Process for reducing defects in oxide layers on silicon carbide
AssigneeCree Research, Inc.
InventorsLori A. Lipkin, David B. Slater, Jr., John W. Palmour
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Abstract
A method is disclosed for obtaining improved oxide layers and resulting improved performance from oxide based devices. The method comprises exposing an oxide layer on a silicon carbide layer to an oxidizing source gas at a temperature below the temperature at which SiC would begin to oxidize at a significant rate, while high enough to enable the oxidizing source gas to diffuse into the oxide layer, and while avoiding any substantial additional oxidation of the silicon carbide, and for a time sufficient to densify the oxide layer and improve the interface between the oxide layer and the silicon carbide layer.
Claims34
A method of obtaining oxide layers on silicon carbide and resulting improved performance from oxide based silicon carbide devices, the method comprising:
- preparing the surface of a silicon carbide layer for an oxidation layer;
- producing an oxide layer on the prepared silicon carbide surface;
- and thereafter
- exposing the oxide layer and the underlying silicon carbide layer to an oxidizing source gas at a temperature of between about 600 and 1000.degree. C., and while avoiding any substantial additional oxidation of the silicon carbide under the oxide layer, and for a time sufficient to densify the oxide layer and improve the interface between the oxide layer and the underlying silicon carbide layer.
A method of obtaining oxide layers on silicon carbide and resulting improved performance from oxide based silicon carbide devices, the method comprising:
- preparing the surface of a silicon carbide layer for an oxidation layer;
- thermally oxidizing the prepared layer of silicon carbide at a temperature of between about 1050.degree. and 1100.degree. C. to produce an oxide layer on the layer of silicon carbide;
- and thereafter
- exposing the oxide layer and the underlying silicon carbide layer to an oxidizing source gas at a temperature between about 600 and 1000.degree. C., and while avoiding any substantial additional oxidation of the silicon carbide, and for a time sufficient to densify the oxide layer and improve the interface between the oxide layer and the underlying silicon carbide layer.
An improved silicon carbide and oxide structure comprising:
- a silicon carbide substrate;
- and
- an oxide layer on the silicon carbide substrate, said oxide layer having an interface state density less than 1.6.times.10.sup.11 per square centimeter per electron-volt (cm.sup.-2 /eV).
An improved silicon carbide and oxide structure comprising:
- a silicon carbide substrate;
- and
- an oxide layer on the silicon carbide substrate, said oxide layer having an oxide charge less than 2.5.times.10.sup.12 cm.sup.-2.
Dependencies are inferred from the claim text.