Method of cleaning semiconductor substrate using an aqueous acid solution
AssigneeNEC Corporation
InventorYoshimi Shiramizu
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Abstract
Cleaning methods for semiconductor substrates which can remove metallic impurities and natural oxide films from the surface of the substrate. As a cleaning solution, aqueous acid solution containing 0.0001-0.001 weight % of ammonia based on a conversion off the amount off ammonium hydroxide or 0.0005-0.01 weight % of EDTA is used. The cleaning solution preferably contains 1-10 weight % of hydrogen fluoride. Metallic impurities removed from the surface of the substrate into the cleaning solution form complexes or chelates with ammonia molecules or EDTA molecules, thereby masking the metallic impurities.
Claims4
A method of cleaning a semiconductor substrate, comprising the steps of:
- providing a cleaning solution containing an aqueous acid solution containing 0.0001-0.001 weight % of ammonia based on a conversion of an amount of ammonium hydroxide and 1-10 weight % of hydrogen fluoride;
- and
- immersing a semiconductor substrate in said cleaning solution.
A method of cleaning a semiconductor substrate, comprising the steps of:
- providing a cleaning solution containing an aqueous acid solution containing 0.0005-0.01 weight % of ethylenediaminetetraacetic acid and 1-10 weight % of hydrogen fluoride;
- and
- immersing a semiconductor substrate in said cleaning solution.
Dependencies are inferred from the claim text.