A unidirectional capacitive TVS device with two photomasks

Abstract

This invention relates to the field of TVS device technology, specifically to a processing apparatus for a unidirectional permeable TVS device with two photomasks. The apparatus includes a housing with side grooves on both sides. A placement plate, a servo motor, and a rotating rod are provided. After the TVS device to be cleaned is placed in the corresponding placement groove, the servo motor is driven, causing the rotating rod to rotate. The rotating rod drives multiple rotating plates on the outer side to agitate the cleaning fluid inside the housing. Simultaneously, the rotating rod also drives the bottom grooved wheels at both ends to rotate. The bottom grooved wheels drive the top grooved wheel to rotate via a belt. The top grooved wheel drives a round shaft to rotate, which in turn drives a gear to rotate. The gear drives a rack to move, which in turn drives a movable plate to move. The movable plate drives a connecting plate to move. The two connecting plates together drive multiple placement plates on a U-shaped frame to move back and forth repeatedly inside the housing. Combined with the agitation of the rotating plates, this allows the cleaning fluid to repeatedly flush the TVS device, achieving a good cleaning effect.

Description

Technical Field

[0001] This invention relates to a unidirectional capacitive TVS device, specifically a unidirectional capacitive TVS device with two photomasks and its fabrication method. Background Technology

[0002] TVS devices are overvoltage protection devices. When the two poles of a TVS device are subjected to a reverse transient high-energy impact, it can use its avalanche principle to change the high impedance between its two poles to a low impedance at a speed on the order of 10 to the power of -12 seconds, absorbing surge power of up to several kilowatts, clamping the voltage between the two poles to a predetermined value, and effectively protecting the precision components in electronic circuits from damage by various surge pulses.

[0003] In the manufacturing process of a unidirectional capacitive TVS device with two photomasks, metal deposition and etching processes are required. Before metal deposition, cleaning is necessary. Existing cleaning equipment typically uses conventional rinsing methods, which, while capable of cleaning, have poor cleaning results, cannot perform simultaneous cleaning of large batches of products, and are inefficient, failing to meet the demands of large-scale production. Furthermore, the cleaning process lacks water circulation, resulting in significant water waste. Therefore, this invention proposes a unidirectional capacitive TVS device with two photomasks and its fabrication method. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a unidirectional permeable TVS device with two photomasks.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] A processing apparatus for a unidirectional permeable TVS device with a two-layer photomask includes a housing. Side grooves are formed on both the left and right sides of the housing. A servo motor is located on the right side of the housing. A rotating rod is fixedly connected to the left side of the servo motor. The left end of the rotating rod passes through the housing and is rotatably connected to it. Several rotating plates are fixedly connected to the outer side of the rotating rod. Round shafts are rotatably connected to the top of both the left and right sidewalls of the housing. A transmission mechanism is provided between two of the round shafts and the rotating rod. Gears are fixedly connected to the ends of the two round shafts that are furthest apart. Racks mesh with the tops of the two gears. Movable plates are fixedly connected to the tops of the two racks. The movable plate extends through a side groove on the side away from the rack and is movably connected to the bottom of the inner wall of the side groove. Connecting plates are fixedly installed on opposite sides of both movable plates. A round rod is fixedly connected between the two connecting plates, and a U-shaped frame is inserted into both connecting plates. Several placement plates are fixedly installed on the bottom inner wall of the U-shaped frame. Several placement slots are opened on the top of each placement plate, and several round holes are opened on the bottom inner wall of each placement slot. A spraying mechanism is jointly provided on the top of both connecting plates. A guide plate is fixedly connected to the bottom inner wall of the outer casing. The guide plate is triangular in shape, with its tip pointing upwards.

[0007] As a preferred embodiment of the present invention, the transmission mechanism includes two grooved wheels, which are respectively sleeved on the outer side of the round shaft and the rotating rod, and a belt is provided on the outer side of the two grooved wheels. The two grooved wheels are connected by belt drive.

