Method to prevent formation of defects during multilayer interconnect processing

Claim 1

A process for preventing the formation of defects in aluminum-containing interconnects formed over a semiconductor substrate and employed in silicon-based semiconductor devices, said semiconductor substrate having a surface, wherein said interconnects are formed by: (a) depositing an aluminum-containing interconnect layer over a first oxide layer supported over a silicon substrate at a first temperature T s , said aluminum-containing interconnect layer having only one degree of freedom for movement in the direction perpendicular to said surface of said semiconductor substrate; (b) forming an anti-reflection coating on said aluminum-containing interconnect layer at a second temperature T ARC , wherein T ARC is measured in °C. and is given by (T s -100) ≦T ARC ≦T s ; (c) depositing a hard mask on said anti-reflection coating at a third temperature T m wherein T m is measured in °C. and is given by (T s -100)≦T m ≦T s ; (d) patterning said hard mask to form an interconnect pattern for transfer to said aluminum-containing interconnect layer; and (e) etching in succession said hard mask, said anti-reflection coating, and said aluminum-containing interconnect layer to transfer said interconnect pattern from said hard mask to said aluminum-containing interconnect layer, thereby forming said aluminum-containing interconnects, thereby preventing the formation of voids in said aluminum-containing interconnect layer or ting defects on said first oxide layer while avoiding compression of said aluminum-containing interconnect layer during cooling.