TWI700518B - Metal-dielectric optical filter, sensor device, and fabrication method - Google Patents

Abstract

An optical filter, a sensor device including the optical filter, and a method of fabricating the optical filter are provided. The optical filter includes one or more dielectric layers and one or more metal layers stacked in alternation. The metal layers are intrinsically protected by the dielectric layers. In particular, the metal layers have tapered edges that are protectively covered by one or more of the dielectric layers.

Description

Metal dielectric optical filter, sensor device and manufacturing method

The present invention relates to a metal dielectric optical filter, a sensor device including the optical filter, and a method of manufacturing the optical filter.

Optical sensors are used in optical sensor devices (such as image sensors, ambient light sensors, proximity sensors, hue sensors, and UV sensors) to convert optical signals into electrical signals, thereby Allow optical signal detection or image capture. An optical sensor usually includes one or more sensor elements and one or more optical filters disposed on the one or more sensor elements.

For example, a color image sensor includes a plurality of color filters arranged in an array (ie, a color filter array (CFA)). CFA includes different types of color filters with different color passbands, such as red, green, and blue (RGB) filters.

Conventionally, absorption filters formed using dyes are used as color filters. Unfortunately, these dye-based color filters have relatively wide color passbands, resulting in less shiny colors. Alternatively, a dichroic filter (ie, interference filter) formed of stacked dielectric layers may be used as a color filter. These all-dielectric color filters have higher transmission levels and narrower color passbands, resulting in brighter and more shiny colors. However, the color passband of the all-dielectric color filter undergoes a relatively large center wavelength shift accompanied by a change in incident angle, resulting in an undesirable color shift.

In addition, all-dielectric color filters usually include a large number of stacked dielectric layers and are relatively thick. Therefore, full dielectric color filters are expensive and difficult to manufacture. In particular, it is difficult to chemically etch a full dielectric color filter. Therefore, it is preferable to use the lift-off process for patterning. An example of the lift-off process for the full dielectric color filter used in patterned CFA is in Hanrahan's U.S. Patent No. 5,120,622 issued on June 9, 1992, and the Buchsbaum U.S. Patent issued on January 27, 1998 No. 5,711,889, Edlinger et al. U.S. Patent No. 6,238,583 issued on May 29, 2001, Buchsbaum et al. U.S. Patent No. 6,638,668 issued on October 28, 2003, and in January 2010 It is disclosed in US Patent No. 7,648,808 of Buchsbaum et al. issued on the 19th. However, the lift-off process is usually limited to the filter interval being approximately twice the height of the filter, which makes it difficult to achieve a full dielectric CFA suitable for smaller color image sensors.

In addition to transmitting visible light in the color passband, both dye-based color filters and fully dielectric color filters also transmit infrared (IR) light, which causes noise. Therefore, a color image sensor usually also includes an IR blocking filter placed on the CFA. IR blocking filters are also used in other optical sensor devices operating in the visible spectrum. Conventionally, absorption filters formed of colored glass or dichroic filters formed of stacked dielectric layers are used as IR blocking filters. Alternatively, an induced transmission filter formed of stacked metal and dielectric layers can be used as an IR blocking filter. Examples of metallic dielectric IR blocking filters are in U.S. Patent No. 5,648,653 of Sakamoto et al. issued on July 15, 1997 and U.S. Patent No. 7,133,197 of Okenfuss et al. issued on November 7, 2006. reveal.

In order to avoid the use of an IR blocking filter, an induced transmission filter formed of stacked metal and dielectric layers can be used as a color filter. Metal dielectric optical filters (such as metal dielectric color filters) inherently perform IR blocking. Generally, a metal dielectric color filter has a relatively narrow color passband, which does not significantly shift the wavelength but is accompanied by a change in the incident angle. In addition, metal dielectric color filters are generally much thinner than full dielectric color filters. Examples of metallic dielectric color filters are in McGuckin et al. U.S. Patent No. 4,979,803 issued on December 25, 1990, in Wang U.S. Patent No. 6,031,653 issued on February 29, 2000, and in 2009 In the US Patent Application No. 2009/0302407 of Gidon et al. published on December 10, in the US Patent Application No. 2011/0204463 of Grand published on August 25, 2011, and on April 12, 2012 The published U.S. Patent Application No. 2012/0085944 of Gidon et al.

Generally, the metal layer in a metal dielectric optical filter (such as a metal dielectric color filter) is a silver layer or an aluminum layer, which is unstable in the environment and is also exposed to even small amounts of water or sulfur. Will deteriorate. Chemical etching of the silver layer exposes the edge of the silver layer to the environment, thereby deteriorating it. Therefore, in most cases, the metal dielectric color filter in the CFA is patterned by only adjusting the thickness of the dielectric layer to select different color passbands for the metal dielectric color filter. In other words, different types of metal dielectric color filters with different color passbands need to have the same number of silver layers and the same thickness of each other. Unfortunately, these requirements severely limit the possible optical designs for metal dielectric color filters.

The present invention provides metal dielectric optical filters that do not have these requirements. They are particularly suitable for image sensors and other sensor devices, such as ambient light sensors, proximity sensors, hue sensors, and UV sensor.

Accordingly, the present invention relates to an optical filter arranged on a substrate, which includes: one or more dielectric layers; and one or more metal layers, etc., on the substrate and the one or more The dielectric layers are alternately stacked, wherein each of the one or more metal layers has a tapered edge extending along an entire periphery of the metal layer at a periphery of the optical filter and along the The entire periphery of the metal layer is protectively covered by at least one of the one or more dielectric layers.

The present invention also relates to a sensor device, which includes: one or more sensor elements And one or more optical filters, which are disposed on the one or more sensor elements, wherein each of the one or more optical filters includes: one or more dielectric layers; And one or more metal layers, which are alternately stacked with the one or more dielectric layers, wherein each of the one or more metal layers has a tapered edge, and the tapered edge is in the optical filter A periphery extends along an entire periphery of the metal layer and is protectively covered by at least one of the one or more dielectric layers along the entire periphery of the metal layer.

The present invention further relates to a method of manufacturing an optical filter, the method comprising: providing a substrate; coating a photoresist layer on the substrate; patterning the photoresist layer to expose a filter region of the substrate, Thereby, an overhang is formed in the patterned photoresist layer around the filter area; a multilayer stack is deposited on the patterned photoresist layer and the filter area of the substrate, the multilayer stack includes and one or more A dielectric layer is alternately stacked with one or more metal layers; the patterned photoresist layer and part of the multilayer stack on the patterned photoresist layer are removed, so that a part of the multilayer stack remaining on the filter area of the substrate is formed An optical filter, wherein each of one or more of the metal layers in the optical filter has a tapered edge extending along the entire periphery of one of the metal layers at a periphery of the optical filter And along the entire periphery of the metal layer is protectively covered by at least one of the one or more dielectric layers.

