EP0255973A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Contacts formed in minimum surface area of semiconductor devices
Assignee: Vishay Siliconix Inc
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Filing: 1987-07-23
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Granted: —
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Expires: 2007-07-23
Abstract
Abstract A technique for providing a contact to regions of a substrate (12) using a minimun of substrate surface (13) area by anisotropically etching a vertical trench (30) exposing silicon for preferential deposit of conductive material (40), such as tungsten, to form a contact.
Inventors
- 👤 Richard A. Blanchard
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 00:21
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/20; H10D64/01; H10D64/011; H10D64/0111; H10D64/0113; H10W; H10W20/00; H10W20/01; H10W20/021
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
85 words
A process for providing a vertical contact connecting at least one region beneath the surface of a silicon substrate to a metallization lead over the surface, characterized by the steps of: protecting said surface with a mask exposing a selected area; anisotropically etching said selected area to form a trench with steep walls exposing areas of at least one region beneath said surface; and depositing conductive contact material by selective chemical vapor deposition on exposed silicon sidewalls of the trench to form a vertical contact.
Claim 2
Dependent Claim
85 words
A process for providing a vertical contact connecting at least one region beneath the surface of a silicon substrate to a metallization lead over the surface, characterized by the steps of: protecting said surface with a mask exposing a selected area; anisotropically etching said selected area to form a trench with steep walls exposing areas of at least one region beneath said surface; and depositing conductive contact material by selective chemical vapor deposition on exposed silicon sidewalls of the trench to form a vertical contact.
Claim 3
Dependent Claim
21 words
The process of Claim 1 characterized by beginning with a substrate having a top surface in a <100> crystal index plane.
Claim 4
Dependent Claim
13 words
The process of Claim 1 characterized by the anisotropic etching being plasma etching.
Claim 5
Dependent Claim
14 words
The process of Claim 1 characterized by the anisotropic etching being reactive ion etching.
Claim 6
Dependent Claim
24 words
A process as in Claim 1 characterized by the contact being for connecting a conductor to a substrate region which has already been doped.
Claim 7
Dependent Claim
52 words
The process of Claim 5 characterized by beginning with a first conductivity type substrate, within which a first region is doped second conductivity type, within which first region a smaller second region is doped first conductivity type, and wherein the trench penetrates from said surface down through the first and second regions.
Claim 8
Dependent Claim
17 words
The process of Claim 6 characterized by substrate regions adjacent the contact trench comprising a DMOS transistor.
Claim 9
Dependent Claim
19 words
The process of Claim 6 characterized by substrate regions adjacent the contact trench comprising an insulated gate bipolar transistor.
Claim 10
Dependent Claim
20 words
The process of Claim 6 characterized by the first conductivity type being N and the second conductivity type being P.
Claim 11
Dependent Claim
27 words
The process of Claim 1 characterized by the step of etching being followed by chemical vapor deposition of polycrystalline silicon to provide a lining inside the trench.
Claim 12
Dependent Claim
45 words
The process of Claim 10 characterized by chemical vapor deposition providing a polycrystalline silicon lining at a selected light second conductivity doping, and after deposition, the lining and substrate are heated to diffuse substrate dopant into, and impart its type conductivity to, the trench lining.
Claim 13
Dependent Claim
30 words
The process of Claim 10 characterized by the polycrystalline silicon lining having a selected second conductivity doping concentration for later diffusion to increase the second conductivity of the body region.
Claim 14
Dependent Claim
13 words
The process of Claim 1 characterized by the conductive material comprising polycrystalline silicon.
Claim 15
Dependent Claim
14 words
The process as in Claim 1 characterized by the conductive contact material being tungsten.
Claim 16
Dependent Claim
28 words
The process as in Claim 5 characterized by the step of forming a contact in the trench being followed by the step of depositing metallization over said contact.
Claim 17
Dependent Claim
12 words
The process as in Claim 15 characterized by the metallization being aluminum.
Claim 18
Dependent Claim
9 words
A contact formed by the process of Claim 1.
Claim 19
Dependent Claim
43 words
A contact for connecting a conductor to at least one region beneath the top surface of a semiconductor substrate, characterized by a conductive material deposited preferentially by CVD on silicon walls in a trench extending from the surface of, and into, the substrate.
Claim 20
Dependent Claim
43 words
A contact for connecting a conductor to at least one region beneath the top surface of a semiconductor substrate, characterized by a conductive material deposited preferentially by CVD on silicon walls in a trench extending from the surface of, and into, the substrate.
References Cited (Backward Citations)
No citation records indexed.
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