CN112054086B - A method for preparing a silicon-based photodetector with a lateral junction - Google Patents

Abstract

The invention relates to a preparation method of a lateral junction silicon-based photoelectric detector, which is characterized in that a lateral pn junction or a heterojunction is formed by the carrier conductivity type or concentration difference between the surface of black silicon prepared by pulse laser and an unprocessed silicon region, and the black silicon photoelectric detector with the lateral junction can be formed through subsequent processes of annealing, passivation, photoetching, electrode preparation and the like. The lateral junction silicon-based photoelectric detector can efficiently absorb photons to generate electron-hole pairs under the reverse bias voltage, and can transversely migrate under the action of an external electric field to finally form a lateral photocurrent, so that optical signal detection is realized. The invention has the advantages of simple process, easily obtained raw materials, easy operation and control, compatibility with the existing semiconductor device process and the like, and compared with the traditional vertical structure detector, the horizontal junction silicon-based photoelectric detector prepared by the invention has the advantages of effectively inhibiting dark current, improving the detection rate of the device, simplifying the preparation flow of the device and being more beneficial to the preparation and integration of the device.

Description

A method for preparing a silicon-based photodetector with a lateral junction

Technical Field

The invention relates to the field of silicon-based photoelectric devices, and in particular to a method for preparing a photoelectric detector, which is a lateral junction silicon-based photoelectric detector with lower dark current.

Background technique

In recent decades, with the rapid development of semiconductor technology, semiconductor devices with various functions have continuously improved people's lives and have great potential for the next generation of industrial revolution (such as artificial intelligence, the Internet of Everything, unmanned driving, etc.). As the most common and important semiconductor material, silicon material has the advantages of abundant content, low price, high purity and few defects. So far, silicon has exerted great potential in the field of microelectronics, constantly breaking the limits of Moore's Law, and promoting the innovation and development of semiconductor technology. However, in the field of optoelectronics, due to the limitation of the energy band width of 1.12eV and the high reflectivity of the single crystal silicon surface, the absorption rate of silicon is suppressed, especially the absorption in the infrared band, which greatly limits the development of silicon photonics.

Doping with different elements is an important method to improve the photoelectric properties of semiconductor materials, and is a common modification method in the fields of photodetectors, solar cells, etc. However, due to the limitation of solid solubility, it is difficult to achieve supersaturated doping of doping elements by traditional thermal diffusion process. With the development of semiconductor technology, ion implantation and ultrafast pulse laser supersaturated doping can achieve supersaturated doping beyond solid solubility. In particular, after ultrafast pulse laser modification, micro-cone structure and supersaturated doping layer can be formed on the surface of crystalline silicon at the same time, which can realize the characteristics of broad spectrum and high response of photodetectors. However, this modification process will inevitably introduce a large number of impurities and lattice defects, which will have an adverse effect on the dark current and signal-to-noise ratio of the device, which greatly reduces the performance of semiconductor devices and limits the application range of the devices.

Summary of the invention

In order to solve the above problems, the inventors have proposed a method for preparing a lateral junction silicon-based photodetector after long-term experiments and research. On the one hand, it improves the shortcomings of high dark current and low signal-to-noise ratio of traditional silicon-based photodetectors, and on the other hand, it makes up for the disadvantage that silicon-based materials are difficult to be compatible with existing CMOS after supersaturated doping.

According to the technical solution of the present invention, a method for preparing a lateral junction silicon-based photodetector is provided, comprising the following steps:

Step 1: Select a semiconductor single crystal silicon wafer and perform pretreatment, including but not limited to slicing, RCA cleaning, and pre-coating a film containing doping elements on the silicon surface;

Step 2: Select the processed single crystal silicon material, irradiate a specific area of its surface with an ultrafast pulse laser in a specific atmosphere to prepare a supersaturated doping layer, that is, obtain a black silicon surface;

Step 3: Annealing the prepared black silicon material to activate the impurity atoms in the supersaturated doped black silicon layer, repair the lattice, and remove structural defects;

Step 4: A passivation layer is plated on the black silicon and the silicon surface areas where electrode contact is not required to protect the detector surface and isolate it from air pollution and oxidation;

Step 5: Contact electrodes are plated on the silicon and black silicon regions respectively; thus, the preparation of the lateral junction silicon-based photodetector is completed;

The dark current of the lateral junction silicon-based photodetector under -5V bias can be reduced to 783nA, which is much smaller than the traditional vertical structure black silicon photodetector; at the same time, the device has a response band of 500nm-1400nm, and a peak responsivity of 3.23A/W under -5V bias, with the peak wavelength appearing around 1080nm. The specific meanings of the mathematical symbols are: nm: nanometer, V: volt, A/W: ampere/watt, nA: nanoampere.

