Manufacturing method of semiconductor device

Abstract

The embodiment of the invention discloses a manufacturing method of a semiconductor device, and the method comprises the steps: forming a second protection layer on at least one side of a semiconductor substrate, the second protection layer comprising one or more of silicon oxide, silicon nitride, silicon carbide, polycrystalline silicon, glass, polyimide, photoresist, wax, green oil, black glue and silica gel; a part of the second protection layer is removed through a laser process to form a groove window exposing a to-be-grooved area of the semiconductor substrate, and the laser comprises at least one of ultraviolet laser, infrared laser, blue laser, green laser and carbon dioxide laser; and performing corrosion treatment on the to-be-grooved area to form a groove. According to the technical scheme provided by the embodiment of the invention, the mask is removed by laser instead of photoetching to realize pattern transfer.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a method for manufacturing a semiconductor device. Background Art

[0002] In the existing semiconductor device manufacturing process, pattern transfer is achieved through photolithography. The photolithography process may include wafer surface pretreatment, photoresist coating, soft baking, alignment exposure, development, hardening, table etching, and degumming. Due to the large number of photolithography process flows, the operation process is cumbersome, the environmental temperature, humidity and cleanliness requirements are high, the production cycle is long, abnormal rework is prone to occur in the intermediate process, the equipment investment is large, and the production cost is high. Summary of the invention

[0003] An embodiment of the present invention provides a method for manufacturing a semiconductor device, which uses laser to remove masks and replaces photolithography to achieve pattern transfer, thereby reducing or eliminating the use of photolithography processes, reducing waste liquid and waste glue generated by the photolithography process, and being more environmentally friendly. Laser etching operations are convenient, reducing wafer fabrication time and costs.

[0004] An embodiment of the present invention provides a method for manufacturing a semiconductor device, including: one or more of a first process, a second process, and a third process:

[0005] The first process includes:

[0006] forming a first protective layer on at least one side of the semiconductor substrate;

[0007] Removing a portion of the first protective layer by a laser process to form a doping window exposing the to-be-doped region of the semiconductor substrate;

[0008] Performing a doping treatment on the region to be doped to form a doped region;

[0009] The second process includes:

[0010] forming a second protective layer on at least one side of the semiconductor substrate;

[0011] Removing a portion of the second protective layer by a laser process to form a trench window exposing the to-be-dug trench area of ​​the semiconductor substrate;

[0012] Etching the area to be grooved to form a groove;

[0013] The third process includes:

[0014] forming a third protective layer on at least one side of the semiconductor substrate;

[0015] removing a portion of the third protective layer by a laser process to form an electrode window;

[0016] A conductive material layer is formed in the electrode window to form an electrode.

[0017] Further, forming a first protective layer on at least one side of the semiconductor substrate includes: forming a first protective layer on a first side and a second side opposite to the semiconductor substrate;

[0018] Removing a portion of the first protective layer by a laser process to form a doping window exposing the to-be-doped region of the semiconductor substrate includes:

[0019] removing a portion of the first protective layer on the first side of the semiconductor substrate by a laser process to form a doping window exposing the to-be-doped region on the first side of the semiconductor substrate;

[0020] Acquire the position of the doping window of the to-be-doped region on the first side of the semiconductor substrate through the image acquisition module;

[0021] According to the position of the doping window of the to-be-doped region on the first side of the semiconductor substrate, adjusting the position of the laser spot on the second side of the semiconductor substrate;

[0022] A portion of the first protection layer on the second side of the semiconductor substrate is removed by a laser process to form a doping window exposing the to-be-doped region on the second side of the semiconductor substrate.

[0023] Further; forming a second protective layer on at least one side of the semiconductor substrate includes: forming a second protective layer on a first side and a second side opposite to the semiconductor substrate;

[0024] Removing a portion of the second protective layer by a laser process to form a trench window exposing the to-be-dug region of the semiconductor substrate includes:

[0025] Removing a portion of the second protective layer on the first side of the semiconductor substrate by a laser process to form a trench window exposing the to-be-dug region on the first side of the semiconductor substrate;

[0026] Acquire the position of the groove window of the to-be-grooved area of ​​the first side of the semiconductor substrate through the image acquisition module;

[0027] According to the position of the groove window of the to-be-grooved area on the first side of the semiconductor substrate, adjusting the position of the laser spot on the second side of the semiconductor substrate;

[0028] A portion of the second protection layer on the second side of the semiconductor substrate is removed by a laser process to form a trench window exposing the to-be-dug region on the second side of the semiconductor substrate.

[0029] Further; forming a third protective layer on at least one side of the semiconductor substrate includes: forming a third protective layer on a first side and a second side opposite to the semiconductor substrate;

[0030] Removing part of the third protective layer by a laser process to form an electrode window includes:

[0031] removing a portion of the third protective layer on the first side of the semiconductor substrate by a laser process to form an electrode window on the first side of the semiconductor substrate;

[0032] Acquire the position of the electrode window on the first side of the semiconductor substrate through the image acquisition module;

[0033] According to the position of the electrode window on the first side of the semiconductor substrate, adjusting the position of the laser spot on the second side of the semiconductor substrate;

[0034] A portion of the third protection layer on the second side of the semiconductor substrate is removed by a laser process to form an electrode window on the second side of the semiconductor substrate.

[0035] Furthermore, a laser provided with a galvanometer is used in the laser process.

[0036] Furthermore, before the doping process is performed on the region to be doped, the method further includes:

[0037] The bottom and side walls of the doping window are damaged and repaired.

[0038] Furthermore, the bottom and sidewalls of the doping window are damaged and repaired by chemical and / or physical methods.

[0039] Further, the chemical and / or physical method includes one or more of the following: cleaning with an acid solution and / or an alkaline solution, and dry etching.

[0040] Further, one or more of the first process, the second process and the third process are performed multiple times.

[0041] Furthermore, the semiconductor device includes at least one of the following: a transient suppression diode, a rectifier diode, a voltage regulator, a trigger tube, a field effect tube, a semiconductor discharge tube, a thyristor, a triode, a Schottky diode, a light-emitting tube, a solar cell, a photosensitive tube and a fast recovery tube.

