the adjacent pixel,
The central portion of the first infrared absorbing portion is exposed toward the direction in which the infrared rays enter through the central opening provided in the second infrared absorbing portion,
The total area of the first infrared absorbing section and the second infrared absorbing section where the infrared rays can be incident is larger than the area of the first infrared absorbing section on the side opposite to the substrate side.

この熱型赤外線検出器でも、前記したのと同様に、金属薄膜により反射されようとする赤外線と、金属薄膜を通過した後に赤外線反射膜やコンタクトパッド等により反射されて金属薄膜に再び入射する赤外線とが打ち消し合う干渉を起こし、干渉を起こした赤外線同士が金属薄膜内の自由電子により吸収されて熱になり、金属薄膜の温度が上昇し、それが第１および第２の赤外線吸収部を介して温度検出部に伝わる。金属薄膜によって、第１および第２の赤外線吸収部の熱が温度検出部に速く伝わるようになっている。このように金属薄膜で赤外線同士を干渉させて金属薄膜を加熱するように構成された熱型赤外線検出器においても、赤外線受光部の第１の赤外線吸収部から突出した第２の赤外線吸収部（庇部）によって、赤外線受光部の電極部、支持部、および基板のコンタクトパッドを覆い、第２の赤外線吸収部の、基板側と反対側の面全体にまで金属薄膜を延ばすことにより、熱型赤外線検出器の各画素の開口率を増加させて、赤外線をより多く吸収することができる。その結果、熱型赤外線検出器の感度を高くすることができる。 In this thermal infrared detector, as described above, the infrared rays that are to be reflected by the metal thin film, and the infrared rays that are reflected by the infrared reflective film and the contact pads after passing through the metal thin film and are incident on the metal thin film again. And the interference infrared rays are absorbed by free electrons in the metal thin film to become heat, and the temperature of the metal thin film rises, which is passed through the first and second infrared absorption parts. Is transmitted to the temperature detector. With the metal thin film, the heat of the first and second infrared absorbing parts is quickly transmitted to the temperature detecting part. Even in the thermal infrared detector configured to heat the metal thin film by causing infrared rays to interfere with each other with the metal thin film, the second infrared absorbing portion protruding from the first infrared absorbing portion of the infrared light receiving portion ( By covering the electrode part of the infrared light receiving part, the support part, and the contact pad of the substrate with the heel part), and extending the metal thin film to the entire surface of the second infrared absorbing part opposite to the substrate side, By increasing the aperture ratio of each pixel of the infrared detector, more infrared rays can be absorbed. As a result, the sensitivity of the thermal infrared detector can be increased.

温度検出部が、サーミスターボロメータ薄膜、焦電型薄膜、またはサーモパイルのいずれかであることが好ましい。 It is preferable that the temperature detection unit is any of a thermistor bolometer thin film, a pyroelectric thin film, or a thermopile.

本発明の第１の熱型赤外線検出器の製造方法は、
赤外線を吸収すると赤外線により加熱される第１の赤外線吸収部、第１の赤外線吸収部から伝えられる熱による温度変化を検出する温度検出部、および温度検出部と電気的に接続された電極部を備えた赤外線受光部と、
赤外線受光部を基板上に浮かせて支持する支持部と、
第１の赤外線吸収部から突出する庇部からなり、赤外線を吸収すると赤外線により加熱されその熱を第１の赤外線吸収部を介して温度検出部に伝える第２の赤外線吸収部とを有し、
第１の赤外線吸収部および第２の赤外線吸収部の赤外線入射可能な面の総面積は、第１の赤外線吸収部の、基板側と反対側の面の面積よりも大きい、熱型赤外線検出器の製造方法であって、
コンタクトパッドを有する基板を準備する工程と、
基板のコンタクトパッド側の表面の一部に赤外線反射膜を形成する工程と、
赤外線反射膜を覆うように、赤外線反射膜および基板の表面に第１の絶縁保護膜を形成する工程と、
第１の絶縁保護膜の、赤外線受光部を形成すべき位置に第１の犠牲層を形成する工程と、
第１の犠牲層を覆うように、第１の犠牲層および第１の絶縁保護膜の表面に、第１の材料膜を形成する工程と、
第１の材料膜の、第１の犠牲層の上方に位置する部分の表面に温度検出部を形成する工程と、
温度検出部を覆うように、温度検出部および第１の材料膜の表面に、第２の材料膜を形成する工程と、
第１の絶縁保護膜と第１および第２の材料膜の、コンタクトパッドの上方の位置に第１の開口部を形成する工程と、
第２の材料膜に、温度検出部の一部を露出させる第２の開口部を形成する工程と、
第１および第２の開口部の内部と第２の材料膜の表面に金属膜を形成する工程と、
金属膜をパターニングして、温度検出部上の第２の材料膜を露出させるとともに、第２の開口部内に位置し温度検出部に接続される電極部と、電極部とコンタクトパッドを接続する配線とを形成する工程と、
金属膜を覆うように、金属膜および第２の材料膜の表面に、一部が第１の赤外線吸収部となる第３の材料膜を形成する工程と、
第１〜第３の材料膜をパターニングしてスリットを形成し、スリットを介して第１の犠牲層を露出させる工程と、
第３の材料膜の表面および第１の犠牲層の露出面に第２の犠牲層を形成する工程と、
第３の材料膜の、温度検出部の中央部の上方に位置する部分を露出させるように、第２の犠牲層をパターニングする工程と、
第２の犠牲層の表面および第３の材料膜の露出面に、一部が第２の赤外線吸収部となる第４の材料膜を形成する工程と、
第３の材料膜の、温度検出部の中央部の上方に位置する部分を露出させて第１の赤外線吸収部とし、かつ第２の犠牲層の一部を露出させるように第４の材料膜をパターニングして、赤外線受光部の縁部から、および／または電極部の内側に位置する根元から赤外線受光部の外側に向けて延びて赤外線受光部の中央部に対向する部分が開口している第２の赤外線吸収部を形成する工程と、
第１の犠牲層を除去することにより、第１の赤外線吸収部を含む赤外線受光部を支持部によって基板との間に空間を隔てて浮かせて支持した状態にする工程と、
第２の犠牲層を除去することにより、第２の赤外線吸収部を、電極部、支持部、およびコンタクトパッドをそれぞれ空間を隔てて覆う状態にする工程とを含む。 The manufacturing method of the first thermal infrared detector of the present invention is as follows:
A first infrared absorbing portion that is heated by infrared when absorbing infrared rays, a temperature detecting portion that detects a temperature change due to heat transmitted from the first infrared absorbing portion, and an electrode portion that is electrically connected to the temperature detecting portion An infrared light receiving unit,
A support part for supporting the infrared light receiving part by floating on the substrate;
A second infrared absorbing part that comprises a collar projecting from the first infrared absorbing part and is heated by the infrared when absorbing the infrared and transmits the heat to the temperature detecting part via the first infrared absorbing part;
A thermal infrared detector in which the total area of the first infrared absorbing section and the second infrared absorbing section where the infrared rays can be incident is larger than the area of the first infrared absorbing section on the side opposite to the substrate side A manufacturing method of
Preparing a substrate having contact pads;
Forming an infrared reflective film on a part of the surface of the substrate on the contact pad side;
Forming a first insulating protective film on the surface of the infrared reflective film and the substrate so as to cover the infrared reflective film;
Forming a first sacrificial layer at a position of the first insulating protective film where the infrared light receiving portion is to be formed;
Forming a first material film on the surfaces of the first sacrificial layer and the first insulating protective film so as to cover the first sacrificial layer;
Forming a temperature detecting portion on a surface of a portion of the first material film located above the first sacrificial layer;
Forming a second material film on the surface of the temperature detection unit and the first material film so as to cover the temperature detection unit;
Forming a first opening at a position above the contact pad of the first insulating protective film and the first and second material films;
Forming a second opening in the second material film to expose a part of the temperature detection unit;
Forming a metal film inside the first and second openings and on the surface of the second material film;
The metal film is patterned to expose the second material film on the temperature detection unit, and the electrode unit located in the second opening and connected to the temperature detection unit, and the wiring connecting the electrode unit and the contact pad Forming a process; and
Forming a third material film partly serving as a first infrared absorbing portion on the surfaces of the metal film and the second material film so as to cover the metal film;
Patterning the first to third material films to form slits and exposing the first sacrificial layer through the slits;
Forming a second sacrificial layer on the surface of the third material film and the exposed surface of the first sacrificial layer;
Patterning the second sacrificial layer so as to expose a portion of the third material film located above the central portion of the temperature detection unit;
Forming a fourth material film, a part of which becomes a second infrared absorbing portion, on the surface of the second sacrificial layer and the exposed surface of the third material film;
The fourth material film is formed such that a portion of the third material film located above the central portion of the temperature detection unit is exposed to form a first infrared absorption unit and a part of the second sacrificial layer is exposed. Is patterned to extend from the edge of the infrared light receiving part and / or from the root located inside the electrode part to the outside of the infrared light receiving part and facing the central part of the infrared light receiving part. Forming a second infrared absorbing portion;
Removing the first sacrificial layer so that the infrared light receiving unit including the first infrared absorbing unit is supported by the support unit with a space between the substrate and the substrate;
Removing the second sacrificial layer to bring the second infrared absorbing portion into a state of covering the electrode portion, the support portion, and the contact pad with a space therebetween.

第４の材料膜をパターニングする工程の前に、第４の材料膜の表面に金属薄膜を形成する工程をさらに有し、第４の材料膜をパターニングする工程で、第４の材料膜と共に金属薄膜をパターニングして、第１および第２の赤外線吸収部のそれぞれの表面層をなす金属薄膜を残してもよい。 Before the step of patterning the fourth material film, the method further includes the step of forming a metal thin film on the surface of the fourth material film, and in the step of patterning the fourth material film, the metal together with the fourth material film The thin film may be patterned to leave the metal thin film that forms the surface layer of each of the first and second infrared absorbing portions.

本発明の第２の熱型赤外線検出器の製造方法は、
赤外線が照射される表面層として金属薄膜が形成されている絶縁膜からなる第１の赤外線吸収部、第１の赤外線吸収部から伝えられる熱による温度変化を検出する温度検出部、および温度検出部と電気的に接続された電極部を備えた赤外線受光部と、
赤外線受光部を基板上に浮かせて支持する支持部と、
第１の赤外線吸収部から突出する庇部からなり、赤外線を吸収すると赤外線により加熱されその熱を第１の赤外線吸収部を介して温度検出部に伝える第２の赤外線吸収部とを有し、
第１の赤外線吸収部および第２の赤外線吸収部の赤外線入射可能な面の総面積は、第１の赤外線吸収部の、基板側と反対側の面の面積よりも大きい、熱型赤外線検出器の製造方法であって、
コンタクトパッドを有する基板を準備する工程と、
基板のコンタクトパッド側の表面の一部に赤外線反射膜を形成する工程と、
赤外線反射膜を覆うように、赤外線反射膜および基板の表面に第１の絶縁保護膜を形成する工程と、
第１の絶縁保護膜の、赤外線受光部を形成すべき位置に第１の犠牲層を形成する工程と、
第１の犠牲層を覆うように、第１の犠牲層および第１の絶縁保護膜の表面に、第１の材料膜を形成する工程と、
第１の材料膜の、第１の犠牲層の上方に位置する部分の表面に温度検出部を形成する工程と、
温度検出部を覆うように、温度検出部および第１の材料膜の表面に、第２の材料膜を形成する工程と、
第１の絶縁保護膜と第１および第２の材料膜の、コンタクトパッドの上方の位置に第１の開口部を形成する工程と、
第２の材料膜に、温度検出部の一部を露出させる第２の開口部を形成する工程と、
第１および第２の開口部の内部と第２の材料膜の表面に金属膜を形成する工程と、
金属膜をパターニングして、温度検出部上の第２の材料膜を露出させるとともに、第２の開口部内に位置し温度検出部に接続される電極部と、電極部とコンタクトパッドを接続する配線とを形成する工程と、
金属膜を覆うように、金属膜および第２の材料膜の表面に、一部が第１の赤外線吸収部となる第３の材料膜を形成する工程と、
第１〜第３の材料膜をパターニングしてスリットを形成し、スリットを介して第１の犠牲層を露出させる工程と、
第３の材料膜の表面および第１の犠牲層の露出面に第２の犠牲層を形成する工程と、
第３の材料膜の、温度検出部の中央部の上方に位置する部分を露出させるように、第２の犠牲層をパターニングする工程と、
第２の犠牲層の表面および第３の材料膜の露出面に、一部が第２の赤外線吸収部となる第４の材料膜を形成する工程と、
第４の材料膜の表面全体に、第１および第２の赤外線受光部の表面層を構成する金属薄膜である第５の材料膜を形成する工程と、
第３の材料膜の、温度検出部の中央部の上方に位置する部分を露出させて第１の赤外線吸収部とし、かつ第２の犠牲層の一部を露出させるように第４および第５の材料膜をパターニングして、赤外線受光部の縁部から、および／または電極部の内側に位置する根元から赤外線受光部の外側に向けて延びて赤外線受光部の中央部に対向する部分が開口している第２の赤外線吸収部およびその表面層を形成する工程と、
第１の犠牲層を除去することにより、第１の赤外線吸収部を含む赤外線受光部を支持部によって基板との間に空間を隔てて浮かせて支持した状態にする工程と、
第２の犠牲層を除去することにより、第２の赤外線吸収部を、電極部、支持部、およびコンタクトパッドをそれぞれ空間を隔てて覆う状態にする工程とを含む。 The manufacturing method of the second thermal infrared detector of the present invention is as follows:
A first infrared absorbing portion made of an insulating film on which a metal thin film is formed as a surface layer irradiated with infrared rays, a temperature detecting portion for detecting a temperature change due to heat transmitted from the first infrared absorbing portion, and a temperature detecting portion An infrared light receiving portion including an electrode portion electrically connected to the
A support part for supporting the infrared light receiving part by floating on the substrate;
A second infrared absorbing part that comprises a collar projecting from the first infrared absorbing part and is heated by the infrared when absorbing the infrared and transmits the heat to the temperature detecting part via the first infrared absorbing part;
A thermal infrared detector in which the total area of the first infrared absorbing section and the second infrared absorbing section where the infrared rays can be incident is larger than the area of the first infrared absorbing section on the side opposite to the substrate side A manufacturing method of
Preparing a substrate having contact pads;
Forming an infrared reflective film on a part of the surface of the substrate on the contact pad side;
Forming a first insulating protective film on the surface of the infrared reflective film and the substrate so as to cover the infrared reflective film;
Forming a first sacrificial layer at a position of the first insulating protective film where the infrared light receiving portion is to be formed;
Forming a first material film on the surfaces of the first sacrificial layer and the first insulating protective film so as to cover the first sacrificial layer;
Forming a temperature detecting portion on a surface of a portion of the first material film located above the first sacrificial layer;
Forming a second material film on the surface of the temperature detection unit and the first material film so as to cover the temperature detection unit;
Forming a first opening at a position above the contact pad of the first insulating protective film and the first and second material films;
Forming a second opening in the second material film to expose a part of the temperature detection unit;
Forming a metal film inside the first and second openings and on the surface of the second material film;
The metal film is patterned to expose the second material film on the temperature detection unit, and the electrode unit located in the second opening and connected to the temperature detection unit, and the wiring connecting the electrode unit and the contact pad Forming a process; and
Forming a third material film partly serving as a first infrared absorbing portion on the surfaces of the metal film and the second material film so as to cover the metal film;
Patterning the first to third material films to form slits and exposing the first sacrificial layer through the slits;
Forming a second sacrificial layer on the surface of the third material film and the exposed surface of the first sacrificial layer;
Patterning the second sacrificial layer so as to expose a portion of the third material film located above the central portion of the temperature detection unit;
Forming a fourth material film, a part of which becomes a second infrared absorbing portion, on the surface of the second sacrificial layer and the exposed surface of the third material film;
Forming a fifth material film, which is a metal thin film constituting the surface layers of the first and second infrared light receiving parts, on the entire surface of the fourth material film;
The fourth and fifth portions of the third material film are exposed so that a portion located above the central portion of the temperature detecting portion is exposed to be a first infrared absorbing portion and a part of the second sacrificial layer is exposed. The material film is patterned to open from the edge of the infrared light receiving part and / or from the root located inside the electrode part toward the outside of the infrared light receiving part and facing the central part of the infrared light receiving part Forming the second infrared absorbing portion and the surface layer thereof,
Removing the first sacrificial layer so that the infrared light receiving unit including the first infrared absorbing unit is supported by the support unit with a space between the substrate and the substrate;
Removing the second sacrificial layer to bring the second infrared absorbing portion into a state of covering the electrode portion, the support portion, and the contact pad with a space therebetween.

