Patent ID: 8916479

Claim:
A method for processing semiconductor substrates, the method comprising: providing a semiconductor substrate comprising a first structure and a second structure; exposing the semiconductor substrate to an etching solution; and etching the first structure; wherein the first structure comprises titanium nitride; wherein the second structure comprises aluminum; wherein the etching solution comprises ammonium hydroxide and hydrogen peroxide; wherein a weight ratio of ammonium hydroxide to hydrogen peroxide is between about 1:600 and about 1:3,000 such that ammonium hydroxide is operable as a catalyst during etching of the first structure; wherein an etching rate of the first structure is greater than an etching rate of the second structure; wherein the etching rate of the first structure is between 200 Angstroms per minute and 2,000 Angstroms per minute; and wherein the etching rate of the second structure is less than 15 Angstroms per minute.