JP3366226B2 - Divided photodiode and light receiving element with built-in circuit - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a divided photodiode in which a light receiving region is divided into a plurality of light detecting portions, and a light receiving element with a built-in circuit in which the divided photodiode and a signal processing circuit are formed on the same substrate. More specifically, the present invention relates to a split photodiode in which the surface structure of a light-shielding film or an insulating cover film is improved, and electrostatic resistance characteristics are improved, and a light receiving element with a built-in circuit including the split photodiode.

[0002]

2. Description of the Related Art A split photodiode of this type has been conventionally used as a signal detecting element for an optical pickup, for example. More specifically, it is used to obtain a focus error signal for adjusting the focus position of the semiconductor laser on the disc and a radial error signal for adjusting (tracking) the focus position of the semiconductor laser to a pit on the disc. . In recent years, the speed of optical pickups used in CD-ROM drives and the like has been increasing, and development of high-speed, high-performance split photodiodes and photodetectors with a built-in circuit has been advanced.

Here, in recent photodiodes, in addition to a high response speed, a high photosensitivity and a reduction in high frequency noise are required. Of these, the optical sensitivity is the electrical signal (current) with respect to the power of the incident light.
It is a standard to show whether or not it can be converted into, and the higher the sensitivity, the higher the performance.

This requirement is usually achieved by forming an antireflection film on the surface of the photodiode to prevent light incident on the surface of the photodiode from being reflected.

On the other hand, in order to speed up the response speed and reduce high frequency noise, it is necessary to reduce the capacitance of the photodiode. As an example of the prior art taking such a technique, there is a photodetector with a built-in circuit, which the applicant of the present application has previously proposed in Japanese Patent Application No. 8-260043. FIG. 5 shows this light receiving element with a built-in circuit.

In this light receiving element with a built-in circuit, the p ⁺ type buried diffusion layer 22 and the p ⁺ type diffusion layer 26, which are formed in order to increase the response speed, are formed only in the minimum necessary portion. The junction capacitance of the split photodiode is reduced without lowering the responsiveness. More specifically, as shown in FIG. 5, the p ⁺ -type buried diffusion layer 22 and the p ⁺ -type diffusion layer 26 are formed only in the vicinity of the divided portion of the divided photodiode corresponding to the central portion of the light receiving region. There is.

In FIG. 5, reference numeral 21 is a p-type silicon substrate, 23 is an n ⁺ -type buried diffusion layer, and 24 is an n-type epitaxial layer.

However, according to the above structure, since a pn junction can be formed on the silicon surface of the light receiving region, there is a problem that the junction leak current increases. To prevent this, a silicon oxide film is required on the surface. Become.

The photosensitivity varies depending on the wavelength of incident light and the antireflection film structure. In the case of an antireflection film consisting of only a silicon oxide film, at a wavelength of semiconductor laser light used in DVDs and CD-ROMs (for example, 780 nm), the reflectance is about 15% even if the film thickness of the silicon oxide film is optimized. It can only be done and the light sensitivity is poor.

Therefore, the applicant of the present application previously proposed in Japanese Patent Application No. 8-235670 as an antireflection film capable of reducing the junction capacitance of the split photodiode without lowering the response speed and further reducing the reflectance as much as possible. There are split photodiodes and photodetectors with built-in circuits. 6 and 7 show the structure.

As shown in FIGS. 6 and 7, the antireflection films 25 and 35 are both thin (about 10 nm) silicon oxide films 25a and 35a, and a silicon nitride film (about 50 n) is formed on them.
m) It has a two-layer structure in which 25b and 35b are laminated.

FIG. 6 shows a divided photodiode using a p-type silicon substrate 21, and FIG. 7 shows a divided photodiode using an n-type silicon substrate 31. 6, parts corresponding to those in FIG. 5 are designated by the same reference numerals. Further, in FIG. 7, reference numeral 32 indicates a p-type diffusion layer.

In addition, in each of the split photodiodes shown in FIGS. 6 and 7, the light shielding metal 27, 37 made of a light shielding material such as AlSi is provided in the antireflection film so that light does not enter into a region other than a predetermined light receiving region. 25 and 35 are stacked on top of each other to block light.

An insulating cover (for example, PSG) made of an insulating material is provided on the light shielding metals 27 and 37 so as to cover portions other than the light receiving portion and the pad portion of the divided photodiode.
The films 28 and 38 are laminated.

