Horizontal photodiode and method of manufacturing the same

Abstract

This invention provides a horizontal photodiode and its manufacturing method. The horizontal photodiode includes a raised epitaxial layer, a second conductivity type epitaxial layer, a transparent substrate, and an optical bonding layer. The raised epitaxial layer has laser-sintered sidewalls disposed on its outer periphery. The second conductivity type epitaxial layer is disposed below the raised epitaxial layer, and the optical bonding layer is sandwiched between the transparent substrate and the second conductivity type epitaxial layer to block external light from entering the second conductivity type epitaxial layer through the transparent substrate.

Description

Technical Field

[0001] This invention relates to a horizontal photodiode and its manufacturing method, and more particularly, to a horizontal photodiode with high structural strength and high signal-to-noise ratio and its manufacturing method. Background Technology

[0002] A photodiode is an electronic component that converts external light signals into electrical signals. Its core function is to absorb external light, detecting the light signal and converting it into a measurable current. This conversion is crucial for various applications, such as optical communication, optical measurement, and imaging.

[0003] The way photodiodes absorb external light is by utilizing the semiconductor material (e.g., a silicon substrate) inside the diode. When a photon enters the photodiode and is absorbed, the photon's energy causes electrons in the valence band to jump to the conduction band, thus creating electron-hole pairs. These photogenerated carriers separate under the influence of the diode's built-in electric field and generate current.

[0004] However, traditional photodiodes suffer from two problems. First, the material structure of traditional short-wave infrared (SWIR) photodiodes, with a spectral range of 0.9 to 1.7 micrometers, is typically grown layer-by-layer on an indium phosphide (InP) substrate. However, InP substrates are very fragile and easily break during chip fabrication, affecting yield and increasing manufacturing costs, making it difficult to meet the requirements of economical mass production. Second, in practical applications, external light can easily penetrate the exposed sidewalls of traditional photodiodes, interfering with internal photoelectric interactions and affecting the accuracy of the photosensitive area's function, leading to calculation errors in subsequent applications. To overcome these problems, the industry urgently needs a novel photodiode architecture that not only addresses the insufficient structural strength of photodiode chips but also overcomes the issue of low signal-to-noise ratio caused by external noise interference. Summary of the Invention

[0005] The main objective of this invention is to provide a novel horizontal photodiode and its manufacturing method. Compared to traditional photodiodes, the photodiode of this invention utilizes wafer transfer and bonding technology to transfer the epitaxial structure of the photodiode from a fragile epitaxial growth substrate to a high-strength transparent substrate, thereby strengthening the structural strength of the chip body, improving process yield, and reducing production costs to meet the requirements of economical production. In particular, this invention further utilizes laser sintering technology to set laser-sintered sidewalls in the device structure to effectively block external light interference from the device sidewalls, thereby suppressing noise interference and improving the signal-to-noise ratio (SNR) and photocurrent gain of the device.

[0006] To achieve the above objectives, the present invention provides a horizontal photodiode comprising a mesa epitaxial layer, a second conductivity type epitaxial layer, a transparent substrate, and an optical bonding layer. The mesa epitaxial layer comprises an intrinsic epitaxial layer, a first conductivity type in-situ doped epitaxial layer, and laser-sintered sidewalls. The first conductivity type in-situ doped epitaxial layer is disposed on the intrinsic epitaxial layer, and the laser-sintered sidewalls are disposed on the outer periphery of the first conductivity type in-situ doped epitaxial layer to substantially block external light from entering the first conductivity type in-situ doped epitaxial layer via the laser-sintered sidewalls. The mesa epitaxial layer is disposed on the second conductivity type epitaxial layer, and the optical bonding layer is sandwiched between the transparent substrate and the second conductivity type epitaxial layer to block external light from entering the second conductivity type epitaxial layer via the transparent substrate.

[0007] According to an embodiment of the present invention, in a horizontal photodiode, the laser sintered sidewalls are further disposed in an intrinsic epitaxial layer.

