Patent ID: 6642138
Filing Date: 2003-11-04
Classification: H01L

Abstract:
A method making dual damascene structures comprising the steps of:a) forming a sacrificial layer comprising a sacrificial polymer over an oxide layer; b) depositing a first hard mask at a temperature below 400 degrees Celsius over the sacrificial layer; c) depositing as a second hard mask at a temperature below 400 degrees Celsius over the first hard mask; d) depositing and patterning a photoresist via pattern; e) etching the second hard mask to form a via in the second hard mask; f) etching the first hard mask to extend the via through the first hard mask; g) depositing and patterning a photoresist line pattern; h) etching the second hard mask to form a line in the second hard mask; i) etching the sacrificial layer using the first hard mask as a via mask, whereby the via extends through the sacrificial layer; j) etching the first hard mask using the second hard mask as a line mask, whereby the line extends through the first hard mask; and k) etching off the second hard mask and etching into the oxide layer. 2., The method of claim 1, wherein the step of forming the sacrificial layer further comprises spin coating.