发明名称 |
MASKING OF REPEATED OVERLAY AND ALIGNMENT MARKS TO ALLOW REUSE OF PHOTOMASKS IN A VERTICAL STRUCTURE |
摘要 |
In formation of monolithic three dimensional memory arrays, a photomask may be used more than once. Reuse of a photomask creates second, third or more instances of reference marks used by the stepper to achieve alignment (alignment marks) and to measure alignment achieved (overlay marks) directly above prior instances of the same reference mark. The prior instances of the same reference mark may cause interference with the present instance of the reference mark, complicating alignment and measurement. Using the methods of the present invention, blocking structure is created vertically interposed between subsequent instances of the same reference mark, preventing interference. |
申请公布号 |
EP1866701(A1) |
申请公布日期 |
2007.12.19 |
申请号 |
EP20060748959 |
申请日期 |
2006.03.31 |
申请人 |
SANDISK 3D, LLC |
发明人 |
CHEN, YUNG-TIN;PETTI, CHRISTOPHER, J.;RADIGAN, STEVEN, J.;KUMAR, TANMAY |
分类号 |
G03F9/00;G03F7/20;H01L23/00 |
主分类号 |
G03F9/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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