EP0726594A2
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EP
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Semiconductor device and method of manufacturing the same
Assignee: NGK Insulators Ltd
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Filing: 1996-02-07
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Granted: —
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Expires: 2016-02-07
Abstract
Abstract A method of manufacturing a joined-type semiconductor device having a gate structure. The semiconductor device includes a first and second semiconductor substrates (10,20) each having a substrate body, and a first and a second main surfaces (10a,20a), (10b,20b) which are opposite to each other. A gate structure is formed in the first main surface (10a) of the first substrate (10). A highly-doped semiconductor layer (21) is formed in the first main surface (20a) of the second substrate (20) and has an impurity-concentration which is higher than that of the substrate body of the second substrate (10). The first main surfaces (10a,20a) of the two substrates are joined with each other, by subjecting the two substrates to a heat treatment so that impurities in the highly-doped semiconductor layer (21) of the second substrate (20) are driven into the surface region of the first substrate (10), and a diffusion layer (15) is thereby formed in the first main surface (10a) of the first substrate (10).
Inventors
- 👤 Yoshio Terasawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 22:27
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/64; H10D30/66; H10D30/668; H10D12/00; H10D12/01; H10D12/021; H10D12/031; H10D12/032; H10D12/038; H10D12/211; H10D12/212; H10D12/411; H10D12/441; H10D12/461; H10D12/481; H10D18/00; H10D18/60; H10D62/00; H10D62/10; H10D62/117; H10D84/00; H10D84/01; H10D84/0102; H10P; H10P10/00; H10P10/12; H10P10/128; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/517; H10D64/519; Y; Y10; Y10S; Y10S148/00; Y10S148/012
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
207 words
A method of manufacturing a joined-type semiconductor device having a gate structure, comprising the steps of: preparing a first semiconductor substrate having a substrate body with a first impurity concentration, and a first and a second main surfaces which are opposite to each other, and a second semiconductor substrate having a substrate body with a second impurity, and a first and second main surfaces which are opposite to each other; forming a gate structure in said first main surface of the first semiconductor substrate; forming a highly-doped semiconductor layer having a third impurity concentration in said first main surface of the second semiconductor substrate, said third impurity concentration being higher than the second impurity concentration; and joining the first main surface of the first semiconductor substrate with the first main surface of the second semiconductor substrate, and heating the first and second semiconductor substrates to drive the impurities in the highly-doped semiconductor layer of the second semiconductor substrate into the first main surface of the first semiconductor substrate- such that a diffusion layer is formed in the main surface of the first semiconductor substrate, said diffusion layer having a forth impurity concentration higher than said first impurity concentration of the substrate body of the first semiconductor substrate.
Claim 2
Dependent Claim
64 words
The method according to Claim 1, wherein said highly-doped semiconductor layer of the second semiconductor substrate is formed such that said highly-doped semiconductor layer has a same conductive type as a surface region of the first main surface of the first semiconductor substrate and has an impurity concentration higher than that of said surface region of the main surface of the first semiconductor substrate.
Claim 3
Dependent Claim
29 words
The method according to Claim 2, wherein said highly-doped semiconductor layer of the second semiconductor substrate and said surface region of the first semiconductor substrate have a n-conductive type.
Claim 4
Dependent Claim
66 words
The method according to Claim 1, wherein said highly-doped semiconductor layer of the second semiconductor substrate is formed such that said highly-doped semiconductor layer has an opposite conductive type to that of a surface region of the first main surface of the first semiconductor substrate and has an impurity concentration higher than that of said surface region of the main surface of the first semiconductor substrate.
Claim 5
Dependent Claim
33 words
The method according to Claim 4, wherein said highly-doped semiconductor layer of the second semiconductor substrate has a n-conductive type and said surface region of the first semiconductor substrate has a p-conductive type.
Claim 6
Dependent Claim
54 words
The method according to Claim 2, wherein said third impurity concentration of said highly-doped semiconductor layer of the second semiconductor substrate is not less than 1×10 17 atom/cm 3 , and said second impurity concentration of said substrate body of the second semiconductor substrate is on the order of 1×10 16 atom/cm 3 .
Claim 7
Dependent Claim
30 words
The method according to Claim 6, wherein said third impurity concentration of said highly-doped semiconductor layer of the second semiconductor substrate is not less than 1×10 18 atom/cm 3 .
Claim 8
Dependent Claim
54 words
The method according to Claim 4, wherein said third impurity concentration of said highly-doped semiconductor layer of the second semiconductor substrate is not less than 1×10 19 atom/cm 3 , and said second impurity concentration of said substrate body of the second semiconductor substrate is on the order of 1×10 16 atom/cm 3 .
Claim 9
Dependent Claim
23 words
The method according to Claim 1, wherein said highly-doped semiconductor layer of the second semiconductor substrate is formed by an ion implantation process.
Claim 10
Dependent Claim
23 words
The method according to Claim 1, wherein said highly-doped semiconductor layer of the second semiconductor substrate is formed by a thermal diffusion process.
Claim 11
Dependent Claim
23 words
The method according to Claim 1, wherein said highly-doped semiconductor layer of the second semiconductor substrate is formed by an epitaxial growing process.
Claim 12
Dependent Claim
22 words
The method according to Claim 1, wherein said semiconductor layer of the second semiconductor substrate is formed by chemical vapor deposition process.
Claim 13
Dependent Claim
19 words
The method according to Claim 1, wherein said joining step is carried out by a heating process under pressure.
Claim 14
Dependent Claim
39 words
The method according to Claim 1, wherein said impurity of the surface region of the first main surface of the first semiconductor substrate is lower than said second impurity concentration of the substrate body of the second semiconductor substrate.
