Browse Prior Art Database

Composite Blocking and Pattern Defining Mask

IP.com Disclosure Number: IPCOM000075587D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Youlton, FW: AUTHOR

Abstract

These two methods provide reduction of pinholes in metal-on-glass masks and eliminate the necessity of using separate blocking masks on each wafer, by providing a composite blocking and pattern defining mask.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Composite Blocking and Pattern Defining Mask

These two methods provide reduction of pinholes in metal-on-glass masks and eliminate the necessity of using separate blocking masks on each wafer, by providing a composite blocking and pattern defining mask.

The mask shown in Fig. 1 is fabricated as follows. A standard single-layer pattern defining mask comprising glass plate 10 and chromium layer 12 is selectively covered with a strippable photoresist 14 in all pattern areas, except large opaque areas of the pattern to be defined. Thereafter, a second layer 16 of chromium is uniformly applied over the entire mask, as shown in Fig. 1A. Photoresist 14 is then stripped away, removing chromium overlying the original pattern and leaving the composite mask shown in Fig. 1B having a double- chromium layer in all large opaque areas.

A second method is shown in Fig. 2. A standard single-layer mask comprising a first pattern defining layer 18 of tantalum, for example, on glass plate 20 is uniformly covered with a layer of second metal 22 which may be selectively etched, such as chromium. Photoresist material 24 is applied over all normally opaque areas of the original pattern, as shown in Fig. 2A. Thereafter, exposed areas are selectively etched to remove only the second layer 22. Finally, the photoresist 24 is removed leaving the mask shown in Fig. 2B.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]