JPH07106537A - Manufacture of solid-state image sensing device - Google Patents
Manufacture of solid-state image sensing deviceInfo
- Publication number
- JPH07106537A JPH07106537A JP5265391A JP26539193A JPH07106537A JP H07106537 A JPH07106537 A JP H07106537A JP 5265391 A JP5265391 A JP 5265391A JP 26539193 A JP26539193 A JP 26539193A JP H07106537 A JPH07106537 A JP H07106537A
- Authority
- JP
- Japan
- Prior art keywords
- solid
- film
- transparent film
- thin film
- manufacturing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000004519 manufacturing process Methods 0.000 title description 14
- 239000010408 film Substances 0.000 abstract description 41
- 239000010409 thin film Substances 0.000 abstract description 41
- 239000000463 material Substances 0.000 abstract description 22
- 239000004065 semiconductor Substances 0.000 abstract description 11
- 239000000758 substrate Substances 0.000 abstract description 11
- 230000000694 effects Effects 0.000 abstract description 9
- 238000001039 wet etching Methods 0.000 abstract description 8
- 238000010438 heat treatment Methods 0.000 abstract description 5
- 238000000465 moulding Methods 0.000 abstract 1
- 238000004806 packaging method and process Methods 0.000 abstract 1
- 238000000034 method Methods 0.000 description 20
- 239000012535 impurity Substances 0.000 description 11
- 239000010410 layer Substances 0.000 description 10
- 238000003384 imaging method Methods 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 7
- 238000005530 etching Methods 0.000 description 7
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 229910052814 silicon oxide Inorganic materials 0.000 description 6
- 229910052581 Si3N4 Inorganic materials 0.000 description 5
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 5
- 238000004528 spin coating Methods 0.000 description 5
- 238000001505 atmospheric-pressure chemical vapour deposition Methods 0.000 description 4
- 238000005229 chemical vapour deposition Methods 0.000 description 4
- 239000006059 cover glass Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 239000011368 organic material Substances 0.000 description 3
- 239000012780 transparent material Substances 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 239000012790 adhesive layer Substances 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000005380 borophosphosilicate glass Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 238000000059 patterning Methods 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 238000005268 plasma chemical vapour deposition Methods 0.000 description 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 1
- 229920005591 polysilicon Polymers 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Landscapes
- Solid State Image Pick-Up Elements (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、固体撮像装置の製造
方法に関し、特に感度を向上させるためのマイクロレン
ズを備えた固体撮像装置の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a solid-state image pickup device, and more particularly to a method for manufacturing a solid-state image pickup device having a microlens for improving sensitivity.
【０００２】[0002]
【従来の技術】一般に、ＣＣＤやＣＭＤ（Charge Modul
ation Device）等を用いた固体撮像装置においては、半
導体主面に光電変換部及び信号読み出し部を備えている
ので、実際に光電変換に寄与する領域は、20〜50％程度
に制限されている。この欠点を解決するための手段とし
て、集光のためのマイクロレンズを画素毎に設け、入射
光を光電変換部に集光する方法が特公昭６０−５９７５
２号公報などに提案されている。2. Description of the Related Art Generally, CCD and CMD (Charge Modul)
In the solid-state imaging device using a photoelectric conversion device, etc., since the semiconductor main surface is provided with the photoelectric conversion unit and the signal readout unit, the area actually contributing to photoelectric conversion is limited to about 20 to 50%. . As a means for solving this drawback, a method of providing a microlens for condensing each pixel for condensing incident light on a photoelectric conversion part is disclosed in JP-B-60-5975.
It is proposed in Japanese Patent Publication No. 2 and the like.
【０００３】図４は、上記公報記載のマイクロレンズ付
の固体撮像装置の画素部の構造を示す断面図であり、図
において、11はシリコン基板、12はチャネルストップ、
13は拡散層等よりなるＣＣＤ転送路、14はフォトダイオ
ード、15は絶縁膜、16はポリシリコンゲート、17は例え
ばホトレジスト等の有機材料よりなるマイクロレンズ集
束体であり、この構成により、Ｄで示す範囲の入射光が
フォトダイオード14に照射されるようになっている。FIG. 4 is a sectional view showing the structure of a pixel portion of the solid-state image pickup device with a microlens described in the above publication. In the figure, 11 is a silicon substrate, 12 is a channel stop,
13 is a CCD transfer path made of a diffusion layer, 14 is a photodiode, 15 is an insulating film, 16 is a polysilicon gate, and 17 is a microlens focusing body made of an organic material such as photoresist. The incident light in the range shown is applied to the photodiode 14.