第１および第２の犠牲層の材料としてポリイミドを用いることが好ましい。 It is preferable to use polyimide as the material for the first and second sacrificial layers.

前記した本発明の方法によれば、開口率が高く赤外線をより多く吸収することが可能な高感度の熱型赤外線検出器を製造することができる。 According to the method of the present invention described above, it is possible to manufacture a highly sensitive thermal infrared detector that has a high aperture ratio and can absorb more infrared rays.

本発明は、赤外線受光部の第１の赤外線吸収部から突出した庇部からなる第２の赤外線吸収部によって、赤外線受光部の電極部、赤外線受光部を基板から浮かせて支持するための支持部、および基板のコンタクトパッドのそれぞれを空間を隔てて覆うことで、熱時定数を殆ど増加させることなく開口率を高めることができる。その結果、より高感度で実時間の赤外画像が得られる熱型赤外線検出器を実現することができる。また、本発明の熱型赤外線検出器の製造方法によれば、開口率が高く、赤外線をより多く吸収することが可能な高感度の熱型赤外線検出器を製造することができる。 The present invention provides a support portion for floating and supporting the electrode portion of the infrared light receiving portion and the infrared light receiving portion from the substrate by the second infrared absorbing portion including the flange protruding from the first infrared absorbing portion of the infrared light receiving portion. By covering each of the contact pads of the substrate with a space therebetween, the aperture ratio can be increased without substantially increasing the thermal time constant. As a result, it is possible to realize a thermal infrared detector that can obtain a more sensitive and real-time infrared image. Moreover, according to the manufacturing method of the thermal infrared detector of the present invention, a highly sensitive thermal infrared detector having a high aperture ratio and capable of absorbing more infrared rays can be manufactured.

次に、本発明の実施の形態について図面を参照して説明する。 Next, embodiments of the present invention will be described with reference to the drawings.

（第１の実施の形態）
図１は、本発明の第１の実施形態の熱型赤外線検出器を示す平面図である。図２は図１のＸ−Ｘ’線断面図であり、図３は図１のＹ−Ｙ’線断面図である。図４は、図１〜図３に示した熱型赤外線検出器における電流経路に沿った断面図であり、図５は図２のＡ−Ａ’線断面図である。本実施形態の熱型赤外線検出器は、画素ピッチが４０μｍの２次元アレイセンサであり、図１には４つの画素が示されている。 (First embodiment)
FIG. 1 is a plan view showing a thermal infrared detector according to the first embodiment of the present invention. 2 is a cross-sectional view taken along line XX ′ of FIG. 1, and FIG. 3 is a cross-sectional view taken along line YY ′ of FIG. 4 is a cross-sectional view taken along a current path in the thermal infrared detector shown in FIGS. 1 to 3, and FIG. 5 is a cross-sectional view taken along the line AA ′ of FIG. The thermal infrared detector of this embodiment is a two-dimensional array sensor with a pixel pitch of 40 μm, and FIG. 1 shows four pixels.

図２および図３に示すようにシリコン基板１の表面には、Ｔｉから成る厚さ２００ｎｍの赤外線反射膜２が形成されている。赤外線反射膜２の表面には、酸化シリコンから成る厚さ２００ｎｍの第１の絶縁保護膜３が形成されており、第１の絶縁保護膜３によって赤外線反射膜２が覆われている。本実施形態では、赤外線反射膜２を構成する金属材料としてＴｉを用いたが、その金属材料として、波長８〜１２μｍ帯の赤外線をほぼ１００％反射するものであれば、Ｔｉ以外にＡｌ、Ｗ、ＷＳｉまたはＴｉＮ等を用いても構わない。また、本実施形態では第１の絶縁保護膜３がシリコン酸化膜であるが、第１の絶縁保護膜３はシリコン窒化膜またはシリコン酸窒化膜であってもよい。 As shown in FIGS. 2 and 3, an infrared reflective film 2 made of Ti and having a thickness of 200 nm is formed on the surface of the silicon substrate 1. On the surface of the infrared reflective film 2, a first insulating protective film 3 made of silicon oxide and having a thickness of 200 nm is formed, and the infrared reflective film 2 is covered with the first insulating protective film 3. In the present embodiment, Ti is used as the metal material constituting the infrared reflecting film 2, but as the metal material, Al, W other than Ti can be used as long as it reflects almost 100% of infrared rays in the wavelength band of 8 to 12 μm. WSi or TiN may be used. In the present embodiment, the first insulating protective film 3 is a silicon oxide film, but the first insulating protective film 3 may be a silicon nitride film or a silicon oxynitride film.

本実施形態の熱型赤外線検出器では、図１〜図５のそれぞれに示すようにシリコン基板１の第１の絶縁保護膜３側の面の上方に、複数の赤外線受光部５が配列されている。それぞれの赤外線受光部５は、２つの支持部６によって空洞部４を隔てて第１の絶縁保護膜３の表面から浮かせられて支持されており、１つの画素に１つの赤外線受光部５が配置されている。それぞれの支持部６は、図１および図５に示すように、赤外線受光部５の上面から見て、赤外線受光部５の外周に沿って延びている。また、それぞれの支持部６は、赤外線受光部５とシリコン基板１との間の熱コンダクタンスを小さくするために、赤外線受光部５における互いに隣り合う２つの辺に渡って長く延びている。この支持部６は、シリコン基板１の表面に対して平行な梁６ａと、梁６ａの一端に接続された支持脚６ｂとから成る。 In the thermal infrared detector of this embodiment, as shown in each of FIGS. 1 to 5, a plurality of infrared light receivers 5 are arranged above the surface of the silicon substrate 1 on the first insulating protective film 3 side. Yes. Each infrared light receiving portion 5 is supported by two support portions 6 so as to float from the surface of the first insulating protective film 3 with the cavity portion 4 therebetween, and one infrared light receiving portion 5 is arranged in one pixel. Has been. As shown in FIGS. 1 and 5, each support portion 6 extends along the outer periphery of the infrared light receiving portion 5 when viewed from the upper surface of the infrared light receiving portion 5. Each support portion 6 extends long over two adjacent sides of the infrared light receiving portion 5 in order to reduce the thermal conductance between the infrared light receiving portion 5 and the silicon substrate 1. The support portion 6 includes a beam 6a parallel to the surface of the silicon substrate 1 and a support leg 6b connected to one end of the beam 6a.

赤外線受光部５は、温度検出部であるサーミスターボロメータ薄膜７と、サーミスターボロメータ薄膜７に接した２つの電極部１３と、サーミスターボロメータ薄膜７および２つの電極部１３を取り囲む、第１の赤外線吸収部である絶縁保護膜８とから構成されている。サーミスターボロメータ薄膜７および赤外線受光部５の外形形状はほぼ矩形であり、サーミスターボロメータ薄膜７の一辺と平行な方向にそれぞれの電極部１３が延びている。１つの赤外線受光部５に備えられた２つの電極部１３のうち一方の電極部１３がサーミスターボロメータ薄膜７の一端部に接触してサーミスターボロメータ薄膜７と電気的に接続されている。また、他方の電極部１３がサーミスターボロメータ薄膜７の他端部に接触してサーミスターボロメータ薄膜７と電気的に接続されている。 The infrared light receiving unit 5 surrounds the thermistor bolometer thin film 7 which is a temperature detection unit, the two electrode units 13 in contact with the thermistor bolometer thin film 7, the thermistor bolometer thin film 7 and the two electrode units 13. It is comprised from the insulating protective film 8 which is an infrared rays absorption part. The outer shape of the thermistor bolometer thin film 7 and the infrared light receiving part 5 is substantially rectangular, and each electrode part 13 extends in a direction parallel to one side of the thermistor bolometer thin film 7. One of the two electrode portions 13 provided in one infrared light receiving portion 5 is in contact with one end portion of the thermistor bolometer thin film 7 and is electrically connected to the thermistor bolometer thin film 7. The other electrode portion 13 is in contact with the other end portion of the thermistor bolometer thin film 7 and is electrically connected to the thermistor bolometer thin film 7.

一方、支持部６を構成する板状の支持脚６ｂの一端部は、シリコン基板１のコンタクトパッド１１上に固定されている。支持脚６ｂは、シリコン基板１側の一端部からシリコン基板１から離れる方向に向かってシリコン基板１の表面に対して斜めに延びている。その支持脚６ｂの、シリコン基板１側と反対側の他端部に、シリコン基板１の表面に対して平行な梁６ａの一端部が接続されている。梁６ａは、赤外線受光部５の角部の近傍で９０度に折れ曲がっており、梁６ａの他端部が赤外線受光部５の側面に接続されている。 On the other hand, one end of the plate-like support leg 6 b constituting the support portion 6 is fixed on the contact pad 11 of the silicon substrate 1. The support leg 6b extends obliquely with respect to the surface of the silicon substrate 1 in a direction away from the silicon substrate 1 from one end portion on the silicon substrate 1 side. One end of a beam 6a parallel to the surface of the silicon substrate 1 is connected to the other end of the support leg 6b opposite to the silicon substrate 1 side. The beam 6 a is bent at 90 degrees near the corner of the infrared light receiving unit 5, and the other end of the beam 6 a is connected to the side surface of the infrared light receiving unit 5.

支持部６の梁６ａおよび支持脚６ｂはそれぞれ、金属配線９が第２の絶縁保護膜１０により被覆されて成るものである。金属配線９のシリコン基板１側の一端部がコンタクトパッド１１と電気的に接続され、金属配線９の赤外線受光部５側の他端部が電極部１３の一端部に電気的に接続されている。よって、赤外線受光部５の電極部１３と、シリコン基板１のコンタクトパッド１１とが支持部６内の金属配線９を介して電気的に接続されている。それぞれの画素には２つのコンタクトパッド１１が配置されており、それぞれのコンタクトパッド１１が、図４に示されるようにシリコン基板１内に形成された読出回路１６と電気的に接続されている。 Each of the beam 6a and the support leg 6b of the support portion 6 is formed by covering the metal wiring 9 with the second insulating protective film 10. One end of the metal wiring 9 on the silicon substrate 1 side is electrically connected to the contact pad 11, and the other end of the metal wiring 9 on the infrared light receiving unit 5 side is electrically connected to one end of the electrode portion 13. . Therefore, the electrode part 13 of the infrared light receiving part 5 and the contact pad 11 of the silicon substrate 1 are electrically connected via the metal wiring 9 in the support part 6. Two contact pads 11 are arranged in each pixel, and each contact pad 11 is electrically connected to a readout circuit 16 formed in the silicon substrate 1 as shown in FIG.

製造工程の説明として後述する通り、空洞部４は、ポリイミド膜からなる第１の犠牲層を一旦形成しておいて、製造工程の最終段階でそのポリイミド膜を、例えば酸素プラズマによるアッシングで除去することによって形成されている。上記のように支持部６によって赤外線受光部５をシリコン基板１から浮かせて支持する熱分離構造により、赤外線受光部５に蓄積された熱が、ヒートシンクであるシリコン基板１に逃げ難くなっている。 As will be described later in the description of the manufacturing process, the cavity 4 once forms a first sacrificial layer made of a polyimide film, and removes the polyimide film by, for example, oxygen plasma ashing at the final stage of the manufacturing process. It is formed by. As described above, the heat separating structure in which the infrared light receiving unit 5 is supported by being floated from the silicon substrate 1 by the support unit 6 makes it difficult for the heat accumulated in the infrared light receiving unit 5 to escape to the silicon substrate 1 as a heat sink.

赤外線受光部５の、シリコン基板１側と反対側の面、すなわち絶縁保護膜８の、赤外線が照射される上面からは庇部１２が突出している。庇部１２は、赤外線受光部５内の電極部１３との間、支持部６との間、およびシリコン基板１のコンタクトパッド１１との間に空間を隔てて、電極部１３、支持部６およびコンタクトパッド１１を覆うように延びている。すなわち、電極部１３の、シリコン基板１側と反対側の面、金属配線９の、シリコン基板１側と反対側の面、およびコンタクトパッド１１の表面がそれぞれ、空間を隔てて庇部１２によって覆われている。庇部１２はシリコン窒化膜であり、赤外線を吸収してその赤外線を熱に変換する第２の赤外線吸収部である。この庇部１２は、シリコン窒化膜の他に、シリコン酸化膜、シリコン酸窒化膜、ＳｉＣ膜、あるいはそれらの膜のうち少なくとも２つを組み合わせた積層膜であってもよい。 A flange 12 protrudes from the surface of the infrared light receiving portion 5 opposite to the silicon substrate 1 side, that is, the upper surface of the insulating protective film 8 on which infrared rays are irradiated. The eaves part 12 is spaced from the electrode part 13 in the infrared light receiving part 5, the support part 6, and the contact pad 11 of the silicon substrate 1, and the electrode part 13, the support part 6, and It extends so as to cover the contact pad 11. That is, the surface of the electrode portion 13 opposite to the silicon substrate 1 side, the surface of the metal wiring 9 opposite to the silicon substrate 1 side, and the surface of the contact pad 11 are each covered with the flange portion 12 with a space therebetween. It has been broken. The collar portion 12 is a silicon nitride film, and is a second infrared absorbing portion that absorbs infrared rays and converts the infrared rays into heat. The flange 12 may be a silicon oxide film, a silicon oxynitride film, a SiC film, or a laminated film in which at least two of these films are combined in addition to the silicon nitride film.

