- 专利标题: METHOD OF ANISOTROPIC EXTRACTION OF SILICON NITRIDE MANDREL FOR FABRICATION OF SELF-ALIGNED BLOCK STRUCTURES
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申请号: US15904157申请日: 2018-02-23
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公开(公告)号: US20180277386A1公开(公告)日: 2018-09-27
- 发明人: Sonam D. Sherpa , Alok Ranjan
- 申请人: Tokyo Electron Limited
- 主分类号: H01L21/311
- IPC分类号: H01L21/311 ; H01L21/033
摘要:
A method of preparing a self-aligned block (SAB) structure is described. The method includes providing a substrate having raised features defined by a first material containing silicon nitride and a second material containing silicon oxide formed on side walls of the first material, and a third material containing an organic material covering some of the raised features and exposing some raised features according to a block pattern formed in the third material. The method further includes forming a first chemical mixture by plasma-excitation of a first process gas containing H and optionally a noble gas, and exposing the first material on the substrate to the first chemical mixture. Thereafter, the method includes forming a second chemical mixture by plasma-excitation of a second process gas containing N, F, O, and optionally a noble element, and exposing the first material on the substrate to the second plasma-excited process gas to selectively etch the first material relative to the second and third material.