【０００４】[0004]
【発明が解決しようとする課題】ところで固体撮像装置
の用途によっては、図５に示すように、図４に示したマ
イクロレンズ付の固体撮像装置上に、カバーガラス19及
びカバーガラス接着層18を形成することが要求される場
合がある。更にはまた、クリアモールド実装の場合に
も、マイクロレンズ上に接してクリアモールド材が形成
されることとなる。このような構成とした場合には、通
常の有機材料で形成されたマイクロレンズの屈折率は約
1.６であり、一方カバーガラス接着層あるいはクリアモ
ールド材の屈折率も、ほぼマイクロレンズ材料の屈折率
値に近いため、マイクロレンズ効果が大幅に低下する。Depending on the application of the solid-state image pickup device, as shown in FIG. 5, a cover glass 19 and a cover glass adhesive layer 18 are provided on the solid-state image pickup device with the microlens shown in FIG. It may be required to be formed. Furthermore, in the case of clear mold mounting, the clear mold material is formed in contact with the microlens. With such a structure, the refractive index of a microlens made of a normal organic material is about
On the other hand, the refractive index of the cover glass adhesive layer or the clear mold material is close to that of the microlens material, so that the microlens effect is significantly reduced.
【０００５】この点を改善するため、特開昭５８−２２
０１０６号公報には、クリアモールド等の実装に適する
マイクロレンズの構造が開示されている。図６は、その
公報開示中の一実施例であり、21は半導体基板、22は該
半導体基板21中に形成されたフォトダイオード、23は酸
化膜、24は凹形状を有するガラス，樹脂等よりなる薄
膜、25は薄膜24の凹部に充填された、透光性を有し薄膜
24よりも高屈折率を有する材料である。この図６に示す
ような構成とすることにより、入射光26は、充填材料25
及び薄膜24のマイクロレンズ効果により効果的にフォト
ダイオード22に集光されることとなる。しかしながら、
この公報には薄膜24は樹脂よりなり、一方、薄膜24の凹
部の充填材料25は透光性材料としか記載されておらず、
具体的な材料は開示されていない。In order to improve this point, JP-A-58-22
Japanese Patent Laid-Open No. 0106 discloses a structure of a microlens suitable for mounting a clear mold or the like. FIG. 6 shows an embodiment disclosed in the publication, in which 21 is a semiconductor substrate, 22 is a photodiode formed in the semiconductor substrate 21, 23 is an oxide film, and 24 is a glass having a concave shape, a resin or the like. Thin film, which is filled with the concave portion of the thin film 24, has a light-transmitting thin film.
It is a material having a refractive index higher than 24. With the structure shown in FIG. 6, the incident light 26 is filled with the filling material 25.
And, the microlens effect of the thin film 24 effectively collects the light on the photodiode 22. However,
In this publication, the thin film 24 is made of resin, while the filling material 25 in the recess of the thin film 24 is only described as a translucent material,
No specific material is disclosed.
【０００６】また、特開昭６２−２３１６１号公報に
は、図６に示したものと同様に、クリアモールド実装に
適したマイクロレンズの製法が開示されており、図７を
用いてその構成を説明する。図７において、31はシリコ
ン中に形成されたフォトダイオード部、32はシリコン酸
化膜からなる凹形状を有する薄膜、33は窒化シリコンよ
りなるレンズである。薄膜32に凹形状を形成する方法
は、窒化シリコン膜を堆積させ、パターニングした後、
部分的に酸化させ、窒化シリコン端にテーパ形状をもた
せ、凹形状を有するシリコン酸化膜を形成するものであ
るが、テーパ形状あるいは凹形状の曲面を正確に制御す
るのは困難である。また窒化シリコンからなるレンズ33
の形成方法は、まずＣＶＤ法等により厚く窒化シリコン
を堆積し、その後エッチバック法により、その表面を平
坦化するという工程がとられており、そのプロセス工程
が煩雑である欠点を有しており、また厚い窒化シリコン
は応力等によりクラックが発生し易いという欠点も有す
るものである。Further, Japanese Laid-Open Patent Publication No. 62-23161 discloses a method of manufacturing a microlens suitable for clear mold mounting, similar to that shown in FIG. explain. In FIG. 7, 31 is a photodiode portion formed in silicon, 32 is a concave thin film made of a silicon oxide film, and 33 is a lens made of silicon nitride. The method for forming the concave shape in the thin film 32 is as follows.