従って、庇部１２の、絶縁保護膜８との接続部、すなわち庇部１２の根元部は、電極部１３の近傍の領域で、図２および図４に示すように赤外線受光部５の上面側から見て電極部１３よりも赤外線受光部５の内側に配置されている。他の領域、すなわち電極部１３の近傍ではない領域では、庇部１２の根元部が、図３および図５に示すように赤外線受光部５の上面側から見て赤外線受光部５の縁部に配置されている。庇部１２の、電極部１３の近傍にある部分と、電極部１３との距離は、サーミスターボロメータ薄膜７上の絶縁保護膜８の厚さ以上の値に設定されていることが好ましい。 Therefore, the connection portion of the flange portion 12 with the insulating protective film 8, that is, the base portion of the flange portion 12 is a region near the electrode portion 13, and is on the upper surface side of the infrared light receiving portion 5 as shown in FIGS. When viewed from the side, the electrode part 13 is disposed inside the infrared light receiving part 5. In the other region, that is, the region that is not in the vicinity of the electrode portion 13, the base portion of the flange portion 12 is located at the edge of the infrared light receiving portion 5 when viewed from the upper surface side of the infrared light receiving portion 5 as shown in FIGS. Has been placed. The distance between the electrode portion 13 and the portion of the collar portion 12 near the electrode portion 13 is preferably set to a value equal to or greater than the thickness of the insulating protective film 8 on the thermistor bolometer thin film 7.

サーミスターボロメータ薄膜７の材質としては酸化バナジウムが用いられており、サーミスターボロメータ薄膜７の厚さは約１００ｎｍとなっている。電極部１３は厚さ約１００ｎｍのＴｉから成り、絶縁保護膜８は厚さ約５００ｎｍのシリコン窒化膜８から成る。サーミスターボロメータ薄膜７の材質としては、抵抗温度係数が大きいものであればどのようなものを用いてもよく、不純物をドーピングした非晶質シリコンや非晶質ゲルマニウム、不純物を添加した酸化バナジウム、チタン等を用いてもよい。 Vanadium oxide is used as the material of the thermistor bolometer thin film 7, and the thickness of the thermistor bolometer thin film 7 is about 100 nm. The electrode portion 13 is made of Ti having a thickness of about 100 nm, and the insulating protective film 8 is made of a silicon nitride film 8 having a thickness of about 500 nm. As the material of the thermistor bolometer thin film 7, any material having a large temperature coefficient of resistance may be used. Amorphous silicon doped with impurities, amorphous germanium, vanadium oxide doped with impurities, Titanium or the like may be used.

梁６ａおよび支持脚６ｂ内の金属配線９はＴｉから成り、その金属配線９の断面形状は、厚さ１００ｎｍで幅１μｍの矩形である。金属配線９を取り囲む第２の絶縁保護膜１０はシリコン窒化膜から成り、梁６ａおよび支持脚６ｂの断面形状は、厚さ５００ｎｍで幅２．６μｍの矩形になっている。１本の梁６ａと１本の支持脚６ｂの合計の長さは約８６μｍである。絶縁保護膜８および第２の絶縁保護膜１０はそれぞれ、シリコン窒化膜の他に、シリコン酸化膜、シリコン酸窒化膜、ＳｉＣ膜、あるいはそれらの膜のうち少なくとも２つを組み合わせた積層膜であってもよい。絶縁保護膜８および庇部１２の材料は、赤外線を効率良く吸収するものであることが要求される。 The metal wiring 9 in the beam 6a and the support leg 6b is made of Ti, and the cross-sectional shape of the metal wiring 9 is a rectangle having a thickness of 100 nm and a width of 1 μm. The second insulating protective film 10 surrounding the metal wiring 9 is made of a silicon nitride film, and the cross-sectional shape of the beam 6a and the support leg 6b is a rectangle having a thickness of 500 nm and a width of 2.6 μm. The total length of one beam 6a and one support leg 6b is about 86 μm. The insulating protective film 8 and the second insulating protective film 10 are each a silicon oxide film, a silicon oxynitride film, a SiC film, or a laminated film in which at least two of these films are combined in addition to the silicon nitride film. May be. The material of the insulating protective film 8 and the collar part 12 is required to absorb infrared rays efficiently.

サーミスターボロメータ薄膜７を覆う絶縁保護膜８、および支持部６の第２の絶縁保護膜１０は、後述する製造工程によって形成された、図４に示される絶縁保護膜３２，３３，３７によって構成されている。熱型赤外線検出器の製造工程を簡略化するためには、このように絶縁保護膜８および第２の絶縁保護膜１０を同じ絶縁保護膜によって構成し、絶縁保護膜８および第２の絶縁保護膜１０の材質として同じものを用いることが好ましい。絶縁保護膜８が、絶縁保護膜３２，３３，３７の、サーミスターボロメータ薄膜７の周囲にある一部分から構成されている。また、第２の絶縁保護膜１０が、絶縁保護膜３２，３３，３７のそれぞれの他の部分から構成されている。さらに、赤外線受光部５の電極部１３、および支持部６内の金属配線９は、図４に示される金属膜３６により構成されていて、同じ配線材料によって形成されている。その金属膜３６におけるサーミスターボロメータ薄膜７との接続部分が電極部１３となっている。 The insulating protective film 8 covering the thermistor bolometer thin film 7 and the second insulating protective film 10 of the support 6 are constituted by insulating protective films 32, 33, and 37 shown in FIG. Has been. In order to simplify the manufacturing process of the thermal infrared detector, the insulating protective film 8 and the second insulating protective film 10 are thus formed of the same insulating protective film, and the insulating protective film 8 and the second insulating protective film are thus formed. It is preferable to use the same material for the film 10. The insulating protective film 8 is composed of a part of the insulating protective films 32, 33, and 37 around the thermistor bolometer thin film 7. The second insulating protective film 10 is composed of other portions of the insulating protective films 32, 33, and 37. Furthermore, the electrode part 13 of the infrared light receiving part 5 and the metal wiring 9 in the support part 6 are composed of the metal film 36 shown in FIG. 4 and are formed of the same wiring material. A connecting portion of the metal film 36 with the thermistor bolometer thin film 7 is an electrode portion 13.

コンタクトパッド１１の大きさは約７．５μｍ角であり、コンタクトパッド１１の殆どの領域（約６μｍ角）が、厚さ１００ｎｍのＴｉ膜と厚さ２００ｎｍのＡｌ膜とで覆われている。このようにコンタクトパッド１１がＴｉ膜およびＡｌ膜で覆われていて、コンタクトパッド１１の上方で赤外線の反射率が高くなると共に、コンタクトパッド１１上のＴｉ膜およびＡｌ膜がシリコン基板１内の読出回路１６と電気的に接続されている。シリコン基板１の内部には、図４および図５に示すように、互いに平行な方向に延びる信号線１７、および画素への配線１８がそれぞれ複数形成されている。信号線１７、および画素への配線１８のそれぞれの上方に複数のコンタクトパッド１１が配列されており、信号線１７上のコンタクトパッド１１が信号線１７と電気的に接続され、画素への配線１８上のコンタクトパッド１１が、画素への配線１８と電気的に接続されている。 The size of the contact pad 11 is about 7.5 μm square, and most regions (about 6 μm square) of the contact pad 11 are covered with a Ti film having a thickness of 100 nm and an Al film having a thickness of 200 nm. As described above, the contact pad 11 is covered with the Ti film and the Al film, the infrared reflectance is increased above the contact pad 11, and the Ti film and the Al film on the contact pad 11 are read out in the silicon substrate 1. The circuit 16 is electrically connected. As shown in FIGS. 4 and 5, a plurality of signal lines 17 extending in parallel to each other and a plurality of wirings 18 to the pixels are formed inside the silicon substrate 1. A plurality of contact pads 11 are arranged above each of the signal line 17 and the wiring 18 to the pixel. The contact pad 11 on the signal line 17 is electrically connected to the signal line 17, and the wiring 18 to the pixel. The upper contact pad 11 is electrically connected to the wiring 18 to the pixel.

コンタクトパッド１１を覆う金属膜は、ＴｉとＡｌの積層膜の他に、Ａｌ、Ｗ、ＷＳｉ、ＴｉＮ等の膜や、これらの金属膜にＴｉ膜を含めた積層構造の膜であってもよい。コンタクトパッド１１上にＴｉ膜およびＡｌ膜を積層した本実施形態の構成の場合、熱コンダクタンスは８．２×１０^-8Ｗ／Ｋ、赤外線受光部５の開口率は４７％、赤外線受光部５の熱容量は９×１０^-10Ｊ／Ｋとなった。また、熱時定数は１１ｍsecとなって、テレビのフレームレートに対応する時間３３ｍsecに比べて十分小さくなり、実時間画像化の際、問題が無かった。 The metal film covering the contact pad 11 may be a film of Al, W, WSi, TiN or the like, or a film having a laminated structure including a Ti film in these metal films, in addition to the Ti and Al laminated film. . In the case of the configuration of this embodiment in which a Ti film and an Al film are laminated on the contact pad 11, the thermal conductance is 8.2 × 10 ⁻⁸ W / K, the aperture ratio of the infrared light receiving part 5 is 47%, and the infrared light receiving part 5 The heat capacity was 9 × 10 ⁻¹⁰ J / K. Further, the thermal time constant was 11 msec, which was sufficiently smaller than the time 33 msec corresponding to the television frame rate, and there was no problem in real-time imaging.

このように赤外線受光部５が支持部６によって支持されている構成において、電極部１３が無い領域では赤外線受光部５の外周から、電極部１３が有る領域ではその内側約０．５〜１μｍの領域から、赤外線を吸収する第２の赤外線吸収部である庇部１２を出すことで、開口率を増やすことができる。本実施形態では、電極部１３が無い領域では庇部１２の根元を赤外線受光部５の縁部に配置し、電極部１３が有る領域では電極部１３より０．５μｍ内側に入ったところに庇部１２の根元を配置した。すなわち、庇部１２は、赤外線受光部５の縁部または電極部１３の内側に位置する根元から赤外線受光部５の外側に向けて延びている。そして、図１〜５に明確に示されているように、庇部１２は赤外線受光部５の外側に向けて四方に延びており、庇部の中央部分（画素の中央に相当）は開口しており、この中央開口を介して赤外線受光部５の絶縁保護膜８が、赤外線１５が入射してくる方向（図２，３参照）に向けて露出している。 As described above, in the configuration in which the infrared light receiving unit 5 is supported by the support unit 6, from the outer periphery of the infrared light receiving unit 5 in the region where the electrode unit 13 is not present, and about 0.5 to 1 μm inside the region where the electrode unit 13 is present. From the region, the opening ratio can be increased by taking out the collar portion 12 which is the second infrared ray absorbing portion that absorbs infrared rays. In the present embodiment, the base of the collar part 12 is arranged at the edge of the infrared light receiving part 5 in the area where the electrode part 13 is not present, and the part where the base part is 0.5 μm inside the electrode part 13 in the area where the electrode part 13 is present. The root of part 12 was placed. That is, the collar portion 12 extends from the edge of the infrared light receiving portion 5 or the root located inside the electrode portion 13 toward the outside of the infrared light receiving portion 5. As clearly shown in FIGS. 1 to 5, the collar portion 12 extends in four directions toward the outside of the infrared light receiving portion 5, and a central portion (corresponding to the center of the pixel) of the collar portion is opened. Through this central opening, the insulating protective film 8 of the infrared light receiving unit 5 is exposed in the direction in which the infrared rays 15 enter (see FIGS. 2 and 3).

その結果、赤外線受光部５の第１の赤外線吸収部である絶縁保護膜８と、第２の赤外線吸収部である庇部１２とを合わせた開口率は９０％となり、赤外線受光部５の第１の赤外線吸収部である絶縁保護膜８だけの場合（開口率６０〜７０％程度が一般的である）よりも、検出器の感度が１．９倍高くなった。そして、図１〜５に明確に示されているように、１つの画素内において、絶縁保護膜８および庇部１２の赤外線入射可能な面の総面積、すなわち、庇部１２の、赤外線１５が入射してくる方向（図２，３参照）に向いている部分の面積と、赤外線受光部５の絶縁保護膜８の、中央開口を介して、赤外線１５が入射してくる方向（図２，３参照）に向けて露出している部分の面積の合計が、絶縁保護膜８の、基板１側と反対側の面（庇部１２に覆われていて露出していない部分も含む）の面積よりも大きくなっている。 As a result, the aperture ratio of the insulating protective film 8 that is the first infrared absorbing portion of the infrared receiving portion 5 and the flange portion 12 that is the second infrared absorbing portion is 90%. The sensitivity of the detector was 1.9 times higher than that of the case of only the insulating protective film 8 being the infrared absorbing portion 1 (the opening ratio is generally about 60 to 70%). As clearly shown in FIGS. 1 to 5, in one pixel, the total area of the surface on which the insulating protective film 8 and the flange 12 can receive infrared rays, that is, the infrared ray 15 of the flange 12 is The area of the portion facing the incident direction (see FIGS. 2 and 3) and the direction in which infrared rays 15 are incident through the central opening of the insulating protective film 8 of the infrared light receiving unit 5 (see FIGS. 2 and 2). 3), the total area of the exposed portions of the insulating protective film 8 is the area of the surface of the insulating protective film 8 opposite to the substrate 1 side (including the portion that is covered with the flange 12 and is not exposed). Is bigger than.

なお、本実施形態では、庇部１２の根元の位置について、電極部１３が有る領域では０．５μｍ内側に入ったところに設定したが、必ずしも０．５μｍである必要はなく、サーミスターボロメータ薄膜７の上に形成された絶縁保護膜８の厚さ程度でもよい。庇部１２としては、波長１０μｍ帯の赤外線を吸収するものであれば、非晶質ＳｉＣ、シリコン酸化膜またはシリコン酸窒化膜、あるいはそれらの膜のうち少なくともいずれか２つを組み合わせた積層膜を用いてもよい。 In the present embodiment, the base position of the collar portion 12 is set to be 0.5 μm inside in the region where the electrode portion 13 is provided, but it is not necessarily 0.5 μm, and the thermistor bolometer thin film is not necessarily required. 7 may be about the thickness of the insulating protective film 8 formed on the substrate 7. As the collar portion 12, an amorphous SiC, a silicon oxide film, a silicon oxynitride film, or a laminated film combining at least two of these films can be used as long as it absorbs infrared rays having a wavelength of 10 μm. It may be used.

