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US5043773A Expired / Lapsed US ⏱️ 0.0 years remaining

Wafer base for silicon carbide semiconductor devices, incorporating alloy substrates

Assignee: Advanced Technology Materials Inc
•
Filing: 1990-06-04
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Granted: 1991-08-27
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Expires: 2010-06-04
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Abstract

Abstract A semiconductor wafer base is disclosed which is suitable for fabrication of devices in silicon carbide, comprising a single crystal substrate which is a transition metal carbide alloy having cubic crystal structure and an unpolytyped, single crystal 3C-silicon carbide overlay epitaxially related to the substrate. Preferably, the substrate is an alloy of two or more of titanium carbide, tantalum carbide, vanadium carbide, and niobium carbide, with alttice parameter differing from 3C-silicon carbide by less than about 1%. Use of the transition metal carbide alloys enables the preparation of large, single crystal substrates free from cracks, dislocations, or other defects, suitable for epitaxial deposition of 3C-silicon carbide. The 3C-silicon carbide epitaxial overlay may be deposited by any suitable technique, including chemical vapor deposition and reactive evaporation, and may be doped with n- or p-type dopants. The 3C-silicon carbide is useful for fabricating semiconductor devices for use at high temperatures, high powers, and in corrosive environments.

Inventors

  • 👤 Walter Precht
  • 👤 Richard Koba
  • 👤 Donald Kupp
  • 👤 Delwyn Cummings

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 04:10
CPC Classifications
H; H10; H10W; H10W70/00; H10W70/60; H10W70/67; H10W70/69; H10W70/692; Y; Y10; Y10S; Y10S438/00; Y10S438/931

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 51 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure, said substrate comprising a material selected from the group consisting of alloys of two or more of TiC, VC, NbC, TaC, ZrC, HfC, WC, and MoC; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate.
Claim 2
Dependent Claim 51 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure, said substrate comprising a material selected from the group consisting of alloys of two or more of TiC, VC, NbC, TaC, ZrC, HfC, WC, and MoC; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate.
Claim 3
Dependent Claim 18 words
The wafer base of claim 1, wherein the thickness of said overlay is about 0.05 to 100 micrometers.
Claim 4
Dependent Claim 41 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure, said substrate comprising an alloy of TiC and VC with VC mole % ranging from 5-90%; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate.
Claim 5
Dependent Claim 41 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure, said substrate comprising an alloy of TiC and VC with VC mole % ranging from 5-90%; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate.
Claim 6
Dependent Claim 77 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure, said substrate being selected from the group consisting of alloys of two or more of TiC, VC, NbC, TaC, ZrC, HfC, WC, and MoC; and an unpolytyped, single crystal overlay epitaxially related to said substrate, said overlay layer having a cubic crystal structure and comprising an alloy of SiC and one or more of TiC, HfC, ZrC, VC, TaC, MoC, WC, NbC, and AlN.
Claim 7
Dependent Claim 77 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure, said substrate being selected from the group consisting of alloys of two or more of TiC, VC, NbC, TaC, ZrC, HfC, WC, and MoC; and an unpolytyped, single crystal overlay epitaxially related to said substrate, said overlay layer having a cubic crystal structure and comprising an alloy of SiC and one or more of TiC, HfC, ZrC, VC, TaC, MoC, WC, NbC, and AlN.
Claim 8
Dependent Claim 56 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure, said substrate comprising a material selected from the group consisting of alloys of two or more of TiC, VC, NbC, TaC, ZrC, HfC, WC, and MoC; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate, wherein the overlay is doped.
Claim 9
Dependent Claim 56 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure, said substrate comprising a material selected from the group consisting of alloys of two or more of TiC, VC, NbC, TaC, ZrC, HfC, WC, and MoC; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate, wherein the overlay is doped.
Claim 10
Dependent Claim 53 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate, wherein the single crystal substrate comprises an alloy of two or more of TiC, NbC, TaC and VC, having a lattice parameter of from 4.25 to 4.45 Å.
Claim 11
Dependent Claim 53 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate, wherein the single crystal substrate comprises an alloy of two or more of TiC, NbC, TaC and VC, having a lattice parameter of from 4.25 to 4.45 Å.
Claim 12
Dependent Claim 47 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate, wherein the single crystal substrate comprises an alloy of TiC and WC, with WC content ranging from 2 to 10 mole %.
Claim 13
Dependent Claim 47 words
A semiconductor wafer base comprising: a single crystal substrate having cubic crystal structure; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate, wherein the single crystal substrate comprises an alloy of TiC and WC, with WC content ranging from 2 to 10 mole %.
Claim 14
Dependent Claim 59 words
A semiconductor wafer base comprising: a substantially defect-free single crystal substrate at least 0.5 inches in diameter having cubic crystal structure, said substrate comprising a material selected from the group consisting of alloys of two or more of TiC, VC, NbC, TaC, ZrC, HfC, WC, and MoC; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate.
Claim 15
Dependent Claim 59 words
A semiconductor wafer base comprising: a substantially defect-free single crystal substrate at least 0.5 inches in diameter having cubic crystal structure, said substrate comprising a material selected from the group consisting of alloys of two or more of TiC, VC, NbC, TaC, ZrC, HfC, WC, and MoC; and an unpolytyped, single crystal 3C-SiC overlay epitaxially related to said substrate.
Claim 16
Dependent Claim 17 words
The wafer base of claim 8, wherein the substrate has a diameter of at least 2 inches.

References Cited (Backward Citations)

US3661599A Cited
US4568792A Cited
US4697202A Cited
US4767666A Cited
US4738937A Cited
US4616672A Cited
WO1989006438A1 Cited
US4916088A Cited
US4923716A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-08-26 1995-02-25 1995-08-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-08-26 1999-02-25 1999-08-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-08-26 2003-02-25 2003-08-27 $7700.00 Window Closed / Lapsed

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