Although the silicon oxide film having a concave shape is formed by partially oxidizing the silicon nitride end to have a tapered shape, it is difficult to accurately control the curved surface of the tapered shape or the concave shape. A lens made of silicon nitride 33
The method of forming (1) involves the steps of first depositing thick silicon nitride by a CVD method or the like and then flattening the surface by an etch back method, which has a drawback that the process steps are complicated. Also, thick silicon nitride has a drawback that cracks are easily generated due to stress or the like.
【０００７】本発明は、従来のマイクロレンズを備えた
固体撮像装置の製造方法における上記問題点を解消する
ためになされたもので、クリアモールド実装等の場合に
おいても、レンズ効果が消失しないようなマイクロレン
ズを正確且つ容易に、しかもクラック等も発生しないよ
うに形成することが可能な固体撮像装置の製造方法を提
供することを目的とする。The present invention has been made to solve the above-mentioned problems in the conventional method for manufacturing a solid-state image pickup device having a microlens, and the lens effect does not disappear even in the case of clear mold mounting or the like. It is an object of the present invention to provide a method for manufacturing a solid-state image pickup device, which is capable of forming a microlens accurately and easily without causing a crack or the like.
【０００８】[0008]
【課題を解決するための手段及び作用】上記問題点を解
決するため、本発明は、半導体基板の表面領域にマトリ
クス状に配設された複数の光電変換素子と、前記半導体
基板上の前記各光電変換素子に対応する部分に入射光を
収束するマイクロレンズをそれぞれ備えた固体撮像装置
の製造方法において、前記半導体基板上に上層ほどエッ
チングレートが大なる２層以上の多層膜からなる第１の
透明膜を形成し、レジストパターニング後にエッチング
処理により第１の透明膜の上部にマイクロレンズ用の凹
部を形成し、次いで凹部を形成した第１の透明膜上に、
該第１の透明膜より屈折率の高い金属種を含むＳＯＧ材
料をスピンコートすることにより第２の透明膜を形成し
て、マイクロレンズを形成するものである。In order to solve the above problems, the present invention provides a plurality of photoelectric conversion elements arranged in a matrix on the surface region of a semiconductor substrate, and each of the photoelectric conversion elements on the semiconductor substrate. In a method of manufacturing a solid-state image pickup device, each of which includes a microlens for converging incident light in a portion corresponding to a photoelectric conversion element, a first multilayer film including two or more layers having an etching rate higher on an upper layer on the semiconductor substrate. A transparent film is formed, and after the resist patterning, an etching process is performed to form a concave portion for a microlens on the upper portion of the first transparent film, and then on the first transparent film having the concave portion formed,
A microlens is formed by spin-coating an SOG material containing a metal species having a higher refractive index than the first transparent film to form a second transparent film.
【０００９】このような構成の製造方法においては、第
１の透明膜は、上層ほどエッチングレートが大なる２層
以上の多層膜で形成されるため、凹部形成の際、その湾
曲形状を膜厚とエッチングレート比により適確に制御す
ることができる。また第２の透明膜は金属種を含むＳＯ
Ｇ材料をスピンコートすることにより形成するので、大
面積を均一にコートすることが容易に行え、また多数回
スピンコートすることによりクラックの発生を防止する
ことができる。また第２の透明膜の屈折率は第１の透明
膜の屈折率より高く設定されているので、クリアモール
ド実装等においても、レンズ効果を消失しないマイクロ
レンズを備えた固体撮像装置を容易に製造することがで
きる。In the manufacturing method having such a structure, since the first transparent film is formed of a multilayer film of two or more layers having an etching rate higher in the upper layer, the curved shape of the first transparent film is formed when forming the recess. And the etching rate ratio can be controlled appropriately. The second transparent film is SO containing a metal species.
Since the G material is formed by spin coating, it is possible to easily coat a large area uniformly, and it is possible to prevent the occurrence of cracks by spin coating a large number of times. Further, since the refractive index of the second transparent film is set higher than that of the first transparent film, a solid-state imaging device including a microlens that does not lose the lens effect can be easily manufactured even in clear mold mounting or the like. can do.