Furthermore, the single crystal silicon substrate described in step 1 can be either n-type or p-type, with a thickness of 5μm-500μm (micrometers), and the crystal orientation, resistivity and size of the semiconductor wafer are not limited; the surface of the single crystal silicon substrate is flat, and the surface flatness, that is, the difference between the highest point and the lowest point on the material surface is less than or equal to 10μm.

Furthermore, the pretreatment in step 1 may be selected from but not limited to the following processes: (a) cutting the single crystal silicon wafer into small pieces of a certain size; (b) cleaning the single crystal silicon by RCA cleaning method; (c) depositing a thin film containing doped substances of a certain thickness on the silicon surface by coating process or thin film growth process.

Furthermore, the specific steps of preparing the supersaturated doped black silicon layer by ultrafast pulse laser irradiation described in step 2 are as follows:

(1) The cleaned single crystal silicon is fixed on a three-dimensional translation stage in a vacuum chamber. Driven by the translation stage, the sample moves two-dimensionally on a plane perpendicular to the incident laser. The appropriate moving range and moving speed are selected by setting the parameters of the three-dimensional translation stage, and the shutter is switched on and off to achieve the preparation of different patterns and structures;

(2) Evacuate the chamber to a vacuum degree of 10 ⁰ -10 ^-5 Pa, then fill it with a gas with a pressure less than 1 standard atmosphere, such as sulfur hexafluoride, nitrogen, etc., or evacuate it to a vacuum state;

(3) Control the movement of the sample stage: Control the area and scanning speed of the ultrafast pulse laser supersaturation doping and modification by controlling the moving speed and moving range, that is, make a two-dimensional movement on a plane perpendicular to the incident laser direction; adjust the polarization direction and power of the laser irradiated to the single crystal silicon surface through a Glan-Taylor prism and a half-wave plate, so that the laser flux irradiated to the single crystal silicon surface is 0.01kJ/ ^m2-100kJ / ^m2 , the number of pulses received per unit area is 1-5000, and the pulse width of the ultrafast pulse laser is 5fs-100ns, thereby controlling the surface modification intensity and doping concentration; it can not only scan and process a large area of supersaturated doped layer line by line, but also set different scanning patterns and paths and cooperate with the shutter switch to prepare micro-area supersaturated doped layers and supersaturated doped layers of different patterns;

(4) After the scan is completed, the gas in the vacuum chamber is evacuated and then filled with nitrogen to a standard atmospheric pressure. The vacuum chamber cover is opened, and the sample silicon wafer is taken out. The processed area (i.e., the black silicon layer) is detected to be black or dark gray. The surface of the single crystal silicon material processed by the above steps forms a quasi-periodic micro-nano structure and is doped with a large amount of impurity elements.

Preferably, the annealing method described in step 3 can be selected from but not limited to: rapid thermal annealing, tube furnace annealing, ultrafast pulse laser annealing, femtosecond laser annealing and the like.

Furthermore, the preparation method of the passivation layer in step 4 includes resistance thermal evaporation, magnetron sputtering, electron beam _evaporation , pulsed laser deposition, chemical _vapor deposition, heteroepitaxial growth, etc.; the passivation material is one or a combination of passivation materials such as _Al2O3 , _SiNx , _Si2O3 , a-Si:H, phosphosilicate glass, polyimide, etc. The preparation method can be to prepare the passivation layer after photolithography patterning, or to prepare the passivation layer after metal mask masking.

Furthermore, the contact electrodes of the black silicon and silicon regions in step 5 are prepared by resistance thermal evaporation, magnetron sputtering, electron beam evaporation or pulsed laser deposition; the electrode material is one or a combination of aluminum, gold, silver, chromium, nickel, titanium or platinum; the electrode shape can be prepared into a rectangular, annular, circular, elliptical, or other irregular shapes.

Beneficial Effects

Compared with the prior art, the present invention has the following advantages:

1. The lateral junction silicon-based photodetector prepared by the present invention has a more stable lateral pn junction or heterojunction, and compared with the vertical structure silicon-based photodetector, it reduces its dark current and improves the stability of the device.

