Optical sensor and electronic device

Abstract

To provide an optical sensor in which electromagnetic noise resistance of a light receiving part is enhanced.SOLUTION: The optical sensor 1 includes a semiconductor substrate 201, a light receiving portion 150 formed on the semiconductor substrate 201, an interlayer insulating film 204 covering the light receiving portion 150, and a transparent conductive film 208 formed on the interlayer insulating film 204 so as to cover the light receiving portion 150. Preferably, the semiconductor substrate 201 is of a first conductivity type, and the light-absorbing part 150 includes an impurity region 202 of a second conductivity type. The photodiode 101 is formed by the semiconductor substrate 201 and the impurity region 202 of the second conductivity type. A portion of the transparent conductive film 208 covering the light-receiving portion 150 is connected to a conductive layer to which a fixed potential is applied.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to optical sensors and electronic devices. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2023-124978 (Patent Document 1) discloses an optical sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-124978

[0004] [overview] Optical sensors may be affected by electrical noise, and there is a need to improve their noise resistance. For this reason, in the optical sensor disclosed in JP 2023-124978 A (Patent Document 1), a P+ layer is provided in an N layer formed on a P-type substrate. In this optical sensor, the P+ layer serves as an electromagnetic shield that reduces electrical noise.

[0005] However, other methods of forming electromagnetic shields have not been fully explored and could be improved.

[0006] The present disclosure aims to provide an optical sensor and an electronic device that reduce electrical noise.

[0007] The present disclosure relates to an optical sensor including a semiconductor substrate, a light receiving portion formed on the semiconductor substrate, an interlayer insulating film covering the light receiving portion, and a transparent conductive film formed on the interlayer insulating film so as to cover the light receiving portion. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating an example of an electronic device 100 equipped with an optical sensor 1 of the present disclosure. [Figure 2] 1 is a block diagram showing an example of the configuration of an optical sensor 1. FIG. [Figure 3] 1 is a cross-sectional view of an optical sensor 1 according to a first embodiment. [Figure 4] FIG. 10 is a cross-sectional view of an optical sensor of a comparative example. [Figure 5] FIG. 2 is a top view of the optical sensor chip according to the present embodiment. [Figure 6] 6 is a cross-sectional view taken along the line VI-VI in FIG. 5. [Figure 7] FIG. 2 is a first diagram showing a manufacturing process of the optical sensor chip according to the present embodiment. [Figure 8] FIG. 2 is a second diagram showing the manufacturing process of the optical sensor chip according to the present embodiment. [Figure 9] FIG. 10 is a third diagram showing the manufacturing process of the optical sensor chip according to the present embodiment. [Figure 10] FIG. 4 is a fourth diagram showing the manufacturing process of the optical sensor chip according to the present embodiment. [Figure 11] FIG. 5 is a fifth diagram showing the manufacturing process of the optical sensor chip according to the present embodiment. [Figure 12] FIG. 4 is a cross-sectional view of an optical sensor according to a modified example of the first embodiment. [Figure 13] FIG. 10 is a top view of the optical sensor chip according to the second embodiment. [Figure 14] FIG. 14 is a cross-sectional view taken along the line XIV-XIV in FIG. 13. [Figure 15] 10A and 10B are diagrams for explaining the possible light incidence angle of the optical sensor of the present embodiment. [Figure 16] FIG. 2 is a top view of a state in which the optical sensor chip is mounted on a glass substrate. [Figure 17] FIG. 17 is a cross-sectional view taken along the line XVII-XVII in FIG. 16.

[0009] [Detailed explanation] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0010] <First Embodiment> FIG. 1 is a diagram showing an example of an electronic device 100 equipped with an optical sensor 1 of the present disclosure. In the example of FIG. 1, the electronic device 100 is a smartphone. The electronic device 100 has a rectangular parallelepiped housing 151. Electronic components such as the optical sensor 1 are housed inside the housing 151. The housing 151 has a front surface and a back surface. The front surface and the back surface are rectangular. The front surface and the back surface are connected by four side surfaces. A touch panel 152 is formed on the front surface. The touch panel 152 provides an input interface to the user.

