US5858855A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor substrate, process for production thereof, and semiconductor device
Assignee: Renesas Electronics Corp
•
Filing: 1997-06-13
•
Granted: 1999-01-12
•
Expires: 2017-06-13
Abstract
Abstract The present invention relates to a semiconductor substrate which is a composite substrate obtained by (1) forming, on one side of a first single-crystal silicon substrate of first conductivity and low impurity content, a polycrystalline silicon layer of first conductivity and higher impurity content than the impurity content of the first single-crystal silicon substrate, which layer later becomes a life-time killer of a second-conductivity carrier, (2) bonding, on the polycrystalline silicon layer, a second single-crystal silicon substrate of second conductivity and high impurity content, and (3) subjecting the resulting bonded wafer to a heat treatment, as well as to a process for production of the semiconductor substrate. The present invention relates particularly to a semiconductor substrate useful for formation of a vertical power semiconductor device and a process for production of the semiconductor substrate. The present invention relates also to a semiconductor device obtained using the above semiconductor substrate.
Inventors
- 👤 Kenya Kobayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:36
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/19; H10P90/1904; H10P90/1906; H10P90/1914; H10W; H10W10/00; H10W10/10; H10W10/181
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
101 words
A process for producing a semiconductor substrate comprising: (1) forming, on one side of a first single-crystal silicon substrate of first conductivity and low impurity content, a polycrystalline silicon layer of said first conductivity and higher impurity content than the impurity content of the first single-crystal silicon substrate, which layer later becomes a lifetime killer of a second-conductivity carrier; (2) bonding, on the polycrystalline silicon layer, a second single-crystal silicon substrate of second conductivity and high impurity content; (3) subjecting the resulting bonding wafer to a heat treatment to obtain a composite substrate; and (4) forming a vertical power semiconductor device.
Claim 2
Dependent Claim
101 words
A process for producing a semiconductor substrate comprising: (1) forming, on one side of a first single-crystal silicon substrate of first conductivity and low impurity content, a polycrystalline silicon layer of said first conductivity and higher impurity content than the impurity content of the first single-crystal silicon substrate, which layer later becomes a lifetime killer of a second-conductivity carrier; (2) bonding, on the polycrystalline silicon layer, a second single-crystal silicon substrate of second conductivity and high impurity content; (3) subjecting the resulting bonding wafer to a heat treatment to obtain a composite substrate; and (4) forming a vertical power semiconductor device.
Claim 3
Dependent Claim
132 words
A process for producing a semiconductor substrate comprising: (1) forming, on one side of a first single-crystal silicon substrate of a first conductivity and low impurity content, a polycrystalline silicon layer of said first conductivity and higher impurity content than the impurity content of the first single-crystal silicon substrate, which layer later becomes a lifetime killer of a second-conductivity carrier; (2) forming, on one side of a second single crystal silicon substrate of second conductivity and high impurity content, a polycrystalline silicon layer of said second conductivity and high impurity content; (3) bonding the two substrates so that the respective polycrystalline silicon layers come in contact with each other; (4) subjecting the resulting bonded wafer to a heat treatment to obtain a composite substrate; and (5) forming a vertical power semiconductor device.
Claim 4
Dependent Claim
132 words
A process for producing a semiconductor substrate comprising: (1) forming, on one side of a first single-crystal silicon substrate of a first conductivity and low impurity content, a polycrystalline silicon layer of said first conductivity and higher impurity content than the impurity content of the first single-crystal silicon substrate, which layer later becomes a lifetime killer of a second-conductivity carrier; (2) forming, on one side of a second single crystal silicon substrate of second conductivity and high impurity content, a polycrystalline silicon layer of said second conductivity and high impurity content; (3) bonding the two substrates so that the respective polycrystalline silicon layers come in contact with each other; (4) subjecting the resulting bonded wafer to a heat treatment to obtain a composite substrate; and (5) forming a vertical power semiconductor device.
Claim 5
Dependent Claim
123 words
A process for producing a semiconductor substrate comprising: (1) forming, on one side of a first single-crystal silicon substrate of first conductivity and low impurity content, a polycrystalline silicon layer of said first conductivity and higher impurity content than the impurity content of the first single-crystal silicon substrate, which layer later becomes a lifetime killer of a second-conductivity carrier; (2) forming, on one side of a second single-crystal silicon substrate of second conductivity and high impurity content, an intrinsic polycrystalline silicon layer; (3) bonding the two substrates so that the respective polycrystalline silicon layers come in contact with each other; (4) subjecting the resulting bonding wafer to a heat treatment to obtain a composite substrate; and (5) forming a vertical power semiconductor device.
Claim 6
Dependent Claim
123 words
A process for producing a semiconductor substrate comprising: (1) forming, on one side of a first single-crystal silicon substrate of first conductivity and low impurity content, a polycrystalline silicon layer of said first conductivity and higher impurity content than the impurity content of the first single-crystal silicon substrate, which layer later becomes a lifetime killer of a second-conductivity carrier; (2) forming, on one side of a second single-crystal silicon substrate of second conductivity and high impurity content, an intrinsic polycrystalline silicon layer; (3) bonding the two substrates so that the respective polycrystalline silicon layers come in contact with each other; (4) subjecting the resulting bonding wafer to a heat treatment to obtain a composite substrate; and (5) forming a vertical power semiconductor device.
Claim 7
Dependent Claim
46 words
A process for producing a semiconductor substrate according to claim 1, wherein the grinding and polishing of the other side of the first single-crystal silicon substrate is conducted between the heat treatment of the resulting bonded wafer and the formation of a vertical power semiconductor device.
Claim 8
Dependent Claim
46 words
A process for producing a semiconductor substrate according to claim 2, wherein the grinding and polishing of the other side of the first single-crystal silicon substrate is conducted between the heat treatment of the resulting bonded wafer and the formation of a vertical power semiconductor device.
Claim 9
Dependent Claim
46 words
A process for producing a semiconductor substrate according to claim 3, wherein the grinding and polishing of the other side of the first single-crystal silicon substrate is conducted between the heat treatment of the resulting bonded wafer and the formation of a vertical power semiconductor device.
References Cited (Backward Citations)
US4948748A
Cited
US5308776A
Cited
US5298449A
Cited
US5234535A
Cited
US5476809A
Cited
US5346848A
Cited
US5529947A
Cited
US5616512A
Cited
US5478758A
Cited
US5573972A
Cited
US5444014A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-01-11 | 2002-07-13 | 2003-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-01-11 | 2006-07-13 | 2007-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-01-11 | 2010-07-13 | 2011-01-12 | $7700.00 | Window Closed / Lapsed |