【００１０】[0010]
【実施例】次に本発明に係る固体撮像装置の製造方法の
実施例を、図１に示す製造工程図を用いて説明する。ま
ず図１の（Ａ）に示すように、半導体基板１にマトリク
ス状に配設される画素を構成する多数のＰＮ接合フォト
ダイオード２を形成し、半導体基板表面に、その中に凹
部を形成する透明材料からなる薄膜３を設ける。この薄
膜３を形成する透明材料としては、アルミ合金配線上に
形成されるものであるため、その形成温度は、せいぜい
450 ℃に限定される。そのため、本実施例においては、
常圧ＣＶＤ（ＡＰ−ＣＶＤ）法を用い、400 ℃から420
℃の温度で形成されるシリコン酸化膜を用いている。そ
して、このＡＰ−ＣＶＤ法でシリコン酸化膜を形成する
方法は、不純物を容易にドープすることが可能で、反応
ガスとしてSiＨ4 ，ＰＨ3 ，Ｂ2 Ｈ6 ，Ｏ2 等を用いる
ことによって、リン（Ｐ）あるいはボロン（Ｂ）をドー
プしたＰＳＧ，ＢＰＳＧ膜等が形成できるものである。EXAMPLE An example of a method for manufacturing a solid-state image pickup device according to the present invention will be described below with reference to the manufacturing process chart shown in FIG. First, as shown in FIG. 1A, a large number of PN junction photodiodes 2 that form pixels arranged in a matrix are formed on a semiconductor substrate 1, and recesses are formed in the semiconductor substrate surface. A thin film 3 made of a transparent material is provided. Since the transparent material for forming the thin film 3 is formed on the aluminum alloy wiring, the forming temperature is at most.
Limited to 450 ° C. Therefore, in this embodiment,
Using atmospheric pressure CVD (AP-CVD) method, 400 ℃ to 420
A silicon oxide film formed at a temperature of ℃ is used. The method of forming a silicon oxide film by the AP-CVD method allows impurities to be easily doped, and by using SiH 4 , PH 3 , B 2 H 6 , O 2 or the like as a reaction gas, A PSG or BPSG film doped with phosphorus (P) or boron (B) can be formed.
【００１１】また、図２に示すＰＳＧ膜の不純物濃度と
ウェットエッチングレートとの関係を表した図からわか
るように、ＰＳＧ膜のエッチングレートは不純物濃度に
依存し、不純物濃度を高くするとエッチングレートが大
となる特性を有している。そこで、本実施例において
は、図１の（Ａ）に示すように、Ｐ濃度を下層から３ m
ol％，５ mol％，７ mol％程度に設定した３層のＰＳＧ
膜３-1，３-2，３-3で薄膜３を形成している。この薄膜
３の厚さは、その構成材料の屈折率及び画素ピッチによ
り決まり、画素ピッチが10μｍとすると厚さは15〜20μ
ｍ程度、画素ピッチが５μｍとすると、約５μｍ前後の
厚さが望ましいため、この薄膜の厚さに合わせて、各Ｐ
ＳＧ膜３-1，３-2，３-3の厚さを設定する。Further, as can be seen from the diagram showing the relationship between the impurity concentration of the PSG film and the wet etching rate shown in FIG. 2, the etching rate of the PSG film depends on the impurity concentration, and the higher the impurity concentration, the higher the etching rate. It has great characteristics. Therefore, in this embodiment, as shown in FIG. 1A, the P concentration is set to 3 m from the lower layer.
3 layers of PSG set to ol%, 5 mol% and 7 mol%
The thin film 3 is formed by the films 3-1, 3-2 and 3-3. The thickness of this thin film 3 is determined by the refractive index of its constituent material and the pixel pitch. If the pixel pitch is 10 μm, the thickness is 15-20 μm.
If the pixel pitch is about 5 m and the pixel pitch is about 5 m, a thickness of about 5 μm is desirable.
The thickness of the SG films 3-1, 3-2, 3-3 is set.
