CN116825804A - Silicon carbide device termination structure and method of making same - Google Patents
Silicon carbide device termination structure and method of making same Download PDFInfo
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- CN116825804A CN116825804A CN202210281170.6A CN202210281170A CN116825804A CN 116825804 A CN116825804 A CN 116825804A CN 202210281170 A CN202210281170 A CN 202210281170A CN 116825804 A CN116825804 A CN 116825804A
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- silicon carbide
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- groove
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- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 78
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 78
- 238000004519 manufacturing process Methods 0.000 title claims description 23
- 239000002184 metal Substances 0.000 claims abstract description 12
- 238000005530 etching Methods 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 18
- 229920002120 photoresistant polymer Polymers 0.000 claims description 8
- 238000000151 deposition Methods 0.000 claims description 6
- 238000005468 ion implantation Methods 0.000 claims description 3
- 238000001259 photo etching Methods 0.000 claims description 3
- 238000000206 photolithography Methods 0.000 description 3
- 239000002131 composite material Substances 0.000 description 2
- 210000000746 body region Anatomy 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
Classifications
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- H01L29/0615—
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
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- H01L29/06—
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- H01L29/0684—
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- H01L29/66053—
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- Condensed Matter Physics & Semiconductors (AREA)
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- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Electrodes Of Semiconductors (AREA)
Abstract
The terminal structure of the silicon carbide device provided by the embodiment of the invention comprises: an n-type silicon carbide layer; one first trench in the n-type silicon carbide layer and at least one second trench on one side of the first trench; the lateral walls of the first groove and the second groove are at least divided into two sections in the vertical direction and are in stepped steps, and the transverse widths of the first groove and the second groove are gradually reduced from top to bottom in the vertical direction; a first p-type region within the n-type silicon carbide layer proximate the first trench sidewall and bottom and a second p-type region proximate the second trench sidewall and bottom; an insulating layer covering the surface of the n-type silicon carbide layer and filling the first trench and the second trench; and a metal layer which is positioned on the insulating layer and covers part of the first groove. The silicon carbide device terminal structure provided by the embodiment of the invention has the advantages of small area and high stability.
Description
Technical Field
The invention belongs to the technical field of silicon carbide devices, and particularly relates to a silicon carbide device terminal structure and a manufacturing method thereof.
Background
Silicon carbide devices of the prior art typically use field-limiting rings and Junction Termination Extension (JTE) structures as the termination structures of the device. The adoption of the field limiting ring structure as a terminal structure can lead the terminal area of the silicon carbide device to be larger, and the chip size of the silicon carbide device can not be effectively reduced; the junction terminal extension structure is adopted as the terminal structure of the silicon carbide device, the manufacturing process is complex, and particularly, the control difficulty of the doping amount of the junction terminal extension region is high, and the manufacturing cost is high.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a silicon carbide device termination structure and a method for manufacturing the same, which can improve the withstand voltage capability and stability of a silicon carbide device without increasing the chip area of the silicon carbide device.
The terminal structure of the silicon carbide device provided by the embodiment of the invention comprises:
an n-type silicon carbide layer;
one first trench in the n-type silicon carbide layer and at least one second trench on one side of the first trench;
the lateral walls of the first groove and the second groove are at least divided into two sections in the vertical direction and are in stepped steps, and the transverse widths of the first groove and the second groove are gradually reduced from top to bottom in the vertical direction;
a first p-type region within the n-type silicon carbide layer proximate the first trench sidewall and bottom and a second p-type region proximate the second trench sidewall and bottom;
an insulating layer covering the surface of the n-type silicon carbide layer and filling the first trench and the second trench;
and a metal layer which is positioned on the insulating layer and covers part of the first groove.
Optionally, in the silicon carbide device termination structure of the present invention, an opening width of the first trench is greater than an opening width of the second trench.
The invention discloses a manufacturing method of a silicon carbide device terminal structure, which comprises the following steps:
step one: forming a hard mask layer on the provided n-type silicon carbide layer, depositing photoresist, defining the positions of the first groove and the second groove through a photoetching process, and etching the hard mask layer to expose the n-type silicon carbide layer;
step two: removing the photoresist, and etching the n-type silicon carbide layer by taking the residual hard mask layer as a mask to form a first shallow groove and a second shallow groove in the n-type silicon carbide layer;
step three: isotropically etching the hard mask layer, reducing the thickness and the width of the rest hard mask layer, and respectively etching the n-type silicon carbide layer in the first shallow trench and the second shallow trench by taking the rest hard mask as a mask to form a first trench and a second trench with two sections of side walls and in a step shape;
step four: isotropically etching the hard mask layer, reducing the thickness and width of the rest hard mask layer, and performing p-type ion implantation to form a first p-type region positioned on the side wall and the bottom of the first groove and a second p-type region positioned on the side wall and the bottom of the second groove in the n-type silicon carbide layer;
step five: and removing the hard mask layer, depositing to form an insulating layer, depositing a metal layer, etching the metal layer, and covering part of the first groove by the metal layer remained after etching.