In the structures shown in FIGS. 6 and 7, the light-receiving regions of the divided photodiodes are determined by the light-shielding metals 27 and 37, and the portions covered with the light-shielding metals 27 and 37 are completely shielded from light. The photosensitivity ratio between the region and the light-shielded region can be increased. Further, since the light shielding metals 27 and 37 are covered with the PSG films 28 and 38, respectively, there is no possibility that the light shielding metals 27 and 37 will corrode.

[0016]

By the way, a semiconductor IC
In the manufacturing process, the above divided photodiodes are manufactured in a wafer state, and finally cut into individual chips in a dicing process. Here, the dicing process includes a process of attaching the wafer to a dicing sheet, a process of cutting, a process of cleaning and drying.

Of these steps, a large amount of static electricity may be generated on the wafer during the step of attaching the wafer to the dicing sheet or the step of cutting, and the divided photodiodes may be electrostatically destroyed. This is because a large amount of static electricity is generated due to friction with pure water sprayed in these steps and friction between the wafer and a blade for cutting the wafer.

Therefore, it is usually devised to prevent static electricity from accumulating, for example, by working on an electrostatic mat or by mixing carbon dioxide in pure water sprayed in a cutting process to increase the conductivity.

However, it is impossible to completely suppress static electricity, and a thin (about 10 nm) silicon oxide film 25a,
Silicon nitride film (about 50 nm) 25b, 3 on 35a
The structure of the antireflection films 25 and 35 in which 5b is laminated is
Since the structure is weak against static electricity, the yield of normal divided photodiodes is low.

More specifically, taking the case of the silicon oxide film 25a and the silicon nitride film 25b as an example, negative charges are accumulated at the interface between the silicon oxide film 25a and the silicon nitride film 25b due to static electricity, and the silicon surface The n-type semiconductor is inverted to a p-type semiconductor (hereinafter, this phenomenon is referred to as p-type inversion).

At this time, in the case of the structure shown in FIG. 6, since the n-type semiconductor portion of the divided region of the divided photodiode becomes p-type, it is connected to the adjacent divided photodiode region, and the adjacent photodiodes of the divided photodiode are connected. The junction capacitance of the photodiode increases due to the short circuit.

Further, in the case of the structure shown in FIG. 7, the surface of the n-type epitaxial layer is inverted to p-type, and a new pn junction is formed between the n-type epitaxial layer and the inverted p-type layer. , The junction capacitance of the photodiode increases.

As described above, when the junction capacitance increases, as shown in FIG.
As shown in, the response speed of the divided photodiode is reduced. In addition, high frequency noise increases, which is inconvenient. That is, there is a problem that the capacitance of the divided photodiode becomes abnormal due to static electricity in the dicing process.
For example, as shown in the example in FIG. 8, the junction capacitance C _PD in the normal state increases to 1.4 to 4.5 pF with respect to C Op = 0.7 OpF. Incidentally, C _PD = 3.8 in the case of abnormality 1 in FIG.
9pF, C _PD = 4.13pF in the case of error 2 is a C _PD = 4.27pF in the case of abnormal 3.

The present invention has been made in view of the above circumstances, and it is possible to reliably prevent the junction capacitance of the photodiode from becoming abnormal due to static electricity generated during the manufacturing process, and as a result, the response speed is improved. It is an object of the present invention to provide a segmented photodiode capable of improving the noise and reducing high frequency noise.

Another object of the present invention is to provide a circuit built-in light receiving element in which such a divided photodiode and a signal processing circuit are formed on the same substrate.

[0026]

In the split photodiode of the present invention, a semiconductor layer of the first conductivity type is formed on a semiconductor substrate of the second conductivity type, and the semiconductor layer of the first conductivity type is the second conductivity type. Photodetector with multiple light-receiving regions
As divided, is divided into a plurality, the semiconductor layer of the divided individual first conductivity type and the said semiconductor substrate, receiving
In split photodiode for detecting the signal light irradiated on the optical domain, consists of two or more layers of film, the antireflection film formed on the light receiving region, a conductive material, formed in a peripheral portion of the light receiving region And covers the peripheral portion of the antireflection film.
It consists of a light-shielding film grounded together with an insulating material,
The edge of the light-shielding film located on the center side of the light receiving region is exposed
The protective film formed on the light-shielding film is provided so that the above-mentioned object can be achieved.