【００１２】薄膜３中に凹部を形成する方法としては、
本実施例ではウェットエッチング法を用いており、次
に、その説明を行う。まず、図１の（Ａ）に示すよう
に、薄膜３を不純物濃度の異なる３層のＰＳＧ膜３-1，
３-2，３-3で形成した後、レジスト膜４をウェハー表面
に塗布し、次いで露光・現像工程により、フォトダイオ
ード２の中心に対応する部分に、所望の大きさを有する
開口部５を形成する。その後、ＨＦ系のウェットエッチ
ング法により、図１の（Ｂ）に示すように、凹部６を薄
膜３中に形成する。ＨＦ系のウェットエッチングを行う
際、先に述べたように、薄膜３を構成している３層のＰ
ＳＧ膜３-1，３-2，３-3は、上層ほど不純物濃度が高
く、すなわちエッチングレートが大きい特性をもってい
るため、アスペクト比が１／２以下の曲面状の凹部６が
形成可能になる。したがって、光学設計により最適な凹
部形状が設定された場合、その最適な凹部形状をウェッ
トエッチング法で形成可能なように、薄膜３を構成する
各ＰＳＧ膜の不純物濃度の条件並びに膜厚を設定すれば
よいことになる。As a method of forming a recess in the thin film 3,
In this embodiment, the wet etching method is used, which will be described next. First, as shown in FIG. 1A, the thin film 3 is formed into three layers of PSG films 3-1 having different impurity concentrations,
After forming 3-2 and 3-3, a resist film 4 is applied on the wafer surface, and then an opening 5 having a desired size is formed in a portion corresponding to the center of the photodiode 2 by an exposure / development process. Form. Thereafter, the recess 6 is formed in the thin film 3 by the HF-based wet etching method, as shown in FIG. When performing the HF-based wet etching, as described above, the P of the three layers forming the thin film 3 is formed.
Since the SG films 3-1, 3-2, and 3-3 have the characteristics that the impurity concentration is higher toward the upper layers, that is, the etching rate is higher, the curved concave portion 6 having an aspect ratio of 1/2 or less can be formed. . Therefore, when the optimum recess shape is set by the optical design, the impurity concentration condition and the film thickness of each PSG film forming the thin film 3 should be set so that the optimum recess shape can be formed by the wet etching method. It will be good.
【００１３】次に、図１の（Ｂ）に示す断面形状の凹部
６が形成された透明薄膜３が得られた後、レジスト膜４
を除去し、次いでスピンコート法により、薄膜３の構成
材料よりも高屈折率を有する透明材料を塗布し、続いて
乾燥，熱処理を行うことにより、図１の（Ｃ）に示すよ
うに、薄膜３よりも高屈折率を有する透明薄膜７が形成
される。透明薄膜３の形成材料はＣＶＤ法によるシリコ
ン酸化膜であるため、屈折率は1.45前後である。そのた
め、透明薄膜７の形成材料としては、有機溶剤に溶解し
たTi，Ta，Zr等の金属種を含むＳＯＧ（Spin On Glass
）材料が挙げられるが、シリコン酸化膜より高い屈折
率を有するものであれば、この限りではない。Next, after the transparent thin film 3 in which the recess 6 having the sectional shape shown in FIG. 1B is formed, the resist film 4 is formed.
Is removed, and then a transparent material having a refractive index higher than that of the constituent material of the thin film 3 is applied by spin coating, followed by drying and heat treatment, whereby a thin film is formed as shown in FIG. A transparent thin film 7 having a refractive index higher than 3 is formed. Since the material for forming the transparent thin film 3 is a silicon oxide film formed by the CVD method, the refractive index is around 1.45. Therefore, as a material for forming the transparent thin film 7, SOG (Spin On Glass) containing metal species such as Ti, Ta, and Zr dissolved in an organic solvent is used.
) Materials may be used, but not limited to these as long as they have a higher refractive index than the silicon oxide film.
【００１４】前記凹部を有する薄膜３と組み合わせて良
好なレンズ効果を得るには、薄膜７の屈折率は２前後の
値を有する材料がより好ましい。したがって本実施例に
おいては、Tiを含むＳＯＧ材料を用いて透明薄膜７を形
成している。Tiを含むＳＯＧ膜は、図３に示すようにス
ピンコート後に350 ℃の熱処理を行うことにより、屈折
率は２前後の値が得られ、良好な材料である。また、Ti
を含むＳＯＧ材料を、熱処理を含めて多数回塗布するこ
とにより、薄膜３の凹部６を完全に埋め、薄膜７の表面
をクラックなしに平坦化することができる。In order to obtain a good lens effect in combination with the thin film 3 having the concave portion, a material having a refractive index of the thin film 7 of about 2 is more preferable. Therefore, in this embodiment, the transparent thin film 7 is formed using the SOG material containing Ti. As shown in FIG. 3, the SOG film containing Ti is a good material because a refractive index of about 2 can be obtained by performing heat treatment at 350 ° C. after spin coating. Also, Ti
By applying the SOG material containing a plurality of times including heat treatment, the recess 6 of the thin film 3 can be completely filled and the surface of the thin film 7 can be planarized without cracks.
