Browse Prior Art Database

Novel Method of Eliminating Repeating Defects on Photomasks

IP.com Disclosure Number: IPCOM000045224D
Original Publication Date: 1983-Feb-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 2 page(s) / 37K

Publishing Venue

IBM

Related People

Cook, FD: AUTHOR

Abstract

The objective here is to eliminate the use of a mask with repeating defects on device wafers resulting in zero yield. The technique requires the use of two segments to generate the lx mask and to inspect the mask with an automatic mask inspection tool. Assumption.

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 68% of the total text.

Page 1 of 2

Novel Method of Eliminating Repeating Defects on Photomasks

The objective here is to eliminate the use of a mask with repeating defects on device wafers resulting in zero yield. The technique requires the use of two segments to generate the lx mask and to inspect the mask with an automatic mask inspection tool. Assumption.

1. Post process data is correct

2. All 10x segment (reticle) defects are process or tool-related. Procedure.

1. Generate two 10x product segments (same part number) for each 1x mask.

2. Determine lx mask array configuration from the distance between the automatic inspection tool, two microscope objectives and the product chip size.

3. Step the lx mask array, using the two 10x segments with the determined configuration (Fig. 1).

4. Process the mask using normal chrome mask making process.

5. Inspect the mask with the automatic inspection tool. Hypothesis

Since the 1x mask has been generated with two different 10x segments, repeating defects will be manifested as random defects which can be easily detected by automatic inspection systems using the comparison of chips for the inspection technique. Actual Observations.

Feasibility tests have been made using product devices as the test vehicle. Via holes were added (extra via) and substrated (missing via) to the "L" layer first via (using, for example, KLA-100).

a) The tool was able to detect both the missing vias and the extra vias in all cases. There were more than 20,000 via holes per chip on the...