A question to the lithography blogosphere: who invented pellicles for photomask protection?
Lithographers have been practicing safe exposures – with masks wrapped in a thin sheet of plastic to protect them from particles – since before my time. What is the first reference to pellicles in the literature? Who was the first to use them? The earliest reference that I have found is Ron Hershel, “Pellicle protection of integrated circuit (IC) masks”, SPIE Vol. 275 (1981) pp. 23 – 28.
I’ve also just found an IBM patent from 1977 that clearly describes pellicles: patent #4131363.
Pellicles were used in other optical applications, prior to their adoption by the semiconductor industry. As I recall, IBM and Intel were the first IC producers to evaluae pellicle usage. The primary supplier was Advanced Semiconductor Products (ASP) in Santa Cruz, CA (Robert Turnage and Ray Winn). Intel (Fab 1 on Whisman Rd, Mountain View) partnered with JASCO (Electronics Chemical iv.) in Mountain View to develop pellicles. The JASCO product line did not prevail. Anne Miller, the JASCO pellicle inventor, got funding from EKC Technology in Hawyard and founded MicroPel. Not much later, Chris Yen (then of Xerox in Palo Alto) founded Micro Lithography Inc. (MLI). Sometime later Dupont go into the fray.
A related question. How long after the pellicle was invented was the first one broken on a microscope? I broke one in 1983 trying to look at a mask on a microscope. The photo supervisor wasn’t too happy with me.
I "popped" my first pellicle putting a cannon reticle into an nikon box — but that was in 1993.
Ray Winn here. My company, Advanced Semiconductor Products, was the first to produce practicle pellicles that I patented. I won several legal battles, and eventually I licensed MLI, DuPont, Canon, FST (Korea) and five other companies and enjoyed an income flow of many millions of dollars until my patents expired. FST is still an ongoing company listed on the Korean stack exchange of which I am a founder and major stockholder.
Enough said!