100: optical filter

101: The periphery of the optical filter

102: The central part of the optical filter

103: Multi-layer stacking

110: substrate

120: Dielectric layer

130: metal layer

131: tapered edge

140: photoresist layer

141: Overhang

150: protective coating

200: optical filter

210: substrate

220: Dielectric layer

230: metal layer

231: tapered edge

260: Corrosion Inhibition Layer

300: optical filter

310: substrate

570: Transmission spectrum of red filter

571: Transmission spectrum of green filter

572: Transmission spectrum of blue filter

573‧‧‧Optical filter transmission spectrum

574‧‧‧Optical filter transmission spectrum

680‧‧‧Color gamut of RGB filter set

681‧‧‧Color gamut of dye-based RGB filter set

682‧‧‧Color track with red filter

683‧‧‧Full-dielectric red filter color track

684‧‧‧Optical filter color track

700‧‧‧Optical filter

711‧‧‧Sensor components

790‧‧‧Sensor device

800‧‧‧Optical filter

804‧‧‧Optical filter

811‧‧‧Sensor components

890‧‧‧Sensor device

900‧‧‧Optical filter

903‧‧‧Coating

910‧‧‧Substrate

940‧‧‧Photoresist layer

1000‧‧‧Optical filter

1003‧‧‧Discontinuous coating

1041‧‧‧Overhang

1042‧‧‧Top/top photosensitive layer

1043‧‧‧Bottom layer/Bottom release layer

1100‧‧‧Optical filter

1103‧‧‧Coating

1121‧‧‧Top Dielectric Layer

1141‧‧‧Overhang

1142‧‧‧Top photosensitive layer

1143‧‧‧Bottom layer/bottom release layer

Transmission spectrum of 1370‧‧‧UVA filter

1371‧‧‧Transmission spectrum of UVA filter

1372‧‧‧Transmission spectrum of UVB filter

1373‧‧‧UVB filter transmission spectrum

Transmission spectrum of 1374‧‧‧220nm center filter

Transmission spectrum of 1375‧‧‧220nm center filter

1470‧‧‧Optical filter transmission spectrum

1471‧‧‧Optical filter transmission spectrum

1472‧‧‧Optical response curve

1500‧‧‧First optical filter

1505‧‧‧Second optical filter

1511‧‧‧First sensor element

1512‧‧‧Second sensor element

1513‧‧‧Joint pad

1590‧‧‧Sensor device

1600‧‧‧Optical filter

1604‧‧‧Optical Filter

1605‧‧‧Second optical filter

1606‧‧‧First optical filter

1611‧‧‧First sensor element

1612‧‧‧Second sensor element

1690‧‧‧Sensor device

d‧‧‧Filter interval

h‧‧‧Filter height

w‧‧‧Filter width

The present invention will be described in more detail with reference to the accompanying drawings, in which: Fig. 1A is a schematic diagram of a cross-section of a first embodiment of an optical filter; Figs. 1B to 1G are for manufacturing the optical filter of Fig. 1A A schematic diagram of the steps in a method; FIG. 2 is a schematic diagram of a cross section of a second embodiment of an optical filter; FIG. 3 is a schematic diagram of a cross section of a plurality of optical filters; FIG. 4A It is a table of the layer number, material and thickness of an exemplary red filter; FIG. 4B is a table of the layer number, material and thickness of an exemplary green filter; FIG. 4C is an exemplary blue filter A table of the layer number, material and thickness of the device; Figure 4D is a table of the layer number, material and thickness of an exemplary optical filter; Figures 5A and 5B are the exemplary red of Figures 4A to 4C, Green and blue filter A diagram of the transmission spectrum; FIG. 5C is a diagram of the transmission spectrum of the exemplary optical filter of FIG. 4D at an incident angle of 0° to 60°; FIG. 6A is the exemplary red, green, and red of FIGS. 4A to 4C. A diagram of the color gamut of a blue (RGB) filter set and a conventional dye-based RGB filter set; FIG. 6B is the exemplary red filter of FIG. 4A and a conventional full dielectric red A diagram of the color track of the optical filter at an incident angle of 0° to 60°; FIG. 6C is a diagram of the color track of the exemplary optical filter of FIG. 4D at an incident angle of 0° to 60°; Fig. 7 is a schematic diagram of a cross section of a first embodiment of a sensor device; Fig. 8 is a schematic diagram of a cross section of a second embodiment of a sensor device; Figs. 9A and 9B are A scanning electron micrograph of a cross section of a continuous coating deposited on a patterned photoresist layer and a substrate; Figure 9C is one of an optical filter formed by the continuous coating of Figures 9A and 9B An optical micrograph of the top view showing corrosion after exposure to high humidity and high temperature; Figure 10 is a cross section of a discontinuous coating deposited on a patterned photoresist layer and a substrate. Scanning electron Photomicrograph; Figures 11A and 11B are scanning electron micrographs of a cross section of a discontinuous coating deposited on a patterned photoresist layer and a substrate, the patterned photoresist layer has a thicker Bottom release layer and a larger overhang; Figure 12 is a table of exemplary ultraviolet A (UVA), ultraviolet B (UVB) and 220nm central filter layer numbers, materials and thickness; Figure 13A is Figure 12 A diagram of the transmission spectrum of the exemplary UVA filter at an incident angle of 0° to 60°; Fig. 13B is the transmission spectrum of the exemplary UVB filter of Fig. 12 at an incident angle of 0° to 60° A picture Fig. 13C is a diagram of the transmission spectrum of the exemplary 220nm central filter of Fig. 12 at an incident angle of 0° to 60°; Fig. 14 is an exemplary optical filter of 0° to 60° incidence A diagram of the transmission spectrum of the angle; FIG. 15A is a schematic diagram of a cross section of a third embodiment of a sensor device; FIG. 15B is a schematic diagram of a top view of the sensor device of FIG. 15A; FIG. 15C is a system FIG. 15A is a schematic diagram of a top view of an alternative layout of a sensor device; and FIG. 16 is a schematic diagram of a top view of a fourth embodiment of a sensor device.

The present invention provides a metal dielectric optical filter with a protected metal layer, which is particularly suitable for a sensor device, such as an image sensor, an ambient light sensor, a proximity sensor, and a hue The sensor or an ultraviolet (UV) sensor. The optical filter includes alternately stacking one or more dielectric layers and one or more metal layers. The metal layer is inherently protected by the dielectric layer. In particular, the metal layer has a tapered edge protectively covered by one or more of the dielectric layers. Accordingly, the metal layer has increased resistance to environmental degradation, resulting in a more durable optical filter in the environment.

In some embodiments, one or more dielectric layers and one or more metal layers are stacked without any intermediate layers. 1A, a first embodiment of an optical filter 100 disposed on a substrate 110 includes three dielectric layers 120 and two metal layers 130 alternately stacked. The metal layers 130 are each disposed between and adjacent to the two dielectric layers 120, thereby protecting them from the environment. The dielectric layer 120 and the metal layer 130 are continuous layers without any microstructures formed therein.

The metal layer 130 has a tapered edge 131 at one of the periphery 101 of the optical filter 100. In other words, the thickness of the metal layer 130 is substantially uniform throughout a central portion 102 of the optical filter 100, but the thickness gradually decreases at the periphery 101 of the optical filter 100. The tapered edge 131 extends along the entire periphery of the metal layer 130 at the periphery 101 of the optical filter 100. same Ground, the thickness of the dielectric layer 120 is substantially uniform throughout the central portion 102 of the optical filter 100, but the thickness gradually decreases at the periphery 101 of the optical filter 100. Accordingly, the height of the central portion 102 of the optical filter 100 is substantially uniform, but the periphery 101 of the optical filter 100 is inclined. In other words, the optical filter 100 has a substantially flat top and inclined sides. Generally, the side surface of the optical filter 100 is inclined from the horizontal at an angle less than about 45°. Preferably, the side surface of the optical filter 100 is inclined from the horizontal plane at an angle of less than about 20°, and more preferably, is inclined from the horizontal plane at an angle of less than about 10°.

Advantageously, the tapered edge 131 of the metal layer 130 is not exposed to the environment. In contrast, the tapered edge 131 of the metal layer 130 is protectively covered by one or more of the dielectric layers 120 along the entire periphery of the metal layer 130. The one or more dielectric layers 120 inhibit the environmental degradation of the metal layer 130, such as corrosion, by preventing sulfur and water from diffusing into the metal layer 130. Preferably, the metal layer 130 is substantially encapsulated by the dielectric layer 120. More preferably, the tapered edge 131 of the metal layer 130 is protectively covered by the adjacent dielectric layer 120, and the metal layer 130 is substantially encapsulated by the adjacent dielectric layer 120. In some cases, a top dielectric layer 120 (ie, a dielectric layer 120 at the top of the optical filter 100) protectively covers the tapered edges 131 of all the metal layers 130 below.