2. The present invention simultaneously plates positive and negative electrodes on the black silicon and silicon material areas on the front side after ultrafast pulse laser irradiation. Compared with the conventional method of plating positive and negative electrodes on the front and back sides of black silicon photodetectors or etching the table top before plating electrodes, the present invention not only ensures the stability of the device, reduces the leakage noise of the device, but also simplifies the preparation process;

3. The external quantum efficiency of the lateral junction silicon-based photodetector prepared by the present invention exceeds 100% in the 640-1170nm band under a bias of -5V, achieving the characteristics of wide spectrum and high gain under low bias; in addition, the dark current of the lateral junction silicon-based photodetector prepared by the present invention is 783nA under a bias of -5V, overcoming the shortcomings of femtosecond laser oversaturation doping and the difficulty in suppressing the dark current of the modified photodetector.

4. The preparation processes adopted by the present invention are all CMOS compatible processes, which have the advantage of being compatible with existing semiconductor processes such as CMOS and CCD.

5. The present invention has the advantages of simple structure, simple process, easy acquisition of raw materials, easy processing and easy storage.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic flow chart of a method for preparing a lateral junction silicon-based photoelectric detector provided by the present invention.

FIG2 is a cross-sectional structural diagram of the lateral junction silicon-based photoelectric detection provided by the present invention.

Detailed ways

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In addition, the scope of protection of the present invention should not be limited to the following specific structures or components or specific parameters.

The present invention utilizes the lateral interface formed between black silicon and unprocessed silicon after ultrafast pulse laser modification, and through subsequent passivation, metal electrode preparation and other processes, utilizes the difference in carrier types and concentrations at the lateral interface between black silicon and silicon to form a lateral pn junction or n ⁺ -i junction heterostructure, thereby forming a lateral junction silicon-based photodetector. Among them, the surface of the black silicon layer has a quasi-periodic arrangement of micro-cone structures, and the surface has supersaturated doped impurity elements. After subsequent annealing treatment, the impurity elements in the black silicon doping layer are activated, so that it has a light absorption rate greater than 80% in a wide spectrum range (0.25μm-2.5μm), which greatly improves the absorption rate of semiconductor silicon materials and expands its spectral absorption range. The lateral junction silicon-based photodetector works under reverse bias voltage, absorbs photons to generate photogenerated electron-hole pairs, and migrates laterally to the electrodes on both sides under the action of the electric field, and is collected by the electrodes to form a lateral photocurrent, thereby realizing light response and detection.

In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the preparation method of the lateral junction silicon-based photodetector of the present invention is further described below in conjunction with the accompanying drawings, including the following specific steps:

Figure 1 is a cross-sectional structural diagram of a lateral junction silicon-based photodetector provided by the present invention, wherein 1-1 is a single crystal silicon substrate, 1-2 is a black silicon layer after femtosecond laser supersaturation doping, 1-3 is a surface passivation layer, and 1-4 are contact electrodes of black silicon and silicon, respectively.

FIG2 is a schematic flow chart of a method for preparing a lateral junction silicon-based photodetector provided by the present invention.

In conjunction with and referring to FIG. 2 , a more detailed method for preparing a lateral junction silicon-based photodetector provided by the present invention is described, which comprises the following steps:

Step 1: Select a single crystal silicon substrate with a clean and flat surface;

Step 2: pre-processing the selected single crystal silicon wafer, including but not limited to slicing, RCA cleaning, and coating a thin film containing the element to be doped on the silicon surface;

Step 3: Place the processed single crystal silicon into a vacuum chamber and fix it on a sample holder so that the incident laser is vertically irradiated onto the sample surface;

Step 4: Evacuate to 10 ⁰ -10 ^-5 Pa, fill with specific gas below 1 atmosphere pressure or maintain vacuum according to the doping elements;

Step 5: Surface micro-nano structures and supersaturated doping layers are prepared by irradiating specific areas of the single crystal silicon surface with pulsed laser in a specific pressure and atmosphere. The sample is driven by a three-dimensional translation stage to perform two-dimensional plane scanning motion. By controlling the scanning speed and scanning line by line, a large area of black silicon layer can be processed.