[0042] In the technical solution of the embodiment of the present invention, the method for manufacturing a semiconductor device includes: one or more of the first process, the second process and the third process: wherein the first process includes: forming a first protective layer on at least one side of the semiconductor substrate; removing part of the first protective layer by laser process to form a doping window exposing the to-be-doped region of the semiconductor substrate; performing doping treatment on the to-be-doped region to form a doping region; the second process includes: forming a second protective layer on at least one side of the semiconductor substrate; removing part of the second protective layer by laser process to form a groove window exposing the to-be-grooved region of the semiconductor substrate; performing etching treatment on the to-be-grooved region to form a groove; the third process includes: forming a third protective layer on at least one side of the semiconductor substrate; removing part of the third protective layer by laser process to form an electrode window; forming a conductive material layer in the electrode window to form an electrode. By removing the mask by laser, the pattern transfer is realized instead of photolithography, the use of the photolithography process is reduced or eliminated, and the waste liquid and waste glue generated by the photolithography process is reduced, which is more environmentally friendly, and the laser etching operation is convenient, reducing the tape-out time and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A flowchart of a method for manufacturing a semiconductor device provided by an embodiment of the present invention;

[0044] Figure 2 A schematic cross-sectional structure diagram corresponding to each step of the first process provided by an embodiment of the present invention;

[0045] Figure 3 A flowchart of another method for manufacturing a semiconductor device provided by an embodiment of the present invention;

[0046] Figure 4 A schematic cross-sectional structure diagram corresponding to each step of the second process provided by an embodiment of the present invention;

[0047] Figure 5 A flowchart of another method for manufacturing a semiconductor device provided by an embodiment of the present invention;

[0048] Figure 6 A schematic cross-sectional structure diagram corresponding to each step of the third process provided by an embodiment of the present invention;

[0049] Figure 7 A flowchart of another method for manufacturing a semiconductor device provided by an embodiment of the present invention;

[0050] Figure 8 A flowchart of another method for manufacturing a semiconductor device provided by an embodiment of the present invention;

[0051] Fig. 9 A flowchart of another method for manufacturing a semiconductor device provided by an embodiment of the present invention;

[0052] Fig.10 A schematic cross-sectional structure diagram corresponding to each step of the second process provided by an embodiment of the present invention;

[0053] Fig.11 A schematic cross-sectional structure diagram corresponding to each step of the third process provided by an embodiment of the present invention;

[0054] Fig.12 A flowchart of another method for manufacturing a semiconductor device provided by an embodiment of the present invention;

[0055] Fig.13 A flowchart for refining a first process provided by an embodiment of the present invention;

[0056] Fig.14 A flowchart for refining the first process provided in another embodiment of the present invention;

[0057] Fig.15 A schematic cross-sectional structure diagram corresponding to each step of the first process provided by an embodiment of the present invention;

[0058] Fig.16 A schematic diagram of a structure for alignment before patterning a first protective layer on a second side of a semiconductor substrate provided by an embodiment of the present invention;

[0059] Fig.17 A flowchart for refining the second process provided by an embodiment of the present invention;

[0060] Fig.18 A schematic diagram of a structure for alignment before patterning a second protective layer on a second side of a semiconductor substrate provided by an embodiment of the present invention;

[0061] Fig.19 A flowchart for refining the third process provided by an embodiment of the present invention;

[0062] Fig. 20 A schematic diagram of a structure for alignment before patterning a third protective layer on a second side of a semiconductor substrate provided by an embodiment of the present invention;

[0063] Fig.21 A schematic structural diagram of a semiconductor discharge tube provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0064] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0065] An embodiment of the present invention provides a method for manufacturing a semiconductor device. Figure 1 A flowchart of a method for manufacturing a semiconductor device provided by an embodiment of the present invention. Figure 2 A schematic cross-sectional structure diagram corresponding to each step of the first process provided by an embodiment of the present invention. The method for manufacturing the semiconductor device includes:

[0066] Step 110 : forming a first protection layer on at least one side of the semiconductor substrate.

[0067] Among them, optional semiconductor devices include but are not limited to: one or more of transient voltage suppressor diodes (Transient Voltage Suppressor, referred to as TVS), rectifier diodes, voltage regulators, trigger tubes, field effect transistors, semiconductor discharge tubes (Thyristor Sure Suppresser, referred to as TSS), thyristors (Silicon Controlled Rectifier, referred to as SCR), transistors, Schottky diodes, light emitting diodes (Light Emitting Diode, referred to as LED), solar cells, photosensitive tubes and fast recovery tubes. Figure 2 The cross-sectional structural schematic diagram corresponding to each step of the first process when manufacturing a semiconductor discharge tube is exemplarily drawn. Figure 2 The first protective layer 20 is formed on the first and second sides of the semiconductor substrate 10, where a first protective layer 20-1 is formed on the first side of the semiconductor substrate 10, and the first protective layer 20-1 covers the first side of the semiconductor substrate 10; a first protective layer 20-2 is formed on the second side of the semiconductor substrate 10, and the first protective layer 20-2 covers the second side of the semiconductor substrate 10. Optionally, the semiconductor substrate 10 may be a pure intrinsic semiconductor such as germanium or silicon, or the semiconductor substrate 10 may be formed by doping a proper amount of pentavalent elements such as arsenic, phosphorus, and antimony, and / or a proper amount of trivalent elements such as boron, indium, and gallium in a pure intrinsic semiconductor such as germanium or silicon before step 110 through ion implantation or diffusion. Figure 2 The exemplary semiconductor substrate 10 includes a body region 11, and a first doped region 12 and a second doped region 13 located on opposite sides of the body region 11. The body region 11 may be of a first conductivity type, and the first doped region 12 and the second doped region 13 may be of a second conductivity type. The first conductivity type and the second conductivity type are different. The first conductivity type is an electron type (N type) or a hole type (P type). Optionally, the first conductivity type is a hole type (P type), and the second conductivity type is an electron type (N type). Optionally, as Figure 2As shown, the first conductivity type is electron type (N type), and the second conductivity type is hole type (P type). Optionally, the first protective layer 20 includes at least one of the following materials: one or more materials selected from silicon oxide, silicon nitride, silicon carbide, polysilicon, glass, polyimide, photoresist, wax, green oil, black glue and silica gel. The thickness of the first protective layer 20 can be set as required, and the embodiment of the present invention is not limited thereto.