[0011] A microphone 153 is provided on one side of the housing 151. The microphone 153 functions as a sound collector for the telephone function of the electronic device 100. A speaker 154 is disposed near one of the pair of short sides of the housing 151 opposite the short side on which the microphone 153 is located. The speaker 154 functions as a sound output device for the telephone function. A diffuser 105 is disposed next to the speaker 154. The diffuser 105 diffuses incident light over a wide area and emits the light. An optical sensor 1 is housed in the housing 151 at a position opposite the diffuser 105. The diffuser 105 makes it difficult for the user to see the optical sensor 1, and as a result, the electronic device 100 can give the user an impression of simplicity.

[0012] The optical sensor 1 is used, for example, to calculate illuminance. Therefore, the illuminance according to the location where the electronic device 100 is located is calculated, and control according to the illuminance is performed. The control according to the illuminance includes, for example, control to adjust the brightness of the touch panel 152 according to the illuminance.

[0013] The electronic device incorporating the optical sensor 1 may be other devices, such as mobile devices such as mobile phones, notebook PCs (Personal Computers), and tablets, car navigation devices, and digital cameras.

[0014] Fig. 2 is a block diagram showing an example configuration of the optical sensor 1. As shown in Fig. 2, the optical sensor 1 includes a photodiode 101, an amplifier unit 15, an ADC (analog-digital converter) 30, a calculation unit 40, an oscillator 61, and an external terminal 21. The optical sensor 1 is a semiconductor integrated circuit in which the photodiode 101, the amplifier unit 15, the ADC 30, and the calculation unit 40 are formed on a single semiconductor substrate.

[0015] When irradiated with light, the photodiode 101 generates a current or voltage according to the amount of light irradiated, and outputs an analog signal according to the current or voltage. The amplifier unit 15 receives the analog signal output from the photodiode 101.

[0016] The amplifier unit 15 amplifies the analog signal to generate an amplified signal. The amplifier unit 15 may be, for example, a programmable gain amplifier (PGA) capable of adjusting the gain as desired. The ADC 30 receives the amplified signal from the amplifier unit 15.

[0017] The ADC 30 is, for example, an integral analog-to-digital conversion circuit. The amplifier unit 15 is electrically connected to the ADC 30. The ADC 30 converts the analog signal (amplified signal) from the amplifier unit 15 into a digital signal.

[0018] The calculation unit 40 includes an integrated circuit such as an LSI (Large Scale Integration). This integrated circuit includes various circuit elements such as transistors, capacitors, and registers. The calculation unit 40 receives digital signals from the ADC 30. The calculation unit 40 calculates a predetermined optical parameter using a numerical value based on these digital signals. The predetermined optical parameter is, for example, any one of illuminance, light intensity, and light brightness. In this way, the optical sensor 1 calculates the optical parameter based on the signal from the photodiode 101.

[0019] The optical sensor 1 is connected to a power supply terminal (VCC) via an external terminal 21. The optical sensor 1 is also connected to ground (GND) via the external terminal 21. The optical sensor 1 generates a predetermined voltage by stepping up or stepping down the voltage applied to the external terminal 21, and supplies the voltage to the amplifier unit 15, the ADC 30, the calculation unit 40, and the like.

[0020] The calculation unit 40 is connected to the control circuit 170 by a communication line via the external terminal 21. In the example of FIG. 1, the communication line is composed of a serial data bus (SDA: Serial Data Access) and a serial clock (SCL: Serial CLock). The calculation unit 40 outputs a signal indicating the calculated illuminance to the control circuit 170 via the communication line. The control circuit 170 receives the optical parameters and performs control according to the received optical parameters. The oscillator 61 generates a clock signal that is pulse-driven at a predetermined frequency and outputs the clock signal to the calculation unit 40.