[0008] According to an embodiment of the present invention, in a horizontal photodiode, the first conductivity type in-situ doped epitaxial layer is an N-type in-situ doped indium phosphide (InP) epitaxial layer, the dopant being one of sulfur (S) and silicon (Si), and the doping concentration is 10. 17~19 cm -3 .

[0009] According to an embodiment of the present invention, the optical bonding layer of the horizontal photodiode is a distributed Bragg reflector (DBR) layer.

[0010] According to an embodiment of the present invention, the horizontal photodiode has a transparent substrate that further includes a passivation layer for bonding with an optical bonding layer.

[0011] According to an embodiment of the present invention, the passivation layer of the horizontal photodiode is selected from the group consisting of silicon oxide, titanium oxide, and combinations thereof.

[0012] According to an embodiment of the present invention, the horizontal photodiode further includes an optical layer, which is a multi-channel bandpass filter (MBPF) layer covering the surface and sidewalls of the platform epitaxial layer to allow light of a specific wavelength in the external light to pass through while blocking other light in the external light besides that specific wavelength.

[0013] According to an embodiment of the present invention, the optical layer of the horizontal photodiode further includes an anti-reflection (AR) layer to reduce surface reflection loss of the optical layer.

[0014] According to an embodiment of the present invention, the horizontal photodiode further includes a first metal ring, which is disposed on the surface of a first conductive in-situ doped epitaxial layer inside the laser sintering sidewall and is partially covered by an optical layer.

[0015] According to an embodiment of the present invention, the horizontal photodiode further includes a second metal ring disposed adjacent to the sidewall of the raised epitaxial layer and electrically connected to the second conductive epitaxial layer.

[0016] To achieve the above objectives, the present invention provides a method for manufacturing a horizontal photodiode, the method comprising the following steps: First, providing an epitaxial growth substrate, and sequentially epitaxially growing a first conductivity type in-situ doped epitaxial layer, an intrinsic epitaxial layer, and a second conductivity type epitaxial layer on the epitaxial growth substrate; second, providing an optical bonding layer on the second conductivity type epitaxial layer; next, after bonding a transparent substrate to the optical bonding layer, removing the epitaxial growth substrate; providing a laser-sintered sidewall disposed on the outer periphery of the first conductivity type in-situ doped epitaxial layer; removing a portion of the first conductivity type in-situ doped epitaxial layer and the intrinsic epitaxial layer to form a raised epitaxial layer; finally, providing an optical layer covering the surface and sidewalls of the raised epitaxial layer.

[0017] According to an embodiment of the present invention, the step of providing laser sintered sidewalls in the manufacturing method of a horizontal photodiode includes providing a laser to form laser sintered sidewalls disposed on the outer periphery of a first conductivity type in-situ doped epitaxial layer and in the intrinsic epitaxial layer.

[0018] According to an embodiment of the present invention, the step of providing a first conductivity type in-situ doped epitaxial layer is to provide an N-type in-situ doped indium phosphide (InP) epitaxial layer.

[0019] According to an embodiment of the present invention, the method for manufacturing a horizontal photodiode involves simultaneously doping one of sulfur (S) or silicon (Si) during the indium phosphide (InP) epitaxial layer formation by means of metal-organic chemical vapor deposition (MOCVD), with a doping concentration of 10. 17~19 cm -3 .

[0020] According to an embodiment of the present invention, in the method for manufacturing a horizontal photodiode, a distributed Bragg reflector layer is provided during the step of providing the optical bonding layer.

[0021] According to an embodiment of the present invention, a method for manufacturing a horizontal photodiode further includes a step of providing a first metal ring after the step of providing a laser sintered sidewall, wherein the first metal ring is disposed around the surface of a first conductivity type in-situ doped epitaxial layer inside the laser sintered sidewall.

[0022] A method for manufacturing a horizontal photodiode according to an embodiment of the present invention further includes providing a second metal ring disposed adjacent to a sidewall of a raised epitaxial layer and electrically connected to a second conductive epitaxial layer.

