US4887144A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Topside substrate contact in a trenched semiconductor structure and method of fabrication
Assignee: Texas Instruments Inc
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Filing: 1987-02-27
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Granted: 1989-12-12
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Expires: 2007-02-27
Abstract
Abstract A process for forming a topside substrate contact in a trenched semiconductor structure. A trench (24, 26) is etched into a P- block of substrate (10) material. The trench (24, 26) is filled with silicon dioxide, and then the substrate material (10) circumscribed by the trench (24, 26) is removed to form a well. A subcollector (48) is implanted in the well of the P. substrate. Epi material (50) is grown in the well to the top of the silicon dioxide-filled trench. A device (59) is formed in the epi (50). Ohmic contacts (70) are formed on the topside of the substrate to the device (59) within the well, and to the P- substrate itself outside the trench.
Inventors
- 👤 Brian E. Cook
- 👤 Ralph S. Keen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:03
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/10; H10D62/17; H10D10/00; H10D10/40; H10D10/421; H10D62/80; H10D62/83; H10D64/00; H10D64/60; H10D64/62; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/014; H10W10/018; H10W10/10; H10W10/13; H10W10/17; H10W20/00; H10W20/01; H10W20/021
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
169 words
A trenched semiconductor structure, comprising: a silicon substrate of one conductivity type having a concentration of dopant, and a circumferential trench therein extending to a top surface thereof and wherein a top surface of said substrate within the trench is intermediate a bottom of the trench and a top surface of said trench outside of the trench; a column of isolating dielectric filling said trench to said top surface; an silicon subcollector region of a second conductivity type formed in a top surface of said substrate within said trench and above a bottom level of said trench; an epitaxial silicon region of a third conductivity type above said subcollector region, said epitaxial silicon region extending upwardly to a level coplanar with the top surface of said substrate; a device formed in said silicon epitaxial material region; ohmic contacts to said device on the top surface thereof and within said trench; and a further ohmic contact on the top surface of said substrate and to said substrate outside the trench.
Claim 2
Dependent Claim
169 words
A trenched semiconductor structure, comprising: a silicon substrate of one conductivity type having a concentration of dopant, and a circumferential trench therein extending to a top surface thereof and wherein a top surface of said substrate within the trench is intermediate a bottom of the trench and a top surface of said trench outside of the trench; a column of isolating dielectric filling said trench to said top surface; an silicon subcollector region of a second conductivity type formed in a top surface of said substrate within said trench and above a bottom level of said trench; an epitaxial silicon region of a third conductivity type above said subcollector region, said epitaxial silicon region extending upwardly to a level coplanar with the top surface of said substrate; a device formed in said silicon epitaxial material region; ohmic contacts to said device on the top surface thereof and within said trench; and a further ohmic contact on the top surface of said substrate and to said substrate outside the trench.
Claim 3
Dependent Claim
14 words
The trenched semiconductor structure of claim 1 wherein the device is a bipolar device.
Claim 4
Dependent Claim
32 words
The trenched semiconductor structure of claim 1 further comprising a region of said first conductivity type formed at the surface of the substrate to interface said further ohmic contact to the substrate.
Claim 5
Dependent Claim
30 words
The trenched semiconductor structure of claim 1 further comprising a region of a fourth conductivity type at a bottom portion of the trench to serve as a channel stop region.
Claim 6
Dependent Claim
21 words
The trenched semiconductor structure of claim 1 wherein said further ohmic contact is coplanar with said ohmic contacts to said device.
Claim 7
Dependent Claim
21 words
The trenched semiconductor structure of claim 1 wherein said ohmic contacts to said device include an ohmic contact to said subcollector.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-11 | 1993-06-12 | 1993-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-11 | 1997-06-12 | 1997-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-11 | 2001-06-12 | 2001-12-12 | $7700.00 | Window Closed / Lapsed |