Oxide/nitride etching having high selectivity to photoresist
A single-step plasma etch process for etching both oxide and nitride selectively to photoresist and silicon. The etching gas includes a fluorocarbon, difluoromethane, oxygen, and carbon monoxide. The fluorocarbon is preferably hydrogen free. Preferred fluorocarbons are hexafluorobutadiene (C4F6), octafluorocyclobutane (C4F8), and carbon tetrafluoride (CF4), of which C4F6 is the most preferred. Approximately equal amounts are supplied of the fluorocarbon, difluoromethane, and oxygen and a significantly larger amount of carbon monoxide. The chemistry is also applicable to etching organo silicate glass selectively to photoresist.
Applied Materials, Inc.
H H
H01L H01L
inventional inventional
Claes H. Yungsang Hongqing Takehiko
Bjorkman Kim Shan Komatsu