1B to 1G, the first embodiment of the optical filter 100 can be manufactured by a lift-off process. With particular reference to FIG. 1B, in a first step, a substrate 110 is provided. With particular reference to FIG. 1C, in a second step, a photoresist layer 140 is coated on the substrate 110. Generally, the photoresist layer 140 is applied by spin coating or spray coating.

1D in particular, in a third step, the photoresist layer 140 is patterned to expose a region (ie, a filter region) of the substrate 110 where the optical filter 100 is to be placed. The other areas of the substrate 110 remain covered by the patterned photoresist layer 140. Generally, the photoresist layer 140 is first exposed to UV light through a mask covering a region of the photoresist layer 140 covering the filter region of the substrate 110, and then the photoresist layer is made by using a suitable developer or solvent. The exposed area of 140 is developed (ie, etched) and patterned.

The photoresist layer 140 is formed with an overhang 141 (ie, an undercut) around the filter area The patterned photoresist layer 140 is patterned in one way. Generally, the overhang 141 is formed by, for example, chemically modifying a top part of the photoresist layer 140 by using a suitable solvent so that the top part develops more slowly than a bottom part of the photoresist layer 140. Alternatively, the overhang 141 may be formed by coating a double-layer photoresist layer 140 (which is composed of a top layer that develops slower and a bottom layer that develops faster) to the substrate 100.

The overhang 141 should be large enough to ensure that the coating (ie, the multilayer stack 103) subsequently deposited on the patterned photoresist layer 140 and the substrate 110 is discontinuous from the substrate 110 to the patterned photoresist layer 140, as shown in FIG. 1E Shown in. The overhang 141 is generally larger than 2 μm, preferably larger than 4 μm. Generally speaking, the coating should not cover the side surface of the patterned photoresist layer 140.

9A and 9B, when the coating 903 is continuous on the substrate 910 and the patterned photoresist layer 940, during the subsequent peeling of the portion of the photoresist layer 940 and the upper coating 903, the coating 903 is in the patterned light The bottom edge of the barrier layer 940 is broken, thereby exposing the edge of the optical filter formed by the coating 903 (in particular, the edge of the metal layer of the optical filter) to the environment. Unfortunately, for a silver-containing optical filter 900, the exposed edge is susceptible to environmental attacks (for example, when exposed to high humidity and high temperature), resulting in corrosion, as shown in FIG. 9C.

Referring to FIG. 10, in an embodiment of providing a discontinuous coating 1003, the photoresist layer has a double-layer structure and includes a top layer 1042 and a bottom layer 1043. The top layer 1042 is photosensitive and can be patterned by selective exposure to UV light. The bottom layer 1043 is generally non-photosensitive and serves as a release layer. Suitable examples of photoresists include AZ electronic material nLOF 2020 for the top photosensitive layer 1042 and Microchem Corp. LOR 10 B for the bottom release layer 1043.

When the photoresist layer is developed, the extent of the overhang 1041 is controlled by the development time. In FIG. 10, the development time is selected to provide an overhang 1041 of about 3 μm. Preferably, the thickness of the bottom release layer 1043 is greater than about 500 nm, and the overhang 1041 is greater than about 2 μm. In order to ensure clean peeling (ie, peeling without cracking of the deposited coating 1003), the thickness of the coating 1003 is usually It should be less than about 70% of the thickness of the bottom release layer 1043. In FIG. 10, the thickness of the bottom release layer 1043 is about 800 nm, the thickness of the top photosensitive layer 1042 is about 2 μm, and the thickness of the coating is about 500 nm. The side surface of the optical filter 1000 below the overhang 1041 is inclined at an angle of about 10°.

Referring to Figure 11, in some cases, a thicker bottom release layer 1143 is used, and a larger overhang 1141 is achieved by using a longer development time (for example, for some processes, about 80s to about 100s ) And produced. These features improve the edge durability by reducing the slope of the side surface of the optical filter 1100 and increasing the thickness of the top dielectric layer 1121 at the periphery of the optical filter 1100. In FIG. 11, the development time is selected to provide an overhang 1141 of about 6 μm. Preferably, the thickness of the bottom release layer 1143 is greater than about 2 μm, and the overhang portion 1141 is greater than about 4 μm. The thickness of the coating 1103 should generally be less than about 30% of the thickness of the bottom release layer 1143. In FIG. 11, the thickness of the bottom release layer 1143 is about 2.6 μm, the thickness of the top photosensitive layer 1142 is about 2 μm, and the thickness of the coating 1103 is about 500 nm. The side surface of the optical filter 1100 below the overhanging portion 1141 is inclined at an angle of about 5°.

With particular reference to FIG. 1E, in a fourth step, a multilayer stack 103 is deposited as a discontinuous coating on the patterned photoresist layer 140 and the filter area of the substrate 110. A part of the multilayer stack 103 disposed on the filter area of the substrate 110 forms the optical filter 100. The layers of the multilayer stack 103 corresponding to the layers of the optical filter 100 can be deposited using various deposition techniques (such as: evaporation, such as thermal evaporation, electron beam evaporation, plasma assisted evaporation, or reactive ion evaporation; sputtering) Plating, such as magnetron sputtering, reactive sputtering, alternating current (AC) sputtering, direct current (DC) sputtering, pulsed DC sputtering or ion beam sputtering; chemical vapor deposition, such as plasma enhanced chemical vapor Deposition; and atomic layer deposition) and deposition. In addition, different layers can be deposited by using different deposition techniques. For example, the metal layer 130 can be deposited by sputtering a metal target, and the dielectric layer 120 can be deposited by reactive sputtering a metal target in the presence of oxygen.

Since the overhang 141 covers the periphery of one of the filter regions of the substrate 110, the thickness of the deposited layer gradually decreases toward the periphery 101 of the optical filter 100. The overhang 141 faces the optical filter 100 The periphery 101 produces a soft roll off of the coating. When a dielectric layer 120 is deposited on a metal layer 130, the dielectric layer 120 not only covers the top surface of the metal layer 130, but also covers the tapered edge 131 of the metal layer 130, thereby protecting the metal layer 130 from the environment. harm. In addition, the top dielectric layer 120 is usually used as a protective layer of the lower metal layer 130. For example, in the embodiment of FIG. 11, a top dielectric layer 1121 having a thickness of about 100 nm extends to the less durable metal layer (specifically, the tapered edge of the metal layer) and protectively covers it. , As shown in Figure 11A.

1F, in a fifth step, a part of the multilayer stack 103 on the patterned photoresist layer 140 and the photoresist layer 140 are removed (ie, peeled off). Generally, the photoresist layer 140 is peeled off by using a suitable peeling agent or solvent. A portion of the multilayer stack 103 remaining on the filter area of the substrate 110 forms the optical filter 100. The substrate 110 may be, for example, a conventional sensor device.

It should be noted that the peeling process of FIGS. 1B to 1F can also be used to simultaneously form a plurality of optical filters 100 of the same type (ie, having the same optical design) on the substrate 110. In addition, the lift-off process can be repeated to subsequently form one or more optical filters of a different type (ie, having a different optical design) on the same substrate 110. In some cases, one or more optical filters that are more durable in the environment may be subsequently formed on the substrate 110 by using a lift-off process or in some cases by using a dry or wet etching process , So that it partially overlaps with one or more optical filters 100 that are less durable in the environment, as described in more detail later. Thereby, an optical filter array can be formed on the substrate 110. The substrate 110 may be, for example, a conventional sensor array.