[0023] According to an embodiment of the present invention, in the method for manufacturing a horizontal photodiode, the step of providing an optical layer is to provide a multi-band bandpass filter layer to allow light of a specific band in the external light to pass through while blocking other light in the external light besides that specific band.

[0024] According to an embodiment of the present invention, the method for manufacturing a horizontal photodiode further includes providing an anti-reflection layer to reduce surface reflection loss of the optical layer.

[0025] Other objects of the invention, as well as the technical means and embodiments of the invention, will become apparent to those skilled in the art upon reference to the accompanying drawings and the embodiments described below. Attached Figure Description

[0026] Figures 1 to 9 A cross-sectional view of the manufacture of a horizontal photodiode according to an embodiment of the present invention is shown; and Figure 10 A schematic diagram illustrating the process steps of a horizontal photodiode according to an embodiment of the present invention is shown. Detailed Implementation

[0027] The following embodiments will explain the content of the present invention. These embodiments are not intended to limit the implementation of the invention to any specific environment, application, or special method as described in the embodiments. Therefore, the descriptions of the embodiments are for illustrative purposes only and are not intended to limit the invention. It should be noted that in the following embodiments and drawings, elements not directly related to the present invention have been omitted and are not shown or described, and the dimensional relationships between the elements in the drawings are for ease of understanding only and are not intended to limit the actual scale.

[0028] Merge reference Figures 1 to 9 , Figures 1 to 9 A cross-sectional view of the fabrication of a horizontal photodiode according to an embodiment of the present invention is shown. Specifically, the horizontal photodiode is a compound semiconductor horizontal photodiode. In this embodiment, the horizontal photodiode 10 is fabricated by first epitaxially growing an ohmic contact epitaxial layer 110 on an epitaxial growth substrate 100, which serves as the basis for forming ohmic contacts with the metal layer in subsequent metal interconnect processes. Specifically, the epitaxial growth substrate 100 may be, but is not limited to, an indium phosphide (InP) substrate. The ohmic contact epitaxial layer 110 may be, but is not limited to, an indium gallium arsenide (InGaAs) epitaxial layer.

[0029] Next, a first conductivity type in-situ doped epitaxial layer 120 and an intrinsic epitaxial layer 130 are sequentially epitaxially grown on the ohmic contact epitaxial layer 110, such as... Figure 1 As shown. Specifically, the first conductivity type in-situ doped epitaxial layer 120 is an N-type doped epitaxial layer formed by metal-organic chemical vapor deposition (MOCVD). For example, doping is performed simultaneously during the epitaxial growth of indium phosphide (InP) epitaxial layer, for example, but not limited to, using sulfur (S) or silicon (Si) as a dopant, with a doping concentration of approximately 10. 17~19 cm -3 This establishes a suitable built-in electric field to drive electron drift. Furthermore, the intrinsic epitaxial layer 130 can be an indium gallium arsenide (InGaAs) epitaxial layer disposed on the first conductivity type in-situ doped epitaxial layer 120. The intrinsic epitaxial layer 130 has a low doping concentration of approximately 10⁻⁶. 14~ 15 cm -3This ensures a long carrier drift distance, prevents carrier recombination within the intrinsic epitaxial layer, effectively separates and drifts electrons and holes, and improves photoresponse efficiency. It should be noted that the first conductivity type in-situ doped epitaxial layer 120 of this invention has a uniform doping distribution formed by an "in-situ doping" process. Compared to conventional doping distributions formed by ion doping and diffusion processes, the first conductivity type in-situ doped epitaxial layer 120 of this invention has a uniform ion doping distribution, thus improving the photoresponse efficiency and gain current of the photodiode.