The split photodiode of the present invention is
A plurality of second-conductivity-type semiconductor layers are formed on the first-conductivity-type semiconductor substrate, and the light-receiving region is divided into a plurality of photodetection sections by the plurality of semiconductor layers and the semiconductor substrate.
In split photodiode for detecting the signal light irradiated on the optical domain, consists of two or more layers of film, the antireflection film formed on the light receiving region, a conductive material, formed in a peripheral portion of the light receiving region And covers the peripheral portion of the antireflection film.
It consists of a light-shielding film grounded together with an insulating material,
The edge of the light-shielding film located on the center side of the light receiving region is exposed
The protective film formed on the light-shielding film is provided so that the above-mentioned object can be achieved.

Preferably, the thickness of the portion of the antireflection film located in the peripheral portion of the light receiving region is thicker than that of the central portion and other portions, and the light shielding film is thicker than the antireflection film. Only the surrounding area is covered.

The circuit-embedded light receiving element of the present invention comprises the divided photodiode according to any one of claims 1 to 3 and a signal processing circuit for processing an electric signal photoelectrically converted by the divided photodiode. It is formed on the same substrate, and thereby the above-mentioned object is achieved.

The operation of the present invention will be described below.

As described above, according to the structure in which the central end of the light-receiving region of the protective film is located on the peripheral side of the central end of the light-shielding film, the central end of the light-shielding film is It is not covered by a protective film and is exposed. Therefore, as shown in FIG. 2, which will be described later, the generated static electricity escapes to a position away from the antireflection film 5 through the exposed conductive light shielding metal 7 (light shielding film). As a result, the silicon oxide film 5a and the silicon nitride film 5 which constitute the antireflection film are formed.
Negative charges do not accumulate at the interface of b.

Therefore, since the junction capacitance of the divided photodiode does not increase abnormally, the responsiveness of the divided photodiode does not deteriorate. Also, high frequency noise does not increase.

Further, according to the structure in which the light shielding film covers only the peripheral portion where the thickness of the antireflection film is increased, the parasitic per unit area is larger than that in the case where the light shielding film is superposed on the thin antireflection film. The MOS capacity can be reduced to, for example, about 1/10.

Here, it is important to reduce the capacitance of the divided photodiode as much as possible in order to obtain a more desirable effect in terms of increasing the response speed and reducing high frequency noise, and there is no parasitic MOS capacitance. Is preferable.

Therefore, according to this structure, it is possible to more effectively achieve a higher response speed and a reduction in high frequency noise.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings.

(First Embodiment) FIGS. 1 and 2 show a first embodiment of a split photodiode according to the present invention. First, the schematic structure will be described with reference to FIG. An n-type epitaxial layer 4 is formed on the p-type silicon substrate 1. At the boundary portion between the p-type silicon substrate 1 and the n-type epitaxial layer 4, the p ⁺ -type buried diffusion layer 2 is selectively formed.
On the surface portion of the type epitaxial layer 4, a p ⁺ type isolation diffusion layer 2 ′ is formed so as to reach the p ⁺ type embedded diffusion layer 2.

The n ⁺ type epitaxial layer 4 is divided into a plurality of n type epitaxial regions by the p ⁺ type buried diffusion layer 2 and the p ⁺ type isolation diffusion layer 2'which is connected thereto. Then, the divided individual n-type epitaxial regions and the corresponding portions of the p-type silicon substrate 1 below the divided n-type epitaxial regions form photodiodes for detecting signal light, and the divided photodiodes are formed as a whole.

Then, in this divided photodiode,
The n ⁺ -type buried diffusion layer 3 is formed only in the vicinity of the divided portion of the p-type silicon substrate 1 that constitutes each photodetection portion. In addition, the p ⁺ -type diffusion layer 6 is formed on the surface of the n-type epitaxial region including the p ⁺ -type isolation diffusion layer 2 ′ serving as the division so as to cover the n ⁺ -type buried diffusion layer 3 near the division. Has been formed.

Next, the manufacturing process will be described.

First, the p ⁺ -type buried diffusion layer 2 is formed on the surface of the p-type silicon substrate 1 in the part where the divided photodiode is separated from other elements and in the region of the divided photodiode which is to be the divided photodiode. Further, the n ⁺ -type buried diffusion layer 3 is formed only in the vicinity of the divided portion in the region where the photodetection portion is to be formed on the p-type silicon substrate 1.