[0068] Step 120 : removing a portion of the first protective layer by a laser process to form a doping window exposing the to-be-doped region of the semiconductor substrate.

[0069] Among them, Figure 2 As shown, the first protective layer 20-1 on the first side of the semiconductor substrate 10 is partially removed by a laser process to form a doping window 21-1 exposing the region to be doped on the first side of the semiconductor substrate; the first protective layer 20-2 on the second side of the semiconductor substrate 10 is partially removed by a laser process to form a doping window 21-2 exposing the region to be doped on the second side of the semiconductor substrate. The shape and size of the doping window can be set as needed, and the embodiment of the present invention is not limited to this. The shape and size of the doping window 21 can play a decisive role in the shape and size of the doping region 22 formed in step 310. Optionally, the laser in the first process includes, but is not limited to: one or more of ultraviolet laser, infrared laser, blue laser, green laser and carbon dioxide laser. The laser in the first process includes ultraviolet laser, which is a cold light source, which can reduce thermal effects and avoid the occurrence of cracks due to excessive local temperature. The ultraviolet laser in the first process can be a picosecond ultraviolet laser or a nanosecond ultraviolet laser. Removing part of the first protective layer by a laser process replaces removing part of the first protective layer by a photolithography process. The pattern of the first protective layer 20 to be stripped and laser parameters (depth, width, etc.) can be input into the computer control software to control the laser stripping device to strip the first protective layer 20 according to the preset pattern in the computer.

[0070] Step 130 : performing a doping treatment on the region to be doped to form a doped region.

[0071] Among them, the doping process is performed on the doped area exposed by the doping window through a diffusion process or an ion implantation method, so as to achieve the electrical properties required by the device. Figure 2As shown, the doping treatment is performed on the doped region to form a doped region 22-1 on the first side of the semiconductor substrate 10, and a doped region 22-2 on the second side of the semiconductor substrate 10. The doped region 22-1 and the doped region 22-2 may be of the first conductivity type. The first protective layer 20 may serve as a barrier layer (or mask layer) to achieve the purpose of selective diffusion. The dopant doped in the N-type doped region may include elements such as arsenic, phosphorus or antimony, and the dopant doped in the P-type doped region may include elements such as boron, indium or gallium. The doping concentration of the doped region 22-1 and the doped region 22-2 may be greater than the doping concentration of the body region 11. The dopant type, doping concentration, doping depth, etc. of the doped region 22 may be set as needed, and the embodiment of the present invention does not limit this.

[0072] In the technical solution of this embodiment, a first protective layer is formed on at least one side of the semiconductor substrate; a portion of the first protective layer is removed by laser to form a doping window exposing the area to be doped of the semiconductor substrate; the area to be doped is doped to form a doped area, and the mask is removed by laser to replace photolithography to achieve pattern transfer, thereby reducing or eliminating the use of the photolithography process, reducing waste liquid and waste glue generated by the photolithography process, being more environmentally friendly, and convenient laser etching operation, reducing wafer flow time and cost.

[0073] An embodiment of the present invention provides yet another method for manufacturing a semiconductor device. Figure 3 A flowchart of a method for manufacturing a semiconductor device provided by an embodiment of the present invention. Figure 4 A schematic cross-sectional structure diagram corresponding to each step of the second process provided by an embodiment of the present invention. Based on the above embodiment, the method for manufacturing the semiconductor device includes:

[0074] Step 210: Form a second protection layer on at least one side of the semiconductor substrate.

[0075] in, Figure 4 The cross-sectional structural schematic diagram corresponding to each step of the second process when manufacturing a semiconductor discharge tube is exemplarily drawn. Figure 4 The second protective layer 30 is formed on the first and second sides of the semiconductor substrate 10, where a second protective layer 30-1 is formed on the first side of the semiconductor substrate 10, and the second protective layer 30-1 covers the first side of the semiconductor substrate 10; a second protective layer 30-2 is formed on the second side of the semiconductor substrate 10, and the second protective layer 30-2 covers the second side of the semiconductor substrate 10. Optionally, the second protective layer 30 includes, but is not limited to, one or more materials selected from silicon oxide, silicon nitride, silicon carbide, polysilicon, glass, polyimide, photoresist, wax, green oil, black glue, and silicone. The thickness of the second protective layer 30 can be set as needed, and the embodiment of the present invention is not limited thereto.

[0076] Step 220 : removing a portion of the second protective layer by laser processing to form a trench window exposing the to-be-dug region of the semiconductor substrate.

[0077] Among them, Figure 4 As shown, a portion of the second protective layer 30-1 on the first side of the semiconductor substrate 10 is removed by a laser process to form a groove window 31-1 exposing the grooved area of ​​the first side of the semiconductor substrate; a portion of the second protective layer 30-2 on the second side of the semiconductor substrate 10 is removed by a laser process to form a groove window 31-2 exposing the grooved area of ​​the second side of the semiconductor substrate. The shape and size of the groove window 31 can be set as needed, and the embodiment of the present invention is not limited to this. The shape and size of the groove window 31 play a decisive role in the shape and size of the groove 32 formed in step 160. Optionally, the laser in the second process includes, but is not limited to: one or more of ultraviolet laser, infrared laser, blue laser, green laser and carbon dioxide laser. The ultraviolet laser in the second process can be a picosecond ultraviolet laser or a nanosecond ultraviolet laser. A portion of the second protective layer is removed by a laser process to replace the removal of a portion of the second protective layer by a photolithography process. The pattern of the second protective layer 30 to be peeled off and laser parameters (depth, width, etc.) can be input into the computer control software to control the laser peeling device to peel off the second protective layer 30 according to the preset pattern in the computer.

[0078] Step 230: etching the area to be grooved to form a groove.

[0079] The etching liquid can contact the grooved area 32 through the groove window 31 to perform groove etching. Figure 4 As shown, the trenching area is etched to form a trench 32-1 on the first side of the semiconductor substrate 10, and a trench 32-2 on the second side of the semiconductor substrate 10. The etching time can be set as needed so that the depth and width of the trench 32 meet the requirements, which is not limited in the embodiment of the present invention. The second protective layer 30 can be used as a barrier layer (or anti-corrosion layer) to achieve the purpose of selective etching.

