WO2020103395A1

WO2020103395A1 - Waveguide-type photodetector and manufacturing method therefor

Info

Publication number: WO2020103395A1
Application number: PCT/CN2019/083946
Authority: WO
Inventors: 汪巍; 方青; 余明斌
Original assignee: 上海新微技术研发中心有限公司
Priority date: 2018-11-19
Filing date: 2019-04-23
Publication date: 2020-05-28
Also published as: CN111211181A; CN111211181B

Abstract

A waveguide-type photodetector (1) and a manufacturing method therefor, the waveguide-type photodetector (1) comprising: a first insulating layer (12) located on a surface of a substrate (11); a lower contact layer (13) located on a surface of the first insulating layer (12); a photo-electric conversion layer (14) located on a surface of the lower contact layer (13), the material of the photo-electric conversion layer (14) comprising Ge; an upper contact layer (15) located on a surface of the photo-electric conversion layer (14); and a silicon nitride waveguide (16) formed above the first insulating layer (12), the silicon nitride waveguide (16) extending in the lateral direction parallel to the surface of the substrate (11), and one end part (161) of the silicon nitride waveguide (16) being connected in the lateral direction to the photo-electric conversion layer (14), wherein light transferred by the silicon nitride waveguide (16) enters the photo-electric conversion layer (14), and a photo-electric current is generated in the photo-electric conversion layer (14). SiN is used to form the waveguide (16), and therefore light transmission efficiency may be improved; moreover, the SiN waveguide (16) is coupled to an end surface of the photo-electric conversion layer (14), which may improve light detection efficiency.

Description

Waveguide photoelectric detector and manufacturing method thereof

This application requires the priority of the prior application for the patent application number 201811379149.X submitted to the State Intellectual Property Office of China on November 19, 2018, and the invention titled "a waveguide photodetector and its manufacturing method". The entire text of the prior application is incorporated into this application by reference.

Technical field

The present application relates to the field of semiconductor technology, in particular to a waveguide type photodetector and a manufacturing method thereof.

Background technique

Silicon (Si) -based photodetectors, especially silicon-based germanium photodetectors, are widely cited in the fields of optical communication, optical interconnection, and optical sensing because of their compatibility with CMOS processes and ease of integration. According to the direction of light entry, the detector can be divided into a vertical incidence detector and a waveguide detector. Compared with the vertical incidence detector, the waveguide detector can avoid the problem of mutual restriction between the speed and quantum efficiency of the photodetector, and can be integrated with the waveguide optical path, which is easier to achieve high speed and high responsiveness, which is to achieve high speed optical communication and optical interconnection One of the core devices of the chip.

Compared with traditional III-V and II-V infrared photodetectors, Group IV germanium (Ge) detectors are small in size, easy to integrate, low cost, because of their preparation process compatible with Si-based CMOS processes Potential advantages such as high performance are widely used in the fields of optical communication and optical sensing. However, when the wavelength of Ge material is greater than 1.55μm, the absorption coefficient drops sharply, which makes the Ge detector unable to meet the application of short-wave infrared and even mid-infrared. As a new type IV material, GeSn has a large absorption coefficient from short-wave infrared to mid-infrared because its energy band gap decreases with the increase of Sn composition. It is an ideal material for preparing infrared detectors. In recent years, GeSn infrared detectors have received extensive research.

It should be noted that the above introduction to the technical background is set forth only to facilitate a clear and complete description of the technical solutions of the present application and to facilitate understanding by those skilled in the art. It cannot be considered that the above technical solutions are known to those skilled in the art just because these solutions are described in the background part of the present application.

Summary of the invention

The inventor of the present application found that the current waveguide Ge detectors mostly use Si materials as optical waveguides, and then the light enters the Ge photoelectric conversion layer through the evanescent wave coupling mode, which is limited by the evanescent wave coupling efficiency. In order to achieve high responsivity, The length of the detector needs to be greater than 10 microns, which makes it difficult to further optimize the capacitance and dark current of the detector; in order to improve the light absorption efficiency, a waveguide detector based on the coupling of the Si waveguide and the end face of the Ge photoelectric conversion layer is proposed, however, through selective epitaxy It is extremely difficult to achieve a high-quality Si / Ge interface by the process; in addition, Si waveguides have higher transmission losses in the infrared band.