Step 6: After the processing is completed, the gas in the processing chamber is evacuated, and nitrogen is then filled to a standard atmospheric pressure. The chamber cover is opened, and the sample is taken out. The processed area is black or dark gray when observed with the naked eye. The surface of the silicon material treated by the above steps forms a quasi-periodic arrangement of micro-nano structures and is doped with a large amount of impurity elements, thereby obtaining a black silicon surface;

Step 7: Select a suitable annealing method to further process the prepared black silicon material, such as rapid thermal annealing, tube furnace annealing, nanosecond laser melting annealing or femtosecond laser annealing, etc., and adjust the annealing temperature and annealing time and other parameters to activate the doping elements in the black silicon layer, remove defects, and repair damaged lattices;

Step 8: Prepare a passivation layer in the area other than the black silicon and silicon contacting the electrode, and reserve the area that needs to contact the electrode through a photolithography mask process or a physical mask process. The preparation method of the passivation layer can be resistance thermal evaporation, magnetron sputtering, electron beam evaporation, chemical vapor deposition, pulsed laser deposition, heteroepitaxial growth method, etc.; the passivation material can be one of _{Al2O3 , SiNx} , _Si2O3 , a-Si:H, phosphosilicate glass, polyimide, etc. _, or a combination thereof.

Step 9: Through a photolithography mask process or a physical mask process, in the electrode contact area retained in step 8, a black silicon contact electrode and a silicon contact electrode are prepared respectively. The metal contact electrodes of black silicon and silicon can be prepared at the same time or separately. The preparation method of the metal electrode can be resistive thermal evaporation, magnetron sputtering, electron beam evaporation, pulsed laser deposition, etc.; the electrode material can be one of aluminum, gold, silver, chromium, nickel, titanium or platinum or a combination thereof; the electrode shape can be rectangular, annular, circular, elliptical, or other irregular shapes.

Among them, the single crystal silicon substrate described in step 1 can be either n-type or p-type, with a thickness of 100μm-500μm (micrometers), and the crystal orientation, resistivity and size of the semiconductor wafer are not limited; the single crystal silicon substrate requires a flat surface, and the surface flatness, that is, the difference between the highest point and the lowest point on the material surface is less than or equal to 10μm.

Furthermore, the gas in step 4 can be one of nitrogen, hydrogen, sulfur hexafluoride, oxygen, helium, argon, carbon tetrafluoride, etc. or a combination thereof, or can be a vacuum environment, and the pressure can be from 10 ^-5 Pa to 1 atmosphere.

Furthermore, there are many options for the laser parameters and irradiation conditions in the above step 5, such as nanosecond laser, picosecond laser, femtosecond laser, attosecond laser. The laser parameters used in this case are femtosecond laser with a central wavelength of 800nm and a pulse width of 120fs. The polarization direction and power of the laser irradiated to the surface of the single crystal silicon can be continuously adjusted through a combination of a Glan-Taylor prism and a half-wave plate, so that the femtosecond laser flux is 0.8kJ/ ^m2-8kJ / ^m2 . The number of pulses received per unit area can be 1-500 by adjusting the stepper motor.

The dark current of the fabricated lateral junction silicon-based photodetector can be reduced to 783nA under a bias voltage of -5V, which is much smaller than the traditional vertical structure black silicon photodetector; at the same time, the device has a response band of 500nm-1400nm, and a peak responsivity of 3.23A/W under a bias voltage of -5V, with a peak wavelength of around 1080nm. The specific meanings of the mathematical symbols are: nm: nanometer, V: volt, A/W: ampere/watt, nA: nanoampere.

In summary, the lateral junction silicon-based photodetector prepared using the above preparation method includes: preparing a supersaturated doped black silicon surface and forming a black silicon-silicon lateral interface; annealing the prepared black silicon material; passivation to protect the material surface; and making contact electrodes between black silicon and silicon and metal. At this point, the lateral junction silicon-based photodetector device is completed.

Implementation Example 1:

A method for preparing a lateral junction silicon-based photodetector comprises the following steps:

Step 1: Select a 2-inch n-type (100) zone-melting single crystal silicon wafer with a resistivity of 3000-5000Ω·cm and a thickness of 430±10μm;

Step 2: Pre-treat the selected single crystal silicon wafer, the specific steps are: (a) clean the single crystal silicon wafer by a standard RCA cleaning method; (b) cut the single crystal silicon wafer into small units.

