Flash step preparatory to dielectric etch
A dielectric plasma etch method particularly useful for assuring that residue does not form in large open pad areas used for monitoring etching of narrow via and contact holes. The main dielectric etch of the via and contact holes uses a highly polymerizing chemistry, preferably of a low-F/C fluorocarbon such as C4F6 in conjunction with O2 and Ar. A short flash step precedes the main plasma etch using a plasma of a gas less polymerizing than the gas of the main etch, and the plasma is not extinguished between the flash and main steps. The flash step may be used to remove an anti-reflection coating (ARC) covering the dielectric layer and use a lean fluorocarbon, such as CF4, perhaps together with O2 and Ar. In the absence of ARC, an argon flash may be used.
H
H01L
inventional
Jingbao Bryan Zhuxu Claes H.
Liu Pu Wang Bjorkman