Embodiments of the present application provide a waveguide-type photodetector and a manufacturing method thereof. The waveguide is formed of SiN, and the waveguide is coupled to the end face of the photoelectric conversion layer. Since the SiN waveguide has extremely low transmission loss in the near-infrared and even mid-infrared bands, and can realize low-loss coupling with optical fibers or silicon waveguides, it can improve the light transmission efficiency; and, between the SiN waveguide and the Ge photoelectric conversion layer Can form a high-quality SiN / Ge interface, thereby improving light detection efficiency.

According to an aspect of an embodiment of the present application, there is provided a waveguide-type photodetector, including: a first insulating layer on a surface of a substrate; a lower contact layer on the surface of the first insulating layer; and a surface on the lower contact layer Photoelectric conversion layer, the material of the photoelectric conversion layer includes germanium (Ge); an upper contact layer on the surface of the photoelectric conversion layer; and a silicon nitride waveguide formed above the first insulating layer, the nitride A silicon waveguide extends in a lateral direction parallel to the surface of the substrate, and in the lateral direction, one end of the silicon nitride waveguide is connected to the photoelectric conversion layer, and the light transmitted by the silicon nitride waveguide It is incident on the photoelectric conversion layer, and a photocurrent is generated in the photoelectric conversion layer.

According to another aspect of the embodiments of the present application, wherein the waveguide-type photodetector further includes: a second insulating layer formed on the surface of the first insulating layer and surrounding the lower contact layer in the lateral direction, wherein, The silicon nitride waveguide is formed on the surface of the second insulating layer.

According to another aspect of the embodiments of the present application, wherein the difference between the thickness of the second insulating layer and the thickness of the lower contact layer is -10% to 10% of the thickness of the lower contact layer.

According to another aspect of the embodiments of the present application, wherein the difference between the thickness of the silicon nitride waveguide and the thickness of the photoelectric conversion layer is -10% to 10% of the thickness of the photoelectric conversion layer.

According to another aspect of the embodiments of the present application, wherein the lateral dimension of the photoelectric conversion layer is smaller than the lateral dimension of the lower contact layer.

According to another aspect of the embodiments of the present application, wherein the lower contact layer is a doped layer containing silicon and / or germanium, and the photoelectric conversion layer is an undoped layer of germanium (Ge) or germanium tin (GeSn) The upper contact layer is a doped layer of germanium (Ge) or a doped layer of germanium tin (GeSn).

According to another aspect of the embodiments of the present application, there is provided a method for manufacturing a waveguide photodetector, including:

Forming a lower contact material layer on the surface of the first insulating layer on the substrate surface;

Forming a photoelectric conversion layer on the surface of the lower contact material layer, and forming an upper contact layer on the surface of the photoelectric conversion layer, the material of the photoelectric conversion layer containing germanium (Ge);

Etching the lower contact material layer to form a lower contact layer;

Forming a second insulating layer surrounding the lower contact layer on the surface of the first insulating layer; and

A silicon nitride waveguide is formed on the surface of the second insulating layer, the silicon nitride waveguide extends in a lateral direction parallel to the surface of the substrate, and, in the lateral direction, one end of the silicon nitride waveguide Is connected to the photoelectric conversion layer, wherein the light transmitted by the silicon nitride waveguide is incident on the photoelectric conversion layer, and a photocurrent is generated in the photoelectric conversion layer.

According to another aspect of the embodiments of the present application, wherein the steps of forming the photoelectric conversion layer and the upper contact layer include:

Forming a stack of the photoelectric conversion material layer and the upper contact material layer on the surface of the lower contact material layer; and

The upper contact material layer and the photoelectric conversion material layer are etched to form the photoelectric conversion layer and the upper contact layer.

According to another aspect of the embodiments of the present application, wherein the step of forming a silicon nitride waveguide includes:

Depositing a silicon nitride material layer on the surface of the second insulating layer; and

The silicon nitride material layer is etched to form the silicon nitride waveguide.

According to another aspect of the embodiments of the present application, wherein the difference between the thickness of the silicon nitride material layer and the thickness of the photoelectric conversion layer is -10% to 10% of the thickness of the photoelectric conversion layer.

The beneficial effects of this application are:

Since the waveguide is formed by SiN, the light transmission efficiency can be improved; and the SiN waveguide is coupled to the end face of the photoelectric conversion layer, which can improve the light detection efficiency.

With reference to the following description and drawings, specific embodiments of the present application are disclosed in detail, and the manner in which the principles of the present application can be adopted is indicated. It should be understood that the embodiments of the present application are not thus limited in scope. Within the scope of the spirit and terms of the appended claims, the embodiments of the present application include many changes, modifications, and equivalents.