Step 3: Place the cleaned single crystal silicon into a vacuum chamber and fix it on a sample holder so that the incident laser is perpendicular to the sample surface. The sample holder is connected to a three-dimensional moving stage. Driven by the translation stage, the sample can move two-dimensionally on a plane perpendicular to the incident laser.

Step 4: Evacuate to 10 ^-5 Pa, then fill with 0.67 bar sulfur hexafluoride gas, and finally process in a 0.67 bar sulfur hexafluoride atmosphere;

Step 5: The central wavelength of the incident femtosecond laser is 800nm, the pulse width is 120fs, and the laser flux irradiated to the silicon wafer surface is 1.0kJ/ ^m2 . The sample is driven by a two-dimensional translation stage to perform a two-dimensional scanning motion, scanning line by line, scanning a square area of 1cm×1cm, with a scanning line spacing of 50μm and a scanning speed of 1mm/s;

Step 6: After the processing is completed, the chamber is evacuated to 10 ^-5 Pa, and then filled with nitrogen to atmospheric pressure. The chamber cover is opened and the sample is taken out. The processed area is observed by naked eyes to be black or dark gray, that is, a black silicon layer supersaturated with sulfur. The thickness of the doped layer is about 100nm, while the unprocessed area still maintains the smooth polishing characteristics of single crystal silicon;

Step 7: Treat the sample irradiated by femtosecond laser with a rapid thermal annealing method. The first step is to increase the temperature, first to 240°C within 10s, and then to 600°C within 5s; the second step is to maintain a constant temperature, and the temperature is maintained at 600°C for 600s; the third step is to naturally cool down to below 100°C and take out the sample;

Step 8: Use plasma enhanced chemical vapor deposition (PECVD) to prepare a _SiO2 passivation layer on the black silicon surface, and the thickness of the passivation layer is about 1μm; then use ultraviolet photolithography technology to use photoresist to protect the material surface, exposing only some black silicon and silicon areas that need electrode contact; then place the sample in diluted hydrofluoric acid for cleaning for 5 seconds to remove the _SiO2 passivation layer in the area not covered by the photoresist; then remove the photoresist by cleaning with acetone.

Step 9: Use the method of resistive thermal evaporation to prepare aluminum metal electrodes as positive and negative contact electrodes on the black silicon and silicon surface areas. The specific method is as follows: Mask the material surface by spin coating photoresist and ultraviolet photolithography technology. The hollow areas not covered by the photoresist after masking correspond to the black silicon and the areas on the silicon that need to be plated with electrodes. Fix the sample after photolithography masking directly above the molybdenum boat of the evaporation coating machine, put an appropriate amount of aluminum particles in the molybdenum boat, evacuate to 3× ^10-3 Pa, and then evaporate and deposit aluminum electrodes; then remove the photoresist by acetone cleaning, and the device manufacturing is completed.

The dark current of the lateral junction silicon-based photodetector prepared through the above steps can be reduced to 783nA under -5V bias. The lateral heterojunction effectively solves the defect that the dark current of the black silicon photodetector is difficult to suppress; and achieves high gain and wide spectrum characteristics under low bias. The response band of the device is 500nm-1400nm, and the peak responsivity under -5V bias is 3.23A/W, where the peak wavelength appears near 1080nm. The signal-to-noise ratio and dynamic range of the device are effectively improved.

The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. It can be understood by a person of ordinary skill in the art that various modifications can be made in form and details without departing from the spirit and scope of the present invention defined in the appended claims.

Claims (7)

1. A preparation method of a lateral junction silicon-based photoelectric detector with low dark current is characterized by comprising the following steps:

step 1: selecting a monocrystalline silicon wafer, and preprocessing the selected silicon wafer;

step 2: selecting pretreated monocrystalline silicon, irradiating a specific area of the surface of the monocrystalline silicon in a specific atmosphere or vacuum by pulse laser, and preparing a supersaturated doped layer to obtain a black silicon surface;

Step 3: annealing the prepared black silicon material, activating impurity atoms in the supersaturated doped black silicon layer, repairing crystal lattices, and removing structural defects;

Step 4: plating a passivation layer on the black silicon surface except for the electrode contact area to protect the black silicon surface and isolate air pollution and oxidation;

Step 5: plating contact electrodes on the electrode contact areas of the silicon and the black silicon respectively; thus, the preparation of the transverse silicon-based photoelectric detector is completed;

The specific atmosphere is one or a combination of nitrogen, hydrogen, sulfur hexafluoride, oxygen, helium, argon and carbon tetrafluoride; the specific region is a region having a size of 1 μm (micrometer) -1cm (centimeter) and a shape that is one of square, rectangle, circle, ellipse, triangle, or a combination thereof.

