发明授权
- 专利标题： Transparent optical chuck incorporating optical monitoring
- 专利标题（中）： 透明光卡盘包含光学监控
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申请号： US304984申请日： 1994-09-13
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公开(公告)号： US5515167A公开(公告)日： 1996-05-07
- 发明人: Anthony Ledger , Michael Power
- 申请人： Anthony Ledger , Michael Power
- 申请人地址： CA Los Angeles
- 专利权人： Hughes Aircraft Company
- 当前专利权人： Hughes Aircraft Company
- 当前专利权人地址： CA Los Angeles
- 主分类号： B23Q3/15
- IPC分类号： B23Q3/15 ; G03F7/20 ; H01L21/66 ; H01L21/68 ; H01L21/683 ; G01B9/02
摘要：
A transparent chuck is used to force a semiconductor wafer to take a prescribed shape. Any gap which is formed between the chuck and the wafer can be imaged through the transparent chuck. An interferometer is used to illuminate the gap with a narrow band illumination to create interference fringes in the gap. The fringes can be electronically imaged to create a digital input to a computer. Merit functions corresponding to the total volume of fringes in the gap or to the summation of nearest neighbor slopes of such fringes provide a measure of the thickness of such gap.