Abstract: A method of removing materials, and preferably photoresist, from a substrate comprises dispensing a liquid sulfuric acid composition comprising sulfuric acid and/or its desiccating species and precursors and having a water/sulfuiric acid molar ratio of no greater than 5:1 onto an material coated substrate in an amount effective to substantially uniformly coat the material coated substrate. The substrate is preferably heated to a temperature of at least about 90° C., either before, during or after dispensing of the liquid sulfuric acid composition. After the substrate is at a temperature of at least about 90° C., the liquid sulfuric acid composition is exposed to water vapor in an amount effective to increase the temperature of the liquid sulfuric acid composition above the temperature of the liquid sulfuric acid composition prior to exposure to the water vapor. The substrate is then preferably rinsed to remove the material.

Abstract: A metal that can be dissolved in aqua regia or a metal alloy containing a metal that can be dissolved in aqua regia can be effectively removed from a substrate, and particularly a silicon wafer substrate by a method of application of a composition having a HCl (concentrated)/hydrogen peroxide (concentrated) volume ratio of about 1:1 to about 4:1 that is substantially free of added water. In another embodiment, a metal that can be dissolved in aqua regia or a metal alloy containing a metal that can be dissolved in aqua regia is removed from a substrate by a composition comprising HCl (concentrated)/hydrogen peroxide (concentrated)/water in a volume ratio of from about 2:0.5:4 to about 4:2:4. The composition, heated to a temperature of about 60° C. to about 100° C., is applied to a substrate having the metal or metal alloy thereon, which is preferably heated to a temperature of from about 50° C. to about 100° C.