次に、本実施形態の熱型赤外線検出器の動作原理について説明する。 Next, the operation principle of the thermal infrared detector of this embodiment will be described.

まず、赤外線受光部５の絶縁保護膜８（第１の赤外線吸収部）と庇部１２（第２の赤外線吸収部）に赤外線１５が入射すると、入射した赤外線１５の一部が絶縁保護膜８と庇部１２のそれぞれで吸収されて、絶縁保護膜８および庇部１２が加熱される。絶縁保護膜８と庇部１２に入射した赤外線１５の他の部分は、赤外線受光部５や庇部１２、支持部６をそれぞれ透過してシリコン基板１側に向かって進行する。赤外線受光部５や庇部１２、支持部６をそれぞれ透過した赤外線は、赤外線反射膜２や金属配線９およびコンタクトパッド１１により赤外線受光部５および庇部１２に向けて反射されて、再び絶縁保護膜８と庇部１２に入射する。これにより、赤外線反射膜２によって反射された赤外線が絶縁保護膜と庇部１２に吸収されて、絶縁保護膜８および庇部１２がさらに加熱される。 First, when the infrared rays 15 are incident on the insulating protective film 8 (first infrared absorbing portion) and the collar portion 12 (second infrared absorbing portion) of the infrared light receiving portion 5, a part of the incident infrared rays 15 is insulated. The insulating protective film 8 and the flange 12 are heated by being absorbed by the flange 12 and the flange 12, respectively. The other portions of the infrared ray 15 incident on the insulating protective film 8 and the flange portion 12 are transmitted through the infrared light receiving portion 5, the flange portion 12, and the support portion 6, respectively, and travel toward the silicon substrate 1 side. Infrared light that has passed through the infrared light receiving part 5, the collar part 12, and the support part 6 is reflected toward the infrared light receiving part 5 and the collar part 12 by the infrared reflecting film 2, the metal wiring 9, and the contact pad 11, and is again insulated and protected. The light enters the film 8 and the flange 12. Thereby, the infrared rays reflected by the infrared reflecting film 2 are absorbed by the insulating protective film and the collar part 12, and the insulating protective film 8 and the collar part 12 are further heated.

庇部１２の熱は、絶縁保護膜８を通してサーミスターボロメータ薄膜７に伝わる。このように庇部１２および絶縁保護膜８からの熱によりサーミスターボロメータ薄膜７の温度が変化して、サーミスターボロメータ薄膜７の抵抗値が変化する。この抵抗値の変化は、シリコン基板１内の信号読出回路１６により電圧変化に変換されて電気信号として読み出され、その電気信号を基に外部回路により赤外画像化される。ここで、庇部１２や赤外線受光部５を透過した赤外線を、庇部１２と赤外線受光部５に再度入射させるために、赤外線反射膜２、梁６ａ内の金属配線９およびコンタクトパッド１１は平坦であることが望ましい。 The heat of the flange 12 is transmitted to the thermistor bolometer thin film 7 through the insulating protective film 8. Thus, the temperature of the thermistor bolometer thin film 7 is changed by the heat from the flange 12 and the insulating protective film 8, and the resistance value of the thermistor bolometer thin film 7 is changed. This change in resistance value is converted into a voltage change by the signal readout circuit 16 in the silicon substrate 1 and read out as an electrical signal, and an infrared image is formed by an external circuit based on the electrical signal. Here, the infrared reflection film 2, the metal wiring 9 in the beam 6a, and the contact pad 11 are flat so that the infrared rays transmitted through the flange portion 12 and the infrared light receiving portion 5 are incident again on the flange portion 12 and the infrared light receiving portion 5. It is desirable that

上述したように本実施形態の熱型赤外線検出器では、赤外線受光部５の絶縁保護膜８（第１の赤外線吸収部）から庇部１２（第２の赤外線吸収部）が突出し、その庇部１２によって、電極部１３および支持部６の、シリコン基板１側と反対側のそれぞれの面や、コンタクトパッド１１が空間を隔てて覆われている。これにより、熱時定数を殆ど増加させることなく、各画素の開口率が増加し、赤外線をより多く吸収することができる。その結果、熱型赤外線検出器の感度を高くすることができる。また、庇部１２の根元を赤外線受光部５の縁部近傍に配置させることにより、熱容量も殆ど増えず、熱時定数もテレビのフレームレートに対応する時間３３ｍsecより十分小さくすることができる。 As described above, in the thermal infrared detector of the present embodiment, the flange portion 12 (second infrared absorption portion) protrudes from the insulating protective film 8 (first infrared absorption portion) of the infrared light receiving portion 5, and the flange portion thereof. 12, the surfaces of the electrode portion 13 and the support portion 6 opposite to the silicon substrate 1 side and the contact pads 11 are covered with a space therebetween. As a result, the aperture ratio of each pixel is increased and the infrared ray can be absorbed more without increasing the thermal time constant. As a result, the sensitivity of the thermal infrared detector can be increased. Further, by arranging the base of the collar portion 12 in the vicinity of the edge of the infrared light receiving portion 5, the heat capacity hardly increases and the thermal time constant can be sufficiently reduced from the time 33 msec corresponding to the frame rate of the television.

以上で述べた実施形態の熱型赤外線検出器は、サーミスターボロメータ型のものであるが、庇部１２を赤外線受光部５からせり出すことにより開口率を増加させる方法は、強誘電体型（焦電型）やサーモパイル型の熱型赤外線検出器に対しても成り立つ。すなわち、赤外線受光部５の温度検出部として、サーミスターボロメータ薄膜７の代わりに焦電型薄膜またはサーモパイルを用いてもよい。 The thermal infrared detector of the embodiment described above is of the thermistor bolometer type, but the method of increasing the aperture ratio by protruding the collar portion 12 from the infrared light receiving portion 5 is a ferroelectric type (pyroelectric). Type) and thermopile thermal infrared detectors. That is, a pyroelectric thin film or a thermopile may be used in place of the thermistor bolometer thin film 7 as the temperature detection unit of the infrared light receiving unit 5.

次に、上記の熱型赤外線検出器の製造方法について図６〜図１３を参照して説明する。図６〜図１３はそれぞれ、本実施形態の熱型赤外線検出器の製造方法について説明するための図である。図６〜図９、および図１１〜図１３のそれぞれでは、図４と同様に熱型赤外線検出器の電流経路に沿った断面が示されている。 Next, the manufacturing method of said thermal type infrared detector is demonstrated with reference to FIGS. 6 to 13 are diagrams for explaining a method of manufacturing the thermal infrared detector of the present embodiment. Each of FIGS. 6 to 9 and FIGS. 11 to 13 shows a cross section along the current path of the thermal infrared detector, as in FIG.

まず、図６（ａ）において、読出回路１６およびコンタクトパッド１１を複数備えたシリコン基板１を準備する。シリコン基板１の内部に読出回路１６が形成され、シリコン基板１の表面に、読出回路１６と電気的に接続されたコンタクトパッド１１の表面が露出している。 First, in FIG. 6A, a silicon substrate 1 provided with a plurality of readout circuits 16 and contact pads 11 is prepared. A read circuit 16 is formed inside the silicon substrate 1, and the surface of the contact pad 11 electrically connected to the read circuit 16 is exposed on the surface of the silicon substrate 1.

次に、図６（ｂ）において、シリコン基板１の、赤外線受光部５に対応する部分の表面や、コンタクトパッド１１の表面およびその周囲に赤外線反射膜２を形成する。 Next, in FIG. 6B, the infrared reflecting film 2 is formed on the surface of the silicon substrate 1 corresponding to the infrared light receiving unit 5, the surface of the contact pad 11, and the periphery thereof.

次に、図７（ａ）において、シリコン基板１上のそれぞれの赤外線反射膜２を覆うように、シリコン基板１の表面や、それぞれの赤外線反射膜２の表面全体に第１の絶縁保護膜３を形成する。 Next, in FIG. 7A, the first insulating protective film 3 is formed on the surface of the silicon substrate 1 or the entire surface of each infrared reflective film 2 so as to cover each infrared reflective film 2 on the silicon substrate 1. Form.

次に、図７（ｂ）において、第１の絶縁保護膜３の表面における赤外線受光部５に対応する部分やその周囲に、支持部６とシリコン基板１との間の空間や空洞部４を形成するための第１の犠牲層３１を部分的に形成する。第１の犠牲層３１はシリコン基板１上に島状に複数形成されており、第１の犠牲層３１の、支持脚６ｂに対応する部分の表面は、図７（ｂ）に示すようにシリコン基板１の表面に対して傾斜している。第１の犠牲層３１はポリイミドから成るものであり、製造工程の最終段階で除去される。第１の犠牲層３１を形成する際には、まず、第１の絶縁保護膜３の表面全体に感光性ポリイミドを塗布する。そして、露光および現像の工程と、熱処理とによって第１の絶縁保護膜３上の感光性ポリイミドをパターニングして島状に整形し、感光性ポリイミドから成る第１の犠牲層３１を形成する。 Next, in FIG. 7B, a space between the support portion 6 and the silicon substrate 1 and a cavity portion 4 are formed on and around the portion corresponding to the infrared light receiving portion 5 on the surface of the first insulating protective film 3. A first sacrificial layer 31 to be formed is partially formed. A plurality of first sacrificial layers 31 are formed in an island shape on the silicon substrate 1, and the surface of the portion of the first sacrificial layer 31 corresponding to the support legs 6b is silicon as shown in FIG. Inclined with respect to the surface of the substrate 1. The first sacrificial layer 31 is made of polyimide and is removed at the final stage of the manufacturing process. In forming the first sacrificial layer 31, first, photosensitive polyimide is applied to the entire surface of the first insulating protective film 3. Then, the photosensitive polyimide on the first insulating protective film 3 is patterned by exposure and development processes and heat treatment, and shaped into an island shape, thereby forming a first sacrificial layer 31 made of photosensitive polyimide.

次に、第１の犠牲層３１および第１の絶縁保護膜３のそれぞれの表面全体に、プラズマＣＶＤ法により第１の材料膜として絶縁保護膜３２を形成し、絶縁保護膜３２によって第１の犠牲層３１を覆う。絶縁保護膜３２としては、例えばシリコン窒化膜、シリコン酸化膜、またはシリコン酸窒化膜を形成する。 Next, an insulating protective film 32 is formed as a first material film on the entire surface of each of the first sacrificial layer 31 and the first insulating protective film 3 by a plasma CVD method. The sacrificial layer 31 is covered. As the insulating protective film 32, for example, a silicon nitride film, a silicon oxide film, or a silicon oxynitride film is formed.

次に、図８（ａ）において、絶縁保護膜（第１の材料膜）３２の、第１の犠牲層３１上の部分における赤外線受光部５に対応する部分の表面に、温度検出部となるサーミスターボロメータ薄膜７を形成する。サーミスターボロメータ薄膜７を形成する際には、まず、絶縁保護膜３２の表面全体に、熱電変換材料薄膜として、サーミスターボロメータ材料である酸化バナジウムの膜を反応性スパッター法により形成する。そして、露光および現像の工程の後、絶縁保護膜３２上の酸化バナジウムの膜を、特許文献４に記載されているようにＳＦ₆とＣＯ₂の混合ガスのプラズマによりエッチング加工する。このような露光および現像の工程と、エッチング加工とにより酸化バナジウムの膜をパターニングすることで、酸化バナジウムから成るサーミスターボロメータ薄膜７を形成する。 Next, in FIG. 8A, a temperature detection unit is formed on the surface of the insulating protective film (first material film) 32 corresponding to the infrared light receiving unit 5 in the part on the first sacrificial layer 31. The thermistor bolometer thin film 7 is formed. When forming the thermistor bolometer thin film 7, first, a film of vanadium oxide as the thermistor bolometer material is formed on the entire surface of the insulating protective film 32 as a thermoelectric conversion material thin film by a reactive sputtering method. After the exposure and development steps, the vanadium oxide film on the insulating protective film 32 is etched by plasma of a mixed gas of SF ₆ and CO ₂ as described in Patent Document 4. The thermistor bolometer thin film 7 made of vanadium oxide is formed by patterning the vanadium oxide film by such exposure and development processes and etching.

次に、サーミスターボロメータ薄膜７を覆うように、サーミスターボロメータ薄膜７および絶縁保護膜３２のそれぞれの表面全体に、プラズマＣＶＤ法により第２の材料膜として絶縁保護膜３３を形成する。絶縁保護膜３３としては、例えばシリコン窒化膜、シリコン酸化膜、またはシリコン酸窒化膜を形成する。 Next, an insulating protective film 33 is formed as a second material film by plasma CVD on the entire surfaces of the thermistor bolometer thin film 7 and the insulating protective film 32 so as to cover the thermistor bolometer thin film 7. As the insulating protective film 33, for example, a silicon nitride film, a silicon oxide film, or a silicon oxynitride film is formed.

次に、図８（ｂ）において、シリコン基板１内の読出回路１６との電気的なコンタクトを得るために、第１の絶縁保護膜３および絶縁保護膜（第１および第２の材料膜）３２，３３の、コンタクトパッド１１に対応する部分に、コンタクトホールとなる第１の開口部３４を形成する。これにより、第１の開口部３４の底面にコンタクトパッド１１上の赤外線反射膜２の表面が露出する。 Next, in FIG. 8B, in order to obtain electrical contact with the readout circuit 16 in the silicon substrate 1, the first insulating protective film 3 and the insulating protective film (first and second material films) are used. First openings 34 serving as contact holes are formed in portions 32 and 33 corresponding to the contact pads 11. As a result, the surface of the infrared reflective film 2 on the contact pad 11 is exposed on the bottom surface of the first opening 34.

次に、サーミスターボロメータ薄膜７との電気的なコンタクトを得るために、絶縁保護膜３３の、サーミスターボロメータ薄膜７の端部に対応する部分、すなわち図５などに示した電極部１３に対応する部分に、コンタクトホールとなる第２の開口部３５を形成する。第２の開口部３５の形状は、電極部１３の形状に対応して、サーミスターボロメータ薄膜７の縁部に沿って細長く延びたスリット状になっている。これにより、第２の開口部３５の底面にサーミスターボロメータ薄膜７の表面の一部が露出する。 Next, in order to obtain electrical contact with the thermistor bolometer thin film 7, the insulating protective film 33 corresponds to the portion corresponding to the end of the thermistor bolometer thin film 7, that is, the electrode portion 13 shown in FIG. A second opening 35 serving as a contact hole is formed in the portion to be formed. The shape of the second opening 35 is a slit that extends along the edge of the thermistor bolometer thin film 7 corresponding to the shape of the electrode portion 13. Thereby, a part of the surface of the thermistor bolometer thin film 7 is exposed on the bottom surface of the second opening 35.