[0030] Reference Figure 2 Next, a second conductive epitaxial layer 140 is epitaxially grown on the intrinsic epitaxial layer 130. Specifically, this second conductive epitaxial layer 140 can be, but is not limited to, a p-type indium phosphide (InP) epitaxial layer. This p-type indium phosphide epitaxial layer can be grown using a conventional ion doping combined with diffusion process, or, similarly, using an in-situ doping process to dope one of zinc (Zn), magnesium (Mg), or beryllium (Be), with a doping concentration of 10 for each dopant. 17~19 cm -3 .

[0031] Next, an optical bonding layer 150 is grown on the second conductive epitaxial layer 140, such as... Figure 3 As shown, this optical bonding layer 150 is used for subsequent wafer transfer and bonding. Specifically, this optical bonding layer 150 can also serve as an optical reflective layer, for example, but not limited to, a distributed Bragg reflector (DBR) layer. This DBR layer is a reflective thin film constructed using silicon oxide and titanium oxide, consisting of multiple layers stacked with alternating high and low refractive indices. It exhibits strong reflection of light of specific wavelengths due to interference effects between the multilayer interfaces. Therefore, the reason this invention specifically utilizes a DBR thin film as the optical bonding layer 150 is to effectively isolate noise from the underlying layer of the device and improve the response capability of the photodiode through its optical reflection effect.

[0032] Secondly, refer to Figure 4As shown, a transparent substrate 160 is then provided, which may be, for example, but is not limited to, a sapphire substrate. This transparent substrate 160 has a passivation layer 170, specifically selected from one or a combination of silicon oxide and titanium oxide, used in conjunction with an optical bonding layer 150 for transferring and bonding the two wafers, the epitaxial growth substrate 100 and the transparent substrate 160, so that the passivation layer 170 of the transparent substrate 160 is bonded to the optical bonding layer 150 on the epitaxial growth substrate 100. For example, the optical bonding layer 150 and the passivation layer 170 can be surface-treated using a chemical solution to form floating bonds on their surfaces, and then the two wafers can be bonded together by high temperature and high pressure and the application of van der Waals forces. After the optical bonding layer 150 and the passivation layer 170 are bonded, the indium phosphide epitaxial growth substrate 100 is removed by chemical selective etching, and the etching stops at the indium gallium arsenide (InGaAs) ohmic contact epitaxial layer 110.

[0033] Secondly, a first conductive metal layer is formed on the ohmic contact epitaxial layer 110. Then, a portion of the first conductive metal layer and the ohmic contact epitaxial layer 110 are etched away using a patterning process to form a first conductive metal ring 180. The patterned ohmic contact epitaxial layer 110 is disposed on the upper surface of the first conductive in-situ doped epitaxial layer 120. Figure 5 As shown. Specifically, the first conductive metal ring 180 is an N-type metal material, which may be, but is not limited to, one of chromium (Cr), palladium (Pd), gold (Au), titanium (Ti), aluminum (Al), silver (Ag) or an alloy combination thereof.

[0034] Next, refer to Figure 6 To avoid the problem of low signal-to-noise ratio caused by external light affecting the photodiode, this invention specifically provides a first laser at the outer periphery of the horizontal photodiode 10's structural body. A first laser-sintered sidewall 190 is formed using a laser sintering method and disposed at the outer periphery of the first conductivity type in-situ doped epitaxial layer 120. This defines the active region and substantially blocks external light from entering the first conductivity type in-situ doped epitaxial layer 120. Figure 5As shown. Specifically, a first laser-sintered sidewall 190 is disposed on the inner side of the device sidewall, and a first conductive metal ring 180 is disposed around the upper inner edge of the first laser-sintered sidewall 190. The first laser-sintered sidewall 190 blocks unwanted external light from entering the active region of the device through the device sidewall, thus preventing subsequent malfunctions. Specifically, a green laser or an ultraviolet (UV) laser can be used to form a laser-sintered sidewall with a length of not less than 1 micrometer (µm) on the outer periphery of the first conductive in-situ doped epitaxial layer 120 to substantially block external light from entering the first conductive in-situ doped epitaxial layer 120. The length of this first laser-sintered sidewall 190 can be adjusted according to the actual specifications of the horizontal photodiode device. Preferably, the first laser-sintered sidewall 190 can be further disposed in the intrinsic epitaxial layer to ensure that unwanted external light enters the diode device through the device sidewall, erroneously causing noise, and simultaneously increasing the electrostatic discharge protection capability of the horizontal photodiode.

