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US5350944A Expired / Lapsed US ⏱️ 0.0 years remaining

Insulator films on diamonds

Assignee: Massachusetts Institute of Technology
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Filing: 1992-02-20
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Granted: 1994-09-27
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Expires: 2012-02-20
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Abstract

Abstract Electrical quality insulating films on n-type and p-type diamond substrates are provided in which an insulating film such as a silicon dioxide film is deposited onto the exposed face of a diamond substrate, such as by chemical vapor deposition. Forming a conducting layer atop the silicon dioxide allows the creation of a metal-oxide-silicon device with which semiconductor carriers can be controlled through the application of a bias voltage to the conductor surface.

Inventors

  • 👤 Michael W. Geis
  • 👤 Daniel L. Smythe

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 16:56
CPC Classifications
H; H10; H10D; H10D8/00; H10D8/60; H10D30/00; H10D30/01; H10D30/021; H10D30/031; H10D30/60; H10D30/67; H10D30/674; H10D30/6741; H10D62/00; H10D62/80; H10D62/83; H10D62/8303; H10D64/00; H10D64/01; H10D64/013; H10D64/01364; H10D64/60; H10D64/64; H10D64/66; H10D64/68

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 138 words
A semiconductor diamond field-effect transistor device that is substantially free of operational effects from interface states, comprising: a diamond semiconductor substrate having mobile semiconductor charge carriers, a CVD-deposited non-epitaxial silicon dioxide insulating film having a thickness of about 0.1 μm or less on said diamond substrate, and a conducting layer on said insulating film for imposing an electric field in said substrate through said film, said film enabling the formation of a predetermined depletion region in said substrate for control of said mobile carriers when electrical fields are imposed through said film by said conducting layer, said device being substantially free of operational effects due to interface states as characterized by a capacitance versus bias voltage relationship that is substantially unaffected by a change in the frequency of said bias voltage over about 4 KHz to 10 MHz.
Claim 2
Dependent Claim 138 words
A semiconductor diamond field-effect transistor device that is substantially free of operational effects from interface states, comprising: a diamond semiconductor substrate having mobile semiconductor charge carriers, a CVD-deposited non-epitaxial silicon dioxide insulating film having a thickness of about 0.1 μm or less on said diamond substrate, and a conducting layer on said insulating film for imposing an electric field in said substrate through said film, said film enabling the formation of a predetermined depletion region in said substrate for control of said mobile carriers when electrical fields are imposed through said film by said conducting layer, said device being substantially free of operational effects due to interface states as characterized by a capacitance versus bias voltage relationship that is substantially unaffected by a change in the frequency of said bias voltage over about 4 KHz to 10 MHz.
Claim 3
Dependent Claim 12 words
The device of claim 1 wherein said film is SiO 2 .
Claim 4
Dependent Claim 24 words
The device of claim 1 wherein said diamond semiconductor substrate is made of p-type diamond and said CVD-deposited film is on a (100) surface.
Claim 5
Dependent Claim 21 words
The device of claim 3 wherein said conducting layer is selected from the group consisting of doped polysilicon and a metal.
Claim 6
Dependent Claim 13 words
The device of claim 4 wherein said metal is aluminum, chrome-gold or tungsten.
Claim 7
Dependent Claim 25 words
The device of claim 2 or 3 wherein the thickness of said film is determined to inhibit substantial tunneling of charge carriers through said film.
Claim 8
Dependent Claim 17 words
The device of claim 6 wherein said device is incorporated into a depletion mode field effect transistor.
Claim 9
Dependent Claim 18 words
The device of claim 7 wherein the thickness of said film is between about 10 to 100 nm.
Claim 10
Dependent Claim 26 words
The device of claim 4 wherein the thickness of said insulating film is less than or equal to approximately 10 nanometers for forming a rectifying contact.
Claim 11
Dependent Claim 129 words
A semiconductor diamond field-effect transistor device that is substantially free of operational effects from interface states, comprising: a diamond semiconductor substrate having a (111) surface and mobile semiconductor charge carriers, a CVD-deposited non-epitaxial silicon dioxide insulating film having a thickness of about 0.1 μm or less on said (111) surface of said diamond substrate, and a conducting layer on said insulating film, said film enabling control of said mobile carriers in said diamond substrate when electrical fields are imposed on said film through said conducting layer, said device being substantially free of operational effects due to interface states, said device characterized by a capacitance versus bias voltage relationship that is substantially unaffected by a change in the frequency of said bias voltage over about 4 KHz to 10 MHz.
Claim 12
Dependent Claim 129 words
A semiconductor diamond field-effect transistor device that is substantially free of operational effects from interface states, comprising: a diamond semiconductor substrate having a (111) surface and mobile semiconductor charge carriers, a CVD-deposited non-epitaxial silicon dioxide insulating film having a thickness of about 0.1 μm or less on said (111) surface of said diamond substrate, and a conducting layer on said insulating film, said film enabling control of said mobile carriers in said diamond substrate when electrical fields are imposed on said film through said conducting layer, said device being substantially free of operational effects due to interface states, said device characterized by a capacitance versus bias voltage relationship that is substantially unaffected by a change in the frequency of said bias voltage over about 4 KHz to 10 MHz.