Features described and / or illustrated for one embodiment may be used in one or more other embodiments in the same or similar manner, combined with features in other embodiments, or substituted for features in other embodiments .

It should be emphasized that the term "comprising / comprising" as used herein refers to the presence of features, whole pieces, steps or components, but does not exclude the presence or addition of one or more other features, whole pieces, steps or components.

BRIEF DESCRIPTION

The included drawings are used to provide a further understanding of the embodiments of the present application, which form a part of the specification, are used to exemplify the embodiments of the present application, and explain the principle of the present application together with the text description. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without paying any creative labor, other drawings can be obtained based on these drawings. In the drawings:

FIG. 1 is a schematic perspective view of a waveguide-type photodetector according to Example 1 of the present application;

Fig. 2 is a schematic cross-sectional view viewed in the direction A-A 'of Fig. 1;

3 is a schematic diagram of a method of manufacturing a waveguide-type photodetector according to Example 2 of the present application;

4 is a cross-sectional view of the device corresponding to each step in Embodiment 2 of the present application.

detailed description

The foregoing and other features of the present application will become apparent from the following description with reference to the drawings. In the specification and the drawings, specific implementations of the present application are disclosed in detail, which shows some implementations in which the principles of the present application can be adopted. It should be understood that the present application is not limited to the described implementations. The application includes all modifications, variations, and equivalents falling within the scope of the appended claims.

In the description of the embodiments of the present application, for the convenience of description, the direction parallel to the main surface of the first insulating layer of the substrate is referred to as “lateral”, and the direction perpendicular to the main surface of the first insulating layer of the substrate It is called "longitudinal", where the "thickness" of each component refers to the size of the component in the "longitudinal".

Example 1

This embodiment provides a waveguide type photodetector.

Fig. 1 is a schematic perspective view of a waveguide-type photodetector of this embodiment, and Fig. 2 is a schematic cross-sectional view viewed in the direction A-A 'of Fig. 1.

As shown in FIGS. 1 and 2, the waveguide-type photodetector 1 includes:

A first insulating layer 12 on the surface of the substrate 11; a lower contact layer 13 on the surface of the first insulating layer 12; a photoelectric conversion layer 14 on the surface of the lower contact layer 13, the material of the photoelectric conversion layer 14 includes germanium (Ge); The upper contact layer 15 on the surface of the photoelectric conversion layer 14; a silicon nitride waveguide 16 formed above the first insulating layer 12, the silicon nitride (SiN) waveguide 16 extends in a lateral direction parallel to the surface of the substrate 11, and, in this In the lateral direction, one end 161 of the silicon nitride waveguide 16 is connected to the photoelectric conversion layer 14.

In this embodiment, the light transmitted by the silicon nitride waveguide 16 enters the photoelectric conversion layer 14 through the end portion 161, and a photocurrent is generated in the photoelectric conversion layer 14.

According to this embodiment, the waveguide is formed of SiN, and the waveguide is coupled to the end face of the photoelectric conversion layer. Since the SiN waveguide has extremely low transmission loss in the near-infrared and even mid-infrared bands, and can realize low-loss coupling with optical fibers or silicon waveguides, it can improve the light transmission efficiency; Can form a high-quality SiN / Ge interface, thereby improving light detection efficiency.

In this embodiment, the lower contact layer 13 may be a doped layer containing silicon and / or germanium, for example, a heavily doped P-type layer or a heavily doped N-type layer.

In this embodiment, the first insulating layer 12 may be silicon oxide, for example, and the substrate 11 may be silicon, for example.

In this embodiment, the silicon on insulator (SOI) can be processed, the top silicon layer of the SOI can be processed as the lower contact layer 13, the buried oxygen layer of the SOI can be used as the first insulating layer 12, and the silicon of the SOI substrate As the substrate 11. In addition, this embodiment may not be limited to this, for example, bulk silicon may be used as the substrate 11, an insulating layer may be formed on the surface of the bulk silicon as the first insulating layer 12, and methods such as deposition or bonding may be performed on the surface of the first insulating layer 12 A silicon material layer is formed, and the silicon material layer is processed to form the lower contact layer 13.

As shown in FIGS. 1 and 2, the waveguide-type photodetector 1 may further include: a second insulating layer 17 formed on the surface of the first insulating layer 12 and surrounding the lower contact layer 13 in the lateral direction. The silicon nitride waveguide 16 is formed on the surface of the second insulating layer 17.

