AgGeSbTe thin film as a negative heat-mode resist for dry lithography
Xingwang Chen, Lei Chen, Ying Wang, Ying Tian, Jing Hu, Miao Cheng, Qianqian Liu, Wanfei Li, Yun Ling, Bo Liu
Abstract
An AgGeSbTe thin film is proposed as a negative heat-mode resist for dry lithography. It possesses high etching selectivity with the etching rate difference of as high as 62 nm/min in CHF 3 =O 2 mixed gases. The etched sidewall is steep without the obvious lateral corrosion. The lithographic characteristics and underlying physical mechanisms are analyzed. Besides, results of X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy further indicate that laser irradiation causes the formation of Ge, Sb, and AgTe crystals, which is the basis of etching selectivity. In addition, the etching selectivity of Si to AgGeSbTe resist is as high as 19 at SF 6 =Ar mixed gases, possessing good etching resistance. It is believed that the AgGeSbTe thin film is a promising heat-mode resist for dry lithography.