With particular reference to FIG. 1G, in an optional sixth step, an additional protective coating 150 is deposited on the optical filter 100. The protective coating 150 can be deposited by using one of the aforementioned deposition techniques. The protective coating 150 covers both the central portion 102 and the periphery 101 of the optical filter 100 (ie, all exposed portions of the optical filter 100), thereby protecting the optical filter 100 from environmental damage.

In other embodiments, the optical filter includes a plurality of corrosion-inhibiting layers disposed between the dielectric layer and the metal layer, which further protect the metal layer. Referring to FIG. 2, a second embodiment of an optical filter 200 disposed on a substrate 210 is similar to the first embodiment of the optical filter 100, but further includes inserting three dielectric layers 220 and two metal layers 230 between four corrosion inhibiting layers 260.

The metal layers 230 are each disposed between and adjacent to two corrosion-inhibiting layers 260, thereby further protecting against environmental damage. The corrosion inhibiting layer 260 mainly inhibits the corrosion of the metal layer 230 during the deposition process. In particular, the corrosion inhibiting layer 260 protects the part of the metal layer 230 in the optical path, thereby preventing the optical properties of the metal layer 230 from degrading. Preferably, the tapered edge 231 of the metal layer 230 is protectively covered by the adjacent corrosion inhibiting layer 260 and the nearest dielectric layer 220. Therefore, the metal layer 230 is preferably substantially encapsulated by the adjacent corrosion inhibiting layer 260 and the nearest dielectric layer 220.

The second embodiment of the optical filter 200 can be manufactured by a peeling process similar to the peeling process of the first embodiment used to manufacture the optical filter 100. However, the layers of the multilayer stack deposited in the fourth step correspond to the layers of the optical filter 200. Specifically, the corrosion inhibiting layer 260 is deposited before and after each metal layer 230. Advantageously, the corrosion inhibiting layer 260 inhibits corrosion (ie, oxidation) of the metal layer 230 during the deposition of the dielectric layer 220. The corrosion inhibiting layer 260 is particularly useful when the metal layer 230 contains silver or aluminum. In these embodiments, the corrosion inhibiting layer 260 inhibits the reaction between the silver or aluminum from the metal layer 230 and the oxygen from the dielectric layer 220 to form silver oxide or aluminum oxide.

The corrosion inhibiting layer 260 may be deposited as a metal compound (for example, metal nitride or metal oxide) layer by using one of the aforementioned deposition techniques (for example, reactive sputtering). Alternatively, the corrosion inhibiting layer 260 may be formed by first depositing a suitable metal layer by using one of the aforementioned deposition techniques and then oxidizing the metal layer. Preferably, the corrosion inhibiting layer 260 on top of the metal layer 230 is each formed by first depositing a suitable metal layer, oxidizing the metal layer, and then depositing a metal oxide layer. For example, these corrosion inhibiting layers 260 can be sputtered It is formed by plating a suitable metal target, then oxidizing, and then reactively sputtering a suitable metal target in the presence of oxygen. Further details of the method of forming the corrosion inhibiting layer are provided later, and are disclosed in US Patent No. 7,133,197.

The optical filter of the present invention can have various optical designs. The optical design of the exemplary optical filter will be described in more detail later. Generally speaking, the optical design of an optical filter is optimized for a specific passband by selecting an appropriate layer number, material and/or thickness.

The optical filter includes at least one metal layer and at least one dielectric layer. Generally, an optical filter includes a plurality of metal layers and a plurality of dielectric layers. Generally, an optical filter includes 2 to 6 metal layers, 3 to 7 dielectric layers, and optionally 4 to 12 corrosion inhibiting layers. Generally speaking, increasing the number of metal layers provides a passband with steeper edges but a lower transmittance in the frequency band.

1。替代地，光學濾光器可由以一序列(C/M/C/D)_n堆疊之n個金屬層(M)及n個介電層(D)及2n個腐蝕抑制層(C)組成，其中n

1。當底層係一介電層時，光學濾光器可由以一序列D(M/D)_n堆疊之n個金屬層(M)及n+1個介電層(D)組成，其中n

1。替代地，光學濾光器可由以一序列D(C/M/C/D)_n堆疊之n個金屬層(M)、n+1個介電層(D)及2n個腐蝕抑制層(C)組成，其中n

1。 The first layer or bottom layer (ie, the first layer deposited on the substrate) in the optical design can be a metal layer or a dielectric layer. The last layer or top layer (ie, the last layer deposited on the substrate) in an optical design is usually a dielectric layer. When the bottom layer is a metal layer, the optical filter can be composed of n metal layers (M) and n dielectric layers (D) stacked in a sequence (M/D) _n , where n

1. Alternatively, the optical filter may be composed of n metal layers (M) and n dielectric layers (D) and 2n corrosion inhibiting layers (C) stacked in a sequence (C/M/C/D) _n , Where n

1. When the bottom layer is a dielectric layer, the optical filter can be composed of n metal layers (M) and n+1 dielectric layers (D) stacked in a sequence of D (M/D) _n , where n

1. Alternatively, the optical filter may be composed of n metal layers (M), n+1 dielectric layers (D), and 2n corrosion inhibiting layers (C) stacked in a sequence of D (C/M/C/D) _n ) Composition, where n

1.

The metal layers are each composed of metal or alloy. In some embodiments, the metal layers each consist of silver. Alternatively, the metal layers may each consist of a silver alloy. For example, a silver alloy essentially composed of about 0.5 wt% gold and about 0.5 wt% tin can provide improved corrosion resistance. In other embodiments, the metal layers are each composed of aluminum. The choice of metal or alloy depends on the application. Silver is generally preferred for optical filters with a pass band in the visible spectral region, and aluminum is generally preferred It is used for optical filters with a pass band in the UV spectral region, but sometimes silver may be used when the pass band is centered at a wavelength greater than about 350 nm.

The metal layers are usually but not necessarily composed of the same metal or alloy, but have different thicknesses. Generally, the metal layers each have a physical thickness between about 5 nm and about 50 nm, preferably between about 10 nm and about 35 nm.

The dielectric layers are each composed of a dielectric material that is transparent in the passband of the optical filter.

For optical filters with a pass band in the visible spectrum, the dielectric layers are usually composed of a high refractive index dielectric material with a refractive index greater than about 1.65 at 550 nm and transparent in the visible spectrum. Suitable examples of high refractive index dielectric materials for these filters include titanium dioxide (TiO ₂ ), zirconium dioxide (ZrO ₂ ), hafnium dioxide (HfO ₂ ), niobium pentoxide (Nb ₂ O ₅ ), five Tantalum oxide (Ta ₂ O ₅ ) and other mixtures thereof. Preferably, the high refractive index dielectric materials of these filters also absorb UV, that is, absorb UV in the near UV spectral region. For example, a high refractive index dielectric material containing or consisting of TiO ₂ and/or Nb ₂ O ₅ can provide enhanced UV blocking, that is, having lower out-of-band transmittance in the near UV spectral region. Preferably, the refractive index of the high refractive index dielectric material is greater than about 2.0 at 550 nm, more preferably greater than about 2.35 at 550 nm. Usually a higher refractive index can be expected. However, the refractive index of currently available transparent high refractive index dielectric materials is generally less than about 2.7 at 550 nm.