2. The method of fabricating a lateral junction silicon-based photodetector device of claim 1, wherein the single crystal silicon selected in step 1 is either n-type or p-type and has a thickness of 5 μm to 500 μm (micrometers).

3. The method of fabricating a lateral junction silicon-based photodetector of claim 1, wherein the pretreatment process in step 1 comprises: (1) cutting a monocrystalline silicon piece into small pieces of a certain size; (2) cleaning the monocrystalline silicon by an RCA cleaning method; (3) And depositing a layer of film containing doping substances on the surface of the silicon by a film plating process or a film growing process.

4. The method for preparing the lateral junction silicon-based photoelectric detector according to claim 1, wherein the specific steps for preparing the supersaturated doped black silicon surface by pulse laser irradiation in the step 2 are as follows:

(1) Fixing the pretreated monocrystalline silicon material on a three-dimensional translation stage in a vacuum cavity, driving the translation stage to make a sample perform two-dimensional motion on a plane vertical to incident laser, and selecting a proper moving range and a proper moving speed through parameter setting of the three-dimensional translation stage so as to control the area and the scanning speed of a supersaturated doped and modified area of pulse laser and realize preparation of different patterns and structures by matching with a shutter;

(2) Vacuumizing, wherein the vacuum degree is 10 ⁰-10^-5 Pa, and then filling a specific atmosphere with the pressure less than 1 standard atmosphere or maintaining the vacuum state;

(3) Scanning pulse laser: the sample is subjected to two-dimensional motion on a plane perpendicular to the direction of incident laser by controlling the translation stage; the pulse width of the incident pulse laser is 5fs-100ns, the polarization direction and the power of the laser irradiated to the surface of the monocrystalline silicon are regulated through a gram-Taylor prism and a half-wave plate, so that the laser flux irradiated to the surface of the monocrystalline silicon is 0.01kJ/m ²-100kJ/m², and the number of pulses received per unit area is 1-5000, thereby controlling the surface modification strength and the doping concentration; the method can scan and process a large-area supersaturated doped layer line by line, and can set different scanning patterns and paths or be matched with a shutter switch to prepare a micro-area supersaturated doped layer and supersaturated doped layers with different patterns;

(4) After the scanning is finished, the gas in the vacuum cavity is pumped out, then nitrogen is filled to a standard atmospheric pressure, the vacuum cavity cover can be opened, the sample silicon wafer is taken out, and the processed area, namely the black silicon layer, is detected to be black or dark gray; the surface of the silicon material treated by the steps forms a micro-nano structure with quasi-periodic arrangement, and a large amount of impurity elements are doped.

5. The method for manufacturing a lateral junction silicon-based photodetector according to claim 1, wherein the annealing method in step 3 is one of rapid thermal annealing, tube furnace annealing, ultra-rapid pulse laser annealing, femtosecond laser annealing, or a combination thereof.

6. The method for manufacturing a lateral junction silicon-based photodetector according to claim 1, wherein the method for manufacturing a passivation layer in step 4 comprises a resistive thermal evaporation method, a magnetron sputtering method, an electron beam evaporation method, a pulse laser deposition method, a chemical vapor deposition method, a heteroepitaxial growth method; the passivation material is Al ₂O₃、SiN_x、Si₂O₃, a-Si: H. one or a combination of phosphosilicate glass and polyimide, the mask mode can be to prepare the passivation layer after photoetching patterns, remove the passivation layer of the electrode contact area after preparing the passivation layer by photoetching, and also can prepare the passivation layer after masking through a mask plate.

7. The method for manufacturing a lateral junction silicon-based photodetector according to claim 1, wherein the method for manufacturing a contact electrode of the electrode contact region of the black silicon and the silicon in step 5 is a resistive thermal evaporation method, a magnetron sputtering method, an electron beam evaporation method or a pulsed laser deposition method; the electrode material is one or a combination of aluminum, gold, silver, chromium, nickel, titanium or platinum; the electrode shape is prepared into rectangle, ring, round and oval; the mask mode can be to prepare the metal electrode after photoetching patterns, or to prepare the metal electrode after physical mask masking.