[0008] As a preferred embodiment of the present invention, the spraying mechanism includes two crossbeams, which are respectively fixedly connected to the top of the outer casing near the left and right sides. A water pump is fixedly installed on the top of each of the two crossbeams. A water pump pipe is inserted into the side of each of the two water pumps that is away from the water pump. The end of the water pump pipe that is away from the water pump is inserted into the side wall of the outer casing near the bottom. A conduit is inserted into the opposite side of each of the two water pumps. A hollow plate is inserted into the opposite side of the two conduits. Several nozzles are inserted into the bottom of the hollow plate.

[0009] As a preferred embodiment of the present invention, a slider is fixedly connected to the bottom of the movable plate, and a sliding groove is provided on the bottom of the inner wall of the side groove, and the slider is slidably connected to the inner cavity of the corresponding sliding groove.

[0010] As a preferred embodiment of the present invention, two drain pipes are inserted and installed on both the front and rear sides of the outer casing, the two drain pipes are arranged left and right, and each of the two drain pipes is equipped with a valve.

[0011] As a preferred embodiment of the present invention, the connecting plate and the movable plate are connected by two fixing bolts via a common thread.

[0012] As a preferred embodiment of the present invention, the servo motor is fixedly connected to a bracket at its bottom, and the bracket is fixedly connected to the side wall of the housing.

[0013] A method for fabricating a unidirectional capacitive TVS device with two photomasks includes the following steps:

[0014] S1: Substrate Material Preparation: The epitaxial substrate adopts a P-type crystal orientation, is boron-doped, and typically has a resistivity of 0.003-0.004 Ω·cm. Epitaxial growth is performed on the substrate, and the resistivity and thickness of the grown epitaxial layer are determined by the different device breakdown voltages. Typically, the epitaxial thickness is 6-20 μm, the epitaxial resistivity is 0.013-0.5 Ω·cm, and the device breakdown voltage can reach 5V-36V.

[0015] S2: Initial oxygen growth: A layer of SiO2 with a thickness of 6500-10000 angstroms is grown on the surface of the wafer as a barrier layer for doping or implantation.

[0016] S3: Base region formation: The base region window is formed by photolithography and etching of the initial oxide using a base region implantation plate. The N-type region is then formed by doping or implantation and high temperature. The doping resistance is controlled at 9-11 keV, the implantation energy is 60-80 keV, the dose is 8E14-1.4E15, and the propagation conditions are 1100℃ / 120min.

[0017] S4: Metal deposition and etching: Before metal deposition, the wafer is cleaned to remove 500-100 Å of the oxide layer on the wafer surface. A 4µm thick aluminum is deposited. A certain proportion of Cu can be doped into the aluminum to prevent aluminum and silicon from dissolving together. Then, the aluminum is etched by photolithography.

[0018] S5: Passivation layer deposition and etching. The passivation layer is a co-deposit of SRO and SRN at 10KA. The passivation layer window is formed by photolithography and etching using the base region implantation dies.

[0019] S6: Backside Ti-Ni-Ag: Thin the backside of the wafer to about 150um, and evaporate Ti-Ni-Ag on the backside.

[0020] This invention provides a unidirectional capacitive TVS device with two photomasks, which has the following advantages:

[0021] 1. Equipped with a placement plate, servo motor, and rotating rod, after the TVS device to be cleaned is placed in the corresponding placement slot, the servo motor is driven, causing the rotating rod to rotate. The rotating rod drives multiple rotating plates on the outside to agitate the cleaning fluid inside the housing. At the same time, the rotating rod also drives the bottom grooved wheels at both ends to rotate. The bottom grooved wheels drive the top grooved wheel to rotate via a belt. The top grooved wheel drives the round shaft to rotate. The round shaft drives the gear to rotate. The gear drives the rack to move. The rack drives the movable plate to move. The movable plate drives the connecting plate to move. The two connecting plates together drive the multiple placement plates on the U-shaped frame to move back and forth repeatedly inside the housing. In conjunction with the agitation of the rotating plate, the cleaning fluid repeatedly washes the TVS device, achieving a good cleaning effect.

