Semiconductor device manufacturing: process – Chemical etching – Liquid phase etching
Reexamination Certificate
2000-09-21
2002-05-14
Bowers, Charles (Department: 2813)
Semiconductor device manufacturing: process
Chemical etching
Liquid phase etching
C438S747000, C216S042000, C216S036000
Reexamination Certificate
active
06387822
ABSTRACT:
FIELD OF THE INVENTION
The invention is generally related to the field of resist patterning of semiconductor devices and more specifically to resist strip and resist residue removal processes.
BACKGROUND OF THE INVENTION
In the fabrication of semiconductor devices, photoresist patterns are routinely used for delineating certain areas of the semiconductor device, for example, for patterned etching and ion implantation. After the etch or implantation sequence, the resist pattern must be removed. This is referred to as a resist strip. Additionally, any resist residue must also be removed. Currently, an ozonated H
2
SO
4
operated at 130° C. or a combined solution of H
2
SO
4
and H
2
O
2
are widely used for resist strip. To reduce particles, the above resist strip process is followed by a SC1 (H
2
O:NH
4
OH:H
2
O
2
) megasonic cleanup. Alternatively, a deionized water (DIW) scrub may be used for particle removal.
Unfortunately, the chemicals described above for resist strip are not environmentally safe and require special precautions for handling and disposal. Furthermore, sulfur compounds have been found to be left on wafer surfaces after the H
2
SO
4
cleanups, which may cause corrosions or work function shifts on devices. The SC1 clean-up may result in NH
3
abatement. If the alternative DIW scrub is used, two process tools are required. Accordingly, a resist strip and particle removal process is desired that is environmentally safe and overcomes the above mentioned particle removal problems.
U.S. Pat. No. 5,464,480 describes a process for removing organic materials such as photoresist without the use of H
2
SO
4
and H
2
O
2
. Wafers are placed in a tank containing chilled deionized water. Ozone is diffused into the chilled deionized water to oxidize the organic material from the wafer surface. This process requires the addition of a chiller to current process equipment.
SUMMARY OF THE INVENTION
The invention is a method and apparatus for resist pattern strip and resist residue removal that uses an ozonated deionized water mist. An atomizer may be used to mix ozone and deionized water into a fine mist. The ozonated deionized water mist is then sprayed on the wafers.
An advantage of the invention is providing a resist strip and resist residue removal process that offers reduced processing time and that is environmentally safe.
This and other advantages will be apparent to those of ordinary skill in the art having reference to the specification in conjunction with the drawings.
REFERENCES:
patent: 4778532 (1988-10-01), McConnell et al.
patent: 5464480 (1995-11-01), Matthews
patent: 6200387 (2001-03-01), Ni
Jung Claire Ching-Shan
Mathews Danny F.
Murphy Neal T.
Bowers Charles
Brady III W. James
Garner Jacqueline J.
Huynh Yennhu B.
Telecky , Jr. Frederick J.
LandOfFree
Application of an ozonated DI water spray to resist residue... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Application of an ozonated DI water spray to resist residue..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Application of an ozonated DI water spray to resist residue... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2897460