[0080] In the technical solution of this embodiment, a second protective layer is formed on at least one side of the semiconductor substrate; a portion of the second protective layer is removed by a laser grooving process to form a groove window exposing the grooved area of ​​the semiconductor substrate; the grooved area is corroded to form a groove, and the mask is removed by laser to replace photolithography to achieve pattern transfer, thereby reducing or eliminating the use of the photolithography process, reducing waste liquid and waste glue generated by the photolithography process, being more environmentally friendly, and convenient laser etching operation, reducing wafer flow time and cost.

[0081] An embodiment of the present invention provides yet another method for manufacturing a semiconductor device. Figure 5A flowchart of a method for manufacturing a semiconductor device provided by an embodiment of the present invention. Figure 6 A schematic cross-sectional structure diagram corresponding to each step of the third process provided by an embodiment of the present invention. Based on the above embodiment, the method for manufacturing the semiconductor device includes:

[0082] Step 310: Form a third protection layer on at least one side of the semiconductor substrate.

[0083] in, Figure 6 The cross-sectional structural schematic diagram corresponding to each step of the third process when manufacturing a semiconductor discharge tube is exemplarily drawn. Figure 6 The third protective layer 40 is formed on the first and second sides of the semiconductor substrate 10, where a third protective layer 40-1 is formed on the first side of the semiconductor substrate 10, and the third protective layer 40-1 covers the first side of the semiconductor substrate 10; a third protective layer 40-2 is formed on the second side of the semiconductor substrate 10, and the third protective layer 40-2 covers the second side of the semiconductor substrate 10. Optionally, the third protective layer 40 includes, but is not limited to, one or more materials selected from silicon oxide, silicon nitride, silicon carbide, polysilicon, glass, polyimide, photoresist, wax, green oil, black glue, and silicone. The thickness of the third protective layer 40 can be set as needed, and the embodiment of the present invention is not limited thereto.

[0084] Step 320: remove part of the third protective layer by laser process to form an electrode window.

[0085] Among them, Figure 6 As shown, a portion of the third protective layer 40-1 on the first side of the semiconductor substrate 10 is removed by a laser process to form an electrode window 41-1 on the first side of the semiconductor substrate; a portion of the third protective layer 40-2 on the second side of the semiconductor substrate 10 is removed by a laser process to form an electrode window 41-2 exposing the second side of the semiconductor substrate. The shape and size of the electrode window can be set as needed, and the embodiment of the present invention is not limited to this. Optionally, the laser in the third process includes but is not limited to: at least one of ultraviolet laser, infrared laser, blue laser, green laser and carbon dioxide laser. A portion of the third protective layer is removed by a laser process instead of using a photolithography process to remove a portion of the third protective layer. The pattern of the third protective layer 40 to be stripped and the laser parameters (depth, width, etc.) can be input into the computer control software to control the laser stripping equipment to strip the third protective layer 40 according to the preset graphics in the computer.

[0086] Step 330: Form a conductive material layer in the electrode window to form an electrode.

[0087] The conductive material may include a metal material. The conductive material may include, but is not limited to, one or more of nickel, tungsten, copper, aluminum, titanium, nickel, silver, etc. Figure 6 As shown, an electrode 42-1 is formed on a first side of the semiconductor substrate 10, and an electrode 42-2 is formed on a second side of the semiconductor substrate 10. The third protection layer 40 may be an insulating layer.

[0088] In the technical solution of this embodiment, a third protective layer is formed on at least one side of the semiconductor substrate; a portion of the third protective layer is removed by a laser process to form an electrode window; a conductive material layer is formed in the electrode window to form an electrode, and the mask is removed by laser to replace photolithography to achieve pattern transfer, thereby reducing or eliminating the use of photolithography, reducing waste liquid and waste glue generated by the photolithography process, being more environmentally friendly, and convenient laser etching operation, reducing wafer flow time and cost.

[0089] An embodiment of the present invention provides yet another method for manufacturing a semiconductor device. Figure 7 A flowchart of another method for manufacturing a semiconductor device provided by an embodiment of the present invention. Figure 7 , Figure 2 and Figure 4 As shown, based on the above embodiment, the method for manufacturing the semiconductor device includes:

[0090] Step 410: Form a first protection layer on at least one side of a semiconductor substrate.

[0091] Step 420 : removing a portion of the first protective layer by a laser process to form a doping window exposing the to-be-doped region of the semiconductor substrate.

[0092] Step 430 : performing a doping treatment on the region to be doped to form a doped region.

[0093] Step 440 : forming a second protection layer on at least one side of the semiconductor substrate.

[0094] Step 450 : removing a portion of the second protective layer by a laser grooving process to form a trench window exposing the to-be-grooved area of ​​the semiconductor substrate.

[0095] Step 460: perform etching on the area to be grooved to form a groove.

[0096] It should be noted that the first process 1 may include step 410 , step 420 and step 430 ; the second process 2 may include step 440 , step 450 and step 460 .

[0097] In the technical solution of this embodiment, a first protective layer is formed on at least one side of the semiconductor substrate; a portion of the first protective layer is removed by a laser process to form a doping window exposing the area to be doped of the semiconductor substrate; the area to be doped is doped to form a doping area; a second protective layer is formed on at least one side of the semiconductor substrate; a portion of the second protective layer is removed by a laser process to form a groove window exposing the area to be grooved of the semiconductor substrate; the area to be grooved is corroded to form a groove, and the mask is removed by laser to replace photolithography to achieve pattern transfer, thereby reducing or eliminating the use of photolithography, reducing waste liquid and waste glue generated by the photolithography process, being more environmentally friendly, and convenient laser etching operation, reducing wafer flow time and cost.

[0098] An embodiment of the present invention provides yet another method for manufacturing a semiconductor device. Figure 8 A flowchart of another method for manufacturing a semiconductor device provided by an embodiment of the present invention. Figure 8 , Figure 2 and Figure 6 As shown, based on the above embodiment, the method for manufacturing the semiconductor device includes:

[0099] Step 510: Form a first protection layer on at least one side of a semiconductor substrate.

[0100] Step 520: remove a portion of the first protective layer by laser processing to form a doping window exposing the to-be-doped region of the semiconductor substrate.

[0101] Step 530 , performing a doping treatment on the region to be doped to form a doped region.

