发明授权
- 专利标题: Dry etching method for W polycide using sulfur deposition
- 专利标题(中): 使用硫沉积的W型杀虫剂的干蚀刻方法
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申请号: US899181申请日: 1992-06-16
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公开(公告)号: US5368686A公开(公告)日: 1994-11-29
- 发明人: Tetsuya Tatsumi , Tetsuji Nagayama
- 申请人: Tetsuya Tatsumi , Tetsuji Nagayama
- 申请人地址: JPX Tokyo
- 专利权人: Sony Corporation
- 当前专利权人: Sony Corporation
- 当前专利权人地址: JPX Tokyo
- 优先权: JPX3-171882 19910618; JPX3-177743 19910624; JPX4-072514 19920221
- 主分类号: H01L21/28
- IPC分类号: H01L21/28 ; H01L21/302 ; H01L21/3065 ; H01L21/3213 ; H01L29/423 ; H01L29/43 ; H01L29/49 ; H01L21/00
摘要:
A dry etching method for anisotropically etching a polycide film without using chlorofluorocarbon (CFC). For instance, in a W polycide gate electrode forming process, a W polycide film is etched by using sulfur fluorides, like S.sub.2 F.sub.2, with a high S/F ratio (i.e. the ratio of the number of sulfur atoms to that of fluorine atoms). In a first step, at least the upper WSi.sub.x layer of the W polycide film is etched with the wafer kept at temperatures between -20.degree. C. and room temperature or with non-depositional fluorine based compounds like SF.sub.6 added to etching gas, thus decreasing the S/F ratio of the etching system. This first step promotes elimination of WF.sub.x and reduces the quantity of free sulfur. Therefore, WF.sub.x is inhibited from reacting with sulfur to form WS.sub.x for deposition in excessive quantities on the sidewalls of the WSi.sub.x pattern, thus preventing occurrence of critical dimension losses between the resist mask and the W polycide gate electrode. In a second step, the lower polysilicon layer of the W polycide film is etched with the wafer cooled to lower temperatures or with H.sub.2 S, etc. added to etching gas, thus increasing the S/F ratio of the etching system. This second step promotes deposition of sulfur on the sidewalls of the polycide pattern and improves anisotropy.
公开/授权文献
- US6162046A Liquid vaporization and pressurization apparatus and methods 公开/授权日:2000-12-19
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