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US4586240A Expired / Lapsed US ⏱️ 0.0 years remaining

Vertical IGFET with internal gate and method for making same

Assignee: Fairchild Semiconductor Corp
•
Filing: 1985-06-26
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Granted: 1986-05-06
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Expires: 2005-06-26
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Abstract

Abstract A vertical IGFET comprising a substantially planar silicon wafer with a source electrode on one major surface and a drain electrode on the opposite major surface is disclosed. An insulated gate electrode, which includes a conductive finger portion surrounded by an insulating layer, is internally disposed in the silicon wafer such that a predetermined voltage applied to the gate electrode will regulate a current flow between the source and drain electrodes. The device is fabricated utilizing an epitaxial lateral overgrowth technique for depositing monocrystalline silicon over the insulated gate which is disposed on a silicon substrate.

Inventors

  • 👤 Scott C. Blackstone
  • 👤 Lubomir L. Jastrzebski
  • 👤 John F. Corboy, Jr.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 16:43
CPC Classifications
H; H10; H10D; H10D30/00; H10D30/60; H10D30/63; H10D30/01; H10D30/021; H10D30/025; H10D30/635; H10D30/64; H10D30/66; H10D30/668; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/512; H10D64/513; Y; Y10; Y10S; Y10S148/00; Y10S148/019; Y10S148/123; Y10S148/126

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 132 words
A method for fabricating a vertical IGFET, comprising: providing a monocrystalline silicon substrate having first and second opposing major surfaces; forming a first oxide layer across the first surface; forming a pattern of doped polycrystalline silicon on the oxide layer; forming a second oxide layer on all exposed portions of the polycrystalline silicon so as to form an insulated gate; removing the first oxide layer from the first substrate surface in areas not covered by the insulated gate; depositing epitaxial silicon on the first substrate surface and the insulated gate, and terminating said epitaxial deposition after a surface which is substantially parallel to the first surface is formed; and providing source, drain and gate electrodes in ohmic contact with the epitaxial silicon surface, the second substrate surface, and the polycrystalline silicon, respectively.
Claim 2
Independent Claim 132 words
A method for fabricating a vertical IGFET, comprising: providing a monocrystalline silicon substrate having first and second opposing major surfaces; forming a first oxide layer across the first surface; forming a pattern of doped polycrystalline silicon on the oxide layer; forming a second oxide layer on all exposed portions of the polycrystalline silicon so as to form an insulated gate; removing the first oxide layer from the first substrate surface in areas not covered by the insulated gate; depositing epitaxial silicon on the first substrate surface and the insulated gate, and terminating said epitaxial deposition after a surface which is substantially parallel to the first surface is formed; and providing source, drain and gate electrodes in ohmic contact with the epitaxial silicon surface, the second substrate surface, and the polycrystalline silicon, respectively.
Claim 3
Dependent Claim 18 words
A method in accordance with claim 1, further comprising: doping the epitaxial silicon during the epitaxial silicon deposition.
Claim 4
Dependent Claim 25 words
A method in accordance with claim 1, further comprising: doping the epitaxial silicon and the substrate prior to providing the source, drain and gate electrodes.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-05-05 1989-11-04 1990-05-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-05-05 1993-11-04 1994-05-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-05-05 1997-11-04 1998-05-06 $7700.00 Window Closed / Lapsed

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