Optionally, in the method for manufacturing the silicon carbide device terminal structure of the present invention, the number of the first trenches is one, and the number of the second trenches is at least one.
Optionally, in the method for manufacturing a silicon carbide device termination structure of the present invention, an opening width of the first trench is greater than an opening width of the second trench.
Optionally, in the method for manufacturing a silicon carbide device terminal structure of the present invention, after the step three is completed, the step three is repeated, and the number of steps of the sidewalls of the first trench and the second trench formed is controlled by controlling the number of times of the step three.
Optionally, in the method for manufacturing a silicon carbide device termination structure of the present invention, the insulating layer is located on the silicon carbide layer and fills the first trench and the second trench.
The invention adopts the composite structure of the multiple grooves and the field limiting rings as the terminal structure of the silicon carbide device, so that the area of the terminal structure can be reduced, the silicon carbide device has small chip size, and the pressure resistance and the stability of the silicon carbide device are improved.
Drawings
In order to more clearly illustrate the technical solution of the exemplary embodiments of the present invention, a brief description is given below of the drawings required for describing the embodiments.
FIG. 1 is a schematic cross-sectional view of one embodiment of a termination structure for a silicon carbide device provided by the present invention;
fig. 2-7 are schematic cross-sectional views of the principal process nodes of one embodiment of a method of fabricating a silicon carbide device termination structure of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be fully described below by way of specific modes with reference to the accompanying drawings in the embodiments of the present invention.
Fig. 1 is a schematic cross-sectional structure of an embodiment of a silicon carbide device termination structure provided in the present invention, and as shown in fig. 1, the silicon carbide device termination structure of the present invention includes an n-type silicon carbide layer 20, one first trench 61 located in the n-type silicon carbide layer 20, and at least one second trench 62 located on one side of the first trench 61, and in the embodiment of the present invention, 3 second trenches 62 are exemplarily shown.
The side walls of the first groove 61 and the second groove 62 are each divided into at least two sections in the vertical direction and are stepped, and the lateral widths of the first groove 61 and the second groove 62 are each gradually reduced from top to bottom in the vertical direction. In the present embodiment, the sidewalls of the first trench 61 and the second trench 62 are each exemplarily divided into two sections, i.e., having only one step. It should be noted that, the lateral widths of the first trench 61 and the second trench 62 gradually decrease from top to bottom in the vertical direction, which is understood as that the trenches of different segments in the first trench 61 and the second trench 62 correspond to different lateral widths, the trenches of the same segment correspond to the same lateral width, that is, the trenches of the upper segment correspond to a larger lateral width, and the trenches of the lower segment correspond to a smaller lateral width.
A first p-type region 21 located within the n-type silicon carbide layer 20 adjacent to the sidewalls and bottom of the first trench 61 and a second p-type region 22 located within the n-type silicon carbide layer 20 adjacent to the sidewalls and bottom of the second trench 62. Preferably, the opening width A1 of the first trench 61 is larger than the opening width A2 of the second trench 62, and the first p-type body region 21 serves as a main junction region. It should be noted that the opening width A1 of the first trench 61 is larger than the opening width A2 of the second trench 62, and it is understood that the opening width A1 of the first trench 61 in the corresponding segment is larger than the opening width A2 of the second trench 62, that is, the opening width of the upper segment in the first trench 61 is larger than the opening width of the upper segment in the second trench 62, and the opening width of the lower segment in the first trench 61 is larger than the opening width of the lower segment in the second trench 62.
An insulating layer 23 covering the surface of the n-type silicon carbide layer 20 and filling the first trench 61 and the second trench 62, and a metal layer 24 on the insulating layer 23 and covering a part of the first trench 61.
The invention adopts the composite structure of multiple grooves and the field limiting ring as the terminal structure of the silicon carbide device, the side walls of the first groove and the second groove are of ladder-shaped step structures, meanwhile, the first p-type region is close to the side wall and the bottom of the first groove, the second p-type region is close to the side wall and the bottom of the second groove, the doping area of the first p-type region and the second p-type region can be effectively increased, the effect of the first p-type region and the second p-type region is increased, and therefore, the area of the terminal structure can be reduced under the same pressure-resistant condition, the silicon carbide device has small chip size, and the pressure-resistant capability and the stability of the silicon carbide device are improved.
