Apparatus and method for plasma-assisted etching of wafers
AssigneeBell Telephone Laboratories, Incorporated
InventorsHyman J. Levinstein, Frederick Vratny
Life of this patent
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Abstract
In a plasma-assisted etching apparatus and method designed to pattern silicon dioxide in a plasma derived from a mixture of trifluoromethane and ammonia, surfaces in the reaction chamber are coated with a layer of silicon. Contamination of wafers during the etching process is thereby substantially reduced. In practice, this leads to a significant increase in the yield of acceptable chips per wafer.
Claims14
Apparatus for low-contamination plasma-assisted dry etching of a layer of silicon dioxide formed on a wafer, said apparatus comprising
- a reaction chamber,
- means for establishing within said chamber an etching plasma derived from a mixture of trifluoromethane and ammonia gases,
- said chamber including surfaces exposed to said plasma,
- and a coating of silicon on at least the surfaces in the immediate vicinity of said layer to be etched.
Apparatus for low-contamination plasma-assisted dry etching of a layer of silicon dioxide on a wafer that is to be processed to form multiple integrated circuits, said apparatus comprising
- a reaction chamber,
- means for establishing within said chamber an etching plasma derived from a mixture of trifluoromethane and ammonia,
- means within said chamber for holding a number of wafers to be etched,
- said chamber having internal surfaces including surfaces of said holding means in the immediate vicinity of said wafers to be etched,
- and a coating of silicon formed on internal surfaces including at least the surfaces of said holding means in the immediate vicinity of said wafers.
A method for fabricating VLSI devices by delineating fine-line patterns in a layer of silicon dioxide on a wafer in accordance with a process sequence that includes low-contamination plasma-assisted dry etching, said method comprising the steps of
- mounting said wafer to be etched in a reaction chamber at least some of whose surfaces, including surfaces in the immediate vicinity of said layer to be etched, are coated with a layer of silicon,
- introducing a mixture of trifluoromethane and ammonia gases into said reaction chamber,
- and establishing an etching plasma within said chamber.
Apparatus for low-contamination plasma-assisted dry etching of a layer of silicon dioxide formed on a water, said apparatus comprising
- a reaction chamber,
- means for establishing within said chamber an etching plasma derived from trifluoromethane,
- said chamber including surfaces exposed to said plasma,
- and a coating of silicon on at least the surfaces in the immediate vicinity of said layer to be etched.
Apparatus for low-contamination plasma-assisted dry etching of a layer of silicon dioxide on a wafer that is to be processed to form multiple integrated circuits, said apparatus comprising
- a reaction chamber,
- means for establishing within said chamber an etching plasma derived from trifluoromethane,
- means within said chamber for holding a number of wafers to be etched,
- said chamber having internal surfaces including surfaces of said holding means in the immediate vicinity of said wafers to be etched,
- and a coating of silicon formed on internal surfaces including at least the surfaces of said holding means in the intermediate vicinity of said wafers.
A method for fabricating VLSI devices by delineating fine-line patterns in a layer of silicon dioxide on a wafer in accordance with a process sequence that includes low-contamination plasma-assisted dry etching, said method comprising the steps of
- mounting said wafer to be etched in a reaction chamber at least some of whose surfaces, including surfaces in the immediate vicinity of said layer to be etched, are coated with a layer of silicon,
- introducing trifluoromethane gas into said reaction chamber,
- and establishing an etching plasma within said chamber.
Dependencies are inferred from the claim text.