[0021] 3 is a cross-sectional view of the optical sensor 1 according to the embodiment 1. The optical sensor 1 has a light receiving section 150. The optical sensor 1 detects light incident on the light receiving section 150 and calculates the above-mentioned optical parameters.

[0022] In this embodiment, the light receiving section 150 is defined as an XY plane. The thickness direction of the optical sensor 1 (the normal direction to the light receiving surface of the light receiving section 150) is defined as the Z axis direction. The X axis direction, Y axis direction, and Z axis direction are perpendicular to each other.

[0023] The optical sensor 1 has a P-type semiconductor substrate 201. The P-type corresponds to an example of the "first conductivity type" in the present disclosure. The semiconductor substrate 201 is, for example, a substrate in which silicon is doped with P-type impurities.

[0024] In a plan view from the normal direction (Z-axis direction) of the light receiving unit 150, an N-type impurity region 202 is formed in a surface layer portion of the semiconductor substrate 201 by doping an N-type impurity from the surface of the P-type substrate in an inner region separated by a predetermined width from the periphery of the P-type substrate. In this manner, the N-type impurity region 202 is disposed on the semiconductor substrate 201. The N-type corresponds to an example of a "second conductivity type" in the present disclosure. The second conductivity type is different from the first conductivity type.

[0025] The photodiode 101 is formed by a PN junction between the P-type semiconductor substrate 201 and the N-type impurity region 202 .

[0026] After the photodiode 101 is formed, a first wiring layer 203, an interlayer insulating film 204, and a second wiring layer 206 are arranged on the semiconductor substrate 201 and the N-type impurity region 202, and the first wiring layer 203 and the second wiring layer 206 are electrically connected by a contact hole 205.

[0027] A pad PAD2 for wire bonding and a pad PAD1 for connection to the transparent conductive film are formed on the second wiring layer 206. Furthermore, a protective insulating film 207 is formed so as to cover the second wiring layer 206 and the interlayer insulating film 204, and a window W2 for wire bonding and a window W1 for connection to the transparent conductive film are opened in the protective insulating film 207. A transparent conductive film 208 is formed on the protective insulating film 207.

[0028] The pads PAD1 and PAD2 are electrically connected to the ground potential (GND) by the first wiring layer 203 or the second wiring layer 206.

[0029] The optical sensor chip 200 as described above is mounted on a package substrate 209 on which pads 210 are formed, and is wire-bonded with metal wires 211, and then sealed in a transparent package 212 for use as the optical sensor 1.

[0030] Here, the photosensor chip 200 of this embodiment has improved noise resistance by forming a transparent conductive film 208 on the surface. The transparent conductive film will be described below with reference to a comparative example.

[0031] Fig. 4 is a cross-sectional view of a photosensor of a comparative example. In the example shown in Fig. 4, an N-type impurity region 202A is formed in a semiconductor substrate 201, and a P-type impurity region 202B is formed inside the N-type impurity region 202A. The P-type impurity region 202B is connected to the ground potential by a first wiring layer 203. In the comparative example, the sheet resistance of the P-type impurity region 202B is reduced, thereby electrically shielding the photodiode and increasing resistance to external electrical noise.

[0032] That is, in the optical sensor of the examined example, a P-type impurity region 202B is provided in an N-type impurity region 202A formed in a semiconductor substrate 201. In this optical sensor, the P-type impurity region 202B is fixed to the ground potential by the first wiring layer 203, and serves as an electromagnetic shield that reduces electrical noise.

[0033] However, this method determines the spectral characteristics of the photodiode, limiting its optical characteristics. For example, if the P-type impurity region 202B is not connected to the ground potential, the PN junction formed by the P-type impurity region 202B and the N-type impurity region 202A can be used as another photodiode with high sensitivity to short wavelengths.

[0034] It would therefore be desirable to be able to create an electromagnetic shield that reduces electrical noise in other ways.

[0035] Therefore, in this embodiment, instead of the P-type impurity region 202B in the study example, a transparent conductive film 208 is disposed on the surface of the photodiode formation region as shown in FIG.