[0022] 2. The system is equipped with a water pump, a water suction pipe, a conduit, and a nozzle. When the water pump is started, it draws the cleaning fluid from inside the housing through the water suction pipe, then flows into the hollow plate through the conduit, and sprays it from top to bottom through the nozzle at the bottom of the hollow plate. This works in conjunction with the TVS device that moves back and forth to achieve a better cleaning effect. The sprayed cleaning fluid then flows back into the housing, thus achieving circulation. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 This is a schematic diagram of the external structure of the present invention from one angle;

[0025] Figure 2 This is a schematic diagram of the external structure of the present invention from another angle;

[0026] Figure 3 This is a schematic diagram of the cross-sectional structure of the present invention;

[0027] Figure 4 This is a schematic diagram of the structure of the outer casing of the present invention;

[0028] Figure 5 This is a schematic diagram of the internal structure of the present invention from one angle;

[0029] Figure 6 This is a schematic diagram of the internal structure of the present invention from another perspective;

[0030] Figure 7 This is the present invention. Figure 6 A schematic diagram of a local structure in the image;

[0031] Figure 8 This is the present invention. Figure 7 A schematic diagram of a local structure.

[0032] In the diagram: 1. Outer shell; 2. Drain pipe; 3. Valve; 4. Side groove; 5. Horizontal frame; 6. Water pump; 7. Pumping pipe; 8. Conduit; 9. Hollow plate; 10. Nozzle; 11. Guide plate; 12. Support; 13. Servo motor; 14. Rotating rod; 15. Rotating plate; 16. Grooved wheel; 17. Belt; 18. Round shaft; 19. Gear; 20. Rack; 21. Movable plate; 22. Connecting plate; 23. Fixing bolt; 24. U-shaped frame; 25. Placement plate; 26. Placement groove; 27. Round hole; 28. Round rod; 29. ​​Slide groove; 30. Slider. Detailed Implementation

[0033] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0034] Example: Figure 1-8 As shown, a processing apparatus for a unidirectional permeable TVS device with a two-layer photomask includes a housing 1. Side grooves 4 are provided on both the left and right sides of the housing 1. A servo motor 13 is located on the right side of the housing 1. A rotating rod 14 is fixedly connected to the left side of the servo motor 13. The left end of the rotating rod 14 passes through the housing 1 and is rotatably connected to it. Several rotating plates 15 are fixedly connected to the outer side of the rotating rod 14. Round shafts 18 are rotatably connected to the left and right sidewalls of the housing 1 near the top. A transmission mechanism is provided between the two round shafts 18 and the rotating rod 14. Gears 19 are fixedly connected to the ends of the two round shafts 18 that are furthest apart. Racks 20 mesh with the tops of the two gears 19. Movable plates 21 are fixedly connected to the tops of the two racks 20. The movable plate 21, on the side away from the rack 20, passes through the side groove 4 and is movably connected to the bottom of the inner wall of the side groove 4. A connecting plate 22 is fixedly installed on the opposite side of the two movable plates 21. A round rod 28 is fixedly connected between the two connecting plates 22. A U-shaped frame 24 is inserted and installed on both connecting plates 22. Several placement plates 25 are fixedly installed on the bottom of the inner wall of the U-shaped frame 24. Several placement slots 26 are opened on the top of the placement plates 25. Several round holes 27 are opened on the bottom of the inner wall of the placement slots 26. A spraying mechanism is set on the top of the two connecting plates 22. A guide plate 11 is fixedly connected to the bottom of the inner wall of the outer shell 1. The guide plate 11 is triangular and the tip of the guide plate 11 is facing upward.

[0035] The transmission mechanism includes two grooved wheels 16, which are respectively sleeved on the outer side of the round shaft 18 and the rotating rod 14. A belt 17 is provided on the outer side of the two grooved wheels 16. The two grooved wheels 16 are connected by the belt 17. This arrangement realizes the power transmission between the rotating rod 14 and the round shaft 18, which greatly increases the energy utilization rate and reduces the production cost.