For filters with a pass band in the UV spectral region, the dielectric layers are usually each made of an intermediate refractive index dielectric material with a refractive index between about 1.4 and 1.65 at 300 nm, or preferably a refractive index at 300 nm It is greater than about 1.65, more preferably greater than about 2.2 at 300 nm, and is composed of a high refractive index dielectric material that is transparent in the UV spectral region. Suitable examples of intermediate refractive index and high refractive index dielectric materials for filters having a pass band in the UV spectral region include Ta ₂ O ₅ , hafnium dioxide (HfO ₂ ), aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), scandium trioxide (ScO ₃ ), yttrium trioxide (Y ₂ O ₃ ), ZrO ₂ , magnesium oxide (MgO ₂ ), magnesium fluoride (MgF ₂ ), other fluorine Compounds and other mixtures. For example, for a passband centered at a wavelength greater than about 340nm, Ta ₂ O ₅ can be used as a high refractive index dielectric material, and for a passband centered at a wavelength less than about 400 nm, HfO ₂ can be used as a high Refractive index dielectric material.

The dielectric layers are usually but not necessarily composed of the same dielectric material, but have different thicknesses. Generally, the dielectric layers each have a physical thickness between about 20 nm and about 300 nm. Preferably, the top dielectric layer has a physical thickness greater than about 40 nm, more preferably greater than about 100 nm, so that the top dielectric layer serves as a protective layer of the underlying metal layer. The physical thickness of each dielectric layer is selected to correspond to a quarter-wavelength optical thickness (QWOT) required for an optical design. QWOT is defined as 4nt, where n is the refractive index of the dielectric material and t is the physical thickness. Generally, the dielectric layers each have a QWOT between about 200 nm and about 2400 nm.

The corrosion-inhibiting layers are each composed of a corrosion-inhibiting material. Generally, the corrosion inhibiting layer is composed of a corrosion inhibiting dielectric material. Examples of suitable corrosion inhibiting dielectric materials include silicon nitride (Si ₃ N ₄ ), TiO ₂ , Nb ₂ O ₅ , zinc oxide (ZnO), and mixtures thereof. Preferably, the corrosion-inhibiting dielectric material is a compound having an electrical corrosion potential higher than that of the metal or alloy of the metal layer, such as nitride or oxide.

In some cases, the corrosion-inhibiting layer below the metal layer is composed of ZnO, and the corrosion-inhibiting layer above the metal layer includes a very thin layer composed of zinc (for example, having a thickness less than 1 nm) and composed of ZnO One thin layer. The zinc layer is deposited on the metal layer and then oxidized to prevent optical absorption. The ZnO layer below and above the metal layer is usually deposited by reactive sputtering. Advantageously, depositing a zinc layer on the metal layer before depositing the ZnO layer prevents the metal layer from being exposed to activated ionized oxygen species generated during reactive sputtering. The zinc layer preferably absorbs oxygen, thereby inhibiting oxidation of the metal layer.

The corrosion-inhibiting layer is usually suitably thin to substantially avoid affecting the optical design of the optical filter especially when it absorbs in the visible spectral region. Generally, the corrosion inhibiting layers each have a physical thickness between about 0.1 nm and about 10 nm, preferably between about 1 nm and about 5 nm. Further details of suitable corrosion inhibiting layers are disclosed in US Patent No. 7,133,197.

The protective coating used is usually composed of a dielectric material. The protective coating can be combined with dielectric The layers have the same dielectric material composition and can have the same thickness range as the dielectric layer. Generally, the protective coating is composed of the same dielectric material as the top dielectric layer and has a thickness that is a part of the design thickness of the top dielectric layer (ie, the thickness required for optical design). In other words, the top dielectric layer of the optical design is separated between a dielectric layer and a dielectric protective coating. Alternatively, the protective coating may be composed of an organic material (for example, epoxy).

Referring to FIG. 3, the optical filter 300 generally has a filter height h of less than 1 μm and preferably less than 0.6 μm, that is, a height of the center portion of the optical filter 300 from the substrate 310. It should be noted that the height of the filter usually corresponds to the thickness of the aforementioned deposited coating. When used in an image sensor, the optical filter 300 generally has a filter width w of less than 2 μm and preferably less than 1 μm, that is, a width of the central portion of the optical filter 300. Advantageously, the relatively small filter height allows a small filter interval when forming a plurality of optical filters 300 by a lift-off process. Generally, the optical filter 300 in an image sensor has a filter interval d of less than 2 μm and preferably less than 1 μm, that is, an interval between the center portions of the closest optical filter 300. When used in other sensor devices with larger pixel sizes, the filter width can be from about 50 μm to about 100 μm.

The optical filter is a metal dielectric bandpass filter having a high-frequency band transmittance and a low-frequency band transmittance, that is, an induced transmission filter. In some embodiments, the optical filter is a color filter having a relatively narrow color passband in the visible spectrum. For example, the optical filter can be a red, green, blue, cyan, yellow, or magenta filter. In other embodiments, the optical filter has a light-appropriate passband in the visible spectral region (ie, a passband that matches the light-appropriate luminous efficiency function that mimics the spectral response of the human eye to relatively bright light) An optical filter. In still other embodiments, the optical filter is an IR blocking filter having a relatively wide passband in the visible spectrum.

In these embodiments, the optical filter generally has a transmittance in one of the maximum frequency bands greater than about 50%, and an average of less than about 2% between about 300 nm and about 400 nm (ie, in the near UV spectral region). Out-of-band transmittance, and between about 750nm and about 1100nm (ie, In the infrared (IR) spectral region) less than about 0.3% of the average out-of-band transmittance. In contrast, conventional all-dielectric color filters and photo-optical filters are usually not inherently IR blocking. Generally, in these embodiments, the optical filter also has a low angle offset, that is, the center wavelength offset of the incident angle from 0°. Generally, an optical filter has an incident angle of 60° and an amplitude less than about 5% of an optical filter centered at 600 nm or an angular offset of less than about 30 nm. In contrast, the conventional all-dielectric color filters and photo-optical filters are usually highly angle sensitive.

The optical design (ie, layer number, material, and thickness) for the exemplary red, green, and blue filters (ie, an exemplary set of RGB filters) are made in Figure 4A, Figure 4B, and Figure 4C, respectively Into a table. The optical design of an exemplary optical filter is tabulated in Figure 4D. The layers of each optical design are numbered starting from the first layer or bottom layer deposited on the substrate.

The metal layers are each composed of silver and have a physical thickness between about 13 nm and about 34 nm. Each of the dielectric layers is composed of a high refractive index dielectric material (H), and has a QWOT between about 240 nm and about 2090 nm. For example, the high refractive index dielectric material may be a mixture of Nb ₂ O ₅ and TiO ₂ and has a refractive index of about 2.43 at 550 nm. The corrosion inhibiting layers are each composed of ZnO and each have a physical thickness of about 2 nm.

When the high refractive index dielectric material has a refractive index of about 2.43 at 550nm, the filter height of the red filter is 606nm, the filter height of the green filter is 531nm, and the filter height of the blue filter The height of the optical device is 252nm, and the height of the photometric filter is 522nm. The height of these filters is much smaller than that of the conventional full-dielectric color filters and photo-optical filters.

The transmission spectra 570, 571, and 572 of exemplary red, green, and blue filters are plotted in FIGS. 5A and 5B, respectively. The transmission spectrum 570 of the exemplary red filter includes a red pass band centered at about 620 nm, the transmission spectrum 571 of the exemplary green filter includes a green pass band centered at about 530 nm, and the exemplary blue filter The transmission spectrum 572 of the optical device contains a blue passband centered at about 445 nm.

The transmission spectra 573 (0°) and 574 (60°) of the exemplary optical filter plotted in FIG. 5C at an incidence angle of 0° to 60°. The transmission spectrum 573 of the exemplary optical filter at an angle of incidence of 0° includes an optical pass band centered at about 555 nm. In the transmission spectrum 574 of the exemplary optical filter with an incident angle of 60°, the optical pass band is centered at about 520 nm. In other words, the angular deviation of the exemplary optical filter with an incident angle of 60° is about -25 nm. Advantageously, the angular deviation of the exemplary photometric filter is much smaller than that of a conventional all-dielectric photometric filter.

