Vacuum dehydration of negatively working photoresist eliminates trace contamination of conventional stripping methods. The semiconductor substrate is coated with photoresist, exposed, developed, cured, and etched, and then placed in a vacuum. Following dehydration, the resist film is removable with ordinary solvents

Davern, W. E.

Tobin, L. S.

English

NASA Technical Reports Server

September 1970	 Brief 70-10497 
NASA TECH BRIEF 
- -	 -.-	 .-
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage commercial 
application. Tech-Briefs are available on a subscription basis from the Clearinghouse for Federal Scientific and Technical 
Information, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Division, NASA, Code UT, Washington, D.C. 20546. 
New Method for Photoresist Stripping 
S
The problem: 
Conventional methods used to strip cured photo-
resist tend to leave trace contamination that is undesir-
able in semiconductor work. These methods are incon-
venient; they require constant elevated temperature 
baths, and the stripping chemicals have short effective 
life. 
The solution: 
A new stripping procedure for a negative working 
Thotoresist that employs dehydration of the resist in 
i vacuum. Following vacuum dehydration, the resist 
ilm is removable with ordinary solvents. 
How it's done: 
After the semiconductor substrate is coated with 
photoresist, exposed, developed, cured and etched, 
the cured resist-coated substrate is placed in a vacuum 
of 1 x 10- torr for a period of time governed by the 
coating thickness. After vacuum, dehydration, the
substrate is rinsed in ordinary solvent (xylene, acetone, 
etc.) which readily removes the photoresist. 
Since the photoresist itself contains solvent (xylene), 
no contaminating materials are introduced, thus 
eliminating the possibility of adverse chemical reac-
tions which can take place in conventional stripping. 
Note: 
No additional documentation is available. 
Patent status: 
Inquiries about obtaining rights for the commercial 
use of this invention may be made to NASA, Code 
GP, Washington, D.C. 20546. 
Source: W. E. Davern and L. S. Tobin of
General Electric Company 
under contract to
Electronics Research Center
(ERC- 10239) 
Category 04 
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United -States
Government assumes any liability resulting from- the use of the 
information contained in this document, or warrants that such use 
will be free from privately owned-rights.
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New method for photoresist stripping

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