In this embodiment, the difference between the thickness of the second insulating layer 17 and the thickness of the lower contact layer 13 is -10% to 10% of the thickness of the lower contact layer 13, thereby providing nitrogen on the surface of the second insulating layer 17 When the silicon waveguide 16 is made, the lower surface of the silicon nitride waveguide 16 can be flush with the lower surface of the lower contact layer 13.

In this embodiment, the difference between the thickness of the silicon nitride waveguide 16 and the thickness of the photoelectric conversion layer 14 is -10% to 10% of the thickness of the photoelectric conversion layer 14, thereby facilitating the transmission of light transmitted by the silicon nitride waveguide 16 The end surface 161 is coupled into the photoelectric conversion layer 14, which improves the coupling efficiency of light. In addition, the lateral position of the end portion 161 of the silicon nitride waveguide 16 can be aligned with the lateral center position of the photoelectric conversion layer 14, thereby, the light coupling efficiency is further improved.

In this embodiment, the lateral dimension of the photoelectric conversion layer 14 is smaller than the lateral dimension of the lower contact layer 13, and therefore, a portion of the lower contact layer 13 is not blocked by the photoelectric conversion layer 14, and the surface of the unblocked portion can be provided with The electrode that the lower contact layer 13 contacts.

For example, as shown in FIGS. 1 and 2, the first electrode 18 may be located on both sides of the photoelectric conversion layer 14, and the first electrode 18 may be disposed on the surface of the lower contact layer 13 and in contact with the lower contact layer 13; The electrode 19 may be in contact with the upper contact layer 15.

In addition, as shown in FIG. 2, the second insulating layer 17 may also cover a part of the upper contact layer 15 and the side walls of the photoelectric conversion layer 14 and the upper contact layer 15.

In this embodiment, the photoelectric conversion layer 14 may be an undoped layer of germanium (Ge) or an undoped layer of germanium tin (GeSn), that is, the photoelectric conversion layer 14 may be an intrinsic layer of germanium (Ge) or Intrinsic layer of germanium tin (GeSn). For the photoelectric conversion layer 14, by incorporating Sn into Ge, the absorption efficiency of the photoelectric conversion layer 14 can be increased and the detection range of the photoelectric conversion layer 14 can be widened. For example, the composition of Sn can be greater than 0 and less than 40% (mole ratio).

In this embodiment, the upper contact layer 15 may be a doped layer of germanium (Ge) or a doped layer of germanium tin (GeSn). The doping type of the upper contact layer 15 is opposite to that of the lower contact layer 13. For example, the upper contact layer 15 is heavily doped with P type and the lower contact layer 13 is heavily doped with N type; or, the upper contact layer 15 is heavily doped with N type and the lower contact layer 13 is heavily doped with P type.

Both the first insulating layer 12 and the second insulating layer 17 are, for example, silicon oxide.

In this embodiment, light can enter the silicon nitride waveguide 16 through the fiber-SiN waveguide coupler or enter the silicon nitride waveguide 16 through the Si waveguide-SiN waveguide coupler and directly couple into the end through the silicon nitride waveguide 16 Photoelectric conversion layer 14. The photodetector integrated with the silicon nitride waveguide 16 of this embodiment can be integrated with the waveguide optical path, and it is easier to realize the preparation of a photodetector with low dark current, low capacitance, and high response in the communication band.

The waveguide-type photodetector of this embodiment has the following advantages: First, compared with the conventional perpendicular-incidence germanium detector, the photodetector based on the waveguide structure can avoid the mutual restriction between the photodetector rate and quantum efficiency, and It is easy to integrate with other passive optical devices; second, compared with the evanescent wave coupling waveguide detector, the waveguide detector based on the end face coupling of this embodiment has higher absorption efficiency; third, the silicon nitride waveguide is The near-infrared and even mid-infrared bands have extremely low transmission loss and can realize low-loss coupling with optical fibers or silicon waveguides. Fourth, the end face of the silicon nitride waveguide and the end face of the photoelectric conversion layer form a good quality interface, which improves the optical Coupling efficiency.

Example 2

Embodiment 2 provides a method for manufacturing a waveguide-type photodetector, which is used to manufacture the waveguide-type photodetector described in Embodiment 1.