Next, after the n-type epitaxial layer 4 is grown on the entire surface of the p-type silicon substrate 1, impurities are diffused from the surface of the n-type epitaxial layer 4 so that the surface of the n-type epitaxial layer 4 is p ⁺ -type buried. In the region corresponding to the embedded diffusion layer 2, p ⁺
A mold separation diffusion layer 2'is formed. As a result, the divided portion of the divided photodiode is formed.

Subsequently, n is formed only in the divided region of the surface of the n-type epitaxial layer 4 and in the vicinity of both sides thereof.
^The p ⁺ type diffusion layer 6 is formed so as to cover the upper portion of the ⁺ type embedded diffusion layer 3.
To form.

By the heat treatment at that time, a silicon oxide film is simultaneously formed on the surfaces of the n-type epitaxial layer 4, the p ⁺ -type isolation diffusion layer 2 ′ and the p ⁺ -type diffusion layer 6.

Then, in order to form the film thickness of the silicon oxide film used as the antireflection film in the divided photodiode with good control, the photolithography technique and the oxide film etching technique are used to form the antireflection film in the region where the antireflection film is to be formed. The silicon oxide film is removed once.

Then, heat treatment is performed again in an oxidizing atmosphere, and the silicon oxide film 5a is formed again in this region.
Then, a silicon nitride film 5b is formed on the silicon oxide film 5a by a method such as a CVD method. This makes 2
The antireflection film 5 having a layered structure is formed. The thicknesses of the silicon oxide film 5a and the silicon nitride film 5b at this time are set so that the reflectance is low with respect to the wavelength of the light used in the optical pickup.

Next, a conductive light-shielding material such as AlSi is laminated on the entire surface, and subsequently, only the light receiving region of the divided photodiode is opened by the photolithography technique and the metal etching technique. As a result, the light shielding metal 7 is formed only in the peripheral portion of the light receiving region.

Next, a PSG cover film (insulating cover film) 8 is formed on the entire surface so as to cover the light shielding metal 7, and subsequently,
A photolithography technique and an oxide film etching technique are used to open the pad portion and the light shielding metal 7 in the light receiving region of the divided photodiode so as not to cover the pad portion, thereby forming the PSG cover film 8 having the illustrated shape.

Now, the shapes of the antireflection film 5, the light shielding metal 7 and the PSG cover film 8 will be described in more detail. The antireflection film 5 has a two-layer structure of a silicon oxide film 5a and a silicon nitride film 5b. ing. Further, the end portion of the light-shielding metal 7 on the center side of the light receiving region projects further toward the center side than the two-layer structure portion of the antireflection film 5, and the lower end surface of the projecting portion overlaps the silicon nitride film 5b. In addition, the PSG cover film 8
The end of the light-receiving region on the center side is located closer to the base end than the end of the light-shielding metal 7 on the center side, and has a shape that does not cover the tip of the light-shielding metal 7.

Next, the effect of such a structure will be described with reference to FIG. As described above, a large amount of static electricity is generated on the antireflection film 5 in the dicing process as shown in FIG.

However, in the split photodiode of the first embodiment, unlike the conventional structure shown in FIGS. 6 and 7,
The end of the light-shielding metal 7 on the center side is not covered with the PSG cover film 8 and is exposed. Therefore, the generated static electricity escapes to a position away from the antireflection film 5 through the exposed conductive light shielding metal 7.
As a result, according to the structure of the first embodiment, negative charges do not accumulate at the interface between the silicon oxide film 5a and the silicon nitride film 5b.

Therefore, according to the structure of the first embodiment, the junction capacitance of the divided photodiode does not increase abnormally, and the responsiveness of the divided photodiode does not deteriorate. Also, high frequency noise does not increase.

The inventors of the present invention have described the split photodiode of the conventional structure and the split photodiode of the first embodiment as follows.
An experiment was conducted on the occurrence rate of the capacity abnormality (the number of defects / the number of measurements). The conventional structure had a probability of 25% or more, whereas the structure of the first embodiment showed no abnormality. It was

(Embodiment 2) FIG. 3 shows Embodiment 2 of the split photodiode of the present invention. Unlike the split photodiode of the first embodiment, the split photodiode of the second embodiment uses an n-type silicon substrate. The structure will be described below together with the manufacturing process.

First, the p-type diffusion layer 12 is formed from the surface of the n-type silicon substrate 11 in the region which will be the divided photodiode portion. By the heat treatment at this time, the n-type silicon substrate 1
A silicon oxide film is simultaneously formed on the surfaces of the 1 and p-type diffusion layers 12.