第１の開口部３４を形成する工程では、露光および現像の工程の後、ＣＦ₄とＯ₂の混合ガスまたはＣＨＦ₃とＯ₂の混合ガスのプラズマにより第１の絶縁保護膜３および絶縁保護膜３２，３３の、コンタクトパッド１１に対応する部分をエッチングする。第２の開口部３５を形成する工程では、露光および現像の工程の後、ＣＦ₄とＯ₂の混合ガスまたはＣＨＦ₃とＯ₂の混合ガスのプラズマにより絶縁保護膜３３の、サーミスターボロメータ薄膜７の端部に対応する部分をエッチングする。 In the step of forming the first opening 34, after the exposure and development steps, the first insulating protective film 3 and the insulating protection are formed by plasma of a mixed gas of CF ₄ and O ₂ or a mixed gas of CHF ₃ and O _2. The portions of the films 32 and 33 corresponding to the contact pads 11 are etched. In the step of forming the second opening 35, the thermistor bolometer thin film of the insulating protective film 33 by plasma of a mixed gas of CF ₄ and O ₂ or a mixed gas of CHF ₃ and O ₂ after the exposure and development steps. The portion corresponding to the end of 7 is etched.

次に、図９（ａ）において、シリコン基板１内の読出回路１６とサーミスターボロメータ薄膜７とを電気的に接続するために、絶縁保護膜３３の表面全体や、赤外線反射膜２の露出面を含む第１の開口部３４の内壁全体、およびサーミスターボロメータ薄膜７の露出面を含む第２の開口部３５の内壁全体に、例えばチタンまたはニクロムから成る金属膜３６をスパッター法により形成する。次に、露光および現像の工程の後、例えば金属膜３６がチタンから成る場合にはＣｌ₂とＢＣｌ₃の混合ガスのプラズマにより金属膜３６をエッチングして、金属膜３６をパターニングする。これにより、金属膜３６を、サーミスターボロメータ薄膜７とコンタクトパッド１１とを電気的に接続する電気配線の形状に加工する。 Next, in FIG. 9A, in order to electrically connect the readout circuit 16 in the silicon substrate 1 and the thermistor bolometer thin film 7, the entire surface of the insulating protective film 33 or the exposed surface of the infrared reflecting film 2 is used. A metal film 36 made of, for example, titanium or nichrome is formed by sputtering on the entire inner wall of the first opening 34 including, and the entire inner wall of the second opening 35 including the exposed surface of the thermistor bolometer thin film 7. Next, after the exposure and development steps, for example, when the metal film 36 is made of titanium, the metal film 36 is etched by plasma of a mixed gas of Cl ₂ and BCl ₃ to pattern the metal film 36. As a result, the metal film 36 is processed into the shape of electrical wiring that electrically connects the thermistor bolometer thin film 7 and the contact pad 11.

金属膜３６の、サーミスターボロメータ薄膜７と接する部分によって電極部１３が構成されている。また、金属膜３６の、第１の犠牲層３１上に形成された部分の一部によって支持部６内の金属配線９が構成されている。金属膜３６の、第１の開口部３４内の部分は、コンタクトパッド１１上の赤外線反射膜２を介してコンタクトパッド１１と電気的に接続されている。 The electrode portion 13 is constituted by a portion of the metal film 36 that is in contact with the thermistor bolometer thin film 7. Further, the metal wiring 9 in the support portion 6 is constituted by a part of the portion of the metal film 36 formed on the first sacrificial layer 31. A portion of the metal film 36 in the first opening 34 is electrically connected to the contact pad 11 via the infrared reflective film 2 on the contact pad 11.

次に、図９（ｂ）において、金属膜３６を覆うように金属膜３６および絶縁保護膜３３の表面全体に、プラズマＣＶＤ法により第３の材料膜として絶縁保護膜３７を形成する。絶縁保護膜３７としては、例えば、シリコン窒化膜、シリコン酸化膜、またはシリコン酸窒化膜を形成する。 Next, in FIG. 9B, an insulating protective film 37 is formed as a third material film on the entire surfaces of the metal film 36 and the insulating protective film 33 so as to cover the metal film 36 by plasma CVD. As the insulating protective film 37, for example, a silicon nitride film, a silicon oxide film, or a silicon oxynitride film is formed.

次に、図１０において、赤外線受光部５が支持部６によってシリコン基板１から浮かせられている熱分離構造を形成するために、図９（ｂ）に示した絶縁保護膜（第１〜第３の材料膜）３２，３３，３７をパターニングして、それらの絶縁保護膜にスリット３８，３９を形成する。スリット３８が、１つの画素における赤外線受光部５と支持部６との間の隙間となり、スリット３９が、隣り合う２つの支持部同士の間の隙間となる。赤外線受光部５と支持部６との間の隙間となるスリット３８の底面には、第１の犠牲層３１が露出している。 Next, in FIG. 10, in order to form a thermal separation structure in which the infrared light receiving unit 5 is floated from the silicon substrate 1 by the support unit 6, the insulating protective films (first to third) shown in FIG. The material films 32, 33, and 37 are patterned to form slits 38 and 39 in the insulating protective films. The slit 38 becomes a gap between the infrared light receiving part 5 and the support part 6 in one pixel, and the slit 39 becomes a gap between two adjacent support parts. The first sacrificial layer 31 is exposed on the bottom surface of the slit 38 serving as a gap between the infrared light receiving unit 5 and the support unit 6.

スリット３８，３９をそれぞれ形成する際には、露光および現像の工程の後、ＣＦ₄とＯ₂の混合ガスまたはＣＨＦ₃とＯ₂の混合ガスのプラズマにより、絶縁保護膜３２，３３，３７をスリット状にエッチングする。これにより、スリット３８，３９のそれぞれの底面に第１の犠牲層３１のポリイミドを露出させる。絶縁保護膜３２，３３，３７の、サーミスターボロメータ薄膜７の周囲にある部分から、サーミスターボロメータ薄膜７を覆う第１の赤外線吸収部となる絶縁保護膜８が構成される。また、絶縁保護膜３２，３３，３７のそれぞれの他の部分から、支持部６の第２の絶縁保護膜１０が構成される。 When forming the slits 38 and 39, the insulating protective films 32, 33, and 37 are formed by plasma of a mixed gas of CF ₄ and O ₂ or a mixed gas of CHF ₃ and O ₂ after the exposure and development processes. Etch into a slit. Thereby, the polyimide of the first sacrificial layer 31 is exposed on the bottom surfaces of the slits 38 and 39. An insulating protective film 8 serving as a first infrared absorbing portion that covers the thermistor bolometer thin film 7 is formed from portions of the insulating protective films 32, 33, and 37 around the thermistor bolometer thin film 7. Further, the second insulating protective film 10 of the support portion 6 is constituted by the other portions of the insulating protective films 32, 33, and 37.

次に、図１１において、庇部１２の形状を形成するための第２の犠牲層を形成するために絶縁保護膜３７の表面全体に感光性ポリイミドを塗布すると共に、その感光性ポリイミドを、図１０に示したスリット３８，３９内に充填する。そして、その感光性ポリイミドを、露光および現像の工程と、熱処理とによってパターニングして島状に整形し、感光性ポリイミドから成る第２の犠牲層４０を絶縁保護膜３７の表面に形成する。第２の犠牲層４０は、赤外線受光部５の電極部１３と庇部１２との間の空間、支持部６と庇部１２との間の空間、およびコンタクトパッド１１と庇部１２との間の空間を形成するためのものであり、第２の犠牲層４０の表面の形状は、庇部１２の形状に対応して湾曲している。 Next, in FIG. 11, photosensitive polyimide is applied to the entire surface of the insulating protective film 37 in order to form a second sacrificial layer for forming the shape of the flange 12, and the photosensitive polyimide is illustrated in FIG. The slits 38 and 39 shown in FIG. Then, the photosensitive polyimide is patterned by exposure and development processes and heat treatment to be shaped into an island shape, and a second sacrificial layer 40 made of photosensitive polyimide is formed on the surface of the insulating protective film 37. The second sacrificial layer 40 includes a space between the electrode portion 13 and the flange portion 12 of the infrared light receiving portion 5, a space between the support portion 6 and the flange portion 12, and a space between the contact pad 11 and the flange portion 12. The surface shape of the second sacrificial layer 40 is curved corresponding to the shape of the flange portion 12.

この第２の犠牲層４０によって、サーミスターボロメータ薄膜７の中央部を除く部分が全て覆われている。第２の犠牲層４０をパターニングによって整形した直後では、絶縁保護膜３７の、サーミスターボロメータ薄膜７の中央部に対応する部分の表面が露出している。従って、金属膜３６やコンタクトパッド１１の、シリコン基板１側と反対側の面全体が第２の犠牲層４０によって覆われている。上述したようにスリット３８，３９内にも感光性ポリイミドを充填してスリット３８，３９内に第２の犠牲層４０を形成したことにより、スリット３８の底面で露出していた第１の犠牲層３１の表面にも第２の犠牲層４０が形成されている。よって、スリット３８の底面で第１の犠牲層３１と第２の犠牲層４０とが接している。 The second sacrificial layer 40 covers all portions except the central portion of the thermistor bolometer thin film 7. Immediately after shaping the second sacrificial layer 40 by patterning, the surface of the insulating protective film 37 corresponding to the central portion of the thermistor bolometer thin film 7 is exposed. Therefore, the entire surface of the metal film 36 and the contact pad 11 opposite to the silicon substrate 1 side is covered with the second sacrificial layer 40. As described above, the first sacrificial layer exposed at the bottom surface of the slit 38 is formed by filling the slits 38 and 39 with photosensitive polyimide and forming the second sacrificial layer 40 in the slits 38 and 39. A second sacrificial layer 40 is also formed on the surface of 31. Therefore, the first sacrificial layer 31 and the second sacrificial layer 40 are in contact with each other at the bottom surface of the slit 38.

次に、第２の犠牲層４０の表面全体および絶縁保護膜３７の露出面全体に、プラズマＣＶＤ法により第４の材料膜として絶縁保護膜４１を形成する。絶縁保護膜４１としては、例えば、シリコン窒化膜、シリコン酸化膜、またはシリコン酸窒化膜を形成する。 Next, an insulating protective film 41 is formed as a fourth material film on the entire surface of the second sacrificial layer 40 and the entire exposed surface of the insulating protective film 37 by a plasma CVD method. As the insulating protective film 41, for example, a silicon nitride film, a silicon oxide film, or a silicon oxynitride film is formed.

次に、図１２において、赤外線を吸収する第２の赤外線吸収部となる庇部１２を形成するために、露光および現像の工程の後、ＣＦ₄とＯ₂の混合ガスまたはＣＨＦ₃とＯ₂の混合ガスのプラズマにより絶縁保護膜（第４の材料膜）４１をスリット状にエッチングして第２の犠牲層４０を部分的に露出させる。これにより、第２の犠牲層４０上に残った絶縁保護膜４１から成り、絶縁保護膜３７から突出している庇部１２が形成される。図１２では、絶縁保護膜４１の、絶縁保護膜３７の表面に直接形成されている部分が除去されているが、絶縁保護膜４１のその部分、すなわち絶縁保護膜３７に接していた部分を除去しなくともよい。 Next, in FIG. 12, in order to form the flange portion 12 which becomes the second infrared absorbing portion that absorbs infrared rays, a mixed gas of CF ₄ and O ₂ or CHF ₃ and O ₂ is used after the exposure and development steps. The insulating protective film (fourth material film) 41 is etched into a slit shape by using the mixed gas plasma to partially expose the second sacrificial layer 40. As a result, the collar portion 12 that is formed of the insulating protective film 41 remaining on the second sacrificial layer 40 and protrudes from the insulating protective film 37 is formed. In FIG. 12, the portion of the insulating protective film 41 that is directly formed on the surface of the insulating protective film 37 is removed, but that portion of the insulating protective film 41, that is, the portion that is in contact with the insulating protective film 37 is removed. You don't have to.

次に、図１３において、第１の犠牲層３１および第２の犠牲層４０をＯ₂ガスのプラズマを用いたアッシングにより除去することで、庇部１２のシリコン基板１側の空間と、赤外線受光部５のシリコン基板１側の空洞部４を形成する。これにより、庇部１２を備えた赤外線受光部５が支持部６によってシリコン基板１から浮かせられて支持されている熱分離構造が熱型赤外線検出器に形成される。以上の工程を経て、上記の熱分離構造を有する熱型赤外線検出器が作製される。 Next, in FIG. 13, the first sacrificial layer 31 and the second sacrificial layer 40 are removed by ashing using plasma of O ₂ gas, so that the space on the silicon substrate 1 side of the flange portion 12 and infrared light reception A cavity 4 on the silicon substrate 1 side of the part 5 is formed. As a result, a thermal separation structure is formed in the thermal infrared detector in which the infrared light receiving unit 5 including the flange 12 is supported by being suspended from the silicon substrate 1 by the support unit 6. Through the above steps, a thermal infrared detector having the above thermal separation structure is manufactured.

（第２の実施の形態）
図１４および図１５はそれぞれ、本発明の第２の実施形態の熱型赤外線検出器を示す断面図である。本実施形態の熱型赤外線検出器は、第１の実施形態のものと比較して、赤外線同士の干渉により加熱される金属薄膜が赤外線受光部に形成されている点が主に異なっている。図１４および図１５では、第１の実施形態と構成が同じものに同一の符号を付してあり、以下では、第１の実施形態の熱型赤外線検出器と異なる点を中心に説明する。 (Second Embodiment)
14 and 15 are cross-sectional views showing a thermal infrared detector according to the second embodiment of the present invention. The thermal infrared detector of the present embodiment is mainly different from that of the first embodiment in that a metal thin film that is heated by interference between infrared rays is formed in the infrared light receiving part. In FIG. 14 and FIG. 15, the same code | symbol is attached | subjected to the same structure as 1st Embodiment, and it demonstrates below centering on a different point from the thermal type infrared detector of 1st Embodiment.

図１４および図１５のそれぞれに示すように、本実施形態の熱型赤外線検出器の構成は、第１の実施形態と同様な熱型赤外線検出器において庇部（第２の赤外線吸収部）１２および絶縁保護膜（第１の赤外線吸収部）８の、シリコン基板１側と反対側の面に、赤外線吸収膜として、高い熱伝導率の金属薄膜１４が形成されたものである。従って、赤外線受光部５の、シリコン基板１側と反対側の面に金属薄膜１４が形成され、その金属薄膜１４が庇部１２の、シリコン基板１側と反対側の面全体にまで延びている。金属薄膜１４としては厚さ３ｎｍのＮｉＣｒ膜を用い、金属薄膜１４は、真空インピーダンス３７７Ω／□に設定されている。庇部１２としては、波長３〜５μｍ帯の赤外線に対して透明で、かつ波長１０μｍ帯の赤外線を吸収する厚さ５００ｎｍのシリコン窒化膜を用いた。 As shown in FIG. 14 and FIG. 15, the configuration of the thermal infrared detector of the present embodiment is the same as that of the first embodiment. In addition, a thin metal film 14 having high thermal conductivity is formed as an infrared absorption film on the surface of the insulating protective film (first infrared absorption portion) 8 opposite to the silicon substrate 1 side. Accordingly, the metal thin film 14 is formed on the surface of the infrared light receiving portion 5 opposite to the silicon substrate 1 side, and the metal thin film 14 extends to the entire surface of the flange portion 12 opposite to the silicon substrate 1 side. . A 3 nm thick NiCr film is used as the metal thin film 14, and the metal thin film 14 is set to a vacuum impedance of 377 Ω / □. As the flange 12, a silicon nitride film having a thickness of 500 nm that is transparent to infrared rays having a wavelength of 3 to 5 μm and absorbs infrared rays having a wavelength of 10 μm is used.