Claim 15
Dependent Claim
45 words
The method according to Claim 1, wherein first impurity concentration of said semiconductor layer of the second semiconductor substrate is higher than said second impurity concentration of said substrate body of the second semiconductor substrate, by an order of not less than 1×10 2 .
Claim 16
Dependent Claim
96 words
The method according to Claim 1, wherein said first semiconductor substrate has one conductive type, and said step of forming the gate structure comprises the sub-steps of: forming at least one recess in said first main surface of said first semiconductor substrate; forming an insulating layer at a bottom of said recess; forming a hole in said insulating layer and selectively forming a semiconductor region at the bottom of said recess via said hole, said semiconductor region having the other conductive type; and forming a gate electrode on said semiconductor region of the opposite conductive type.
Claim 17
Dependent Claim
60 words
The method according to Claim 1, wherein said step of forming the gate structure comprises the sub-steps of: forming at least one recess in said first main surface of said first semiconductor substrate; forming an insulating layer at a bottom of said recess; and forming a hole in said insulating layer and selectively forming a gate electrode in said hole.
Claim 18
Dependent Claim
53 words
The method according to Claim 1, wherein said step of forming the gate structure comprises the sub-steps of: forming at least one recess in said first main surface of said first semiconductor substrate; forming an insulating layer at a bottom of said recess; and selectively forming a gate electrode on said insulating layer.
Claim 19
Dependent Claim
115 words
The method according to Claim 1, wherein said step of forming the gate structure comprising the sub-steps of selectively forming a semiconductor region of the other conductive type on said first main surface of said first semiconductor substrate, and forming a gate electrode on said semiconductor region on said first semiconductor substrate; and wherein said method further comprises the steps of forming a recess in said first main surface of the second semiconductor substrate in its region corresponding to said gate structure on said first semiconductor substrate, and subsequently performing said joining step and thereby joining the first main surface of the first semiconductor substrate with the first main surface of the second semiconductor substrate.
Claim 20
Dependent Claim
81 words
The method according to Claim 1, wherein said semiconductor device is an SI thyrister and said substrate body of the first semiconductor substrate has one conductive type, further comprising the steps of forming a semiconductor layer of the other conductive type in said second main surface of the first semiconductor substrate, forming a first main electrode on said semiconductor layer of the first semiconductor substrate, and forming a second main electrode on said second main surface of the second semiconductor substrate.
Claim 21
Dependent Claim
195 words
A joined-type semiconductor device comprising: a first semiconductor substrate having a substrate body with a first impurity concentration, and first and second main surfaces which are opposed to each other, said first main surface having a gate structure formed therein; a first main electrode formed on the second main surface of the first semiconductor substrate; a second semiconductor substrate having a substrate body with a second impurity concentration, and first and second main surfaces which are opposed to each other, said first main surface having a highly-doped semiconductor layer formed therein, which has a third impurity concentration higher than the second impurity concentration of the substrate body, said first main surface of the second substrate being joined with said first main surface of the first substrate ; a second main electrode formed on said second main surface of the second substrate; and a diffusion layer formed in the first main surface of the first substrate by thermal diffusion of impurity ions from said highly-doped semiconductor layer into said first main surface of the first substrate, said diffusion layer having impurity concentration higher than said first impurity concentration of the substrate body of the first substrate.
Claim 22
Dependent Claim
43 words
Semiconductor device according to Claim 19, wherein said semiconductor device is an SI thyrister and said first semiconductor substrate further comprises a further semiconductor layer formed in the second main surface and having an opposite conductive type to that of the substrate body.
Claim 23
Dependent Claim
87 words
Semiconductor device according to Claim 19, wherein said semiconductor device is an GTO thyrister and said first semiconductor substrate further comprises a first semiconductor layer formed in the second main surface and a second semiconductor layer formed in the first main surface, said first and second semiconductor layers having an opposite conductive type to that of the substrate body, and said diffusion layer having an opposite conductive type to that of the substrate body of said first semiconductor substrate is formed in the said second semiconductor layer.
Claim 24
Dependent Claim
115 words
Semiconductor device according to Claim 19, wherein said semiconductor device is an GTO thyrister and said first semiconductor substrate further comprises a first semiconductor layer formed in the first main surface and having an opposite conductive type to that of the substrate body, a second semiconductor layer formed in the second main surface and having an opposite conductive type to that of the substrate body, and a third semiconductor layer formed on the second semiconductive layer having a same conductive type to that of the substrate body, and said diffusion layer having a same conductive type to that of the substrate body of said first semiconductor substrate is formed in the said third semiconductor layer.
Claim 25
Dependent Claim
103 words
Semiconductor device according to Claim 19, wherein said semiconductor device is a MOSFET and said first semiconductor substrate further comprises a first semiconductor layer having a same conductive type to that of the substrate body, a second semiconductor layer formed on the first semiconductor layer and having an opposite conductive type to that of the substrate body,and a third semiconductor layer formed on the second semiconductor layer and having a same conductive type to that of the oubstrate body,and said diffusion layer having a same conductive type as the substrate body of the first semiconductor substrate is formed in said third semiconductive layer.
Claim 26
Dependent Claim
103 words
Semiconductor device according to Claim 19, wherein said semiconductor device is an IGBT and said first semiconductor substrate further comprises a first semiconductor layer having an opposite conductive type to that of the substrate body a second semiconductor layer formed on the first semiconductor layer and having a same conductive type to that of the substrate body,and a third semiconductor layer formed on the second semiconductor layer and having an opposite conductive type to that of the substrate body,and said diffusion layer having an opposite conductive type as the substrate body of the first semiconductor substrate is formed in said third semiconductive layer.
References Cited (Backward Citations)
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