Local dry etching method
AssigneeSpeedfam Corporation
InventorsMichihiko Yanagisawa, Tadayoshi Okuya
Life of this patent
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Abstract
This invention provides a local dry etching method comprising the step of removing an oxide film formed on the surface of a semiconductor water before unevenness on the semiconductor wafer is removed by scanning the surface of the semiconductor wafer at a controlled relative speed with a nozzle for applying a flow of activated species gas to the surface of the semiconductor wafer. The removal of this oxide film is carried out by widening an etching profile and a scan pitch and making the nozzle speed constant, and then flattening is carried out in the same local dry etching apparatus. For flattening, the nozzle speed is changed for each area according to initial unevenness.
Claims6
A local dry etching method for flattening a semiconductor wafer by removing unevenness from a surface of the wafer using a nozzle for applying a flow of an activated species gas to the surface of the wafer, the method comprising;
- providing a semiconductor wafer having a silicon oxide film formed on a surface thereof;
- removing the silicon oxide film by moving the nozzle for applying the flow of the activated species gas at a speed relative to the semiconductor wafer so that silicon is exposed on the surface of the semiconductor wafer;
- and
- etching the exposed silicon by moving the nozzle for applying the flow of the activated species gas at a controlled speed relative to the semiconductor wafer.
Dependencies are inferred from the claim text.