また、金属薄膜１４の、絶縁保護膜８と接する部分と、赤外線反射膜２との間隔を約１μｍに設定した。これにより、波長３〜５μｍ帯の赤外線に対しては、金属薄膜１４における赤外線同士の干渉効果を利用して、その波長帯の赤外線が金属薄膜１４に吸収される。従って、本実施形態の熱型赤外線検出器には、金属薄膜１４および赤外線反射膜２から構成された光学的共振構造が形成されている。庇部１２および絶縁保護膜８のシリコン窒化膜には、波長１０μｍ帯の赤外線が効率良く吸収される。この場合、庇部１２の熱容量は５．８×１０^-10Ｊ／Ｋとなり、赤外線受光部５の熱容量と合わせると、１．５×１０^-9Ｊ／Ｋにしかならない。この時、熱時定数は１８ｍsecとなり、テレビのフレームレートに対応する時間３３ｍsecに比べて十分小さく、実時間画像化の際、問題は無かった。 Further, the distance between the portion of the metal thin film 14 in contact with the insulating protective film 8 and the infrared reflective film 2 was set to about 1 μm. Thereby, for the infrared rays in the wavelength band of 3 to 5 μm, the infrared rays in the wavelength band are absorbed by the metal thin film 14 using the interference effect between the infrared rays in the metal thin film 14. Therefore, in the thermal infrared detector of this embodiment, an optical resonance structure composed of the metal thin film 14 and the infrared reflecting film 2 is formed. The silicon nitride film of the flange 12 and the insulating protective film 8 efficiently absorbs infrared rays having a wavelength of 10 μm. In this case, the heat capacity of the collar part 12 is 5.8 × 10 ⁻¹⁰ J / K, and when combined with the heat capacity of the infrared light receiving part 5, the heat capacity is only 1.5 × 10 ⁻⁹ J / K. At this time, the thermal time constant was 18 msec, which was sufficiently smaller than the time 33 msec corresponding to the TV frame rate, and there was no problem in real-time imaging.

本実施形態の熱型赤外線検出器に対して第１の実施形態のものでは、赤外線受光部５に金属薄膜１４が形成されていないため、絶縁保護膜８および庇部１２としてシリコン窒化膜を用いた場合、そのシリコン窒化膜によって波長１０μｍ帯の赤外線だけが吸収される。そのような第１の実施形態の熱型赤外線検出器では、３００Ｋの物体からの熱輻射を検出する限り、本実施形態の熱型赤外線検出器と比較しても信号雑音比は殆ど変わらなかった。庇部１２で波長１０μｍ帯の赤外線を吸収させる場合、庇部１２としては、非晶質ＳｉＣ、シリコン酸化膜またはシリコン酸窒化膜、あるいはそれらの膜のうち少なくともいずれか２つを組み合わせた積層膜を用いることができる。 In the first embodiment, the metal thin film 14 is not formed on the infrared light receiving portion 5 in the first embodiment, so that a silicon nitride film is used as the insulating protective film 8 and the flange portion 12. In this case, only the infrared ray having a wavelength of 10 μm is absorbed by the silicon nitride film. In such a thermal infrared detector of the first embodiment, as long as thermal radiation from a 300K object is detected, the signal-to-noise ratio hardly changed even when compared with the thermal infrared detector of the present embodiment. . When the infrared ray having a wavelength of 10 μm is absorbed by the flange 12, as the flange 12, the amorphous SiC, the silicon oxide film, the silicon oxynitride film, or a laminated film combining at least any two of these films Can be used.

絶縁保護膜８の材料としては、波長３〜５μｍ帯の赤外線に対して透明なものを用いることができ、ＳｉＮおよびＳｉＯの他に、例えばＺｎＳ、ＺｎＳｅ、ＣａＦ₂、ＢａＦ₂、またはＧｅ等を用いることができる。ただし、ＳｉＮは、波長９〜１３μｍの赤外線を吸収する性質があり、ＳｉＯは、波長９．５μｍの赤外線を強く吸収する性質がある。 As a material for the insulating protective film 8, a material transparent to infrared rays having a wavelength of 3 to 5 μm can be used. In addition to SiN and SiO, for example, ZnS, ZnSe, CaF ₂ , BaF ₂ , Ge, or the like can be used. Can be used. However, SiN has a property of absorbing infrared rays having a wavelength of 9 to 13 μm, and SiO has a property of strongly absorbing infrared rays having a wavelength of 9.5 μm.

また、絶縁保護膜８の材料と、支持部６の第２の絶縁保護膜１０の材料とが異なると、製造工程が増えて製造方法が複雑になり、熱型赤外線検出器の製造が困難になるため、絶縁保護膜８と第２の絶縁保護膜１０の材料が同一であることが好ましい。ここで、第２の絶縁保護膜１０の材料としては、熱伝導率の小さいものを用いる必要がある。ＺｎＳｅ、ＣａＦ₂、ＢａＦ₂、およびＧｅは熱伝導率が高く、第２の絶縁保護膜１０の材料には適していない。 Further, if the material of the insulating protective film 8 and the material of the second insulating protective film 10 of the support portion 6 are different, the manufacturing process increases and the manufacturing method becomes complicated, making it difficult to manufacture the thermal infrared detector. Therefore, it is preferable that the materials of the insulating protective film 8 and the second insulating protective film 10 are the same. Here, it is necessary to use a material having a low thermal conductivity as the material of the second insulating protective film 10. ZnSe, CaF ₂ , BaF ₂ , and Ge have high thermal conductivity and are not suitable for the material of the second insulating protective film 10.

本実施形態の熱型赤外線検出器の動作原理について説明する。 The operating principle of the thermal infrared detector of this embodiment will be described.

まず、金属薄膜１４に赤外線１５が入射すると、入射した赤外線１５の一部が金属薄膜１４により反射されようとする。一方、金属薄膜１４に入射した赤外線１５の残りの部分は、金属薄膜１４を通過してシリコン基板１側に向かって進行する。金属薄膜１４を通過した赤外線は、赤外線反射膜２や金属配線９およびコンタクトパッド１１により金属薄膜１４に向けて反射されて、再び金属薄膜１４に入射する。ここで、赤外線反射膜２によって反射されて再び金属薄膜１４に入射する赤外線は、庇部１２、絶縁保護膜８、または第２の絶縁保護膜１０を透過している。 First, when the infrared ray 15 is incident on the metal thin film 14, a part of the incident infrared ray 15 tends to be reflected by the metal thin film 14. On the other hand, the remaining portion of the infrared rays 15 incident on the metal thin film 14 passes through the metal thin film 14 and proceeds toward the silicon substrate 1 side. The infrared rays that have passed through the metal thin film 14 are reflected toward the metal thin film 14 by the infrared reflecting film 2, the metal wiring 9, and the contact pads 11, and enter the metal thin film 14 again. Here, the infrared rays reflected by the infrared reflecting film 2 and incident on the metal thin film 14 again are transmitted through the flange 12, the insulating protective film 8, or the second insulating protective film 10.

赤外線反射膜２によって反射されて再び金属薄膜１４に入射する赤外線は、金属薄膜１４により反射されようとする元の赤外線と打ち消し合う干渉を起こし、干渉を起こした赤外線同士が金属薄膜１４内の自由電子により吸収されて熱になる。その結果、金属薄膜１４が加熱されてその温度が上昇し、金属薄膜１４の熱は、金属薄膜１４に接した絶縁保護膜８および庇部１２を介してサーミスターボロメータ薄膜７に伝わる。また、波長１０μｍ帯の赤外線は庇部１２に直接吸収され、その赤外線によって庇部１２が加熱される。庇部１２の熱は金属薄膜１４および絶縁保護膜８を介してサーミスターボロメータ薄膜７に伝わる。ここで、庇部１２および絶縁保護膜８上に形成された金属薄膜１４によって、庇部１２および絶縁保護膜８の熱がサーミスターボロメータ薄膜７に速く伝わるようになっている。 The infrared rays reflected by the infrared reflecting film 2 and incident again on the metal thin film 14 cause interference that cancels out the original infrared rays that are to be reflected by the metal thin film 14, and the infrared rays that caused the interference are free in the metal thin film 14. It is absorbed by electrons and becomes heat. As a result, the metal thin film 14 is heated and its temperature rises, and the heat of the metal thin film 14 is transmitted to the thermistor bolometer thin film 7 through the insulating protective film 8 and the flange 12 in contact with the metal thin film 14. In addition, infrared rays having a wavelength of 10 μm are directly absorbed by the collar portion 12, and the collar portion 12 is heated by the infrared rays. The heat of the flange portion 12 is transmitted to the thermistor bolometer thin film 7 through the metal thin film 14 and the insulating protective film 8. Here, the metal thin film 14 formed on the collar portion 12 and the insulating protective film 8 allows the heat of the collar portion 12 and the insulating protective film 8 to be quickly transferred to the thermistor bolometer thin film 7.

このように金属薄膜１４、庇部１２、および絶縁保護膜８からのそれぞれの熱によってサーミスターボロメータ薄膜７の温度が変化し、サーミスターボロメータ薄膜７の抵抗値が変化する。この抵抗値の変化は、シリコン基板１内の読出回路により電圧変化に変換されて電気信号として読み出され、その電気信号を基に外部回路により赤外画像化される。本実施形態の熱型赤外線検出器では、赤外線同士が干渉するように赤外線反射膜２と、梁６ａ内の金属配線９と、コンタクトパッド１１とでそれぞれ、赤外線を反射させるため、赤外線反射膜２、梁６ａ内の金属配線９およびコンタクトパッド１１は平坦であることが望ましい。 As described above, the temperature of the thermistor bolometer thin film 7 is changed by the heat from the metal thin film 14, the flange 12, and the insulating protective film 8, and the resistance value of the thermistor bolometer thin film 7 is changed. This change in resistance value is converted into a voltage change by a readout circuit in the silicon substrate 1 and read out as an electrical signal, and an infrared image is formed by an external circuit based on the electrical signal. In the thermal infrared detector of the present embodiment, the infrared reflecting film 2, the metal wiring 9 in the beam 6 a, and the contact pad 11 reflect the infrared rays so that the infrared rays interfere with each other. The metal wiring 9 and the contact pad 11 in the beam 6a are preferably flat.

上述したように金属薄膜１４は、真空インピーダンス３７７Ω／□に設定されているため、金属薄膜１４で吸収する赤外線の波長をλ、金属薄膜１４と赤外線反射膜２との間の実効的な屈折率をｎとすると、金属薄膜１４と赤外線反射膜２との間隔を、λ／（４ｎ）に設定する必要がある。ここで、赤外線受光部５の厚さをｄ_xとし、赤外線受光部５と赤外線反射膜２との距離、すなわち空洞部４の高さをｄ₀とし、絶縁保護膜８の屈折率をｎ_xとし、空洞部４内の空気の屈折率をｎ₀として、上記の実効的な屈折率ｎ＝（ｎ_x・ｄ_x＋ｎ₀・ｄ₀）／（ｄ_x＋ｄ₀）と近似した。空洞部４内の空気の屈折率ｎ₀の値は１である。 As described above, since the metal thin film 14 is set to a vacuum impedance of 377 Ω / □, the wavelength of infrared light absorbed by the metal thin film 14 is λ, and the effective refractive index between the metal thin film 14 and the infrared reflective film 2 is. If n is n, it is necessary to set the distance between the metal thin film 14 and the infrared reflective film 2 to λ / (4n). Here, the thickness of the infrared receiving portion 5 and d _x, the distance between the infrared receiver 5 and the infrared reflecting film 2, i.e. the height of the cavity 4 and d _0, the refractive index of the insulating protective film 8 n _x and then, the refractive index of the air in the cavity 4 as n _0, approximating the effective refractive index of the n = a _{_{(n x · d x + n}} 0 · d 0) / (d x + d 0). The value of the refractive index n ₀ of the air in the cavity 4 is 1.

金属薄膜１４の、絶縁保護膜８に接する部分と、赤外線反射膜２との間隔を上記のλ／（４ｎ）に設定すると、金属薄膜１４の、庇部１２に接する部分と、赤外線反射膜２との間隔はλ／（４ｎ）よりも大きくなる。この場合、金属薄膜１４の、庇部１２に接する部分では、金属薄膜１４と赤外線反射膜２との間隔に対応した波長の赤外線が吸収される。 When the distance between the portion of the metal thin film 14 in contact with the insulating protective film 8 and the infrared reflective film 2 is set to the above-mentioned λ / (4n), the portion of the metal thin film 14 in contact with the flange 12 and the infrared reflective film 2 Is larger than λ / (4n). In this case, infrared rays having a wavelength corresponding to the distance between the metal thin film 14 and the infrared reflection film 2 are absorbed in the portion of the metal thin film 14 that is in contact with the flange 12.

次に、本実施形態の熱型赤外線検出器の製造方法について説明する。本実施形態の熱型赤外線検出器の製造方法では、第１の実施形態で説明した製造方法における図６〜図１１の工程と同様な工程が行われる。それら図６〜図１１の工程において、例えばサーミスターボロメータ薄膜７を覆う絶縁保護膜８および庇部１２の材料や膜厚が第１の実施形態の場合と異なる場合には、それらの材料および膜厚に応じてそれぞれの膜を形成していけばよい。以下では、第１の実施形態で説明した製造方法における図１１の工程の後の段階について図１６〜図１８を参照して説明する。図１６〜図１８はそれぞれ、本実施形態の熱型赤外線検出器の製造方法について説明するための断面図である。 Next, a method for manufacturing the thermal infrared detector of this embodiment will be described. In the manufacturing method of the thermal infrared detector of the present embodiment, the same steps as the steps of FIGS. 6 to 11 in the manufacturing method described in the first embodiment are performed. In the processes of FIGS. 6 to 11, for example, when the materials and film thicknesses of the insulating protective film 8 and the collar portion 12 covering the thermistor bolometer thin film 7 are different from those in the first embodiment, those materials and films Each film may be formed according to the thickness. Below, the stage after the process of FIG. 11 in the manufacturing method described in the first embodiment will be described with reference to FIGS. 16 to 18 are cross-sectional views for explaining a method for manufacturing the thermal infrared detector of the present embodiment.

