Insulator films on diamonds
AssigneeMassachusetts Institute of Technology
InventorsMichael W. Geis, Daniel L. Smythe
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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.
Claims19
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 .mu.m 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.
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 .mu.m 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.
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.sub.2 or BaF.sub.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.
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.sub.2 and BaF.sub.2.
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 .mu.m 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.degree. C., in a gaseous mixture of SiH.sub.4, O.sub.2 and N.sub.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.
Dependencies are inferred from the claim text.