[0036] The spraying mechanism includes two horizontal frames 5, which are fixedly connected to the top of the outer casing 1 near the left and right sides. A water pump 6 is fixedly installed on the top of each of the two horizontal frames 5. A water suction pipe 7 is inserted into the side of each of the two water pumps 6 away from the water pump 6. The end of the water suction pipe 7 away from the water pump 6 is inserted into the side wall of the outer casing 1 near the bottom. A conduit 8 is inserted into the side of each of the two water pumps 6 opposite to the water pump 6. A hollow plate 9 is inserted into the side of each of the two conduits 8 opposite to the water pump 6. Several nozzles 10 are inserted into the bottom of the hollow plate 9. This arrangement enables spraying and cleaning of the top. Combined with the cleaning effect of repeated back-and-forth movement, the cleaning effect is better.

[0037] Among them, a slider 30 is fixedly connected to the bottom of the movable plate 21, and a slide groove 29 is opened on the bottom of the inner wall of the side groove 4. The slider 30 is slidably connected to the inner cavity of the corresponding slide groove 29. This setting limits the movement of the movable plate 21, so that the movable plate 21 can only move within the limited trajectory, thereby improving its stability.

[0038] Two drain pipes 2 are inserted and installed on both the front and rear sides of the outer casing 1. The two drain pipes 2 are arranged left and right, and each drain pipe 2 is equipped with a valve 3. This arrangement allows the cleaning fluid inside the outer casing 1 to be discharged conveniently, which facilitates the subsequent replacement of the cleaning fluid.

[0039] The connecting plate 22 and the movable plate 21 are connected by two fixing bolts 23 through a common thread. This setting allows the connecting plate 22 and the movable plate 21 to be fixed by the fixing bolts 23. This allows for subsequent disassembly, thereby enabling the overall removal and placement of multiple placement plates 25, and realizing the overall material handling and placement of multiple TVS devices.

[0040] The servo motor 13 is fixedly connected to the bottom of the bracket 12, and the bracket 12 is fixedly connected to the side wall of the outer shell 1. This setting enables the servo motor 13 to be fixed to the side wall of the outer shell 1, resulting in better stability when the servo motor 13 is running.

[0041] A method for fabricating a unidirectional capacitive TVS device with two photomasks includes the following steps:

[0042] S1: Substrate Material Preparation: The epitaxial substrate is P-type with a 100 crystal orientation, boron-doped, and typically has a resistivity of 0.003-0.004 Ω·cm. Epitaxial growth is performed on the substrate, and the resistivity and thickness of the grown epitaxial layer are determined by the different device breakdown voltages. Typical epitaxial thickness: 6-20 μm, epitaxial resistivity: 0.013-0.5 Ω·cm, and device breakdown voltage can reach 5V-36V.

[0043] S2: Initial oxygen growth: A layer of SiO2 with a thickness of 6500-10000 angstroms is grown on the surface of the wafer as a barrier layer for doping or implantation.

[0044] S3: Base region formation: The base region window is formed by photolithography and etching of the initial oxide using a base region implantation plate. The N-type region is then formed by doping or implantation and high temperature. The doping resistance is controlled at 9-11 keV, the implantation energy is 60-80 keV, the dose is 8E14-1.4E15, and the propagation conditions are 1100℃ / 120min.

[0045] S4: Metal deposition and etching: Before metal deposition, the wafer is cleaned to remove 500-100 Å of the oxide layer on the wafer surface. A 4µm thick aluminum is deposited. A certain proportion of Cu can be doped into the aluminum to prevent aluminum and silicon from dissolving together. Then, the aluminum is etched by photolithography.

[0046] S5: Passivation layer deposition and etching. The passivation layer is a co-deposit of SRO and SRN at 10KA. The passivation layer window is formed by photolithography and etching using the base region implantation dies.

[0047] S6: Backside Ti-Ni-Ag: Thin the backside of the wafer to about 150um, and evaporate Ti-Ni-Ag on the backside.

