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US7098095B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Method of forming a MOS transistor with a layer of silicon germanium carbon

Assignee: National Semiconductor Corp
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Filing: 2004-02-04
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Granted: 2006-08-29
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Expires: 2024-02-04
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Abstract

Abstract The vertical diffusion of dopants from the gate into the channel region, and the lateral diffusion of dopants from the source and drain regions into the channel region resulting from thermal cycling during the fabrication of a MOS transistor is minimized by forming the source and drain regions in a layer of silicon germanium carbon.

Inventors

  • 👤 Abdalla Aly Naem
  • 👤 Visvamohan Yegnashankaran

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 04:53
CPC Classifications
H; H10; H10D; H10D62/00; H10D62/80; H10D62/82; H10D62/822; H10D30/00; H10D30/01; H10D30/021; H10D30/027; H10D30/0278; H10D30/60; H10D30/751; H10D30/0223; H10D30/0227

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 164 words
A method of forming a MOS transistor on a semiconductor material of a first conductivity type, the semiconductor material having a top surface, the method comprising: forming a first material over the top surface of the semiconductor material; exposing a region of the top surface of the semiconductor material, a portion of the first material being removed and a remaining portion of the first material being left when exposing the region of the top surface of the semiconductor material; forming a semiconductor layer of the first conductivity type on the top surface of the semiconductor material, the semiconductor layer including silicon, germanium, and carbon; removing the remaining portion of the first material from over the top surface of the semiconductor material; forming a layer of insulation material over the semiconductor layer; forming a layer of conductive material on the layer of insulation material; and removing a portion of the layer of conductive material to form a conductive gate that lies over the semiconductor layer.
Claim 2
Independent Claim 164 words
A method of forming a MOS transistor on a semiconductor material of a first conductivity type, the semiconductor material having a top surface, the method comprising: forming a first material over the top surface of the semiconductor material; exposing a region of the top surface of the semiconductor material, a portion of the first material being removed and a remaining portion of the first material being left when exposing the region of the top surface of the semiconductor material; forming a semiconductor layer of the first conductivity type on the top surface of the semiconductor material, the semiconductor layer including silicon, germanium, and carbon; removing the remaining portion of the first material from over the top surface of the semiconductor material; forming a layer of insulation material over the semiconductor layer; forming a layer of conductive material on the layer of insulation material; and removing a portion of the layer of conductive material to form a conductive gate that lies over the semiconductor layer.
Claim 3
Dependent Claim 13 words
The method of claim 1 wherein the semiconductor layer is selectively epitaxially grown.
Claim 4
Dependent Claim 23 words
The method of claim 2 and further comprising forming spaced-apart source and drain regions of a second conductivity type in the semiconductor layer.
Claim 5
Dependent Claim 46 words
The method of claim 2 and further comprising forming a layer of silicon free from germanium and carbon on the semiconductor layer before the remaining portion of the first material is removed, the layer of insulation material contacting a top surface of the layer of silicon.
Claim 6
Dependent Claim 28 words
The method of claim 4 and further comprising forming spaced-apart source and drain regions of a second conductivity type in the semiconductor layer and the layer of silicon.
Claim 7
Dependent Claim 11 words
The method of claim 1 wherein the semiconductor layer is deposited.
Claim 8
Dependent Claim 23 words
The method of claim 6 and further comprising forming spaced-apart source and drain regions of a second conductivity type in the semiconductor layer.
Claim 9
Dependent Claim 46 words
The method of claim 6 and further comprising forming a layer of silicon free from germanium and carbon on the semiconductor layer before the remaining portion of the first material is removed, the layer of insulation material contacting a top surface of the layer of silicon.
Claim 10
Dependent Claim 28 words
The method of claim 8 and further comprising forming spaced-apart source and drain regions of a second conductivity type in the semiconductor layer and the layer of silicon.
Claim 11
Dependent Claim 17 words
The method of claim 1 wherein the first material contacts the top surface of the semiconductor material.
Claim 12
Dependent Claim 23 words
The method of claim 10 and further comprising forming spaced-apart source and drain regions of a second conductivity type in the semiconductor layer.
Claim 13
Dependent Claim 46 words
The method of claim 11 and further comprising forming a layer of silicon free from germanium and carbon on the semiconductor layer before the remaining portion of the first material is removed, the layer of insulation material contacting a top surface of the layer of silicon.
Claim 14
Dependent Claim 28 words
The method of claim 12 and further comprising forming spaced-apart source and drain regions of a second conductivity type in the semiconductor layer and the layer of silicon.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2009-08-28 2010-02-27 2010-08-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2013-08-28 2014-02-27 2014-08-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2017-08-28 2018-02-27 2018-08-29 $7700.00 Window Closed / Lapsed

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