FIG. 3 is a schematic diagram of the manufacturing method of the waveguide-type photodetector of this embodiment. As shown in FIG. 3, in this embodiment, the manufacturing method may include:

Step 301, forming a lower contact material layer 13a on the surface of the first insulating layer 12 on the surface of the substrate 11;

Step 302: Form a photoelectric conversion layer 14 on the surface of the lower contact material layer 13a, and form an upper contact layer 15 on the surface of the photoelectric conversion layer 14, wherein the material of the photoelectric conversion layer 14 includes germanium (Ge);

Step 303, etching the lower contact material layer 13a to form the lower contact layer 13;

Step 304, forming a second insulating layer 17 surrounding the lower contact layer 13 on the surface of the first insulating layer 12;

Step 305, forming a silicon nitride waveguide 16 on the surface of the second insulating layer 17, the silicon nitride waveguide 16 extends in a lateral direction parallel to the surface of the substrate 11, and, in the lateral direction, one end of the silicon nitride waveguide 16 161 is connected to the photoelectric conversion layer 14.

In the present embodiment, the light transmitted by the silicon nitride waveguide 16 is incident on the photoelectric conversion layer 14, and a photocurrent is generated in the photoelectric conversion layer 14.

In this embodiment, step 302 may include:

Step 3021: Form a stack of the photoelectric conversion material layer 14a and the upper contact material layer 15a on the surface of the lower contact material layer 13a, wherein the photoelectric conversion material layer 14a is an undoped material layer and the upper contact material layer 15a is a doped material layer ;as well as

Step 3022, etching the upper contact material layer 15a and the photoelectric conversion material layer 14a to form the photoelectric conversion layer 14 and the upper contact layer 15, wherein the upper contact layer 15 and the photoelectric conversion layer 14 form a mesa.

In this embodiment, the step of forming a silicon nitride waveguide in step 305 may include:

Step 3051, depositing a silicon nitride material layer 16a on the surface of the second insulating layer 17;

Step 3052: The silicon nitride material layer 16a is etched to form a silicon nitride waveguide 16.

In the above step 3051 of this embodiment, the difference between the thickness of the silicon nitride material layer 16a and the thickness of the photoelectric conversion layer 14 is -10% to 10% of the thickness of the photoelectric conversion layer 14.

The manufacturing method of the waveguide-type photodetector of the present application will be described below with reference to a specific example.

4 is a cross-sectional view of the device corresponding to each step in this example. As shown in FIG. 4, in this example, the manufacturing method of the waveguide-type photodetector includes the following steps:

Step 1: Perform ion implantation and high-temperature annealing on the silicon material layer of the first insulating layer 12 on the surface of the substrate 11 so that the silicon material layer becomes the lower contact material layer 13a. For example, the lower contact material layer 13a is heavily doped P-type; Then, a germanium (Ge) or germanium tin (GeSn) material layer is epitaxially grown on the surface of the lower contact material layer 13a, and ion implantation and high temperature annealing are performed on the upper part of the germanium (Ge) or germanium tin germanium (GeSn) material layer to remove The upper part of the germanium (Ge) or germanium tin (GeSn) material layer is prepared as an N-type heavily doped layer, whereby the lower part (ie, intrinsic part) of the germanium (Ge) or germanium tin (GeSn) material layer As the photoelectric conversion material layer 14a, the upper part (ie, the heavily doped portion) of the germanium (Ge) or germanium tin (GeSn) material layer becomes the upper contact material layer 15a. See (a) of FIG. 4.

Step 2: Perform photolithography and dry etching on the upper contact material layer 15a and the photoelectric conversion material layer 14a to form the photoelectric conversion layer 14 and the upper contact layer 15, wherein the upper contact layer 15 and the photoelectric conversion layer 14 form a mesa; and , Performing photolithography and dry etching on the exposed lower contact material layer 13a to form the lower contact layer 13. See (b) of Figure 4.

Step 3: Deposit SiO ₂ as the second insulating layer 17; deposit a silicon nitride material layer 16a on the surface of the second insulating layer 17 whose thickness is equivalent to the thickness of the photoelectric conversion layer 14; then, light the silicon nitride material layer 16a The silicon nitride waveguide 16 is prepared by etching and etching, and the silicon nitride waveguide 16 is directly connected to the Ge photoelectric conversion layer 14. See (c) of Figure 4.

Step 4: Perform photolithography and etching on the second insulating layer 17 to define a metal contact area, and then deposit a metal electrode, and form the first electrode and the second electrode by photolithography and etching, thereby completing device preparation. See (d) of FIG. 4.