[0102] Step 540 : forming a third protection layer on at least one side of the semiconductor substrate.

[0103] Step 550: remove part of the third protective layer by laser process to form an electrode window.

[0104] Step 560: Form a conductive material layer in the electrode window to form an electrode.

[0105] It should be noted that the first process 1 may include step 510 , step 520 and step 530 ; the third process 3 may include step 540 , step 550 and step 560 .

[0106] In the technical solution of this embodiment, a first protective layer is formed on at least one side of the semiconductor substrate; a portion of the first protective layer is removed by a laser process to form a doping window exposing the to-be-doped region of the semiconductor substrate; the to-be-doped region is doped to form a doped region; a third protective layer is formed on at least one side of the semiconductor substrate; a portion of the third protective layer is removed by a laser process to form an electrode window; a conductive material layer is formed in the electrode window to form an electrode, and the mask is removed by laser to replace photolithography to achieve pattern transfer, thereby reducing or eliminating the use of photolithography, reducing waste liquid and waste glue generated by the photolithography process, being more environmentally friendly, and convenient laser etching operation, reducing wafer flow time and cost.

[0107] An embodiment of the present invention provides yet another method for manufacturing a semiconductor device. Fig. 9 A flowchart of a method for manufacturing a semiconductor device provided by an embodiment of the present invention. Fig.10 Another schematic cross-sectional structure diagram corresponding to each step of the second process provided in an embodiment of the present invention. Fig.11 Another schematic cross-sectional structure diagram corresponding to each step of the third process provided by the embodiment of the present invention. Fig. 9 , Fig.10 and Fig.11 As shown, based on the above embodiment, the method for manufacturing the semiconductor device includes:

[0108] Step 610: Form a second protection layer on at least one side of the semiconductor substrate.

[0109] in, Fig.10 and Fig.11 The cross-sectional structural schematic diagram corresponding to each step of the second process and the third process when manufacturing a transient suppression diode is exemplarily drawn. Fig.10 The diagram exemplarily shows a case where the entire second protection layer 30 is formed on one side of the semiconductor substrate 10 , and the second protection layer 30 entirely covers the one side of the semiconductor substrate 10 . Fig.10 The semiconductor substrate 10 exemplarily includes a body region 11 and a first doped region 12 located on one side of the body region 11. The second protection layer 30 may be located on a side of the first doped region 12 away from the body region 11.

[0110] Step 620 , removing a portion of the second protective layer by laser processing to form a trench window exposing the to-be-dug trench area of ​​the semiconductor substrate.

[0111] Among them, Fig.10 As shown, a portion of the second protective layer 30 on one side of the semiconductor substrate 10 is removed by laser processing to form a trench window 31 exposing the trench area to be dug of the semiconductor substrate 10. The laser process is used to remove a portion of the second protective layer instead of using a photolithography process to remove a portion of the second protective layer.

[0112] Step 630: perform etching on the area to be grooved to form a groove.

[0113] The etching liquid can contact the grooved area through the groove window 31 to perform groove etching. Fig.10 As shown, the area to be grooved is etched to form a groove 32 .

[0114] Step 640 : Form a third protection layer on at least one side of the semiconductor substrate.

[0115] in, Fig.11 The diagram exemplarily shows a situation where the entire third protection layer 40 is formed on one side of the semiconductor substrate 10 . The third protection layer 40 entirely covers the one side of the semiconductor substrate 10 .

[0116] Step 350: remove part of the third protective layer by laser process to form an electrode window.

[0117] Among them, Fig.11 As shown, a portion of the third protective layer 40 on one side of the semiconductor substrate 10 is removed by a laser process to form an electrode window 41. The laser process is used to remove a portion of the third protective layer, instead of using a photolithography process to remove a portion of the third protective layer.

[0118] Step 660: Form a conductive material layer in the electrode window to form an electrode.

[0119] Among them, Fig.11 As shown, a conductive material layer is formed in the electrode window to form an electrode 42. Another electrode 43 may be formed on a side of the body region 11 away from the first doped region 12.

[0120] It should be noted that the second process 2 may include step 610 , step 620 and step 630 ; the third process 3 may include step 640 , step 650 and step 660 .

[0121] The technical solution of this embodiment forms a second protective layer on at least one side of the semiconductor substrate; removes part of the second protective layer through a laser process to form a groove window exposing the area to be grooved of the semiconductor substrate; etches the area to be grooved to form a groove; forms a third protective layer on at least one side of the semiconductor substrate; removes part of the third protective layer through a laser process to form an electrode window; forms a conductive material layer in the electrode window to form an electrode, removes the mask through laser, and replaces photolithography to achieve pattern transfer, thereby reducing or eliminating the use of photolithography, reducing waste liquid and waste glue generated by the photolithography process, being more environmentally friendly, and convenient laser etching operation, reducing wafer flow time and cost.

[0122] An embodiment of the present invention provides yet another method for manufacturing a semiconductor device. Fig.12A flowchart of another method for manufacturing a semiconductor device provided by an embodiment of the present invention. Fig.12 , Figure 2 , Figure 4 and Figure 6 As shown, based on the above embodiment, the method for manufacturing the semiconductor device includes:

[0123] Step 710: Form a first protection layer on at least one side of a semiconductor substrate.

[0124] Step 720: remove a portion of the first protective layer by laser processing to form a doping window exposing the to-be-doped region of the semiconductor substrate.

[0125] Step 730 , performing a doping treatment on the region to be doped to form a doped region.

[0126] Step 740: Form a second protection layer on at least one side of the semiconductor substrate.

[0127] Step 750: remove a portion of the second protective layer by laser processing to form a trench window exposing the to-be-dug region of the semiconductor substrate.

[0128] Step 760: perform etching on the area to be grooved to form a groove.

[0129] Step 770: Form a third protection layer on at least one side of the semiconductor substrate.

[0130] The third protection layer 40 may be a glass passivation layer. After the groove 32 is etched to expose the PN junction, it is cleaned by RCA and protected by glass passivation.

[0131] Step 780: remove part of the third protective layer by laser process to form an electrode window.

[0132] After the glass is passivated, the table oxide layer is removed and textured using plasma laser or other methods to prepare for the next step of metallization.

[0133] Step 790: Form a conductive material layer in the electrode window to form an electrode.