The exemplary color filter and the optical filter each have a transmittance in one of the maximum frequency bands greater than about 60%. Advantageously, with respect to the conventional dye-based color filters and full dielectric color filters and photo filters, the exemplary color filters and photo filters provide improved IR blocking, thereby Reduce noise caused by IR leakage. Specifically, the exemplary color filter and the photo-optical filter each have an average out-of-band transmittance of less than about 0.3% between about 750 nm and about 1100 nm (ie, in the IR spectral region). Compared with some conventional metal dielectric color filters, the exemplary color filters and photo filters (especially the exemplary red filter) also provide improved UV blocking, thereby reducing UV leakage The noise caused. Specifically, the exemplary color filter and the photo-optical filter each have an average out-of-band transmittance of less than about 2% between about 300 nm and about 400 nm (ie, in the near UV spectral region).

A color gamut 680 of an exemplary RGB filter set and a color gamut 681 of a conventional dye-based RGB filter set are drawn on a CIE xy chromaticity diagram in FIG. 6A for comparison. Advantageously, the color gamut 680 of the exemplary RGB filter set is much larger than the color gamut 681 of the conventional dye-based RGB filter set.

An exemplary red filter with a color track 682 drawn at an incidence angle of 0° to 60° on a CIE xy chromaticity diagram in FIG. 6B and a conventional full dielectric at an incidence angle of 0° to 60° One of the red filters is color track 683. A color track 684 of an exemplary optical filter with an incident angle of 0° to 60° drawn on a CIE xy chromaticity diagram in FIG. 6C. Advantageously, the angular deviation of the exemplary red filter and the photometric filter is much smaller than that of the conventional fully dielectric red filter and the photometric filter The angle offset.

In some embodiments, the optical filter is a UV filter having a relatively narrow passband in the UV spectral region (for example, between about 180 nm and about 420 nm). For example, the optical filter can be an ultraviolet A (UVA) or ultraviolet B (UVB) filter. In these embodiments, the optical filter generally has a transmittance in one of the maximum frequency bands of greater than about 5%, preferably greater than about 15%, and between about 420 nm and about 1100 nm (ie, in the visible and IR spectral regions Middle) is less than about 0.3% of the average out-of-band transmittance. In contrast, conventional all-dielectric UV filters are generally not inherently IR blocking. Generally, in these embodiments, the optical filter also has a low angle offset, that is, the center wavelength offset of the incident angle from 0°. Generally, the optical filter has an incident angle of 60° and an amplitude less than about 5% of an optical filter centered at 300 nm or an angular offset of less than about 15 nm. In contrast, conventional all-dielectric UV filters are usually very sensitive.

The optical design of exemplary UVA, UVB, and 220nm center filters, namely, layer number, material, and thickness are summarized in FIG. 12. The metal layers are each composed of aluminum and have a physical thickness between about 10 nm and about 20 nm. The dielectric layers are each composed of a high refractive index dielectric material (that is, Ta ₂ O ₅ for UVA filters and HfO ₂ for UVB filters and 220nm center filters), and have a value between about Physical thickness between 40nm and about 60nm. The exemplary UV filter does not include a corrosion inhibiting layer because the additional protection provided by the corrosion inhibiting layer is usually unnecessary when the metal layer is composed of aluminum.

The filter height of the UVA filter is 350nm, the filter height of the UVB filter is 398nm, and the filter height of the 220nm center filter is 277nm. The height of these filters is much smaller than that of conventional all-dielectric UV filters.

The transmission spectra of the exemplary UVA filter 1370 (0°) and 1371 (60°) plotted in Fig. 13A with an incident angle of 0° to 60°, and an example of an incident angle of 0° to 60° in Fig. 13B The transmission spectrum of the UVB filter is 1372 (0°) and 1373 (60°), and the transmission spectrum 1374 (0°) of an exemplary 220nm central filter with an incident angle of 0° to 60° is plotted in Figure 13C. And 1375 (60°). The transmission spectrum 1370 of the exemplary UVA filter at an incident angle of 0° includes a UVA passband centered at about 355 nm, and the transmission spectrum 1372 of the exemplary UVB filter at an incident angle of 0° includes About 295nm is a UVB passband centered, and the transmission spectrum 1374 of a 220nm center filter with an incident angle of 0° includes a passband centered about 220nm. The amplitude of the angular offset of the exemplary UV filter at an incident angle of 60° is less than about 15 nm. Advantageously, the angular offset of the exemplary UV filter is much smaller than that of the conventional all-dielectric UV filter.

The exemplary UV filters each have a transmittance greater than about 10% in one of the maximum frequency bands. In particular, the UVA and UVB filters each have a transmittance in one of the largest frequency bands greater than about 20%. Advantageously, the exemplary UV filter provides improved IR blocking relative to conventional all-dielectric UV filters, thereby reducing noise caused by IR leakage. Specifically, the exemplary UV filters each have an average out-of-band transmittance between about 420 nm and about 1100 nm (ie, in the visible and IR spectral regions), which is less than about 0.3%.

The optical filter of the present invention is particularly useful when included as a part of a sensor device or other active element. The sensor device can be any type of sensor device, including one or more sensor elements in addition to one or more optical filters according to the present invention. In some examples, the sensor device may also include one or more conventional optical filters. For example, the sensor device can be an image sensor, an ambient light sensor, a proximity sensor, a hue sensor, a UV sensor, or a combination thereof. The one or more sensor elements can be any type of conventional sensor elements. Generally, one or more sensor elements are photodetectors, such as photodiodes, charge coupled device (CCD) sensor elements, complementary metal oxide semiconductor (CMOS) sensor elements, silicon detectors, or Dedicated UV sensitive detector. One or more sensor elements can be front-illuminated or back-illuminated. The sensor elements can be made of any typical sensor material (such as silicon, indium gallium arsenide (IN _1-x Ga _x As), gallium arsenide (GaAs), germanium, lead sulfide (PbS), or nitride Gallium (GaN)) is formed.

One or more optical filters are disposed on the one or more sensor elements so that the one or more optical filters filter the light provided to the one or more sensor elements. Generally, each optical filter is arranged on a sensor element. In other words, each pixel of the sensor device communicates Often includes an optical filter and a sensor element. Preferably, the one or more optical filters are directly disposed on the one or more sensor elements, for example on a passivation layer of the one or more sensor elements. For example, one or more optical filters can be formed on one or more sensor elements by a lift-off process. However, in some examples, there may be one or more coatings disposed between the one or more optical filters and the one or more sensor elements. In some examples, one or more optical filters may be integrated with one or more sensor elements.

In some embodiments, the sensor device includes a single sensor element and a single optical filter disposed on the sensor element according to the present invention. Referring to FIG. 7, a first embodiment of the sensor device 790 includes a sensor element 711 and an optical filter 700 disposed on the sensor element 711. For example, the sensor device 790 may be an ambient light sensor, the sensor element 711 may be a photodiode, and the optical filter 700 may be a photo-optical filter, such as the example shown in FIG. 4D Optic filter or an IR blocking filter. For another example, the sensor device 790 may be a UV sensor, the sensor element 711 may be a photodiode, and the optical filter 700 may be a UV filter, such as the example shown in FIG. 12 UVA, UVB or 220nm center filter.

In an exemplary embodiment of an ambient light sensor, an optical filter according to the present invention is integrated with a photodiode. The photo-optical filter is arranged on the photodiode, usually on a planar passivation layer composed of Si ₃ N ₄ such as the photodiode. For example, a protective coating or an encapsulation layer composed of epoxy resin can be placed on the photoelectric filter and the photodiode. The optical design of the photopic filter is optimized by considering the passivation layer and (when present) the encapsulation layer.

