A method for wet etching a metal nitride containing layer overlying a silicon oxide containing layer in a semiconductor device or micro-electro-mechanical device manufacturing process including providing a substrate including a silicon oxide containing layer and an overlying exposed metal nitride containing layer; providing a wet etching solution including phosphoric acid and water; adding a silicon containing compound which undergoes a hydrolysis reaction in the wet etching solution; and, contacting the exposed metal nitride containing layer with the wet etching solution for a period of time to remove the metal nitride containing layer.