[0036] Fig. 5 is a top view of the photosensor chip of this embodiment, and Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5.

[0037] The photosensor chip 200 has an N-type impurity region 202 in the center where a photodiode is formed, and pads 206 (GND), 206 (VCC), 206 (SDA), and 206 (SCL) formed of a second wiring layer 206 are arranged on the right side of the N-type impurity region 202. On the left side of the N-type impurity region 202, a pad 206 (GND) formed of the second wiring layer 206 and connected to a transparent conductive film 208 is arranged. Although not shown in detail, circuits such as the amplifier unit 15, ADC 30, and calculation unit 40 in FIG. 2 are arranged in the area surrounding the N-type impurity region 202, and the transparent conductive film 208 also functions as a shield for these circuits.

[0038] The transparent conductive film 208 is disposed so as to cover the N-type impurity region 202 and the pad 206 (GND) on the left side. For wire bonding, the transparent conductive film 208 has rectangular holes cut out so that the four pads 206 (GND), 206 (VCC), 206 (SDA), and 206 (SCL) on the right side are not covered by the transparent conductive film 208.

[0039] 7 is a first diagram showing the manufacturing process of the photosensor chip of this embodiment. An N-type impurity region 202 is formed in a semiconductor substrate 201, a first wiring layer 203 and an interlayer insulating film 204 are formed, and then contact holes 205 and a second wiring layer 206 are formed, followed by a protective insulating film 207, and then a pad opening 220 is provided. That is, FIG. 7 shows the state in which the semiconductor process up to the pad opening of a normal photosensor chip on which no transparent conductive film is formed has been completed.

[0040] 8 is a second diagram showing the manufacturing process of the photosensor chip of this embodiment. As shown in Fig. 8, a transparent conductive film 208 is formed on the entire surface of the photosensor chip by sputtering. The film formation temperature is, for example, 300°C.

[0041] 9 is a third diagram showing the manufacturing process of the photosensor chip of this embodiment, which shows a state in which photoresist 221 has been formed in the portion where the ITO is to remain.

[0042] Fig. 10 is a fourth diagram showing the manufacturing process of the photosensor chip of this embodiment, which shows a state in which the transparent conductive film 208 in the opening of the photoresist 221 has been removed by etching, and the transparent conductive film 208 on the top of the PAD 206 for wire bonding has been removed.

[0043] Fig. 11 is a fifth diagram showing the manufacturing process of the photosensor chip of this embodiment. Fig. 11 shows the state after the photoresist formed in the portion where the ITO is to remain has been removed. In this way, the photosensor chip shown in Fig. 6 is completed.

[0044] <Modification of the First Embodiment> Fig. 12 is a cross-sectional view of an optical sensor according to a modification of embodiment 1. The optical sensor shown in Fig. 12 has the same configuration as the optical sensor shown in Fig. 3, except that N-type impurity region 202A is formed in semiconductor substrate 201, and P-type impurity region 202B is formed inside N-type impurity region 202A. As the other configuration is the same as that shown in Fig. 3, description thereof will not be repeated.

[0045] In such a configuration, a first diode D1 is formed at a PN junction between the semiconductor substrate 201 and the N-type impurity region 202A, and a second diode D2 is formed at a PN junction between the N-type impurity region 202A and the P-type impurity region 202B.

[0046] The shallower the photodiode is formed from the main surface of the semiconductor substrate 201, the more efficiently the photodiode absorbs light with a shorter wavelength.

[0047] By connecting wiring layers 203 and 206 (not shown), the first diode D1 can be used as the photodiode 101, and the second diode D2 can be used as the photodiode 101. For example, the second diode D2 can be configured to detect light having a shorter wavelength than the first diode D1.

[0048] Therefore, in the modification of the first embodiment, by forming a transparent conductive film on the surface, it is possible to reduce electrical noise and provide a wider range of options for optical properties.