According to this embodiment, the waveguide is formed of SiN, and the waveguide is coupled to the end face of the photoelectric conversion layer. Since the silicon nitride waveguide has extremely low transmission loss in the near-infrared and even mid-infrared bands, and can realize low-loss coupling with the optical fiber or the silicon waveguide, it can improve the light transmission efficiency; and, the silicon nitride waveguide and the Ge photoelectricity A high-quality SiN / Ge interface can be formed between the conversion layers, thereby improving light detection efficiency.

The present application has been described above in conjunction with specific implementations, but those skilled in the art should understand that these descriptions are exemplary and do not limit the protection scope of the present application. A person skilled in the art can make various variations and modifications to the present application according to the spirit and principle of the present application, and these variations and modifications are also within the scope of the present application.

Claims

A waveguide type photodetector, which includes:

A first insulating layer on the surface of the substrate;

A lower contact layer on the surface of the first insulating layer;

A photoelectric conversion layer on the surface of the lower contact layer, the material of the photoelectric conversion layer includes germanium (Ge);

An upper contact layer on the surface of the photoelectric conversion layer; and

A silicon nitride waveguide formed above the first insulating layer, the silicon nitride waveguide extending in a lateral direction parallel to the surface of the substrate, and, in the lateral direction, one of the silicon nitride waveguides The end is connected to the photoelectric conversion layer,

The light transmitted by the silicon nitride waveguide is incident on the photoelectric conversion layer, and a photocurrent is generated in the photoelectric conversion layer.
The waveguide-type photodetector of claim 1, wherein the waveguide-type photodetector further comprises:

A second insulating layer formed on the surface of the first insulating layer and laterally surrounding the lower contact layer, wherein the silicon nitride waveguide is formed on the surface of the second insulating layer.
The waveguide type photodetector according to claim 2, wherein the difference between the thickness of the second insulating layer and the thickness of the lower contact layer is -10% to 10% of the thickness of the lower contact layer.
The waveguide type photodetector according to claim 1 or 2, wherein the difference between the thickness of the silicon nitride waveguide and the thickness of the photoelectric conversion layer is -10% to 10% of the thickness of the photoelectric conversion layer .
The waveguide-type photodetector according to claim 1, wherein the lateral dimension of the photoelectric conversion layer is smaller than the lateral dimension of the lower contact layer.
The waveguide type photodetector according to claim 1, wherein the lower contact layer is a doped layer containing silicon and / or germanium, and the photoelectric conversion layer is an undoped layer of germanium (Ge) or germanium tin (GeSn) undoped layer, the upper contact layer is a doped layer of germanium (Ge) or a doped layer of germanium tin (GeSn).
A method for manufacturing a waveguide photodetector, which includes:

Forming a lower contact material layer on the surface of the first insulating layer on the substrate surface;

Forming a photoelectric conversion layer on the surface of the lower contact material layer, and forming an upper contact layer on the surface of the photoelectric conversion layer, the material of the photoelectric conversion layer containing germanium (Ge);

Etching the lower contact material layer to form a lower contact layer;

Forming a second insulating layer surrounding the lower contact layer on the surface of the first insulating layer; and

A silicon nitride waveguide is formed on the surface of the second insulating layer, the silicon nitride waveguide extends in a lateral direction parallel to the surface of the substrate, and, in the lateral direction, one end of the silicon nitride waveguide Is connected to the photoelectric conversion layer,

Wherein, the light transmitted by the silicon nitride waveguide is incident on the photoelectric conversion layer, and a photocurrent is generated in the photoelectric conversion layer.
The method of manufacturing a waveguide-type photodetector according to claim 7, wherein the steps of forming the photoelectric conversion layer and the upper contact layer include:

Forming a stack of the photoelectric conversion material layer and the upper contact material layer on the surface of the lower contact material layer; and

The upper contact material layer and the photoelectric conversion material layer are etched to form the photoelectric conversion layer and the upper contact layer.
The method of manufacturing a waveguide-type photodetector according to claim 7, wherein the step of forming a silicon nitride waveguide includes:

Depositing a silicon nitride material layer on the surface of the second insulating layer; and

The silicon nitride material layer is etched to form the silicon nitride waveguide.
The method of manufacturing a waveguide-type photodetector according to claim 9, wherein the difference between the thickness of the silicon nitride material layer and the thickness of the photoelectric conversion layer is -10% of the thickness of the photoelectric conversion layer 10%.