Patent ID: 7927500

Claim:
A method comprising: forming a patterned photo-resist layer having openings on a polysilicon layer, the polysilicon layer formed on a dielectric layer; adding a first volume of an ammonium hydroxide solution to a second volume of a tetra methyl ammonium hydroxide solution at a first time; immersing the substrate having the patterned photo-resist layer, the polysilicon layer, and the dielectric layer in the ammonium hydroxide and tetra methyl ammonium hydroxide solution within one hour of the first time to remove a portion of the polysilicon layer at the openings and to expose a portion of the dielectric layer at the openings; removing the substrate after expiration of a preselected time period; removing essentially all of the ammonium hydroxide and tetra methyl ammonium hydroxide solution from the substrate; and drying the substrate.