Patent ID: 6180512
Filing Date: 2001-01-30
Classification: G03F,H01L

Abstract:
A method of forming a dual damascene pattern employing a single photoresist layer comprising the steps of:providing a substrate having a composite layer of insulation deposited thereon whereby said composite layer comprises a first layer of dielectric separated from a second layer of dielectric by an intervening intermediate layer of dielectric;forming a layer of photoresist on said composite layer of dielectric insulation;patterning said layer of photoresist by exposing said photoresist using a phase-shifting mask comprising hole and line patterns;post-exposure baking of said layer of photoresist;performing a wet development of said layer of photoresist to form a patterned layer of photoresist;etching said second layer of dielectric using said patterned layer of photoresist as a mask thereby transferring said hole pattern in said layer of photoresist into said second layer of dielectric;etching said intermediate layer of dielectric underlying said second layer of dielectric using said layer of photoresist as a mask thereby transferring said hole pattern in said layer of photoresist into said intermediate layer of dielectric;etching said layer of photoresist to extend downward said line pattern;etching said composite layer of insulation thereby transferring said line pattern in said layer of photoresist into said second layer of dielectric to form a line trench, and simultaneously transferring said hole pattern in said intermediate layer of dielectric into said first layer of dielectric to form a hole;removing said layer of photoresist; anddepositing metal into said trench and said hole to form a dual damascene structure.