Alignment system and method using bright spot and box structure
US6801314B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 28, 2001 |
| Grant date | Oct 5, 2004 |
| Priority date | — |
| Expiry date | Sep 28, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7088
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
There is provided a method for aligning a semiconductor wafer and a mask. A semiconductor wafer is provided having an alignment mark formed thereon. A mask is provided having a pattern formed thereon. The mask is illuminated so as to create a bright spot thereon by a 0_&pgr; phase conflict. The alignment mark is aligned with the bright spot, so as to align the semiconductor wafer with the mask. Preferably, the method includes the step of creating the alignment mark on the semiconductor wafer in a form of a frame. Moreover, preferably, the creating step includes the step of creating the frame to minimize an impact of film stack variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.