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.