Fig. 2-7 are schematic cross-sectional views of the principal process nodes of one embodiment of a method of fabricating a silicon carbide device termination structure of the present invention. As shown in fig. 2 to 7, a method for manufacturing a silicon carbide device termination structure according to the present invention includes:
step one: as shown in fig. 2, a hard mask layer 31 is formed on the provided n-type silicon carbide layer 20, a photoresist layer 32 is deposited and positions of the first trench and the second trench are defined by a photolithography process, and then the hard mask layer 31 is etched to expose the n-type silicon carbide layer 20. By controlling the dimensions of the photoresist pattern width a at the first trench position and the photoresist pattern width b at the second trench position, the opening width of the first trench and the opening width of the second trench to be formed later can be controlled.
Step two: as shown in fig. 3, the photoresist 32 is removed, the n-type silicon carbide layer 20 is etched by using the remaining hard mask layer 31 as a mask, and a first shallow trench and a second shallow trench are formed in the n-type silicon carbide layer 20.
Step three: the hard mask layer 31 is isotropically etched as shown in fig. 4 to reduce the thickness and width of the remaining hard mask layer 31, and then the n-type silicon carbide layer 20 is etched with the remaining hard mask layer 31 as a mask to form a first trench 61 and a second trench 62 having two steps on the sidewalls and having a stepped shape as shown in fig. 5. Since the isotropic etching process is used to etch the hard mask layer 31, there is no need to add a photolithography process, and the etching process of the hard mask layer can be simplified, thereby reducing the manufacturing cost.
In the present invention, the number of the first grooves 61 is one, the number of the second grooves 62 is at least one, and preferably, the opening width of the first grooves 61 is larger than the opening width of the second grooves 62.
After the third step is completed, the third step can be repeated, and the number of steps of the side walls of the first trench 61 and the second trench 62 formed can be controlled by controlling the number of times of the third step.
Step four: the hard mask layer 31 is isotropically etched as in fig. 6, the thickness and width of the remaining hard mask layer 31 are further reduced, and then p-type ion implantation is performed to form first p-type regions 21 in the n-type silicon carbide layer 20 at the sidewalls and bottom of the first trenches and second p-type regions 22 in the sidewalls and bottom of the second trenches 62. Since the isotropic etching process is used to etch the hard mask layer 31, there is no need to add a photolithography process, and the etching process of the hard mask layer can be simplified, thereby reducing the manufacturing cost.
Step five: as shown in fig. 7, the remaining hard mask layer is removed, an insulating layer 23 is deposited, a metal layer is deposited and etched, and the etched metal layer 24 covers a portion of the first trench 61. Preferably, the insulating layer 23 is located on the silicon carbide layer 20 and fills the first trench 61 and the second trench 62.
The manufacturing method of the silicon carbide device terminal structure has the advantages that the first groove 61 and the second groove 62 with the side walls in the shape of the step steps can be formed only by one photoetching process, the manufacturing process is simple, and the control is easy.
Although embodiments of the present invention have been disclosed above, it is not limited to the details and embodiments shown and described, it is well suited to various fields of use for which the invention would be readily apparent to those skilled in the art, and accordingly, the invention is not limited to the specific details and illustrations shown and described herein, without departing from the general concepts defined in the claims and their equivalents.
Claims (7)
1. A silicon carbide device termination structure, comprising:
an n-type silicon carbide layer;
one first trench in the n-type silicon carbide layer and at least one second trench on one side of the first trench;
the lateral walls of the first groove and the second groove are at least divided into two sections in the vertical direction and are in stepped steps, and the transverse widths of the first groove and the second groove are gradually reduced from top to bottom in the vertical direction;
a first p-type region within the n-type silicon carbide layer proximate the first trench sidewall and bottom and a second p-type region proximate the second trench sidewall and bottom;
an insulating layer covering the surface of the n-type silicon carbide layer and filling the first trench and the second trench;
and a metal layer which is positioned on the insulating layer and covers part of the first groove.
2. The silicon carbide device termination structure of claim 1, wherein the first trench has an opening width that is greater than an opening width of the second trench.