[0049] <Embodiment 2> In the first embodiment, an example in which the optical sensor chip is sealed in a transparent package has been described. In the second embodiment, an example in which the optical sensor chip can be mounted as a CSP (Chip Size Package) will be described.

[0050] Fig. 13 is a top view of the photosensor chip according to the second embodiment, and Fig. 14 is a cross-sectional view taken along line XIV-XIV in Fig. 13.

[0051] 13 and 14, an N-type impurity region 202 is formed in a surface layer portion of a semiconductor substrate 201, and a photodiode 101 is formed by a PN junction between the semiconductor substrate 201 and the N-type impurity region 202. A first wiring layer 203, an interlayer insulating film 204, and a second wiring layer 206 are arranged, and the first wiring layer 203 and the second wiring layer 206 are electrically connected by a contact hole 205.

[0052] Furthermore, a protective insulating film 207 is formed so as to cover the second wiring layer 206 and the interlayer insulating film 204, and a window W2 for connection to the transparent conductive film and a window W1 for connection to the transparent conductive film are opened in the protective insulating film 207. A transparent conductive film 208 is formed on the protective insulating film 207.

[0053] The above is basically the same as the configuration shown in Figures 5 and 6. However, optical sensor 250 of embodiment 2 differs from the configuration shown in Figures 5 and 6 in that transparent conductive film 208 is formed not only on the shield portion that covers the photodiode but also on the terminal portion for mounting on a glass substrate or the like.

[0054] That is, the optical sensor 250 includes a transparent conductive film 208 A, a transparent conductive film 208 B, a transparent conductive film 208 C, and a transparent conductive film 208 D. The transparent conductive films 208 B, 208 C, and 208 D are transparent electrodes connected to pads.

[0055] The transparent conductive film 208A is electrically connected to the ground pad 206 (GND) and is formed to cover the ground pad 206 (GND) and the N-type impurity region 202. The transparent conductive film 208B is electrically connected to the power supply pad 206 (VCC) and is formed to cover the power supply pad 206 (VCC). The transparent conductive film 208C is electrically connected to the signal input / output pad 206 (SDA) and is formed to cover the signal input / output pad 206 (SDA). The transparent conductive film 208D is electrically connected to the signal input pad 206 (SCL) and is formed to cover the signal input pad 206 (SCL).

[0056] Fig. 15 is a diagram for explaining the possible light incidence angle of the photosensor of this embodiment. In Fig. 15, since transparent conductive films 208A and 208C, interlayer insulating film 204, and protective insulating film 207 are transparent, the range of light that can be incident on N-type impurity region 202 that forms the photodiode is indicated by the dashed arrow.

[0057] Compared to conventional CSPs that form solder balls on pads, the height of the terminals that block light can be kept lower, so the optical sensor 250 can have a wider beam angle. This is advantageous when directly mounting the optical sensor on a glass substrate, for example.

[0058] Fig. 16 is a top view of the optical sensor chip mounted on a glass substrate, and Fig. 17 is a cross-sectional view taken along line XVII-XVII in Fig. 16.

[0059] Wiring patterns 302A, 302B, 302C, and 302D formed of a transparent conductive film are formed on the glass substrate 301. Bonding materials 303A and 303B formed of anisotropic conductive films (ACFs) are disposed between the optical sensor 250 and the glass substrate 301.

[0060] ACF is a film made by dispersing conductive particles in a resin such as a thermosetting epoxy resin, and when the film is thermocompressed, it exhibits "electrical anisotropy" in that it is conductive in the compression direction (i.e., the vertical direction) at the compression joint, but insulating in the direction perpendicular to the compression direction. ACF is used in smartphones and other devices to electrically connect and physically fix electrodes on glass substrates to electrodes on semiconductor chips or electrodes on flexible printed circuit boards.

[0061] In one example, the thickness of the wiring patterns 302A-302D is 150 nm, the thickness of the ACF is 10 μm, the thickness of the transparent conductive films 208A-208D is 5 μm, and the thickness of the protective insulating film 207 is 2 μm.