【００１５】以上の工程により、本発明に係る製造方法
の工程は終了し、凹部湾曲形状を正確に設定されたマイ
クロレンズが形成される。なお上記実施例においては、
薄膜３をＡＰ−ＣＶＤ法を用いて形成したものを示した
が、この薄膜３はプラズマＣＶＤ法を用いた酸化膜で形
成することも勿論可能であり、温度，圧力，ＲＦパワー
等の形成条件を変えることによりウェットエッチングレ
ートの異なる膜が得られる。Through the above steps, the steps of the manufacturing method according to the present invention are completed, and the microlens with the concave curved shape accurately set is formed. In the above embodiment,
Although the thin film 3 formed by the AP-CVD method is shown, the thin film 3 can of course be formed by an oxide film formed by the plasma CVD method, and the forming conditions such as temperature, pressure, RF power, etc. By changing the value, films having different wet etching rates can be obtained.
【００１６】また薄膜３に対しウェットエッチングを施
して凹部を形成した後、レンズ効果を挙げるために、付
加的に無機のＳＯＧ材料を塗布し、凹部の曲面形状を滑
らかにすることも効果的である。After the thin film 3 is wet-etched to form the concave portion, it is also effective to apply an inorganic SOG material additionally to smooth the curved shape of the concave portion in order to improve the lens effect. is there.
【００１７】また上記実施例では、薄膜３を不純物濃度
の異なる３層のＰＳＧ膜をＣＶＤ法で形成したものを示
したが、ＰＨ3 等の不純物ガスの流量を時系列的に変化
させながら、ＣＶＤ法によりＰＳＧ膜を連続的に堆積さ
せて、不純物濃度を連続的に変化した薄膜を形成するこ
ともでき、この場合は、更に凹部の曲面形状を滑らかに
することができ、レンズ効果を一層向上させることがで
きる。In the above embodiment, the thin film 3 is formed by forming three PSG films having different impurity concentrations by the CVD method. However, while changing the flow rate of the impurity gas such as PH 3 in time series, It is also possible to deposit a PSG film continuously by a CVD method to form a thin film in which the impurity concentration is continuously changed. In this case, the curved surface shape of the recess can be further smoothed to further improve the lens effect. Can be improved.
【００１８】また通常のマイクロレンズ付の固体撮像装
置においては、マイクロレンズより下面にカラーフィル
ターが形成されており、５μｍピッチ等の微小画素を考
えた場合、先に述べたように、半導体基板上の薄膜の膜
厚とカラーフィルターの膜厚の合計を５μｍ以下にする
ことが必要となり、高度な技術が要求され、更に５μｍ
以下の微細画素に対しては、マイクロレンズとフォトダ
イオード表面間の距離を、５μｍ以下のマイクロレンズ
焦点距離より小さくすることは事実上不可能となるが、
本発明において得られる構成では、マイクロレンズを構
成する薄膜７上にカラーフィルターが形成可能であり、
この点からも、本発明に係る製造方法は、画素微細化に
対しても有利であるという特徴を有する。Further, in a normal solid-state image pickup device with a microlens, a color filter is formed on the lower surface of the microlens, and when considering a minute pixel of 5 μm pitch or the like, as described above, on a semiconductor substrate. The total thickness of the thin film and the color filter must be 5 μm or less, which requires advanced technology.
For the following fine pixels, it is practically impossible to make the distance between the microlens and the photodiode surface smaller than the focal length of the microlens of 5 μm or less.
In the structure obtained in the present invention, the color filter can be formed on the thin film 7 forming the microlens,
From this point as well, the manufacturing method according to the present invention has a feature that it is advantageous for pixel miniaturization.
【００１９】[0019]
【発明の効果】以上実施例に基づいて説明したように、
本発明によれば、内部に正確で且つクラックを発生しな
いようにしたマイクロレンズを有する固体撮像装置を、
短時間で容易に製造することができ、また製造された固
体撮像装置は、クリアモールド実装等により表面に空気
とは異なる有機材料等が隣接形成された場合でも、レン
ズ効果消失による感度低下を回避することが可能とな
る。As described above on the basis of the embodiments,
According to the present invention, there is provided a solid-state imaging device having a microlens that is accurate and does not generate cracks inside.
It can be easily manufactured in a short time, and the manufactured solid-state imaging device avoids sensitivity deterioration due to loss of lens effect even when an organic material different from air is formed adjacent to the surface due to clear mold mounting etc. It becomes possible to do.
【図１】本発明に係る固体撮像装置の製造方法の実施例
を説明するための製造工程を示す図である。FIG. 1 is a diagram showing a manufacturing process for explaining an embodiment of a method for manufacturing a solid-state imaging device according to the present invention.
