Patent ID: 7364836

Claim:
A method of photoresist processing on a substrate over which is formed composite layers of insulation comprising a first layer of dielectric and a second layer of dielectric, the method comprising: forming a first photoresist layer over said composite layers of insulation; patterning a via hole pattern in said first photoresist layer by exposing to radiation of a first sensitivity; forming a second photoresist layer over via patterned and said first photoresist layer; patterning a trench line pattern in second photoresist layer by exposing to radiation of a second sensitivity; etching said second layer of dielectric underlying first layer of photoresist using the via hole pattern layer; etching said composite layer of insulation, thereby transferring said trench line pattern into said second layer of dielectric and transferring said via hole pattern into said first layer of dielectric; and filling the trench line and via hole openings with metal.