发明授权
- 专利标题: Ladder poly etching back process for word line poly planarization
- 专利标题(中): 用于字线多平面化的梯形多层刻蚀工艺
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申请号: US11782491申请日: 2007-07-24
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公开(公告)号: US07563675B2公开(公告)日: 2009-07-21
- 发明人: Shih-Chang Liu , Yuan-Hung Liu , Chia-Shiung Tsai
- 申请人: Shih-Chang Liu , Yuan-Hung Liu , Chia-Shiung Tsai
- 申请人地址: TW Hsin-Chu
- 专利权人: Taiwan Semiconductor Manufacturing Co., Ltd.
- 当前专利权人: Taiwan Semiconductor Manufacturing Co., Ltd.
- 当前专利权人地址: TW Hsin-Chu
- 代理商 Duane Morris LLP
- 主分类号: H01L21/8247
- IPC分类号: H01L21/8247
摘要:
A method is disclosed for etching a polysilicon material in a manner that prevents formation of an abnormal polysilicon profile. The method includes providing a substrate with a word line and depositing a polysilicon layer over said substrate and word line. An organic bottom antireflective coating (BARC) layer is then deposited over said polysilicon layer. A ladder etch is performed to remove the BARC layer and a portion of the polysilicon layer. The ladder etch consists of a series of etch cycles, with each cycle including a breakthrough etch and a soft landing etch. The breakthrough and soft landing etches are performed using different etchant gases, and at different source and bias powers, pressures, gas flow rates, and periods of time. The ladder etch results in a smooth polysilicon surface without abrupt steps.
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