Claim 13
Dependent Claim 21 words
The device of claim 10 wherein said conducting layer is selected from the group consisting of doped polysilicon or a metal.
Claim 14
Dependent Claim 13 words
The device of claim 10 wherein said metal is aluminum, chrome-gold or tungsten.
Claim 15
Dependent Claim 15 words
The device of claim 10 or wherein said device is incorporated in a cold cathode.
Claim 16
Dependent Claim 83 words
A semiconductor device comprising an N-type diamond semiconductor substrate and a means for controlling semiconductor charge carriers, said means comprising an insulating film selected from the group consisting of CaF 2 or BaF 2 on said diamond substrate, and a means for imposing an electric field in said substrate through said film, said film enabling the formation of a predetermined depletion region in said substrate for control of said mobile carriers in said diamond substrate when electrical fields are imposed on said film.
Claim 17
Dependent Claim 83 words
A semiconductor device comprising an N-type diamond semiconductor substrate and a means for controlling semiconductor charge carriers, said means comprising an insulating film selected from the group consisting of CaF 2 or BaF 2 on said diamond substrate, and a means for imposing an electric field in said substrate through said film, said film enabling the formation of a predetermined depletion region in said substrate for control of said mobile carriers in said diamond substrate when electrical fields are imposed on said film.
Claim 18
Dependent Claim 17 words
The device of claim 14 wherein said film has a thickness of about 100 nm or less.
Claim 19
Independent Claim 19 words
The device of any one of claims 14 or 15 wherein said device is a three terminal switching device.
Claim 20
Independent Claim 18 words
The device of any one of claims 14 or 15 wherein said device is an NPN gate device.
Claim 21
Dependent Claim 79 words
A semiconductor device comprising: a diamond semiconductor substrate having a (111) surface and means for controlling semiconductor charge carriers, said means comprising a non-diamond insulating film on said (111) surface of said diamond substrate, and a means for imposing an electric field in said substrate through said film, said film enabling control of said mobile carriers in said diamond substrate when electrical fields are imposed on said film, said film being selected from CaF 2 and BaF 2 .
Claim 22
Dependent Claim 79 words
A semiconductor device comprising: a diamond semiconductor substrate having a (111) surface and means for controlling semiconductor charge carriers, said means comprising a non-diamond insulating film on said (111) surface of said diamond substrate, and a means for imposing an electric field in said substrate through said film, said film enabling control of said mobile carriers in said diamond substrate when electrical fields are imposed on said film, said film being selected from CaF 2 and BaF 2 .
Claim 23
Dependent Claim 215 words
A semiconductor diamond field-effect transistor device that is substantially free of operational effects from interface states, comprising a diamond semiconductor substrate having mobile semiconductor charge carriers, a CVD-deposited non-epitaxial silicon dioxide insulating film having a thickness of about 0.1 μm or less on said diamond substrate, and a conducting layer on said insulating film for imposing an electric field in said substrate through said film, said film enabling the formation of a predetermined depletion region in said substrate for control of said mobile carriers when electrical fields are imposed through said film by said conducting layer, said device being substantially free of operational effects due to interface states as characterized by a capacitance versus bias voltage relationship that is substantially unaffected by a change in the frequency of said bias voltage over about 4 KHz to 10 MHz, said semiconductor diamond field-effect transistor device provided by a method comprising the steps of: providing said diamond semiconductor substrate, cleaning said diamond semiconductor substrate, heating said diamond substrate to a temperature of about 620° C., in a gaseous mixture of SiH 4 , O 2 and N 2 to form said silicon dioxide insulating film with the total pressure being near atmospheric pressure, and depositing said conducting layer upon a region of said silicon dioxide insulating film.
Claim 24
Dependent Claim 215 words
A semiconductor diamond field-effect transistor device that is substantially free of operational effects from interface states, comprising a diamond semiconductor substrate having mobile semiconductor charge carriers, a CVD-deposited non-epitaxial silicon dioxide insulating film having a thickness of about 0.1 μm or less on said diamond substrate, and a conducting layer on said insulating film for imposing an electric field in said substrate through said film, said film enabling the formation of a predetermined depletion region in said substrate for control of said mobile carriers when electrical fields are imposed through said film by said conducting layer, said device being substantially free of operational effects due to interface states as characterized by a capacitance versus bias voltage relationship that is substantially unaffected by a change in the frequency of said bias voltage over about 4 KHz to 10 MHz, said semiconductor diamond field-effect transistor device provided by a method comprising the steps of: providing said diamond semiconductor substrate, cleaning said diamond semiconductor substrate, heating said diamond substrate to a temperature of about 620° C., in a gaseous mixture of SiH 4 , O 2 and N 2 to form said silicon dioxide insulating film with the total pressure being near atmospheric pressure, and depositing said conducting layer upon a region of said silicon dioxide insulating film.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-09-26 1998-03-28 1998-09-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-09-26 2002-03-28 2002-09-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-09-26 2006-03-28 2006-09-27 $7700.00 Window Closed / Lapsed

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