Patent ID: 7358192

Claim:
A method for a processing film stack formed on a substrate, the film stack having at least a patterned photoresist layer having a thinner portion formed between thicker sections and disposed over an first metal layer, a first silicon layer underlying the first metal layer, a second silicon layer underlying the first silicon layer, and a second metal layer disposed between the second silicon layer and the substrate, wherein the thinner sections of the patterned photoresist layer is over the second metal layer, wherein the thickness difference between the thin and thick section is sufficient to leave the thicker section of the photoresist layer after the thinner section is removed by an ashing process, the method comprising: etching a portion of the first metal layer in a processing chamber exposed by the patterned photoresist layer to expose a portion of the first silicon layer; and etching the exposed portion of the first silicon layer in the processing chamber.