[0134] After step 790 , testing and dicing may be performed to cut the entire semiconductor substrate into a plurality of devices.

[0135] It should be noted that the first process 1 may include step 710 , step 720 and step 730 ; the second process 2 may include step 740 , step 750 and step 760 ; and the third process 3 may include step 770 , step 780 and step 790 .

[0136] Fig.13A flowchart for refining the first process is provided in an embodiment of the present invention. Based on the above embodiment, the first process includes:

[0137] Step 810: Form a first protection layer on at least one side of a semiconductor substrate.

[0138] Step 820: remove a portion of the first protective layer by laser processing to form a doping window exposing the to-be-doped region of the semiconductor substrate.

[0139] Step 830: Perform damage repair processing on the bottom and side walls of the doping window.

[0140] Among them, Figure 2 As shown, the bottom and side walls of the doping window 21 are damaged and repaired to remove the damaged layer and debris left by laser burning to avoid affecting the subsequent doping effect. Optionally, the bottom and side walls of the doping window 21 are damaged and repaired by chemical and / or physical methods. Optionally, the chemical and / or physical methods include, but are not limited to: one or more of acidic solution and / or alkaline solution cleaning, and dry etching. Acidic solutions may include, but are not limited to: one or more of hydrofluoric acid HF, nitric acid HNO3, glacial acetic acid, sulfuric acid H2SO4, etc. Alkaline solutions may include, but are not limited to: one or more of potassium hydroxide KOH, sodium hydroxide NaOH, etc. The acidic solution may be a mixed acid, etc. Dry etching may include, but is not limited to: plasma etching.

[0141] Step 840 , performing a doping treatment on the region to be doped to form a doped region.

[0142] Fig.14 Another flowchart for refining the first process is provided in an embodiment of the present invention. Fig.15 Another cross-sectional structural schematic diagram corresponding to each step of the first process provided by an embodiment of the present invention. Based on the above embodiment, the first process includes:

[0143] Step 910 : Form a first protection layer on a first side and a second side opposite to each other of a semiconductor substrate.

[0144] Step 920 : removing a portion of the first protection layer on the first side of the semiconductor substrate by a laser process to form a doping window exposing the to-be-doped region on the first side of the semiconductor substrate.

[0145] Step 930: Acquire the position of the doping window of the to-be-doped region on the first side of the semiconductor substrate through the image acquisition module.

[0146] in, Fig.16A schematic diagram of a structure for alignment before patterning the first protective layer on the second side of a semiconductor substrate is provided in an embodiment of the present invention. The semiconductor substrate 10 and the image acquisition module 2 may be located on two opposite sides of a transparent carrier 3. For example, the semiconductor substrate 10 may be placed on the carrier 3, and the image acquisition module 2 may be located below the carrier 3. The first side of the semiconductor substrate 10 may face the carrier 3. The laser 1 and the carrier 3 may be located on two opposite sides of the semiconductor substrate 10. The lens of the image acquisition module 2 may face the first side of the semiconductor substrate 10 to obtain an image of the first side of the semiconductor substrate 10, and then obtain the position of the doping window 21-1 of the to-be-doped region on the first side of the semiconductor substrate 10 in the image. The position of the image acquisition module 2 may be fixed. The semiconductor substrate 10 may be fixed on the carrier 3. The image acquisition module 2 may include a CCD (charge coupled device) or the like.

[0147] Step 940: Adjust the position of the laser spot on the second side of the semiconductor substrate according to the position of the doping window of the to-be-doped region on the first side of the semiconductor substrate.

[0148] Among them, by obtaining the position of the pattern of the doping window 21 on the completed side of the semiconductor substrate 10, the position of the laser spot on the second side of the semiconductor substrate is adjusted to achieve accurate alignment of the double-sided pattern of the semiconductor device, thereby solving the problem that in the photolithography process, the upper and lower masks are first mechanically aligned and calibrated, and then the upper and lower masks are separated, and then the silicon wafer is placed between the upper and lower masks. This alignment and calibration method will cause displacement during repeated operations, resulting in inaccurate alignment.

[0149] The position of the light spot can be precisely adjusted by the galvanometer in the laser. Before step 940, a correspondence between the position of the doping window of the to-be-doped region on the first side of the semiconductor substrate in the image and the correction parameter of the position of the laser spot can be established in advance, so as to determine the current value of the correction parameter of the position of the laser spot according to the current position of the doping window of the to-be-doped region on the first side of the semiconductor substrate in the image and the correspondence between the position of the doping window of the to-be-doped region on the first side of the semiconductor substrate in the image and the correction parameter of the position of the laser spot, and then correct the position of the laser spot to improve the accuracy of the correspondence of the double-sided pattern of the semiconductor substrate.

[0150] Step 950 : removing a portion of the first protection layer on the second side of the semiconductor substrate by a laser process to form a doping window exposing the to-be-doped region on the second side of the semiconductor substrate.

[0151] Step 960 , performing a doping treatment on the region to be doped to form a doped region.

[0152] Fig.17 A flowchart for refining the second process is provided in an embodiment of the present invention. Based on the above embodiment, the second process includes:

[0153] Step 1010 : forming a second protection layer on a first side and a second side opposite to each other of a semiconductor substrate.

[0154] Step 1020 , removing a portion of the second protection layer on the first side of the semiconductor substrate by a laser process to form a trench window exposing the to-be-dug region on the first side of the semiconductor substrate.

[0155] Step 1030: Acquire the position of the trench window in the to-be-dug region on the first side of the semiconductor substrate through an image acquisition module.

[0156] in, Fig.18 A schematic diagram of a structure for alignment before patterning a second protective layer on a second side of a semiconductor substrate is provided in an embodiment of the present invention. Fig.18 and Fig.16 The alignment principle is the same or similar, and will not be repeated here.

[0157] Step 1040: Adjust the position of the laser spot on the second side of the semiconductor substrate according to the position of the groove window in the to-be-grooved area on the first side of the semiconductor substrate.

[0158] Among them, by obtaining the position of the pattern of the groove window 31 on the completed side of the semiconductor substrate 10, the position of the laser spot on the second side of the semiconductor substrate is adjusted to achieve accurate alignment of the double-sided pattern of the semiconductor device, thereby solving the problem that in the photolithography process, the upper and lower masks are first mechanically aligned and calibrated, and then the upper and lower masks are separated, and then the silicon wafer is placed between the upper and lower masks. This alignment and calibration method will cause displacement during repeated operations, resulting in inaccurate alignment.