[0035] Next, a mesa etching process is performed. Using dry or wet etching, a portion of the first conductivity type in-situ doped epitaxial layer 120 and the intrinsic epitaxial layer 130 are removed to form the mesa epitaxial layer in the horizontal device structure, such as... Figure 7 As shown, a portion of the surface of the second conductive epitaxial layer 140 is exposed to serve as the location of the second conductive electrode. Next, a metallization process is performed to form a second conductive metal ring 200 on the exposed surface of the second conductive epitaxial layer 140 outside the sidewalls of the raised epitaxial layer, and electrically connect it to the second conductive epitaxial layer 140. Specifically, the second conductive metal ring 200 is a P-type metal material, which may be, but is not limited to, one of platinum (Pt), palladium (Pd), gold (Au), or an alloy combination thereof.

[0036] Specifically, to control the wavelength range of light entering the photodiode, this invention uses a special optical material to replace the traditional protective layer, thus providing both electrical isolation and filtering functions. (See reference...) Figure 8 , Figure 8 The diagram shows an optical layer 210 covering the surface and sidewalls of the platform epitaxial layer, and partially covering the first conductive metal ring 180 and the second conductive metal ring 200, exposing portions of the upper surfaces of the first conductive metal ring 180 and the second conductive metal ring 200. Specifically, only the exposed upper surface of the first conductive in-situ doped epitaxial layer 120 and the exposed sidewalls of the first conductive in-situ doped epitaxial layer 120 and the intrinsic epitaxial layer 130 are covered. This allows for precise control of external light with specific wavelengths entering the platform epitaxial layer while blocking other light of different wavelengths, thus eliminating unexpected external noise interference.

[0037] Specifically, in a specific embodiment, the optical layer 210 is a multi-channel bandpass filter (MBPF) layer, covering the surface and sidewalls of the raised epitaxial layer. In practical applications, the composition of the multi-channel bandpass filter layer can be adjusted according to the actual filtering band requirements; for example, it can be, but is not limited to, using materials containing silicon oxide (SiO2). x Titanium oxide (TiO) x Dielectric materials such as tantalum oxide (Ta2O3) are used. In a preferred embodiment, the optical layer 210 further includes an anti-reflection (AR) layer to enhance the transmission of light with that specific wavelength and reduce the surface reflection loss of the optical layer 210.

[0038] Finally, refer to Figure 9 The sapphire substrate is diced to form individual horizontal photodiode elements. Specifically, a second laser is provided, and second laser-sintered sidewalls 220 are formed on each sidewall of the transparent substrate 160, passivation layer 170, optical bonding layer 150, second conductive epitaxial layer 140, and second conductive metal ring 200 using laser dicing, thereby forming an individual horizontal photodiode 10. Simultaneously, these second laser-sintered sidewalls 220 also serve to block external light from entering the element through the sidewalls and causing interference.

[0039] Reference Figure 10 , Figure 10 A schematic diagram of the process steps of the horizontal photodiode of the present invention is shown. First, in step S01, an epitaxial growth substrate is provided, and a first conductivity type in-situ doped epitaxial layer, an intrinsic epitaxial layer, and a second conductivity type epitaxial layer are sequentially grown on the substrate. Next, in step S02, an optical bonding layer is provided on the second conductivity type epitaxial layer. In step S03, the epitaxial growth substrate is removed after bonding a transparent substrate to the optical bonding layer. In step S04, laser-sintered sidewalls are provided on the outer periphery of the first conductivity type in-situ doped epitaxial layer. In step S05, portions of the first conductivity type in-situ doped epitaxial layer and the intrinsic epitaxial layer are removed to form a raised epitaxial layer. Finally, in step S06, an optical layer covering the surface and sidewalls of the raised epitaxial layer is provided. The descriptions of the relevant components are as described above and are therefore not repeated here.

