US Patent 7354863 Methods of selectively removing silicon

An etch solution that comprises tetramethylammonium hydroxide (“TMAH”) and at least one organic solvent. The etch solution may be substantially free of water. The etch solution is formulated to selectively etch a silicon layer relative to other layers on an integrated circuit. The TMAH may be present in an amount ranging from approximately 1% by weight to approximately 10% by weight. The at least one organic solvent may be selected from the group consisting of isopropanol, butanol, hexanol, phenol, glycol, glycerol, ethylene glycol, propylene glycol, glycerin, and mixtures thereof. A method of selectively etching a silicon layer and a method of removing a heat-affected zone (“HAZ”) on an integrated circuit are also disclosed.