发明授权
- 专利标题: Method for photo alignment after CMP planarization
- 专利标题(中): CMP平坦化后的光取向方法
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申请号: US09472923申请日: 1999-12-27
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公开(公告)号: US06465897B1公开(公告)日: 2002-10-15
- 发明人: Tsu Shih , Jui-Yu Chang
- 申请人: Tsu Shih , Jui-Yu Chang
- 主分类号: H01L2348
- IPC分类号: H01L2348
摘要:
A method for forming alignment marks are disclosed for performing photoalignment after chemical-mechanical polishing (CMP). A trench is first formed in a silicon substrate and then alignment marks are formed at the bottom of the trench. The aspect ratio of the trench is selected to be so low that the dishing of the CMP pad can be prevented from reaching into the trench to damage the alignment marks therein. A trench structure is also provided whereby the alignment marks can be protected from the abrasive action of the CMP. Steps subsequent to the CMP can therefore proceed unimpeded with the presence of undamaged alignment marks.