【図２】ＰＳＧ膜の不純物濃度とウェットエッチングレ
ートとの関係を示す図である。FIG. 2 is a diagram showing a relationship between an impurity concentration of a PSG film and a wet etching rate.
【図３】Tiを含むＳＯＧ材料の熱処理温度と屈折率との
関係を示す図である。FIG. 3 is a diagram showing a relationship between a heat treatment temperature and a refractive index of an SOG material containing Ti.
【図４】従来のマイクロレンズを備えた固体撮像装置の
構成例を示す断面図である。FIG. 4 is a cross-sectional view showing a configuration example of a solid-state imaging device including a conventional microlens.
【図５】カバーガラスを備えた従来の固体撮像装置の構
成例を示す断面図である。FIG. 5 is a cross-sectional view showing a configuration example of a conventional solid-state imaging device including a cover glass.
【図６】クリアモールド実装に適するマイクロレンズを
備えた従来の固体撮像装置の構成例を示す断面図であ
る。FIG. 6 is a cross-sectional view showing a configuration example of a conventional solid-state imaging device including a microlens suitable for clear mold mounting.
【図７】クリアモールド実装に適するマイクロレンズを
備えた従来の固体撮像装置の他の構成例を示す断面図で
ある。FIG. 7 is a cross-sectional view showing another configuration example of a conventional solid-state imaging device including a microlens suitable for clear mold mounting.
１ 半導体基板 ２ フォトダイオード ３ 薄膜 ３-1，３-2，３-3 ＰＳＧ膜 ４ レジスト膜 ５ 開口部 ６ 凹部 ７ 薄膜 1 Semiconductor Substrate 2 Photodiode 3 Thin Film 3-1, 3-2, 3-3 PSG Film 4 Resist Film 5 Opening 6 Recess 7 Thin Film
Claims (5)
配設された複数の光電変換素子と、前記半導体基板上の
前記各光電変換素子に対応する部分に入射光を収束する
マイクロレンズをそれぞれ備えた固体撮像装置の製造方
法において、前記半導体基板上に上層ほどエッチングレ
ートが大なる２層以上の多層膜からなる第１の透明膜を
形成し、レジストパターニング後にエッチング処理によ
り第１の透明膜の上部にマイクロレンズ用の凹部を形成
し、次いで凹部を形成した第１の透明膜上に、該第１の
透明膜より屈折率の高い金属種を含むＳＯＧ材料をスピ
ンコートすることにより第２の透明膜を形成して、マイ
クロレンズを形成することを特徴とする固体撮像装置の
製造方法。1. A plurality of photoelectric conversion elements arranged in a matrix on a surface region of a semiconductor substrate, and a microlens for converging incident light to a portion corresponding to each photoelectric conversion element on the semiconductor substrate, respectively. In the method for manufacturing a solid-state imaging device, a first transparent film is formed on the semiconductor substrate, the first transparent film being a multilayer film having two or more layers having an etching rate higher toward an upper layer, and the first transparent film is formed by etching after resist patterning. A concave portion for a microlens is formed on an upper portion, and then an SOG material containing a metal species having a refractive index higher than that of the first transparent film is spin-coated on the first transparent film having the concave portion. A method of manufacturing a solid-state imaging device, comprising forming a transparent film to form a microlens.
それぞれ不純物濃度を変えたＣＶＤ法による酸化膜で形
成することを特徴とする請求項１記載の固体撮像装置の
製造方法。2. The multilayer film forming the first transparent film,
2. The method of manufacturing a solid-state image pickup device according to claim 1, wherein the oxide film is formed by a CVD method with different impurity concentrations.
不純物ガス流量を時系列的に変化させながらＣＶＤ法に
より連続的に堆積した酸化膜で形成することを特徴とす
る請求項２記載の固体撮像装置の製造方法。3. The multilayer film forming the first transparent film,
3. The method for manufacturing a solid-state imaging device according to claim 2, wherein the oxide film is formed by an oxide film continuously deposited by a CVD method while changing the impurity gas flow rate in time series.
たTi又はTa又はZrを含むＳＯＧ材料で形成することを特
徴とする請求項１〜３のいずれか１項に記載の固体撮像
装置の製造方法。4. The solid-state imaging device according to claim 1, wherein the second transparent film is made of an SOG material containing Ti, Ta, or Zr dissolved in an organic solvent. Device manufacturing method.