[0159] The position of the light spot can be precisely adjusted by the galvanometer in the laser. Before step 1040, a correspondence between the position of the groove window of the grooved area to be dug on the first side of the semiconductor substrate in the image and the correction parameter of the position of the laser light spot can be established in advance, so as to determine the current value of the correction parameter of the position of the laser light spot according to the current position of the groove window of the grooved area to be dug on the first side of the semiconductor substrate in the image and the correspondence between the position of the groove window of the grooved area to be dug on the first side of the semiconductor substrate in the image and the correction parameter of the position of the laser light spot, and then correct the position of the laser light spot to improve the accuracy of the correspondence of the double-sided pattern of the semiconductor substrate.

[0160] Step 1050: remove a portion of the second protection layer on the second side of the semiconductor substrate by a laser process to form a trench window exposing the to-be-dug region on the second side of the semiconductor substrate.

[0161] Step 1060: perform etching treatment on the area to be grooved to form a groove.

[0162] The patterns on the first side and the second side of the semiconductor substrate may be the same, that is, along the thickness direction Z of the semiconductor substrate 10, the patterns on the first side and the second side of the semiconductor substrate may overlap. For silicon wafers that require double-sided grooving, the laser can identify the pattern that has been cut on the back side when processing the second side, so it is only necessary to cut and groove the second side along the ready-made pattern, so that the groove patterns cut on both sides are accurately aligned.

[0163] Fig.19 A flowchart for refining the third process is provided in an embodiment of the present invention. Based on the above embodiment, the third process includes:

[0164] Step 1110 : forming a third protection layer on a first side and a second side opposite to each other of the semiconductor substrate.

[0165] Step 1120: remove a portion of the third protection layer on the first side of the semiconductor substrate by a laser process to form an electrode window on the first side of the semiconductor substrate.

[0166] Step 1130: Acquire the position of the electrode window on the first side of the semiconductor substrate through the image acquisition module.

[0167] in, Fig. 20 A schematic diagram of a structure for alignment before patterning a third protective layer on a second side of a semiconductor substrate is provided in an embodiment of the present invention. Fig. 20 and Fig.16 The alignment principle is the same or similar, and will not be repeated here.

[0168] Step 1140: adjust the position of the laser spot on the second side of the semiconductor substrate according to the position of the electrode window on the first side of the semiconductor substrate.

[0169] Among them, by obtaining the position of the pattern of the electrode window on the completed side of the semiconductor substrate, the position of the laser spot on the second side of the semiconductor substrate is adjusted to achieve accurate alignment of the double-sided pattern of the semiconductor device, thereby solving the problem that in the photolithography process, the upper and lower masks are first mechanically aligned and calibrated, and then the upper and lower masks are separated, and then the silicon wafer is placed between the upper and lower masks. This alignment and calibration method will cause displacement during repeated operations, resulting in inaccurate alignment.

[0170] The position of the light spot can be precisely adjusted by the galvanometer in the laser. Before step 1140, a correspondence between the position of the electrode window on the first side of the semiconductor substrate in the image and the correction parameter of the position of the laser light spot can be established in advance, so as to determine the current value of the correction parameter of the position of the laser light spot according to the current position of the electrode window on the first side of the semiconductor substrate in the image and the correspondence between the position of the electrode window on the first side of the semiconductor substrate in the image and the correction parameter of the position of the laser light spot, and then adjust the position of the laser light spot to improve the accuracy of the correspondence of the double-sided pattern of the semiconductor substrate.

[0171] Step 1150: remove a portion of the third protection layer on the second side of the semiconductor substrate by a laser process to form an electrode window on the second side of the semiconductor substrate.

[0172] Step 1160: Form a conductive material layer in the electrode window to form an electrode.

[0173] Optionally, based on the above embodiment, one or more of the first process, the second process and the third process are performed multiple times. The first process can be performed once or multiple times. The second process can be performed once or multiple times. The third process can be performed once or multiple times.

[0174] Optionally, based on the above embodiment, the first process is performed multiple times, and the type or concentration of the dopant in each first process is different. At least one of the position, shape and size of the doping window 21 in each first process may be different. Fig.21 A schematic diagram of the structure of a semiconductor discharge tube provided by an embodiment of the present invention. The doping region 22 and the doping region 23 correspond to different first processes respectively. The doping region 23 is formed by one first process; and the doping region 22 is formed by another first process. Along the thickness direction of the semiconductor substrate 10 (parallel to the direction Z), the depth of the doping region 23 is greater than the depth of the doping region 22. The doping region 23 is located inside the doping region 22. The more complex the doping region setting in the semiconductor device is, the more times the first process is repeated.

[0175] Optionally, based on the above embodiment, the second process is performed multiple times, and the position of the groove window in each second process is different. Optionally, based on the above embodiment, the third process is performed multiple times, and the position of the electrode window in each third process is different. Some or all of the processes may be repeated according to product characteristics.

[0176] Optionally, based on the above-mentioned embodiment, the semiconductor device manufacturing method does not include a photolithography process, and the photolithography process is replaced by a laser process to completely eliminate the photolithography process. There is no need to set up a special yellow light workshop, which reduces the waste liquid and waste glue generated by the photolithography process and is more environmentally friendly. Laser etching is convenient to operate, which reduces wafer production time and cost.

[0177] Optionally, the first process 1 may be performed before the second process 2, or the first process 1 may be performed after the second process 2, or the second process 2 may be performed between multiple first processes 1, or the first process 1 may be performed between multiple second processes 2. The execution order of the first process 1 and the second process 2 may be set as required, and the embodiment of the present invention does not limit this. Optionally, the first process 1 and the second process 2 may be performed before the third process 3.

[0178] Optionally, a laser equipped with a galvanometer is used in the laser process. Compared with a mechanical cutting scriber (which can only cut simple patterns on silicon wafers, such as straight lines, right-angled lines, and rectangles), it can cut various complex patterns (such as circles, arcs, non-right-angled lines, etc.), that is, cut doping windows, groove windows, and electrode windows of various complex shapes to meet design requirements.