図１６において、絶縁保護膜４１（第４の材料膜）を形成した後に絶縁保護膜４１の表面全体に、スパッター法により第５の材料膜として金属薄膜１４を形成する。金属薄膜１４の材質として、例えば窒化チタンまたはニクロムを用いる。 In FIG. 16, after forming the insulating protective film 41 (fourth material film), the metal thin film 14 is formed as a fifth material film on the entire surface of the insulating protective film 41 by sputtering. As the material of the metal thin film 14, for example, titanium nitride or nichrome is used.

次に、図１７において、赤外線を吸収する第２の赤外線吸収部となる庇部１２を形成するために、露光および現像の工程の後、Ｃｌ₂とＢＣｌ₃の混合ガスのプラズマにより金属薄膜１４をスリット状にエッチングし、続いてＣＦ₄とＯ₂の混合ガスまたはＣＨＦ₃とＯ₂の混合ガスのプラズマにより絶縁保護膜４１をスリット状にエッチングして第２の犠牲層４０を部分的に露出させる。これにより、第２の犠牲層４０上に残った絶縁保護膜４１から成り、絶縁保護膜３７から突出している庇部１２が形成される。 Next, in FIG. 17, in order to form the flange portion 12 that becomes the second infrared absorbing portion that absorbs infrared rays, the metal thin film 14 is formed by plasma of a mixed gas of Cl ₂ and BCl ₃ after the exposure and development steps. Next, the insulating protective film 41 is etched into a slit shape by plasma of a mixed gas of CF ₄ and O ₂ or a mixed gas of CHF ₃ and O ₂ to partially etch the second sacrificial layer 40. Expose. As a result, the collar portion 12 that is formed of the insulating protective film 41 remaining on the second sacrificial layer 40 and protrudes from the insulating protective film 37 is formed.

次に、図１８において、第１の犠牲層３１および第２の犠牲層４０を、Ｏ₂ガスのプラズマを用いたアッシングにより除去することで、庇部１２のシリコン基板１側の空間と、赤外線受光部５のシリコン基板１側の空洞部４を形成する。これにより、庇部１２および金属薄膜１４を備えた赤外線受光部５が支持部６によってシリコン基板１から浮かせられて支持されている熱分離構造が熱型赤外線検出器に形成される。以上の工程を経て、上記の熱分離構造を有する熱型赤外線検出器が作製される。 Next, in FIG. 18, the first sacrificial layer 31 and the second sacrificial layer 40 are removed by ashing using plasma of O ₂ gas, so that the space on the silicon substrate 1 side of the flange 12 and the infrared rays are removed. A cavity 4 on the silicon substrate 1 side of the light receiving part 5 is formed. As a result, a thermal separation structure is formed in the thermal infrared detector in which the infrared light receiving unit 5 including the flange 12 and the metal thin film 14 is supported by being suspended from the silicon substrate 1 by the support unit 6. Through the above steps, a thermal infrared detector having the above thermal separation structure is manufactured.

図１９は、図１４および図１５に示した熱型赤外線検出器の変形例を示す断面図である。図１９に示される変形例では、図１４および図１５に示した熱型赤外線検出器と比較して、庇部１２の根元の位置、および電極部１３の位置が主に異なっている。図１９に示すように、庇部１２の、電極部１３の近傍にある根元の位置を赤外線受光部５の縁部に配置させると共に、電極部１３の位置を、赤外線受光部５の上面から見て庇部１２の根元から離れるように赤外線受光部５の内側に配置させてもよい。この電極部１３の位置に応じて、サーミスターボロメータ薄膜７の幅が、図１４および図１５に示した場合よりも狭くなっている。 FIG. 19 is a cross-sectional view showing a modification of the thermal infrared detector shown in FIGS. 14 and 15. In the modification shown in FIG. 19, the position of the base of the flange 12 and the position of the electrode 13 are mainly different from those of the thermal infrared detector shown in FIGS. 14 and 15. As shown in FIG. 19, the base position of the collar portion 12 in the vicinity of the electrode portion 13 is arranged at the edge of the infrared light receiving portion 5, and the position of the electrode portion 13 is viewed from the upper surface of the infrared light receiving portion 5. It may be arranged inside the infrared light receiver 5 so as to be away from the base of the flange 12. Depending on the position of the electrode portion 13, the width of the thermistor bolometer thin film 7 is narrower than that shown in FIGS.

ここで、もし、庇部１２の根元、すなわち庇部１２の、絶縁保護膜８との接続部が電極部１３の直上にあると、庇部１２の熱の一部が電極部１３、および梁６ａ内の金属配線９を伝わって、ヒートシンクのシリコン基板１に逃げてしまい、感度が低下する。従って、第１および第２の実施形態の熱型赤外線検出器や、図１９に示される熱型赤外線検出器のように、庇部１２の根元の真下に電極部１３を配置しないようにする。これにより、庇部１２上の金属薄膜１４からの熱、および庇部１２からの熱が電極部１３に直接伝わることが防止され、感度の低下が抑制される。第１および第２の実施形態の熱型赤外線検出器のように、赤外線受光部５の上面から見て、電極部１３よりも赤外線受光部５の内側に庇部１２の根元を配置させる方が、感度をより向上させることができる。 Here, if the base of the flange portion 12, that is, the connection portion of the flange portion 12 to the insulating protective film 8 is directly above the electrode portion 13, a part of the heat of the flange portion 12 is the electrode portion 13 and the beam. It is transmitted through the metal wiring 9 in 6a and escapes to the silicon substrate 1 of the heat sink, and the sensitivity is lowered. Therefore, the electrode part 13 is not arranged directly under the base of the collar part 12 as in the thermal infrared detectors of the first and second embodiments and the thermal infrared detector shown in FIG. Thereby, it is prevented that the heat from the metal thin film 14 on the collar part 12 and the heat from the collar part 12 are directly transmitted to the electrode part 13, and the decrease in sensitivity is suppressed. As in the thermal infrared detectors of the first and second embodiments, it is preferable to arrange the base of the flange portion 12 inside the infrared light receiving unit 5 rather than the electrode unit 13 when viewed from the upper surface of the infrared light receiving unit 5. , Sensitivity can be further improved.

図２０は、図１〜図５に示した第１の実施形態の熱型赤外線検出器の変形例を示す断面図である。すなわち、図２０に示すように、庇部１２上および赤外線受光部５上に金属薄膜１４が形成されていない熱型赤外線検出器においても、電極部１３の近傍にある根元の位置を赤外線受光部５の縁部に配置させると共に、赤外線受光部５の上面から見て電極部１３が庇部１２の根元と重ならないように、電極部１３を赤外線受光部５の内側に配置させてもよい。 FIG. 20 is a cross-sectional view showing a modification of the thermal infrared detector of the first embodiment shown in FIGS. That is, as shown in FIG. 20, even in a thermal infrared detector in which the metal thin film 14 is not formed on the collar portion 12 and the infrared light receiving portion 5, the position of the root near the electrode portion 13 is set as the infrared light receiving portion. 5, and the electrode part 13 may be arranged inside the infrared light receiving part 5 so that the electrode part 13 does not overlap the base of the flange part 12 when viewed from the upper surface of the infrared light receiving part 5.

本発明の熱型赤外線検出器は、以上説明したものに限定されず、赤外線を吸収する庇部（第２の赤外線吸収部）１２を用いて、開口率が高くなるように構成された熱型赤外線検出器は全て、本発明に含まれるものである。例えば、第１の実施形態のように赤外線吸収膜（絶縁保護膜８）のみによって赤外線を吸収する画素と、第２の実施形態のように赤外線同士の干渉により加熱される金属薄膜１４を備えた画素とを有する熱型赤外線検出器に対して、本発明の特徴である庇部１２の構成を適用してもよい。そのような熱型赤外線検出器では、ある画素に、真空インピーダンス３７７Ω／□に整合された金属薄膜１４を赤外線受光部５に形成し、かつ、その金属薄膜１４と、基板１上の赤外線反射膜２との距離を約１μｍにして光学的共振構造を作る。これにより、その画素では、主に波長３〜５μｍ帯の赤外線を吸収して検出する。この場合、サーミスターボロメータ薄膜７を覆う絶縁保護膜８の材料として、波長３〜５μｍ帯の赤外線に対して透明なもの、例えばＺｎＳ、ＺｎＳｅ、ＣａＦ₂、ＢａＦ₂、またはＧｅ等を用いる。そして、他の画素では、金属薄膜１４を形成せずに、サーミスターボロメータ薄膜７を覆う絶縁保護膜８として波長１０μｍ帯の赤外線を吸収するもの、例えばＳｉＮ、ＳｉＯ、ＳｉＯＮ、またはＳｉＣ等を用いる。これにより、他の画素では波長１０μｍ帯の赤外線を吸収して検出する。 The thermal infrared detector of the present invention is not limited to the one described above, and is a thermal type configured to have a high aperture ratio by using a collar portion (second infrared absorbing portion) 12 that absorbs infrared rays. All infrared detectors are included in the present invention. For example, a pixel that absorbs infrared rays only by an infrared absorption film (insulating protective film 8) as in the first embodiment and a metal thin film 14 that is heated by interference between infrared rays as in the second embodiment are provided. You may apply the structure of the collar part 12 which is the characteristics of this invention with respect to the thermal-type infrared detector which has a pixel. In such a thermal infrared detector, a metal thin film 14 matched with a vacuum impedance of 377 Ω / □ is formed on a certain pixel in the infrared light receiving part 5, and the metal thin film 14 and an infrared reflecting film on the substrate 1 are formed. The optical resonance structure is made with a distance of 2 to about 1 μm. As a result, the pixel mainly detects infrared rays having a wavelength band of 3 to 5 μm. In this case, as the material of the insulating protective film 8 that covers the thermistor bolometer thin film 7, a material that is transparent to infrared rays in the wavelength band of 3 to 5 μm, such as ZnS, ZnSe, CaF ₂ , BaF ₂ , or Ge, is used. In the other pixels, an insulating protective film 8 that covers the thermistor bolometer thin film 7 without absorbing the thin metal film 14 is used. For example, SiN, SiO, SiON, or SiC is used. . Thereby, other pixels absorb and detect infrared rays having a wavelength of 10 μm.

このような、１つのアレイセンサで複数の波長帯の赤外線を検出する熱型赤外線検出器においても、それぞれの画素で、赤外線を吸収する方法に応じて庇部１２を設けることにより開口率を高くすることが可能となる。ここで述べたのは一例であって、検出したい波長帯が変われば、光学的共振構造を構成する金属薄膜１４と赤外線反射膜２との距離は、λ／（４ｎ）に応じて変更することができる。 Even in such a thermal infrared detector that detects infrared rays in a plurality of wavelength bands with one array sensor, the aperture ratio is increased by providing the collar 12 according to the method of absorbing infrared rays in each pixel. It becomes possible to do. This is just an example. If the wavelength band to be detected is changed, the distance between the metal thin film 14 and the infrared reflecting film 2 constituting the optical resonance structure is changed according to λ / (4n). Can do.

本発明の第１の実施形態の熱型赤外線検出器を示す平面図である。It is a top view which shows the thermal type infrared detector of the 1st Embodiment of this invention. 図１のＸ−Ｘ’線断面図である。FIG. 2 is a sectional view taken along line X-X ′ in FIG. 1. 図１のＹ−Ｙ’線断面図である。FIG. 2 is a cross-sectional view taken along line Y-Y ′ of FIG. 1. 図１〜図３に示した熱型赤外線検出器における電流経路に沿った断面図である。It is sectional drawing along the electric current path in the thermal type infrared detector shown in FIGS. 図２のＡ−Ａ’線断面図である。FIG. 3 is a cross-sectional view taken along line A-A ′ of FIG. 2. 図１〜図５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIGS. 図１〜図５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIGS. 図１〜図５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIGS. 図１〜図５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIGS. 図１〜図５に示した熱型赤外線検出器の製造方法について説明するための平面図である。It is a top view for demonstrating the manufacturing method of the thermal type infrared detector shown in FIGS. 図１〜図５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIGS. 図１〜図５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIGS. 図１〜図５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIGS. 本発明の第２の実施形態の熱型赤外線検出器を示す断面図である。It is sectional drawing which shows the thermal type infrared detector of the 2nd Embodiment of this invention. 本発明の第２の実施形態の熱型赤外線検出器を示す断面図である。It is sectional drawing which shows the thermal type infrared detector of the 2nd Embodiment of this invention. 図１４および図１５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIG. 14 and FIG. 図１４および図１５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIG. 14 and FIG. 図１４および図１５に示した熱型赤外線検出器の製造方法について説明するための断面図である。It is sectional drawing for demonstrating the manufacturing method of the thermal type infrared detector shown in FIG. 14 and FIG. 図１４および図１５に示した熱型赤外線検出器の変形例を示す断面図である。It is sectional drawing which shows the modification of the thermal type infrared detector shown in FIG. 14 and FIG. 図１〜図５に示した熱型赤外線検出器の変形例を示す断面図である。It is sectional drawing which shows the modification of the thermal type infrared detector shown in FIGS. 熱分離構造を有する従来の熱型赤外線検出器としての二次元赤外線固体撮像素子を示す断面図である。It is sectional drawing which shows the two-dimensional infrared solid-state image sensor as a conventional thermal type infrared detector which has a thermal separation structure. 図２１に示した二次元赤外線固体撮像素子の１個の画素における赤外線吸収部を除いた部分の平面図である。It is a top view of the part except the infrared absorption part in one pixel of the two-dimensional infrared solid-state image sensor shown in FIG. 図２１および図２２に示した従来の二次元赤外線固体撮像素子の別の例を示す断面図である。It is sectional drawing which shows another example of the conventional two-dimensional infrared solid-state image sensor shown in FIG. 21 and FIG. 熱分離構造を有する従来の熱型赤外線検出器を示す断面図である。It is sectional drawing which shows the conventional thermal type infrared detector which has a thermal separation structure. 熱分離構造を有する従来の熱型赤外線検出器を示す斜視図である。It is a perspective view which shows the conventional thermal type infrared detector which has a thermal separation structure. 図２５に示される熱型赤外線検出器のＡ−Ａ’線断面図である。FIG. 26 is a cross-sectional view of the thermal infrared detector shown in FIG. 25 taken along the line A-A ′.