[0048] Working Principle: During use, the TVS device to be cleaned is first placed in the corresponding placement slot 26. Then, sufficient cleaning fluid is injected into the housing 1, and the servo motor 13 is driven, causing the rotating rod 14 to rotate. The rotating rod 14 drives multiple rotating plates 15 on the outside to agitate the cleaning fluid inside the housing 1. Simultaneously, the rotating rod 14 also drives the bottom grooved wheels 16 at both ends to rotate. The bottom grooved wheels 16 drive the top grooved wheel 16 to rotate via the belt 17. The top grooved wheel 16 drives the round shaft 18 to rotate, which in turn drives the gear 19 to rotate. The gear 19 drives the rack 20 to move, which in turn drives the movable plate 21 to move. The movable plate 21 drives the connecting plate 22 to move. The two connecting plates 22 together drive multiple placement plates 25 on the U-shaped frame 24 to move back and forth repeatedly inside the housing 1. This, combined with the agitation of the rotating plates 15, allows the cleaning fluid to repeatedly flush the TVS device, achieving a good cleaning effect. During the cleaning process, two water pumps 6 on the left and right sides can be driven, allowing the water pumps 6 to utilize the water suction pipe 7... The cleaning fluid is extracted from the inside of the outer casing 1 and then enters the hollow plate 9 through the conduit 8. It is then sprayed from top to bottom through the nozzle 10 at the bottom of the hollow plate 9, working in conjunction with the TVS devices that move back and forth to achieve a better cleaning effect. The sprayed cleaning fluid flows back into the outer casing 1 to achieve circulation. After cleaning, the servo motor 13 and water pump 6 are turned off, and then the TVS devices inside the placement tank 26 are removed. If it is necessary to remove the TVS devices as a whole, the fixing bolt 23 between the connecting plate 22 and the movable plate 21 can be removed to disassemble the connecting plate 22 and the movable plate 21. Then, the two connecting plates 22, the U-shaped frame 24 and the multiple placement plates 25 are removed from the inside of the outer casing 1 together, so that the TVS devices on the multiple placement plates 25 can be removed as a whole. The operation is convenient and can be used for subsequent overall feeding. When it is necessary to replace the cleaning fluid, the valves 3 on the multiple drain pipes 2 can be opened to allow the cleaning fluid inside the outer casing 1 to be discharged through the multiple drain pipes 2, so as to avoid the cleaning fluid not being replaced for a long time and affecting the cleaning effect.

[0049] Finally, it should be noted that in the description of this invention, the terms "vertical," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0050] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A processing device of a one-way general-purpose TVS device of a two-layer mask, comprising a shell (1), characterized in that, The shell (1) is provided with a side groove (4) on the left and right sides, and a servo motor (13) is arranged on the right side of the shell (1). The servo motor (13) is fixedly connected with a rotating rod (14) on the left side. The rotating rod (14) penetrates through the shell (1) and is rotatably connected with the shell (1) on the left end. A plurality of rotating plates (15) are fixedly connected with the rotating rod (14) on the outer side. The shell (1) is rotatably connected with a circular shaft (18) near the top on the left and right side walls. A transmission mechanism is arranged between the two circular shafts (18) and the rotating rod (14). The two circular shafts (18) are fixedly connected with a gear (19) on the side away from each other. The two gears (19) are meshed with a rack (20) on the top. The two racks (20) are fixedly connected with a movable plate (21) on the top. The movable plate (21) penetrates through the side groove (4) on the side away from the rack (20) and is movably connected with the inner wall bottom of the side groove (4). The two movable plates (21) are fixedly installed with a connecting plate (22) on the opposite side. A circular rod (28) is fixedly connected between the two connecting plates (22). A U-shaped frame (24) is jointly inserted and installed on the two connecting plates (22). A plurality of placing plates (25) are fixedly installed on the inner wall bottom of the U-shaped frame (24). A plurality of placing grooves (26) are formed on the top of the placing plates (25). A plurality of circular holes (27) are formed on the inner wall bottom of the placing grooves (26). A spraying mechanism is jointly arranged on the top of the two connecting plates (22). A guide plate (11) is fixedly connected on the inner wall bottom of the shell (1). The guide plate (11) is triangularly arranged, and the tip of the guide plate (11) is arranged upward. The transmission mechanism comprises two groove wheels (16). The two groove wheels (16) are respectively sleeved on the outer sides of the circular shaft (18) and the rotating rod (14). The two groove wheels (16) are jointly provided with a belt (17) on the outer side. The two groove wheels (16) are drivingly connected through the belt (17). The spraying mechanism comprises two cross frames (5). The two cross frames (5) are respectively fixedly connected on the top of the shell (1) near the left and right sides. The two cross frames (5) are fixedly installed with a water pump (6) on the top. The two water pumps (6) are respectively inserted and installed with a water suction pipe (7) on the side away from each other. The water suction pipe (7) is inserted in the side wall of the shell (1) near the bottom on the side away from the water pump (6). The two water pumps (6) are respectively inserted and installed with a conduit (8) on the opposite side. The two conduits (8) are jointly inserted and installed with a hollow plate (9) on the opposite side. A plurality of spray heads (10) are inserted and installed on the bottom of the hollow plate (9).

