Method of preparing silicon carbide surfaces for crystal growth
First Claim
1. A method of epitaxially growing a monocrystalline silicon carbide thin film on a silicon carbide surface that reduces defect density in the resulting thin film and in the interface between the thin film and the silicon carbide surface, the method comprising:
- forming a substantially planar surface on a monocrystalline silicon carbide crystal;
exposing the substantially planar surface to an etching plasma until any surface or subsurface damage caused by the mechanical preparation is substantially removed, but for a time period less than that over which the plasma etch will develop new defects in the surface or aggravate existing ones, and while using a plasma gas and electrode system that do not themselves cause substantial defects in the surface; and
depositing a thin film of monocrystalline silicon carbide upon the etched surface by chemical vapor deposition.
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Accused Products
Abstract
The invention is a method of forming a substantially planar surface on a monocrystalline silicon carbide crystal by exposing the substantially planar surface to an etching plasma until any surface or subsurface damage caused by any mechanical preparation of the surface is substantially removed. The etch is limited, however, to a time period less than that over which the plasma etch will develop new defects in the surface or aggravate existing ones, and while using a plasma gas and electrode system that do not themselves aggravate or cause substantial defects in the surface.
633 Citations
25 Claims
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1. A method of epitaxially growing a monocrystalline silicon carbide thin film on a silicon carbide surface that reduces defect density in the resulting thin film and in the interface between the thin film and the silicon carbide surface, the method comprising:
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forming a substantially planar surface on a monocrystalline silicon carbide crystal; exposing the substantially planar surface to an etching plasma until any surface or subsurface damage caused by the mechanical preparation is substantially removed, but for a time period less than that over which the plasma etch will develop new defects in the surface or aggravate existing ones, and while using a plasma gas and electrode system that do not themselves cause substantial defects in the surface; and depositing a thin film of monocrystalline silicon carbide upon the etched surface by chemical vapor deposition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method of etching of a silicon carbide target comprising:
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applying a plasma generating potential across an anode and a quartz cathode; generating a plasma between the anode and the quartz cathode by introducing a mixture of about ten percent nitrous oxide in nitrogen trifluoride therebetween; positioning a silicon carbide target to be etched on the quartz cathode whereby the quartz cathode exhibits a low sputter yield and is reactive with dissociated fluorine from the nitrogen trifluoride; and reacting the plasma with the silicon carbide until any surface or subsurface damage caused by the mechanical preparation is substantially removed, but for a time period less than that over which the plasma etch will develop new defects in the surface or aggravate existing ones, to thereby etch the silicon carbide while the reaction of dissociating fluorine with the quartz cathode, and the cathode'"'"'s low sputter yield prevents contamination of the target with either sputtered materials from the cathode or polymerized fluorine species from the plasma.
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Specification