までＳＯＧ材料を多数回スピンコートして形成すること
を特徴とする請求項１〜４のいずれか１項に記載の固体
撮像装置の製造方法。5. The solid-state imaging device according to claim 1, wherein the second transparent film is formed by spin-coating an SOG material a number of times until the surface becomes flat. Device manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5265391A JPH07106537A (en) | 1993-09-30 | 1993-09-30 | Manufacture of solid-state image sensing device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5265391A JPH07106537A (en) | 1993-09-30 | 1993-09-30 | Manufacture of solid-state image sensing device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH07106537A true JPH07106537A (en) | 1995-04-21 |
Family
ID=17416529
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5265391A Withdrawn JPH07106537A (en) | 1993-09-30 | 1993-09-30 | Manufacture of solid-state image sensing device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH07106537A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10284710A (en) * | 1997-04-09 | 1998-10-23 | Nec Corp | Solid-state imaging device, manufacturing method thereof, and solid-state imaging device |
| JP2006138997A (en) * | 2004-11-11 | 2006-06-01 | Hoya Corp | Method for producing substrate with microlens and method for producing counter substrate for liquid crystal display panel |
| US7064901B2 (en) | 2002-06-12 | 2006-06-20 | Seiko Epson Corporation | Method of manufacturing microlens, microlens, microlens array plate, electrooptic device and electronic equipment |
| JP2006332347A (en) * | 2005-05-26 | 2006-12-07 | Sharp Corp | INLAYER LENS, SOLID-STATE IMAGING DEVICE, ELECTRONIC INFORMATION DEVICE, IN-LAYER LENS FORMATION METHOD, AND SOLID-STATE IMAGING DEVICE MANUFACTURING METHOD |
| CN1317738C (en) * | 2003-12-26 | 2007-05-23 | 精工爱普生株式会社 | Etching method, substrate with multiple recesses, microlens substrate, transmissive screen and rear projector |
| CN111508835A (en) * | 2020-04-26 | 2020-08-07 | 深圳市昭矽微电子科技有限公司 | Graphic structure and method of forming the same |
| JP2021170061A (en) * | 2020-04-15 | 2021-10-28 | セイコーエプソン株式会社 | Optical substrate, electro-optical device, electronic device, and method of manufacturing optical substrate |
-
1993
- 1993-09-30 JP JP5265391A patent/JPH07106537A/en not_active Withdrawn
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10284710A (en) * | 1997-04-09 | 1998-10-23 | Nec Corp | Solid-state imaging device, manufacturing method thereof, and solid-state imaging device |
| US6104021A (en) * | 1997-04-09 | 2000-08-15 | Nec Corporation | Solid state image sensing element improved in sensitivity and production cost, process of fabrication thereof and solid state image sensing device using the same |
| US6291811B1 (en) | 1997-04-09 | 2001-09-18 | Nec Corporation | Solid state image sensing element improved in sensitivity and production cost, process of fabrication thereof and solid state image sensing device using the same |
| KR100302466B1 (en) * | 1997-04-09 | 2001-11-22 | 가네꼬 히사시 | Solid state image pickup device improved in sensitivity and manufacturing stage, its manufacturing method and solid state image pickup device using the same |
| US7064901B2 (en) | 2002-06-12 | 2006-06-20 | Seiko Epson Corporation | Method of manufacturing microlens, microlens, microlens array plate, electrooptic device and electronic equipment |
| CN1317738C (en) * | 2003-12-26 | 2007-05-23 | 精工爱普生株式会社 | Etching method, substrate with multiple recesses, microlens substrate, transmissive screen and rear projector |
| JP2006138997A (en) * | 2004-11-11 | 2006-06-01 | Hoya Corp | Method for producing substrate with microlens and method for producing counter substrate for liquid crystal display panel |
| JP2006332347A (en) * | 2005-05-26 | 2006-12-07 | Sharp Corp | INLAYER LENS, SOLID-STATE IMAGING DEVICE, ELECTRONIC INFORMATION DEVICE, IN-LAYER LENS FORMATION METHOD, AND SOLID-STATE IMAGING DEVICE MANUFACTURING METHOD |
| JP2021170061A (en) * | 2020-04-15 | 2021-10-28 | セイコーエプソン株式会社 | Optical substrate, electro-optical device, electronic device, and method of manufacturing optical substrate |
| CN111508835A (en) * | 2020-04-26 | 2020-08-07 | 深圳市昭矽微电子科技有限公司 | Graphic structure and method of forming the same |
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