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Canon PLA-501 Contact Aligners

Operating procedures are available:
First Wafer without Alignment
With Alignment

Canon PLA-501 Contact Aligners

Process Description:
Lithography is a process for optically projecting an image onto a wafer that has been coated with a thin layer of photosensitive material called photoresist. Contact or proximity printing is the simplest lithography method. When UV light passes through the pattern area of a chrome mask, it exposes the photoresist on the wafer and a chemical process occurs. After a developing solution bath and rinse, a pattern is transferred via the remaining photoresist on the wafer. The next process step, such as etching or ion implanting, can then be performed.

Equipment Description:
The 3" Canon aligner automatically feeds 3-inch wafers into the wafer chuck. A pre-alignment is performed by the system. It uses a standard 4" mask. The 4" Canon aligner automatically feeds 4-inch wafers and uses a standard 5" mask. The light source on both units is a 250-watt super high-pressure mercury lamp that is filtered to produce a combination of g-line, h-line and i-line wavelengths. Alignment is performed by a joystick movement while observing the wafer and mask with a microscope. The scannable range is ±10mm in both the x and y directions.

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Copyright 2007 The Board of Regents of the University of Wisconsin System
Date last modified: 28-Aug-2001
Date created: 28-Aug-2001
Content by: rabauer@facstaff.wisc.edu
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