[0040] like Figure 9As shown, the horizontal photodiode 10 of the present invention utilizes wafer transfer bonding technology to transfer the photodiode device body onto a high-strength sapphire transparent substrate, improving the fragility of the indium phosphide substrate used in traditional SWIR photodiodes, enhancing the structural strength of the device, thereby improving process yield and reducing manufacturing costs to meet the requirements of economical mass production. Furthermore, the horizontal photodiode of the present invention employs various designs to further block external noise interference, thereby improving the signal-to-noise ratio, enhancing the photoresponse efficiency, and increasing current gain. For example, the optical bonding layer 150 disposed above the transparent substrate 160 at the bottom of the device has a mirror structure to reflect external light from the bottom of the device, preventing it from entering the device and causing noise interference. In addition, regarding the device sidewalls, the present invention provides two laser-sintered sidewalls (a first laser-sintered sidewall 190 to prevent noise from entering the active region from the sidewalls and a second laser-sintered sidewall 220 on the outermost sidewall), both of which effectively block noise interference from the device sidewalls. From the top of the device, a multi-band bandpass filter layer controls the passage of only light of a specific wavelength while blocking other wavelengths. Additionally, the anti-reflective layer enhances the passage of this specific wavelength and reduces reflection losses on the surface of this optical layer. In summary, the horizontal photodiode of this invention features a design that comprehensively avoids noise interference, significantly improving the device's signal-to-noise ratio and enhancing photocurrent gain.

[0041] The above embodiments are merely illustrative of the present invention and to explain its technical features, and are not intended to limit the scope of protection of the present invention. Any changes or equivalent arrangements that can be easily made by those skilled in the art are within the scope of the present invention, and the scope of protection of the present invention should be determined by the scope of the patent application.

[0042] [Symbol Explanation] 10: Horizontal photodiode 100: Epitaxial growth substrate 110: Ohmic contact epitaxial layer 120: First conductivity type in-situ doped epitaxial layer 130: Intrinsic epitaxial layer 140: Second conductivity type epitaxial layer 150: Optical bonding layer 160: Transparent substrate 170: Passivation layer 180: First conductive metal ring 190: First laser sintered sidewall 200: Second conductive metal ring 210: Optical layer 220: Second laser sintered sidewall.

Claims

1. A horizontal photodiode, the horizontal photodiode comprising: The elevated epitaxial layer comprises an intrinsic epitaxial layer, a first conductivity type in-situ doped epitaxial layer, and laser-sintered sidewalls. The first conductivity type in-situ doped epitaxial layer is disposed on the intrinsic epitaxial layer, and the laser sintering sidewall is disposed on the outer periphery of the first conductivity type in-situ doped epitaxial layer to block external light from entering the first conductivity type in-situ doped epitaxial layer through the laser sintering sidewall. The second conductive epitaxial layer, and the raised epitaxial layer are disposed on the second conductive epitaxial layer; Transparent substrate; as well as An optical bonding layer is sandwiched between a transparent substrate and a second conductive epitaxial layer to block external light from entering the second conductive epitaxial layer through the transparent substrate.

2. The horizontal photodiode as described in claim 1, wherein, The laser-sintered sidewalls are further disposed within the intrinsic epitaxial layer.

3. The horizontal photodiode as described in claim 1, wherein, The first conductivity type in-situ doped epitaxial layer is an N-type in-situ doped indium phosphide epitaxial layer, with the dopant being either sulfur or silicon, and the doping concentration being 10. 17~19 cm -3 .

4. The horizontal photodiode as described in claim 1, wherein, The optical bonding layer is a distributed Bragg reflector layer.

