Browse Prior Art Database

Method And Chemicals for Mask-Cleaning Process

IP.com Disclosure Number: IPCOM000102454D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 51K

Publishing Venue

IBM

Related People

Vo, CV: AUTHOR

Abstract

The single clean process with a spray method described in this article effectively removes more chrome defects and contamination on mask products, thereby significantly improving the product yields.

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Method And Chemicals for Mask-Cleaning Process

       The single clean process with a spray method described in
this article effectively removes more chrome defects and
contamination on mask products, thereby significantly improving the
product yields.

      The process flow chart illustrates both the current
mask-cleaning procedure (solid line) and the disclosed cleaning
process (dashed line).  Masks normally proceed through exposure 1,
develop 2, ash 3, etch 4 and strip 5 before reaching the
multiple-step cleaning process, by using CA-40*, Nuterg*, AZ-303**,
and brush clean 6.  The mask process is completed following defect
inspection 7, linewidth and dimensional check 8, and final inspection
9.

      The disclosed cleaning process replaces the multiple-step 6 by
a single-step with a spray method 10, which is key to reducing
defects and contamination.  The cleaning chemicals are two premixed
solutions which are composed of the following ingredients (by
volume):
      SOLUTION CG (FOR BOTH SIDES OF MASKS):
           Nitric acid 05.0%
 Potassium perfluoroalkyl sulfonates 0.1%

      Deionized (DI) H2O 64.9%
      SOLUTION C (FOR CHROME SIDE OF MASKS):
           Acetic acid 18.2%
 Ceric acid/cerium (IV) 0.2%
 FC 129 surfactants 0.1%
 Deionized (DI) H2O 81.5%

      The single-step cleaning (10) is programmable for chemicals,
water distribution and drying cycle, with the spray fixture set as
shown below:

     ...