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Alternative Material for Terminal Metal Deposition Mask

IP.com Disclosure Number: IPCOM000040893D
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-02
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Kapner, H: AUTHOR

Abstract

It is proposed that a photosensitive, crystalline glass or glass-ceramic be used as an alternative material for deposition masks used to process semiconductor devices and semiconductor packages. The dimensional and flatness control of the proposed mask is better than that of the conventional one made from molybdenum.

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Alternative Material for Terminal Metal Deposition Mask

It is proposed that a photosensitive, crystalline glass or glass-ceramic be used as an alternative material for deposition masks used to process semiconductor devices and semiconductor packages. The dimensional and flatness control of the proposed mask is better than that of the conventional one made from molybdenum.

With moly masks poor images may result because of poor flatness control which makes it difficult to maintain edge sharpness. Additionally, there is a limitation requiring that hole size not exceed the thickness of the mask material and the masks are susceptible to mechanical damage.

With the use of the proposed materials the pattern of the mask is defined through the entire thickness of the glass, rather than just at the surfaces. This permits a considerably greater length-to-diameter ratio than the 1:1 existent with moly. The cross-section profile of holes etched in the glass will have the desired hour glass shape necessary for the formation of relatively thick metal pads. There is minimal distortion or destruction of the metal pads during subsequent removal of the mask.

The thicker, more rigid and stronger glass-structure is more resistant to mechanical damage from handling during processing operations than the thin moly metal previously used. In addition, the alternative materials are better able to withstand the corrosive effects of chemical agents used to remove metals deposited on the mask...