The transmission spectra 1470 (0°) and 1471 (60°) of an exemplary optical filter optimized to be integrated with a photodiode in the incident angle of 0° to 60° plotted in Fig. 14 A normalized light response curve 1472. The transmission spectra 1470 and 1471 are matched with a Si ₃ N ₄ passivation layer and an epoxy encapsulation layer. The transmission spectrum 1470 of the exemplary optical filter at an angle of incidence of 0° includes an optical pass band centered at about 555 nm. The transmission spectrum 1470 of the exemplary optical filter follows the normalized optical response curve 1472 quite well with an incident angle of 0° to 40°. In addition, the exemplary optical filter blocks both UR light and IR light at an incident angle of 0° to 60°, and has a low angular offset. Advantageously, the exemplary photo-optical filter is also durable in the environment, such as 96 hours at a temperature of 125°C and a relative humidity of 100%.

In other embodiments, the sensor device includes a plurality of sensor elements and a plurality of optical filters arranged on the plurality of sensor elements according to the present invention. Generally, the sensor elements are arranged in an array. In other words, the sensor elements form a sensor array, such as a photodiode array, a CCD array, a CMOS array, or any other type of conventional sensor array. Optical filters are usually also arranged in an array. In other words, the optical filter forms an optical filter array, such as a color filter array (CFA). Preferably, the sensor array and the optical filter array are corresponding two-dimensional arrays, namely mosaics. For example, the array may be a rectangular array with columns and rows.

Generally, in these embodiments, the optical filters are substantially separated from each other. In other words, the peripheries of the optical filter usually do not touch each other. However, in some cases, the dielectric layer of the optical filter may unintentionally contact, while the metal layer, especially the tapered edge, remains separated from each other.

Generally, a plurality of optical filters include different types of optical filters with different passbands from each other. For example, the plurality of optical filters may include color filters (such as red, green, blue, cyan, yellow, and/or magenta filters), optical filters, IR blocking filters, UV Optical filter or a combination of such. In some embodiments, the plurality of optical filters include different types of color filters forming a CFA. For example, a plurality of optical filters may include red, green, and blue filters forming an RGB filter array (such as a Bayer filter array), such as the exemplary red in FIGS. 4A to 4C , Green and blue filters. For another example, the plurality of optical filters may include cyan, magenta, and yellow filters forming a CMY filter array.

Advantageously, different types of optical filters may have different numbers of metal layers and/or different thicknesses of metal layers. In some embodiments, at least two of the different types of optical filters include different numbers of metal layers from each other. In the same or other embodiments, at least two of the different types of optical filters have different metal layer thicknesses from each other. For example, the exemplary blue filter of FIG. 4C has a different number of metal layers than the exemplary red and green filters of FIGS. 4A and 4B. In addition, all of the exemplary red, green, and blue filters of FIGS. 4A to 4C have different metal layer thicknesses from each other.

Referring to FIG. 8, a second embodiment of the sensor device 890 includes a plurality of sensor elements 811 and a plurality of optical filters 800 and 804 disposed on the plurality of sensor elements 811. The plurality of optical filters 800 and 804 include a first type optical filter 800 having a first pass band and a second type optical filter having a second pass band different from the first pass band器804. For example, the sensor device 890 may be an image sensor, a plurality of sensor elements 811 may form a CCD array, and a plurality of optical filters 800 and 804 may form a Bayer filter array, of which only the illustration Part of a column. The first type of optical filter 800 may be a green filter, such as the exemplary green filter of FIG. 4B, and the second type of optical filter 804 may be a red filter (such as the example of FIG. 4A Exemplary red filter), or a blue filter (such as the exemplary blue filter of Figure 4C).

Any of the aforementioned sensor device embodiments can be combined with one or more additional optical filters and one or more additional sensor elements that are more durable in the environment.

Accordingly, in some embodiments, the sensor device includes one or more first optical filters arranged on one or more first sensor elements according to the present invention, and also includes one or more first optical filters arranged on one or more One or more second optical filters on the plurality of second sensor elements. The one or more second optical filters are more durable than the one or more first optical filters in the environment. For example, the one or more first optical filters may be silver dielectric optical filters according to the present invention, wherein the metal layer is composed of silver or a silver alloy. The one or more second optical filters may be an aluminum dielectric optical filter according to the present invention, wherein the metal layer is composed of aluminum. Instead, one The or multiple second optical filters can be conventional optical filters, such as all-dielectric, silicon-dielectric or hydrogenated silicon-dielectric optical filters.

In these embodiments, the one or more second optical filters partially overlap the one or more first optical filters, making the one or more second optical filters more durable in the environment protective Ground covers the periphery of one or more first optical filters that are less durable in the environment. Advantageously, this covering layout provides additional protection for the tapered edges of the one or more first optical filters, especially the metal layer, from environmental degradation (such as corrosion). Due to the small slope of the filter side and the small filter height of one or more first optical filters, one or more second optical filters are placed on one or more first optical filters The inclined sides at the periphery of the optical device and the substrate are conformal, thereby providing a continuous layer in one or more second optical filters.

The one or more second optical filters preferably extend along the entire periphery of the one or more first optical filters to the inclined side surface at the periphery of the one or more first optical filters, including the cone of the metal layer形边。 Shaped edges. Preferably, the one or more second optical filters completely cover the oblique side surface at the periphery of the one or more first optical filters. However, the one or more second optical filters do not cover or block the one or more first sensor elements.

Generally, one or more first optical filters and one or more second optical filters have different passbands from each other. For example, the one or more first optical filters may be color filters (such as red, green, blue, cyan, yellow, or magenta filters), optical filters, IR blocking filters , Or a combination thereof. In particular, the one or more first optical filters may be silver dielectric color filters (such as the exemplary red, green and/or blue filters of FIGS. 4A to 4C), silver dielectric color filters An optical filter (such as the exemplary optical filter of FIG. 4D) or a silver dielectric IR blocking filter.

The one or more second optical filters can be, for example, UV filters or near IR filters or a combination thereof. In particular, the one or more second optical filters can be aluminum dielectric UV filters (such as the exemplary UVA, UVB, and/or 220nm center filters in FIG. 12) or all dielectric UV filter. Alternatively, the one or more second optical filters may be silicon dielectric or hydrogenated silicon dielectric near-IR filters (such as Hendrix et al. U.S. Patent Application Publication No. 2014/ Optical filter described in No. 0014838.

Generally, in these embodiments, the sensor device is multifunctional and the combination has different functions mainly determined by the passband of one or more first optical filters and one or more second optical filters The different types of optical sensors. One or more first optical filters and one or more first sensor elements form a first type of optical sensor, and one or more second optical filters and one or more second The sensor element forms a second type of optical sensor. For example, the first type of optical sensor can be an ambient light sensor that includes a photometric filter or an IR blocking filter, and a hue that includes one or more different types of color filters. A sensor, or an image sensor including a plurality of different types of color filters. The second type of optical sensor can be, for example, a UV sensor including a UV filter or a proximity sensor including a near IR filter.

Referring to FIG. 15, a third embodiment of a sensor device 1590 includes a first sensor element 1511 and a first optical filter 1500 disposed on the first sensor element 1511 according to the present invention, thereby A first type of optical sensor is formed. The sensor device 1590 further includes a second sensor element 1512 and a second optical filter 1505 arranged on the second sensor element 1512 which is more durable in the environment, thereby forming a second type of optical sensor Detector.

For example, the first type of optical sensor may be an ambient light sensor, and the first optical filter 1500 may be a silver dielectric optical filter (such as the exemplary optical filter of FIG. 4D ) Or a silver dielectric IR blocking filter. The second type of optical sensor may be, for example, a UV sensor, and the second optical filter 1505 may be an aluminum dielectric UV filter (such as the exemplary UVA, UVB or 220nm center filter in FIG. 12器) or a full dielectric UV filter. Alternatively, the second type of optical sensor may be a proximity sensor, and the second optical filter The 1505 can be a near IR filter, such as a full dielectric, silicon dielectric or hydrogenated silicon dielectric near IR filter. The first sensor element 1511 and the second sensor element 1512 may be photodiodes.

