Silicon wafer cleaning fluid with HN0.sub.3, HF, HCl, surfactant, and water
AssigneesPurex Corporation, Kabushiki Kaisha Toshiba
InventorHisashi Muraoka
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Abstract
The present invention provides a silicon wafer cleaning fluid, comprising 35 to 65% by weight of HNO.sub.3, 0.05 to 0.5% by weight of HF, 0.05 to 0.5% by weight of HCl, 0.002 to 0.1% by weight of a surface-active agent, and water and a silicon wafer cleaning method, comprising treating the surface of a silicon wafer with said cleaning fluid. According to the present invention, etching of the silicon wafer surface can be carried out simply with the amount of the etching being controlled to several tens A, and particularly about 20 to 30 .ANG., and the smoothness of the surface is not damaged. In addition, contamination with gold and other heavy metals of the order of 10.sup.12 atoms/cm.sup.2 can be decreased to not more than 1/100.
Claims7
A silicon wafer cleaning fluid, consisting essentially of 35 to 65% by weight of HNO.sub.3, 0.05 to 0.5% by weight of HF, 0.05 to 0.5% by weight of HCl, 0.002 to 0.1% by weight of a surface-active agent, and water, said fluid being prepared by mixing the components in a manner such that said surface active agent is not added to the HNO.sub.3 and water before the addition of aqueous HF or aqueous HCl to the HNO.sub.3 and water.
Dependencies are inferred from the claim text.