2. The apparatus of claim 1, wherein the apparatus is configured to process a one-way permissive TVS device having two layers of a photo mask, and the apparatus is configured to perform the following steps: The movable plate (21) is fixedly connected with a sliding block (30) on the bottom. The inner wall bottom of the side groove (4) is provided with a sliding groove (29). The sliding block (30) is slidingly connected in the inner cavity of the corresponding sliding groove (29). ​ 3. The apparatus of claim 1, wherein the apparatus is configured to process a one-way permissive TVS device having two layers of a photo mask, and the apparatus is configured to process the one-way permissive TVS device by performing the following steps: The shell (1) is inserted and installed with two drain pipes (2) on the front and back sides. The two drain pipes (2) are arranged left and right. Valves (3) are installed on the two drain pipes (2). ​ 4. The apparatus of claim 1, wherein the apparatus is configured to process a one-way permissive TVS device having two layers of a photo mask. The connecting plate (22) and the movable plate (21) are threadedly connected with two fixing pins (23).

5. The processing apparatus for a unidirectional capacitive TVS device with two photomasks according to claim 1, characterized in that, The bottom of the servo motor (13) is fixedly connected with a support (12), and the support (12) is fixedly connected with the side wall of the shell (1).

6. A method for fabricating a unidirectional capacitive TVS device with a two-layer photomask according to any one of claims 1-5, characterized in that, The method comprises the following steps: S1: substrate material preparation: the substrate of the epitaxial wafer adopts P-type (100) crystal orientation, boron element doping, and the resistivity is 0.003-0.004 Ω.cm. The epitaxial growth is carried out on the substrate, and the epitaxial resistivity and thickness are determined by different device withstand voltages. The epitaxial thickness is 6-20 um, the epitaxial resistivity is 0.013-0.5 Ω.cm, and the device withstand voltage can reach 5V-36V; S2: initial oxygen growth: a layer of SiO2 with a thickness of 6500-10000 angstroms is grown on the surface of the wafer, which is used as a doping or implantation barrier layer; S3: base region formation: the initial oxygen is photolithographed and etched by using a base region implantation plate to form a window of the base region, and an N-type region is formed by doping or implantation and high-temperature promotion. The doping control is 9-11 square resistance, the implantation energy is 60-80 Kev, the dose is 8E14-1.4E15, and the promotion condition is 1100 DEG C / 120 min; S4: metal deposition and etching: before metal deposition, the wafer surface is cleaned to remove the oxide layer by 500-100A, 4um thick aluminum is deposited, a certain proportion of Cu is doped in the aluminum to prevent aluminum-silicon interdiffusion, and then the aluminum is etched by photolithography; S5: passivation layer deposition and etching: the passivation layer is SRO and SRN co-deposited at 10KA, and the passivation layer window is formed by using the base region implantation plate for photolithography and etching; S6: back Ti-Ni-Ag: the back of the wafer is thinned to about 150um, and Ti-Ni-Ag is evaporated on the back.

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