Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : Dupont Photomasks (DPMI) -- Ignore unavailable to you. Want to Upgrade?

To: Larry Brew who wrote (367)	3/14/1998 8:57:00 PM
From: Duane L. Olson	Read Replies (1) \| Respond to of 955

Larry, Personally, I had thought that the limit for the ArF Eximer lasers (193 nm) was .13u features (DPMI had already announced plans to install equipment capable of producing masks supporting features to .13u at their new operations in LSI facilities at Gresham).. Katherine Derbyshire (who did the best writeup on the UT work) supports your point about costs beyond 193nm...http://www.exchange2000.com/~wsapi/investor/reply-3683903 But the UT work at .08u was ALSO done with an ISI stepper and a CYMI ArF eximer laser (at 193 nm)...which is why a specialized phaseshift photomask from DPMI was required, as I understand it. Although the photomasks are going to be quite expensive, however, it appears they are still MUCH less costly than the direct write methodologies... is that your understanding also?....TSO

To: Larry Brew who wrote (367)	3/14/1998 9:09:00 PM
From: TI2, TechInvestorToo	Respond to of 955

The masks were good work, not new work. The following abstract is similar work done with I line strong phase shift masks. IBM held the patent. It is old and I believe expired. DuPont was acknowledged as the maskmaker in the paper. DUV 248 nm wavelength conventional masks have apparently superceded this application of phase shift at 250 nm design rules. TI2 perl.spie.org Phase shifting and optical proximity corrections to improve CD control on logic devices in manufacturing for sub-0.35-um i-line Ackmann, Paul W.; Brown, Stuart E.; Nistler, John L.; Spence, Christopher A. AA(Advanced Micro Devices, Inc.) Journal:Proc. SPIE Vol. 3051, p. 146-153, Optical Microlithography X, Gene E. Fuller; Ed. Publication Date:07/1997 Origin:SPIE ------------------------------------------------------------------------ Abstract: The use of I-Line exposure wavelength for manufacturing at and beyond 0.35 micrometers presents many challenges in manufacturing. The lack of resolution, depth of focus, exposure latitude, and iso/dense offsets have caused some to switch from I-Line to DUV. With our installed I-Line base we felt it necessary to implement techniques to extend our tool life, reduce manufacturing costs while improving manufacturing margins. The results of the differential modification techniques were used to reduce the effects of topography, density, and low k lens issues. The differences seen between the binary and phase shift plates show the advantage of phase shifting below 0.35 (mu) manufacturing. We have been able to demonstrate between critical dimension (CD) control using phase shift mask with dense iso compensation over a standard binary reticle. The data shows improved CD control across the stepper field, wafer, and overall lot distribution. The impact of this work was improved speed performance. It also allowed us to move the CD's to smaller dimension because of the better control without increasing fallout due to electrical parametric roll-off.

To: Larry Brew who wrote (367)	3/15/1998 8:54:00 PM
From: Duane L. Olson	Respond to of 955

Larry, I was going to make another comment about the difficulty of making the photomasks down to .08u, but couldn't find my reference. The original report on the UT work, however, does make a reference to the difficulty of making the photomask, as well as the three year effort to make the photoresists..etc.. worth another read, perhaps: biz.yahoo.com TSO

To: Larry Brew who wrote (367)	3/18/1998 10:46:00 AM
From: Katherine Derbyshire	Read Replies (2) \| Respond to of 955

>>I realized, it's cheap when one considers no other equipment upgrades are necessary. I believe current Deep UV is 193 nanometers. Dropping<< Just a minor point here. Current DUV is 248 nm, not 193 nm. So yes, major equipment upgrades will absolutely be required for sub-0.13 micron or so features. 193 nm still seems more viable and less expensive than x-ray or E-beam, but the UT work, exciting though it is, is a long long way from production. Also, to my knowledge, DPMI does not hold the patent on phase shift masks. The particular mask type used for the UT work was invented by Marc Levenson and coworkers at IBM. (I'm not sure which names are on the patent, but it is generally known in the industry as a "Levenson phase shift mask.") All of this was long enough ago that the patent may very well have expired, or been broken, by now. Disclaimer: Marc Levenson is a friend and former coworker of mine, so I may be biased. Katherine