[0179] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A method for manufacturing a semiconductor device, characterized in that: include: forming a second protective layer on at least one side of the semiconductor substrate, the second protective layer comprising: one or more of silicon oxide, silicon nitride, silicon carbide, polysilicon, glass, polyimide, photoresist, wax, green oil, black glue and silica gel; removing a portion of the second protective layer by a laser process to form a trench window exposing the to-be-dug region of the semiconductor substrate, wherein the laser comprises at least one of an ultraviolet laser, an infrared laser, a blue laser, a green laser, and a carbon dioxide laser; and The area to be grooved is etched to form a groove.

2. The method for manufacturing a semiconductor device according to claim 1, wherein: The etching process for forming the trench in the area to be grooved includes: Allowing the etching liquid to contact the area to be grooved through the groove window to perform groove etching; and According to the set etching time, the depth and width of the groove meet the requirements.

3. The method for manufacturing a semiconductor device according to claim 2, wherein: Etching the trenched area to form the trench also includes: The second protective layer is used as a barrier layer to achieve selective corrosion.

4. The method for manufacturing a semiconductor device according to claim 1, wherein: The at least one side is a first side and a second side of the semiconductor substrate, and removing a portion of the second protective layer by a laser process to form a trench window exposing a trench area of ​​the semiconductor substrate includes: Removing a portion of the second protective layer on the first side of the semiconductor substrate by a laser process to form a trench window exposing the to-be-dug region on the first side of the semiconductor substrate; Acquire the position of the groove window of the to-be-grooved area of ​​the first side of the semiconductor substrate through the image acquisition module; According to the position of the groove window of the grooved area to be dug on the first side of the semiconductor substrate, adjusting the position of the laser spot on the second side of the semiconductor substrate to achieve accurate alignment of the double-sided pattern of the semiconductor device; and A portion of the second protection layer on the second side of the semiconductor substrate is removed by a laser process to form a trench window exposing the to-be-dug region on the second side of the semiconductor substrate.

5. The method for manufacturing a semiconductor device according to claim 4, characterized in that: Achieving accurate alignment of double-sided patterns of semiconductor devices includes: Pre-establishing a correspondence between the position of the groove window of the to-be-grooved area on the first side of the semiconductor substrate in the image and the correction parameters of the position of the laser spot; and According to the current position of the groove window of the area to be grooved on the first side of the semiconductor substrate in the image, and the correspondence between the position of the groove window of the area to be grooved on the first side of the semiconductor substrate in the image and the correction parameters of the position of the laser spot, the current value of the correction parameter of the position of the laser spot is determined, and then the position of the laser spot is corrected.

6. The method for manufacturing a semiconductor device according to claim 1, wherein: After etching the area to be grooved to form a groove, the method further comprises: forming a third protective layer on at least one side of the semiconductor substrate, wherein the third protective layer is an insulating layer; removing a portion of the third protective layer by a laser process to form an electrode window, wherein the laser comprises at least one of an ultraviolet laser, an infrared laser, a blue laser, a green laser, and a carbon dioxide laser; and A conductive material layer is formed in the electrode window to form an electrode.

7. The method for manufacturing a semiconductor device according to claim 6, wherein: Forming a third protective layer on at least one side of the semiconductor substrate includes: Input the pattern of the third protective layer to be peeled off and the laser parameters in the computer control software; and The laser stripping device is controlled to strip the third protective layer according to the graphics preset in the computer.

8. The method for manufacturing a semiconductor device according to claim 6, wherein: The third protective layer includes: one or more of silicon oxide, silicon nitride, silicon carbide, polysilicon, glass, polyimide, photoresist, wax, green oil, black glue and silica gel, a groove is formed on at least one side of the semiconductor substrate, and forming the third protective layer on at least one side of the semiconductor substrate includes: Clean the PN junction exposed by trench etching via RCA; and The PN junction is protected by the layer cleaned by RCA.

9. The method for manufacturing a semiconductor device according to claim 6, wherein: Removing a portion of the third protective layer by a laser process to form an electrode window includes: The mesa oxide layer is removed and textured by laser, and the mesa oxide layer is included in the third protection layer.

10. The method for manufacturing a semiconductor device according to claim 1 or 6, characterized in that: Before forming the second protection layer on at least one side of the semiconductor substrate, the method further includes: forming a first protective layer on at least one side of the semiconductor substrate; removing a portion of the first protective layer by a laser process to form a doping window exposing a to-be-doped region of the semiconductor substrate; and The region to be doped is subjected to a doping process to form a doped region.

11. The method for manufacturing a semiconductor device according to claim 10, characterized in that: Performing a doping treatment on the to-be-doped region to form the doped region includes: The doping process is performed on the area to be doped exposed by the doping window through a diffusion process or an ion implantation method to achieve the electrical properties required by the semiconductor device, wherein the first protective layer is used as a barrier layer to achieve selective diffusion.

12. The method for manufacturing a semiconductor device according to claim 10, wherein: Before performing a doping treatment on the to-be-doped region to form the doped region, the method comprises: The bottom and sidewalls of the doped window are damaged and repaired by chemical and / or physical methods to remove the damaged layer and debris left by laser burning.

13. The method for manufacturing a semiconductor device according to claim 10, characterized in that: Damage repair treatment of the bottom and sidewalls of the doping window by chemical and / or physical methods includes any of the following: Cleaning with an acidic solution and / or an alkaline solution, wherein the acidic solution includes one or more of hydrofluoric acid, nitric acid, glacial acetic acid, and sulfuric acid, and the alkaline solution includes one or more of potassium hydroxide and sodium hydroxide; or Use dry etching.

14. The method for manufacturing a semiconductor device according to claim 1, wherein: The semiconductor devices include: one or more of transient suppression diodes, rectifier diodes, voltage regulators, trigger tubes, field effect tubes, semiconductor discharge tubes, thyristors, triodes, Schottky diodes, light-emitting tubes, solar cells, photosensitive tubes and fast recovery tubes.

15. The method for manufacturing a semiconductor device according to claim 1, wherein: The semiconductor substrate comprises: a body region configured as a first conductivity type; and The first doped region and the second doped region are located on two opposite sides of the body region, and the first doped region and the second doped region are configured as a second conductivity type.

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