5. The horizontal photodiode as described in claim 1, wherein, The transparent substrate further includes a passivation layer to bond with the optical bonding layer.

6. The horizontal photodiode as described in claim 5, wherein, The passivation layer is selected from one of the groups consisting of silicon oxide, titanium oxide, and combinations thereof.

7. The horizontal photodiode of claim 1, wherein the horizontal photodiode further comprises an optical layer, the optical layer being a multi-band bandpass filter layer covering the surface and sidewalls of the platform epitaxial layer to allow light of a specific band in external light to pass through while blocking other light in external light besides that specific band.

8. The horizontal photodiode as described in claim 7, wherein, The optical layer further includes an anti-reflective layer to reduce surface reflection loss of the optical layer.

9. The horizontal photodiode as claimed in claim 7, wherein the horizontal photodiode further comprises a first metal ring, the first metal ring being disposed on the surface of a first conductive in-situ doped epitaxial layer inside the laser sintering sidewall and partially covered by an optical layer.

10. The horizontal photodiode of claim 1, wherein the horizontal photodiode further comprises a second metal ring disposed adjacent to the sidewall of the raised epitaxial layer and electrically connected to the second conductive epitaxial layer.

11. A method for manufacturing a horizontal photodiode, the method comprising the following steps: An epitaxial growth substrate is provided, and a first conductivity type in-situ doped epitaxial layer, an intrinsic epitaxial layer, and a second conductivity type epitaxial layer are sequentially epitaxially grown on the epitaxial growth substrate. An optical bonding layer is provided on the second conductivity epitaxial layer; After bonding the transparent substrate to the optical bonding layer, the epitaxial growth substrate is removed; A laser-sintered sidewall is provided at the outer periphery of the first conductivity type in-situ doped epitaxial layer; Partial removal of the first conductivity type in-situ doped epitaxial layer and intrinsic epitaxial layer to form a raised epitaxial layer; and Provides an optical layer covering the surface and sidewalls of the platform epitaxial layer.

12. The method for manufacturing a horizontal photodiode as described in claim 11, wherein, The step of providing laser sintered sidewalls is to provide a laser to form laser sintered sidewalls disposed on the outer periphery of the first conductivity type in-situ doped epitaxial layer and in the intrinsic epitaxial layer.

13. The method for manufacturing a horizontal photodiode as described in claim 11, wherein, The step of providing the first conductivity type in-situ doped epitaxial layer is to provide an N-type in-situ doped indium phosphide epitaxial layer.

14. The method for manufacturing a horizontal photodiode as described in claim 13, wherein, The steps for providing an N-type in-situ doped indium phosphide epitaxial layer involve simultaneously doping with either sulfur or silicon during the indium phosphide epitaxial process via metal-organic chemical vapor deposition, with a doping concentration of 10. 17~19 cm -3 .

15. The method for manufacturing a horizontal photodiode as described in claim 11, wherein, The step of providing the optical bonding layer is to provide a distributed Bragg reflector layer.

16. The method for manufacturing a horizontal photodiode as described in claim 11, wherein, The method for manufacturing the horizontal photodiode further includes a step of providing a first metal ring after the step of providing a laser sintered sidewall, wherein the first metal ring is disposed on the surface of a first conductive in-situ doped epitaxial layer inside the laser sintered sidewall.

17. The method of manufacturing a horizontal photodiode as claimed in claim 11, the method of manufacturing a horizontal photodiode further comprising providing a second metal ring disposed adjacent to a sidewall of a raised epitaxial layer and electrically connected to a second conductive epitaxial layer.

18. The method for manufacturing a horizontal photodiode as described in claim 11, wherein, The step of providing the optical layer is to provide a multi-band bandpass filter layer to allow light of a specific band in the external light to pass through while blocking other light in the external light except for that specific band.

19. The method for manufacturing a horizontal photodiode as described in claim 18, wherein, The step of providing the optical layer further includes providing an anti-reflective layer to reduce surface reflection loss of the optical layer.

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