With particular reference to FIG. 15A, the second optical filter 1505 extends along the entire periphery of the first optical filter 1500 to the inclined side surface of the first optical filter 1500. Thereby, the second optical filter 1505 protectively covers the periphery of the first optical filter 1500, including the tapered edge of the metal layer.

With particular reference to FIGS. 15B and 15C, the first optical filter 1500 covers and filters the light provided to the first sensor element 1511. The second optical filter 1505 covers and filters the light provided to the second sensor element 1512, and surrounds but does not cover the first sensor element 1511. In the layout illustrated in FIG. 15B, the first sensor element 1511 and the second sensor element 1512 are arranged in a row between the rows of the bonding pads 1513. In an alternative layout illustrated in FIG. 15C, the second sensor element 1512 is annular and surrounds the first sensor element 1511.

Referring to FIG. 16, a fourth embodiment of a sensor device 1690 includes a plurality of first sensor elements 1611 and a plurality of first optical filters arranged on the plurality of first sensor elements 1611 according to the present invention The sensors 1600, 1604, and 1606 form a first type of optical sensor. The sensor device 1690 further includes a second sensor element 1612 and a second optical filter 1605 disposed on the second sensor element 1612, thereby forming a second type of optical sensor.

For example, the first type of optical sensor can be an image sensor or a hue sensor, and the plurality of first optical filters 1600, 1604, and 1606 can be different types of color filters, such as The exemplary silver dielectric red, green, and blue filters of 4A to 4C. The second type of optical sensor can be, for example, a UV sensor, and the second optical filter 1605 can be a UV filter, such as the exemplary aluminum dielectric UVA, UVB, or 220nm center filter in FIG. 12 Device. Alternatively, the second type of optical sensor may be a proximity sensor, and the second optical filter 1605 may be a near IR filter, such as a full dielectric, silicon dielectric or hydrogenated silicon dielectric Near IR filter. A plurality of first sensor elements 1611 and a second sensor The device element 1612 may form a photodiode array.

1000‧‧‧Optical filter

1003‧‧‧Discontinuous coating

1041‧‧‧Overhang

1042‧‧‧Top/top photosensitive layer

1043‧‧‧Bottom layer/Bottom release layer

Claims (26)

An optical filter arranged on a substrate, comprising: a plurality of dielectric layers; and a plurality of metal layers, wherein each metal layer of the plurality of metal layers is formed by at least two of the plurality of dielectric layers Surrounding, wherein each of the plurality of metal layers is composed of silver, silver alloy or aluminum, and each of the plurality of metal layers has a first tapered edge and a second tapered edge, the first A tapered edge and the second tapered edge are protectively covered by at least one of the plurality of dielectric layers. The optical filter of claim 1, wherein the optical filter has a substantially flat top and inclined sides, and wherein the inclined sides of the optical filter are inclined from the horizontal at an angle of less than about 45° . Such as the optical filter of claim 2, wherein the inclined side surfaces are inclined from the horizontal plane at an angle less than about 20°. The optical filter of claim 1, wherein the optical filter has a filter height of less than about 1 μm. The optical filter of claim 1, wherein the thickness of each of the plurality of metal layers is substantially uniform throughout a central portion of the optical filter. Such as the optical filter of claim 1, wherein the optical filter is a color filter, an optical filter, an infrared blocking filter or an ultraviolet filter. The optical filter of claim 1, wherein the plurality of dielectric layers include a top dielectric layer, and the top dielectric layer protectively covers each metal layer of the plurality of metal layers. The optical filter of claim 7, wherein the top dielectric layer has a size greater than about 40 nm One of the solid thickness. A sensor device comprising: one or more first sensor elements; and one or more first optical filters, which are arranged on the one or more first sensor elements, wherein The one or more first optical filters are one or more color filters, one or more photopic filters, one or more infrared blocking filters, or one of the like Combination, wherein each of the one or more first optical filters includes: a plurality of dielectric layers; and a plurality of metal layers, wherein each metal layer of the plurality of metal layers is formed by the plurality of dielectric layers At least two are surrounded, and each of the plurality of metal layers has a first tapered edge and a second tapered edge, and the first tapered edge and the second tapered edge are covered by the plurality of At least one of the dielectric layers is protectively covered. The sensor device of claim 9, wherein the one or more first optical filters are disposed on a passivation layer of the one or more first sensor elements. The sensor device of claim 9, further comprising an encapsulation layer disposed on the one or more first optical filters and the one or more first sensor elements. Such as the sensor device of claim 9, wherein the sensor device is an image sensor, an ambient light sensor, a proximity sensor, a hue sensor, an ultraviolet sensor, or the like One combination. Such as the sensor device of claim 9, which further includes: one or more second sensor elements; and one or more second optical filters, which are arranged on the one or more second sensors On the detector element, wherein the one or more second optical filters are larger than the one or more second optical filters An optical filter is more durable in the environment, and the one or more second optical filters partially overlap with the one or more first optical filters. The sensor device of claim 13, wherein the one or more first optical filters have a substantially flat top and inclined sides, and wherein the one or more second optical filters extend to the inclined sides side. Such as the sensor device of claim 9, wherein each of the plurality of metal layers is composed of silver or silver alloy. The sensor device of claim 13, wherein the one or more second optical filters are one or more all-dielectric optical filters, one or more aluminum dielectric optical filters, one or more One silicon dielectric optical filter, one or more hydrogenated silicon dielectric optical filters, or a combination thereof. The sensor device of claim 13, wherein the one or more second optical filters are one or more ultraviolet filters, one or more near infrared filters, or a combination thereof. A method of manufacturing an optical filter, the method comprising: providing a substrate; coating a photoresist layer on the substrate; patterning the photoresist layer to expose a filter region of the substrate, thereby An overhang is formed in the patterned photoresist layer around the filter region; a multilayer stack is deposited on the patterned photoresist layer and the filter region of the substrate, the multilayer stack includes and a Or a plurality of dielectric layers are alternately stacked one or more metal layers; and the patterned photoresist layer and a part of the multilayer stack on the patterned photoresist layer are removed, so that the filter remains on the substrate A portion of the multilayer stack on the area forms the optical filter, wherein each of the one or more metal layers in the optical filter has a first tapered edge and a second tapered edge, and the first tapered edge A tapered edge The edge and the second tapered edge are protectively covered by at least one of the one or more dielectric layers in the optical filter, wherein the first tapered edge is located on a first of the optical filter A periphery, and the second tapered edge is located at a second periphery of the optical filter, and the one or more metal layers are not adjacent to any other metal layers with respect to a length of the substrate. The method of claim 18, wherein the one or more metal layers are composed of a plurality of metal layers, and wherein the one or more dielectric layers are composed of a plurality of dielectric layers. The method of claim 19, wherein the substrate is a sensor element. The method of claim 19, wherein the overhang is at least 2 μm. The method of claim 21, wherein the overhang is at least 4 μm. The method of claim 19, wherein the photoresist layer includes a bottom release layer and a top photosensitive layer. The method of claim 23, wherein the multilayer stack is deposited to a thickness less than about 70% of a thickness of the bottom release layer. The method of claim 23, wherein the multilayer stack is deposited to a thickness less than about 30% of a thickness of the bottom release layer. The method of claim 18, further comprising: forming another optical filter that is more durable in the environment than the optical filter on the substrate, so that the other optical filter and the optical filter part Overlap to protect the first periphery and the second periphery.

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