[0062] When connecting using ACF, connections can be made in smaller sizes, thinner thicknesses, and at narrower pitches than with soldering or connector connections.

[0063] If a transparent ACF is used, the ACF may be disposed over the entire surface of the chip.

[0064] [Note] The present embodiment will be summarized below with reference to the drawings again.

[0065] (Item 1) The present disclosure relates to an optical sensor 1. As shown in Fig. 3, the optical sensor 1 includes a semiconductor substrate 201, a light receiving section 150 formed on the semiconductor substrate 201, an interlayer insulating film 204 covering the light receiving section 150, and a transparent conductive film 208 formed on the interlayer insulating film 204 so as to cover the light receiving section 150.

[0066] By adopting such a configuration, the resistance of the light receiving section 150 to electromagnetic noise can be improved.

[0067] (Item 2) In the optical sensor 1 described in item 1, as shown in Fig. 3, the semiconductor substrate 201 is of a first conductivity type (P type), and the light receiving section 150 includes an impurity region 202 of a second conductivity type (N type). The semiconductor substrate 201 and the impurity region 202 of the second conductivity type form a photodiode 101. A portion of the transparent conductive film 208 that covers the light receiving section 150 is connected to a conductive layer (wiring layer 206) to which a fixed potential (GND) is applied.

[0068] By adopting such a configuration, the resistance of the light receiving section 150 to electromagnetic noise can be improved.

[0069] (Item 3) In the photosensor described in item 1, as shown in FIG. 12, the semiconductor substrate 201 is of a first conductivity type (P type). The light receiving section 150 includes a first impurity region 202A of a second conductivity type (N type) and a second impurity region 202B of the first conductivity type (P type) formed inside the first impurity region 202A and shallower than the first impurity region 202A. The semiconductor substrate 201 and the first impurity region 202A form a first diode D1, and the first impurity region 202A and the second impurity region 202B form a second diode D2. One of the first diode D1 and the second diode D2 is a photodiode 101. A portion of the transparent conductive film 208 covering the light receiving section 150 is connected to a conductive layer (wiring layer 206) to which a fixed potential (GND) is applied.

[0070] Such a configuration widens the range of options for the spectral characteristics of the photodiode.

[0071] (Item 4) In the optical sensor described in any one of items 1 to 3, the transparent conductive film 208 includes a shield portion 208A1 formed to cover the light receiving portion, a power supply pad 208B to which a power supply potential is supplied, and a ground pad 208A2 to which a ground potential is supplied.

[0072] This configuration further improves the electromagnetic noise resistance of the light receiving section, and also makes it easier to mount the optical sensor on a substrate in the form of a CSP.

[0073] (Item 5) In the optical sensor described in item 4, the shield portion 208A1 is connected to either the power supply pad 208B or the ground pad 208A2. For example, in Fig. 13, the ground pad 206 (GND) is connected to the shield portion 208A1, but the positions of the ground pad 206 (GND) and the power supply pad 206 (VCC) may be interchanged so that the power supply pad 206 (VCC) is connected to the shield portion 208A1.

[0074] By adopting such a configuration, the resistance of the light receiving section to electromagnetic noise can be further improved.

[0075] (Item 6) In the photosensor according to item 4, the transparent conductive film 208 further includes a signal output pad 208C for outputting a signal SDA to the outside of the photosensor.

[0076] With this configuration, it becomes easy to mount an optical sensor having a signal output terminal on a substrate in the form of a CSP.

[0077] (Item 7) In the photosensor according to item 6, the transparent conductive film 208 further includes a signal input pad 208D for inputting a signal SCL from outside the photosensor.

[0078] With this configuration, it becomes easy to mount an optical sensor having a signal input terminal on a substrate in the form of a CSP.

[0079] (Item 8) In the optical sensor according to item 1, the transparent conductive film 208 contains indium tin oxide (ITO).

[0080] With this configuration, an optical sensor with a light receiving section that is more resistant to electromagnetic noise can be realized.