Next, in order to form the film thickness of the silicon oxide film 15a used as the antireflection film 15 in the divided photodiode with good control, the antireflection film 15 portion is formed by photolithography and oxide film etching techniques. The silicon oxide film is removed once. Then, heat treatment is performed again in the oxidizing atmosphere to again form the silicon oxide film 15a in this region.

Then, a silicon nitride film 15b is formed on the silicon oxide film 15a by a method such as a CVD method. The film thicknesses of the silicon oxide film 15a and the silicon nitride film 15b at this time are set so that the reflectance is low with respect to the wavelength of the light used in the optical pickup.

Thereafter, through the same steps as those of the first embodiment, the light shielding metal 7 and the PSG cover film 8 having the same shape as that of the first embodiment are formed.
To form.

The split photodiode of the second embodiment is also
Similar to the first embodiment, since the PSG cover film 8 does not cover the light shielding metal 7 around the light receiving area of the divided photodiode, the static electricity generated in the dicing process or the like passes through the exposed light shielding metal 7. Escape to a place far away from the antireflection film 15, and remove the silicon oxide film 15
Negative charges do not accumulate at the interface between a and the silicon nitride film 15b.

In this case, since the adjacent photodiode portions of the divided photodiodes do not short-circuit, the junction capacitance does not increase abnormally. Therefore, according to the second embodiment, the responsiveness of the split photodiode does not decrease, and the high frequency noise does not increase.

(Embodiment 3) FIG. 4 shows Embodiment 3 of the split photodiode of the present invention. The divided photodiode of the third embodiment is characterized by the arrangement position of the light shielding metal 7. Specifically, in the third embodiment, the end of the light-shielding metal 7 on the center side of the light-receiving region is the silicon oxide film 5a.
The structure does not overlap the thin portion of the antireflection film 5 made of the silicon nitride film 5b and is different from the structure of the split photodiode of the first embodiment only in this point. The first embodiment
The same reference numerals are given to the portions corresponding to, and the specific description will be omitted.

The advantageous effects of the third embodiment, which are caused by the difference in structure, as compared with the first embodiment will be described below.

First, in the structure of the first embodiment, the end of the light-shielding metal 7 on the center side of the light-receiving region is overlapped on the thin antireflection film 5, so that the potentials of the light-shielding metal 7 and the n-type epitaxial layer 3 are equal to each other. Since they are different, it becomes a parasitic MOS capacitance. Since this anti-reflection film 5 is thin (about 70 nm in terms of silicon nitride film), this parasitic MOS capacitance has a large capacitance per unit area and cannot be ignored.

On the other hand, in the third embodiment, the thick silicon oxide film 5a around the light receiving region overlaps, but the light shielding metal 7 does not overlap the thin antireflection film 5. For this reason, the capacitance per unit area is about 1/10 of that in the case where it is superposed on the thin antireflection film 5. Therefore, the photodiode capacitance is negligible.

Here, it is important to reduce the capacitance of the divided photodiode as much as possible in order to obtain a more desirable effect in terms of increasing the response speed and reducing high frequency noise, and there is no parasitic MOS capacitance. Is preferable.

Therefore, according to the divided photodiode of the third embodiment, the response speed can be increased and the high frequency noise can be reduced more effectively than the divided photodiodes of the first and second embodiments. is there.

(Embodiment of Light-receiving Element with Built-in Circuit) The light-receiving element with built-in circuit of the present invention can be realized by forming the above-mentioned divided photodiode and its signal processing circuit on the same substrate. More specifically, a description will be given, for example, in a region of the above n-type epitaxial layer that is electrically isolated from a region in which the divided photodiode is formed.
This can be realized by forming a circuit element for a signal processing circuit, which includes an NPN transistor and a vertical PNP transistor.

[0068]

The divided photodiode of the present invention described above is
Since the edge of the protective film on the center side of the light receiving area is located on the peripheral side of the edge of the light shielding film on the center side, the edge of the light shielding film on the center side is not covered by the protective film. , Exposed. Therefore, the generated static electricity escapes to a position away from the antireflection film through the exposed conductive light-shielding film. As a result, negative charges do not accumulate at the interface between the silicon oxide film and the silicon nitride film forming the antireflection film.

Therefore, according to the present invention, since the junction capacitance of the divided photodiode does not increase abnormally, the responsiveness of the divided photodiode does not deteriorate. Also, high frequency noise does not increase.