Explanation of symbols

１シリコン基板
２赤外線反射膜
３第１の絶縁保護膜
４空洞部
５赤外線受光部
６支持部
６ａ梁
６ｂ支持脚
７サーミスターボロメータ薄膜（温度検出部）
８絶縁保護膜（第１の赤外線吸収部）
９金属配線
１０第２の絶縁保護膜
１１コンタクトパッド
１２庇部（第２の赤外線吸収部）
１３電極部
１４金属薄膜（第５の材料膜）
１５赤外線
１６読出回路
１７信号線
１８画素への配線
３１第１の犠牲層
３２絶縁保護膜（第１の材料膜）
３３絶縁保護膜（第２の材料膜）
３４第１の開口部
３５第２の開口部
３６金属膜
３７絶縁保護膜（第３の材料膜）
３８、３９スリット
４０第２の犠牲層
４１絶縁保護膜（第４の材料膜） DESCRIPTION OF SYMBOLS 1 Silicon substrate 2 Infrared reflective film 3 1st insulation protective film 4 Cavity part 5 Infrared light-receiving part 6 Support part 6a Beam 6b Support leg 7 Thermistor bolometer thin film (temperature detection part)
8 Insulating protective film (first infrared absorption part)
9 Metal wiring 10 2nd insulating protective film 11 Contact pad 12 Eaves part (2nd infrared absorption part)
13 Electrode part 14 Metal thin film (5th material film)
15 Infrared 16 Read circuit 17 Signal line 18 Pixel wiring 31 First sacrificial layer 32 Insulating protective film (first material film)
33 Insulating protective film (second material film)
34 First opening 35 Second opening 36 Metal film 37 Insulating protective film (third material film)
38, 39 Slit 40 Second sacrificial layer 41 Insulating protective film (fourth material film)

Claims

A substrate with contact pads;
When the infrared ray is absorbed, the first infrared ray absorbing portion heated by the infrared ray, the temperature detecting portion for detecting the temperature change due to the heat transmitted from the first infrared ray absorbing portion, and the temperature detecting portion are electrically connected Infrared light receiving portion provided with an electrode portion and spaced above the contact pad forming surface of the substrate;
The infrared light receiving part is supported by being floated from the contact pad forming surface of the substrate on the substrate, and wiring for electrically connecting the electrode part of the infrared light receiving part to the contact pad of the substrate is configured. A support portion at least partially formed of a conductive material;
The electrode protrudes from the first infrared absorbing part of the infrared light receiving part, extends from the edge of the infrared light receiving part and / or from the root located inside the electrode part toward the outside of the infrared light receiving part, and the electrode The first infrared absorption part is heated by the infrared ray when the infrared ray is absorbed, and the heat is transferred to the first infrared absorption part by separating the space between the electrode part and the surface of the electrode part opposite to the substrate side. A second infrared absorber that communicates to the temperature detector via
The second infrared absorbing portion is physically separated from the second infrared absorbing portion of an adjacent pixel,
The central portion of the first infrared absorbing portion is exposed toward the direction in which infrared rays enter through a central opening provided in the second infrared absorbing portion,
The total area of the first infrared absorption part and the second infrared absorption part on which infrared rays can be incident is larger than the area of the first infrared absorption part on the side opposite to the substrate side. Type infrared detector.

The second infrared absorbing portion covers the surface of the support portion opposite to the substrate side with a space between the support portion and the space between the contact pads of the substrate. The thermal infrared detector according to claim 1, which covers the contact pad at a distance.

The second infrared absorbing portion protrudes from a portion of the first infrared absorbing portion excluding a portion corresponding to the electrode portion, and extends from a root located at an edge of the infrared receiving portion to the outside of the infrared receiving portion. The thermal infrared detector according to claim 1, which extends toward the surface.

A substrate with contact pads;
When the infrared ray is absorbed, the first infrared ray absorbing portion heated by the infrared ray, the temperature detecting portion for detecting the temperature change due to the heat transmitted from the first infrared ray absorbing portion, and the temperature detecting portion are electrically connected Infrared light receiving portion provided with an electrode portion and spaced above the contact pad forming surface of the substrate;
The infrared light receiving part is supported by being floated from the contact pad forming surface of the substrate on the substrate, and wiring for electrically connecting the electrode part of the infrared light receiving part to the contact pad of the substrate is configured. A support portion at least partially formed of a conductive material;
The first infrared absorbing portion of the infrared light receiving portion protrudes from a portion excluding the portion corresponding to the electrode portion, and extends from the root located at the edge of the infrared light receiving portion toward the outside of the infrared light receiving portion. A space between the support portion and a surface of the support portion opposite to the substrate side, and a space between the contact pad of the substrate and the contact pad. Comprising a second infrared absorbing portion that absorbs infrared rays and is heated by the infrared rays and transmits the heat to the temperature detecting portion via the first infrared absorbing portion,
The second infrared absorbing portion is physically separated from the second infrared absorbing portion of an adjacent pixel,
The central portion of the first infrared absorbing portion is exposed toward the direction in which infrared rays enter through a central opening provided in the second infrared absorbing portion,
The total area of the first infrared absorption part and the second infrared absorption part on which infrared rays can be incident is larger than the area of the first infrared absorption part on the side opposite to the substrate side. Type infrared detector.

An infrared reflective film formed on the contact pad forming surface which is a surface of the substrate on the infrared light receiving portion side, and a first insulating protective film formed on the surface of the infrared reflective film so as to cover the infrared reflective film And
5. The thermal infrared detector according to claim 1, wherein the infrared light receiving unit is supported by being floated by the support unit above the first insulating protective film. 6.

The first infrared absorption unit is provided on the surface of the temperature detection unit opposite to the substrate side,
The metal thin film is formed in the surface on the opposite side to the said substrate side of the said 1st infrared absorption part, and the surface on the opposite side to the said substrate side of the said 2nd infrared absorption part. The thermal infrared detector as described.

The substrate includes a readout circuit that is electrically connected to the contact pad of the substrate, converts a temperature change detected by the temperature detection unit into an electrical signal, and reads the electrical signal. The thermal infrared detector according to any one of claims 1 to 6.

The support part is composed of a conductive material constituting a wiring for electrically connecting the electrode part to the contact pad of the substrate, and a second insulating protective film covering the conductive material. The thermal infrared detector according to any one of claims 1 to 7.

A first infrared absorbing portion made of an insulating film having a metal thin film formed as a surface layer irradiated with infrared rays, a temperature detecting portion for detecting a temperature change due to heat transmitted from the first infrared absorbing portion, and temperature detection An infrared light receiving portion comprising an electrode portion electrically connected to the portion;
A substrate having a contact pad electrically connected to the electrode portion;
The infrared rays that are formed on the contact pad side surface of the substrate and that are transmitted through the metal thin film out of the infrared rays that are irradiated onto the metal thin film are reflected toward the metal thin film, whereby infrared rays are generated in the metal thin film. An infrared reflective film for heating the metal thin film by causing mutual interference;
A first insulating protective film formed on the surface of the infrared reflective film so as to cover the infrared reflective film;
A conductive material that constitutes a wiring that electrically connects the electrode portion to the contact pad; and a second insulating protective film that covers the conductive material, and the infrared light receiving layer is disposed above the first insulating protective film. A support part for floating and supporting the part,
Projects from the insulating film of the infrared light receiving part, extends from the edge of the infrared light receiving part and / or from the root located inside the electrode part toward the outside of the infrared light receiving part, and between the electrode part Covering the surface of the electrode portion opposite to the substrate side with a space therebetween, and covering the surface of the support portion opposite to the substrate side with a space between the support portion, And a flange that covers the contact pad with a space between the contact pad and the substrate, and when the infrared ray is absorbed, the infrared ray is heated by the infrared ray and the heat is detected through the first infrared ray absorbing portion. A second infrared absorber that communicates to the
A metal thin film is formed on the second infrared absorbing portion as a surface layer irradiated with infrared rays, and the metal thin film that is the surface layer of the first infrared absorbing portion and the surface of the second infrared absorbing portion. The metal thin film that is a layer is integrally formed so as to be continuous with each other,
The second infrared absorbing portion is physically separated from the second infrared absorbing portion of an adjacent pixel,
The central portion of the first infrared absorbing portion is exposed toward the direction in which infrared rays enter through a central opening provided in the second infrared absorbing portion,
The total area of the first infrared absorption part and the second infrared absorption part on which infrared rays can be incident is larger than the area of the first infrared absorption part on the side opposite to the substrate side. Type infrared detector.

The thermal infrared detector according to any one of claims 1 to 9, wherein the temperature detection unit is any one of a thermistor bolometer thin film, a pyroelectric thin film, and a thermopile.

When the infrared ray is absorbed, the first infrared ray absorbing portion heated by the infrared ray, the temperature detecting portion for detecting the temperature change due to the heat transmitted from the first infrared ray absorbing portion, and the temperature detecting portion are electrically connected An infrared light receiving portion provided with an electrode portion;
A support part for floating and supporting the infrared light receiving part on a substrate;
A second infrared absorbing portion comprising a collar projecting from the first infrared absorbing portion, which is heated by the infrared when the infrared rays are absorbed and transmits the heat to the temperature detecting portion via the first infrared absorbing portion; Have
The total area of the first infrared absorption part and the second infrared absorption part on which infrared rays can be incident is larger than the area of the first infrared absorption part on the side opposite to the substrate side. Type infrared detector manufacturing method,
Preparing the substrate having contact pads;
Forming an infrared reflective film on a part of the surface of the substrate on the contact pad side;
Forming a first insulating protective film on the surface of the infrared reflective film and the substrate so as to cover the infrared reflective film;
Forming a first sacrificial layer at a position of the first insulating protective film where the infrared light receiving portion is to be formed;
Forming a first material film on the surfaces of the first sacrificial layer and the first insulating protective film so as to cover the first sacrificial layer;
Forming a temperature detection portion on a surface of a portion of the first material film located above the first sacrificial layer;
Forming a second material film on the surface of the temperature detection unit and the first material film so as to cover the temperature detection unit;
Forming a first opening at a position above the contact pad of the first insulating protective film and the first and second material films;
Forming a second opening in the second material film to expose a part of the temperature detection unit;
Forming a metal film on the inside of the first and second openings and on the surface of the second material film;
Patterning the metal film to expose the second material film on the temperature detection unit, and an electrode unit located in the second opening and connected to the temperature detection unit; and Forming a wiring connecting the contact pads;
Forming a third material film, a part of which forms the first infrared absorbing portion, on the surfaces of the metal film and the second material film so as to cover the metal film;
Patterning the first to third material films to form slits, exposing the first sacrificial layer through the slits;
Forming a second sacrificial layer on a surface of the third material film and an exposed surface of the first sacrificial layer;
Patterning the second sacrificial layer so as to expose a portion of the third material film located above the central portion of the temperature detection unit;
Forming a fourth material film, a part of which forms the second infrared absorbing portion, on the surface of the second sacrificial layer and the exposed surface of the third material film;
A portion of the third material film located above a central portion of the temperature detection unit is exposed to form the first infrared absorption unit, and a part of the second sacrificial layer is exposed. A fourth material film is patterned to extend from the edge of the infrared light receiving part and / or from the root located inside the electrode part toward the outside of the infrared light receiving part and to the center of the infrared light receiving part Forming the second infrared absorbing portion having a portion facing the first opening,
Removing the first sacrificial layer to bring the infrared light receiving part including the first infrared absorption part into a state of being supported by the support part with a space between the substrate and the substrate;
Removing the second sacrificial layer to bring the second infrared absorbing portion into a state of covering the electrode portion, the support portion, and the contact pad with a space therebetween,
A method for manufacturing a thermal infrared detector including:

Before the step of patterning the fourth material film, further comprising the step of forming a metal thin film on the surface of the fourth material film,
In the step of patterning the fourth material film, the metal thin film is patterned together with the fourth material film to leave the metal thin film that forms the respective surface layers of the first and second infrared absorbing portions. The manufacturing method of the thermal type infrared detector of Claim 11.

A first infrared absorbing portion made of an insulating film having a metal thin film formed as a surface layer irradiated with infrared rays, a temperature detecting portion for detecting a temperature change due to heat transmitted from the first infrared absorbing portion, and the temperature An infrared light receiving unit including an electrode unit electrically connected to the detection unit;
A support part for floating and supporting the infrared light receiving part on a substrate;
A second infrared absorbing portion comprising a collar projecting from the first infrared absorbing portion, which is heated by the infrared when the infrared rays are absorbed and transmits the heat to the temperature detecting portion via the first infrared absorbing portion; Have
The total area of the first infrared absorption part and the second infrared absorption part on which infrared rays can be incident is larger than the area of the first infrared absorption part on the side opposite to the substrate side. Type infrared detector manufacturing method,
Preparing the substrate having contact pads;
Forming an infrared reflective film on a part of the surface of the substrate on the contact pad side;
Forming a first insulating protective film on the surface of the infrared reflective film and the substrate so as to cover the infrared reflective film;
Forming a first sacrificial layer at a position of the first insulating protective film where the infrared light receiving portion is to be formed;
Forming a first material film on the surfaces of the first sacrificial layer and the first insulating protective film so as to cover the first sacrificial layer;
Forming a temperature detection portion on a surface of a portion of the first material film located above the first sacrificial layer;
Forming a second material film on the surface of the temperature detection unit and the first material film so as to cover the temperature detection unit;
Forming a first opening at a position above the contact pad of the first insulating protective film and the first and second material films;
Forming a second opening in the second material film to expose a part of the temperature detection unit;
Forming a metal film on the inside of the first and second openings and on the surface of the second material film;
Patterning the metal film to expose the second material film on the temperature detection unit, and an electrode unit located in the second opening and connected to the temperature detection unit; and Forming a wiring connecting the contact pads;
Forming a third material film, a part of which forms the first infrared absorbing portion, on the surfaces of the metal film and the second material film so as to cover the metal film;
Patterning the first to third material films to form slits, exposing the first sacrificial layer through the slits;
Forming a second sacrificial layer on a surface of the third material film and an exposed surface of the first sacrificial layer;
Patterning the second sacrificial layer so as to expose a portion of the third material film located above the central portion of the temperature detection unit;
Forming a fourth material film, a part of which forms the second infrared absorbing portion, on the surface of the second sacrificial layer and the exposed surface of the third material film;
Forming a fifth material film, which is a metal thin film constituting the surface layer of the first and second infrared light receiving parts, on the entire surface of the fourth material film;
A portion of the third material film located above a central portion of the temperature detection unit is exposed to form the first infrared absorption unit, and a part of the second sacrificial layer is exposed. Patterning the fourth and fifth material films to extend from the edge of the infrared light receiving part and / or from the root located inside the electrode part toward the outside of the infrared light receiving part Forming the second infrared absorbing portion and the surface layer thereof, the portion facing the central portion of the
Removing the first sacrificial layer to bring the infrared light receiving part including the first infrared absorption part into a state of being supported by the support part with a space between the substrate and the substrate;
Removing the second sacrificial layer to bring the second infrared absorbing portion into a state of covering the electrode portion, the support portion, and the contact pad with a space therebetween,
A method for manufacturing a thermal infrared detector including:

The method for manufacturing a thermal infrared detector according to claim 11, wherein polyimide is used as a material for the first and second sacrificial layers.