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Optical Technique for Detecting Defects in Chrome Or Resist Covered Chrome Glass Masks

IP.com Disclosure Number: IPCOM000061982D
Original Publication Date: 1986-Sep-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Arnold, RC: AUTHOR

Abstract

A method is shown for detecting pin holes in chrome plated glass masks used in the production of semiconductors or for detecting defects in a photoresist film covering a chrome plated glass mask.

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Optical Technique for Detecting Defects in Chrome Or Resist Covered Chrome Glass Masks

A method is shown for detecting pin holes in chrome plated glass masks used in the production of semiconductors or for detecting defects in a photoresist film covering a chrome plated glass mask.

Through the utilization of a cylindrical lens and scanning light source, a bar of light can be produced which is useful in the process of detecting pin holes in chrome plated glass masks or defects in photoresist coated chrome plated glass masks.

The figure shows a scanning gas laser light source passing through a cylindrical lens to produce a bar of light. By passing a chrome plated glass mask between the light bar and a photo detection system, pin holes in the chrome film will allow light to pass through the holes in the film and then through the glass substrate to be detected by the lower photo detector. The output of the detector is used as an input to a computer system which can precisely locate pin hole coordinates and produce a surface defect map of the mask. The chrome surface will reflect the light source in areas which do not have pin holes and render the detector inactive.

A second photo detection system (shown in the figure) located above the glass mask is used for detecting photoresist defects in a resist coated chrome plated glass mask. In this case the light source and photo detector are located on the same side of the resist coated mask to be inspected. By passing a res...