Further, in particular, according to the divided photodiode of the third aspect, since the light shielding film covers only the peripheral portion where the thickness of the antireflection film is thick, the light shielding film is superposed on the thin antireflection film. The parasitic MOS capacitance per unit area can be reduced to, for example, about 1/10 of that in the case of the above.

Here, it is important to make the capacitance of the divided photodiode as small as possible in order to obtain a more desirable effect in terms of increasing the response speed and reducing high frequency noise, and there is no parasitic MOS capacitance. Is preferable.

Therefore, according to the present invention, it is possible to more effectively achieve a higher response speed and a reduction in high frequency noise.

In particular, according to the light receiving element with a built-in circuit described in claim 4, it is possible to realize a light receiving element with a built-in circuit in which the divided photodiodes exhibiting such effects are formed on the same substrate as the signal processing circuit. There is.

[Brief description of drawings]

FIG. 1 is a sectional view of a split photodiode showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of a split photodiode for explaining the effect of the split photodiode of FIG. 1 according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a split photodiode showing a second embodiment of the present invention.

FIG. 4 is a sectional view of a split photodiode showing a third embodiment of the present invention.

FIG. 5 is a sectional view showing a split photodiode previously proposed by the applicant of the present application.

FIG. 6 is a sectional view showing another split photodiode previously proposed by the applicant of the present application.

FIG. 7 is a sectional view showing another split photodiode proposed by the applicant of the present application.

FIG. 8 is a graph showing response waveforms when the photodiode capacitance is normal and when the photodiode capacitance is abnormal.

[Explanation of symbols]

1 p-type silicon substrate 2 p ⁺ -type buried diffusion layer 2'p ⁺ -type isolation diffusion layer 3 n ⁺ -type buried diffusion layer 4 n-type epitaxial layers 5, 15 antireflection films 5a, 15a silicon oxide films 5b, 15b silicon Nitride film 6 p ⁺ type diffusion layers 7 and 17 Light shielding metal 8 and 18 PSG cover film 11 n type silicon substrate 12 p type diffusion layer

Continuation of the front page (56) Reference JP-A 64-65867 (JP, A) JP-A 9-92871 (JP, A) JP-A 4-152674 (JP, A) JP-A 8-32100 (JP , A) JP-A-7-273082 (JP, A) JP-A-63-116458 (JP, A) JP-A-8-97463 (JP, A) JP-A-61-168956 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 27/14 H01L 27/146 H01L 27/148 H01L 31/10

Claims (4)

(57) [Claims] 1. A semiconductor layer of the first conductivity type is formed on the second conductive type semiconductor substrate, and a semiconductor layer of said one conductivity type semiconductor layer of the second conductivity type, the light receiving region of the plurality of light Inspection
So as to be divided into a plurality of divided portions , each of which is divided into a plurality of first conductive type semiconductor layers and the semiconductor substrate,
In split photodiode for detecting the signal light irradiated on the light receiving area, consists of two or more layers of film, the antireflection film formed on the light receiving region, a conductive material, the periphery of the light receiving region Formed,
A light-shielding film that covers the peripheral portion of the antireflection film and is grounded, and is made of an insulating material and is located on the central portion side of the light receiving region.
Formed on the light-shielding film so that the edges of the light-shielding film are exposed.
A divided photodiode having a protective film formed thereon . 2. A plurality of second-conductivity-type semiconductor layers are formed on a first-conductivity-type semiconductor substrate, and the plurality of semiconductor layers and the semiconductor substrate divide a light-receiving region into a plurality of photodetector portions.
Is the divided photodiode is, for detecting the signal light irradiated on the light receiving region, consists of two or more layers of film, the antireflection film formed on the light receiving region, a conductive material, the light receiving region Formed on the periphery of
A light-shielding film that covers the peripheral portion of the antireflection film and is grounded, and is made of an insulating material and is located on the central portion side of the light receiving region.
Formed on the light-shielding film so that the edges of the light-shielding film are exposed.
A divided photodiode having a protective film formed thereon . 3. A thickness of a portion of the antireflection film located in a peripheral portion of the light receiving region is thicker than a central portion and other portions, and the light shielding film is thicker than the antireflection film. The split photodiode according to claim 1 or 2, which covers only the peripheral portion. 4. A circuit built-in light receiving device, wherein the divided photodiode according to any one of claims 1 to 3 and a signal processing circuit for processing an electric signal photoelectrically converted by the divided photodiode are formed on the same substrate. element.