[0081] (Item 9) As shown in Figures 16 and 17, the optical sensor described in item 1 further includes a glass substrate 301, wiring patterns 302A, 302B, 302C, and 302D formed on the glass substrate 301, and bonding materials 303A and 303B that connect the wiring patterns 302A, 302B, 302C, and 302D to the transparent conductive film 208.

[0082] By adopting such a configuration, it is possible to realize an optical sensor with a wide beam angle as shown in FIG. 15 when it is mounted on a glass substrate.

[0083] (10) In the optical sensor according to the 9th aspect, the bonding materials 303A and 303B include anisotropic conductive films (ACFs).

[0084] By adopting such a configuration, it is possible to realize an optical sensor with a wide beam angle as shown in FIG. 15 when it is mounted on a glass substrate.

[0085] (Item 11) In another aspect, the present disclosure relates to an electronic device equipped with the optical sensor according to item 1.

[0086] By adopting such a configuration, it is possible to improve the electromagnetic noise resistance of the electronic device. The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0087] 1,250 optical sensor, 15 amplifier section, 21 external terminal, 30 A / D converter, 40 calculation section, 61 oscillator, 100 electronic device, 101 photodiode, 105 diffusion plate, 150 light receiving section, 151 housing, 152 touch panel, 153 microphone, 154 speaker, 170 control circuit, 200 optical sensor chip, 201 semiconductor substrate, 208A1 shield section, 202, 202A, 202B impurity region, 203, 206 wiring layer, 204 interlayer insulating film, 205 contact hole, PAD1, PAD2 pad, 207 protective insulating film, 208, 208A, 208B, 208C, 208D transparent conductive film, 209 package substrate, 211 metal wire, 212 transparent package, 220 pad opening, 221 Photoresist, 301 glass substrate, 302A, 302B, 302C, 302D wiring pattern, 303A, 303B bonding material, D1, D2 diode.

Claims

1. a semiconductor substrate; a light receiving portion formed on the semiconductor substrate; an interlayer insulating film covering the light receiving portion; a transparent conductive film formed on the interlayer insulating film so as to cover the light receiving portion.

2. the semiconductor substrate is of a first conductivity type; the light receiving portion includes a second conductivity type impurity region, a photodiode is formed by the semiconductor substrate and the second conductivity type impurity region; The optical sensor according to claim 1 , wherein a portion of said transparent conductive film covering said light receiving portion is connected to a conductive layer to which a fixed potential is applied.

3. the semiconductor substrate is of a first conductivity type; The light receiving unit a first impurity region of a second conductivity type; a second impurity region of the first conductivity type formed inside the first impurity region and shallower in depth than the first impurity region, a first diode is formed by the semiconductor substrate and the first impurity region; a second diode is formed by the first impurity region and the second impurity region; one of the first diode and the second diode is a photodiode; The optical sensor according to claim 1 , wherein a portion of said transparent conductive film covering said light receiving portion is connected to a conductive layer to which a fixed potential is applied.

4. The transparent conductive film is a shield portion formed to cover the light receiving portion; a power supply pad to which a power supply potential is supplied; 4. The optical sensor according to claim 1, further comprising a ground pad to which a ground potential is supplied.

5. The optical sensor according to claim 4 , wherein the shield portion is connected to one of the power supply pad and the ground pad.

6. The optical sensor according to claim 4 , wherein the transparent conductive film further includes a signal output pad for outputting a signal to an outside of the optical sensor.

7. The optical sensor according to claim 6 , wherein the transparent conductive film further includes a signal input pad for inputting a signal from outside the optical sensor.

8. The optical sensor of claim 1 , wherein the transparent conductive film comprises indium tin oxide (ITO).

9. A glass substrate; a wiring pattern formed on the glass substrate; The optical sensor according to claim 1 , further comprising a bonding material that connects the wiring pattern and the transparent conductive film.

10. The optical sensor according to claim 9 , wherein the bonding material includes an anisotropic conducting film (ACF).

11. An electronic device equipped with the optical sensor according to claim 1.

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