3. A method of fabricating a silicon carbide device termination structure, comprising:
step one: forming a hard mask layer on the provided n-type silicon carbide layer, depositing photoresist, defining the positions of the first groove and the second groove through a photoetching process, and etching the hard mask layer to expose the n-type silicon carbide layer;
step two: removing the photoresist, and etching the n-type silicon carbide layer by taking the residual hard mask layer as a mask to form a first shallow groove and a second shallow groove in the n-type silicon carbide layer;
step three: isotropically etching the hard mask layer, reducing the thickness and the width of the rest hard mask layer, and respectively etching the n-type silicon carbide layer in the first shallow trench and the second shallow trench by taking the rest hard mask as a mask to form a first trench and a second trench with two sections of side walls and in a step shape;
step four: isotropically etching the hard mask layer, reducing the thickness and width of the rest hard mask layer, and performing p-type ion implantation to form a first p-type region positioned on the side wall and the bottom of the first groove and a second p-type region positioned on the side wall and the bottom of the second groove in the n-type silicon carbide layer;
step five: and removing the hard mask layer, depositing to form an insulating layer, depositing a metal layer, etching the metal layer, and covering part of the first groove by the metal layer remained after etching.
4. The method of manufacturing a silicon carbide device termination structure of claim 3, wherein the number of first trenches is one and the number of second trenches is at least one.
5. The method of manufacturing a silicon carbide device termination structure of claim 3, wherein the opening width of the first trench is greater than the opening width of the second trench.
6. The method of manufacturing a silicon carbide device termination structure of claim 3, wherein after step three is completed, repeating step three and controlling the number of steps of the sidewalls of the first trench and the second trench formed by controlling the number of times of step three.
7. The method of manufacturing a silicon carbide device termination structure of claim 3, wherein the insulating layer is on the silicon carbide layer and fills the first trench and the second trench.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210281170.6A CN116825804A (en) | 2022-03-21 | 2022-03-21 | Silicon carbide device termination structure and method of making same |
| PCT/CN2022/107347 WO2023178897A1 (en) | 2022-03-21 | 2022-07-22 | Silicon carbide device terminal structure and manufacturing method therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210281170.6A CN116825804A (en) | 2022-03-21 | 2022-03-21 | Silicon carbide device termination structure and method of making same |
Publications (1)
| Publication Number | Publication Date |
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| CN116825804A true CN116825804A (en) | 2023-09-29 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202210281170.6A Pending CN116825804A (en) | 2022-03-21 | 2022-03-21 | Silicon carbide device termination structure and method of making same |
Country Status (2)
| Country | Link |
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| CN (1) | CN116825804A (en) |
| WO (1) | WO2023178897A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117711938A (en) * | 2024-02-05 | 2024-03-15 | 深圳腾睿微电子科技有限公司 | Isolation groove type terminal IGBT device and manufacturing method thereof |
| CN117711939A (en) * | 2024-02-05 | 2024-03-15 | 深圳腾睿微电子科技有限公司 | Groove type terminal IGBT device and manufacturing method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106783957A (en) * | 2016-12-27 | 2017-05-31 | 西安电子科技大学 | Carborundum multi-step groove knot termination extension terminal structure and preparation method thereof |
| CN107293599A (en) * | 2017-07-19 | 2017-10-24 | 中国科学院微电子研究所 | Silicon carbide power device terminal and manufacturing method thereof |
| JP7297654B2 (en) * | 2019-12-11 | 2023-06-26 | 株式会社東芝 | Semiconductor devices, inverter circuits, drive devices, vehicles, and elevators |
| CN112310195B (en) * | 2020-09-27 | 2022-09-30 | 东莞南方半导体科技有限公司 | Stepped SiC groove field limiting ring terminal structure, preparation method and device thereof |
-
2022
- 2022-03-21 CN CN202210281170.6A patent/CN116825804A/en active Pending
- 2022-07-22 WO PCT/CN2022/107347 patent/WO2023178897A1/en unknown
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117711938A (en) * | 2024-02-05 | 2024-03-15 | 深圳腾睿微电子科技有限公司 | Isolation groove type terminal IGBT device and manufacturing method thereof |
| CN117711939A (en) * | 2024-02-05 | 2024-03-15 | 深圳腾睿微电子科技有限公司 | Groove type terminal IGBT device and manufacturing method thereof |
| CN117711939B (en) * | 2024-02-05 | 2024-06-14 | 深圳腾睿微电子科技有限公司 | Groove type terminal IGBT device and manufacturing method thereof |
| CN117711938B (en) * | 2024-02-05 | 2024-06-14 | 深圳腾睿微电子科技有限公司 | Isolation groove type terminal IGBT device and manufacturing method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023178897A1 (en) | 2023-09-28 |
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