Peter Trefonas

Peter Trefonas
Born 1958 (age 60–61)
Residence Medway, Massachusetts, U.S.[1]
Nationality United States
Alma mater University of New Orleans, University of Wisconsin-Madison
Awards ACS Heroes of Chemistry 2014, Perkin Medal 2016
Scientific career
Fields Lithography
Institutions Dow Chemical
Doctoral advisor Robert West

Peter Trefonas (born 1958) is a DuPont Fellow (a senior scientist) at DuPont, where he works on the development of electronic materials. He is known for innovations in the chemistry of photolithography, particularly the development of anti-reflective coatings and polymer photoresists that are used to create circuitry for computer chips. This work has supported the patterning of smaller features during the lithographic process, increasing miniaturization and microprocessor speed.[2][3]


Peter Trefonas is a son of Louis Marco Trefonas, also a chemist, and Gail Thames.[4] He was inspired by Star Trek and the writings of Isaac Asimov, and created his own chemistry lab at home.[2] Trefonas attended the University of New Orleans, receiving his Bachelor of Science in chemistry in 1980.[1]

While an undergraduate, Trefonas earned money by writing early computer games for personal computers. These included Worm, the first version of Snake to be written for a personal computer, and a clone of Hustle. Both were based on the Blockade arcade game.[5][6] Trefonas also wrote a game based on Dungeons and Dragons.[7]

Trefonas studied at the University of Wisconsin-Madison with Robert West,[1] completing a Ph.D. in inorganic chemistry in late 1984.[2] Trefonas became interested in electronic materials after working with West and chip makers from IBM to create organosilicon bilayer photoresists.[2] His thesis topic was Synthesis, properties and chemistry of organosilane and organogermane high polymers (1985).[8]


Trefonas joined MEMC Electronic Materials in late 1984. In 1986, he and others co-founded Aspect Systems Inc., utilizing photolithography technology acquired from MEMC.[2] Trefonas worked at Aspect from 1986-1989. Then, through a succession of company acquisitions, he moved to Shipley Company (1990-2000), Rohm and Haas (1997-2008), to The Dow Chemical Company (2008-2019), and finally to DuPont (2019-current).[9][10][11][2]

Trefonas has published at least 115 journal articles and technical publications. He has received 103 American patents, and has more than 25 active patent applications pending.[12][13]


Throughout his career, Trefonas has focused on materials science and the chemistry of photolithography. By understanding the chemistry of photoresists used in lithography, he has been able to develop anti-reflective coatings and polymer photoresists that support finely-tuned etching used in the production of integrated circuits. These materials and techniques make it possible to fit more circuits into a given area.[13][3] Over time, lithographic technologies have developed to allow lithography to use smaller wavelengths of light. Trefonas has helped to overcome a number of apparent limits to the sizes that are achievable, developing photoresists that are responsive to 436-nm and 365-nm ultraviolet light, and as small as 193 nm deep.[14][15]

In 1989, Trefonas and others at Aspect Systems Inc. reported on extensive studies of polyfunctional photosensitive groups in positive photoresists. They studied diazonaphthoquinone (DNQ), a chemical compound used for dissolution inhibition of novolak resin in photomask creation. They mathematically modeled effects, predicted possible optimizations, and experimentally verified their predictions. They found that chemically bonding together three of the molecules of DNQ to create a new molecule containing three dissolution inhibitors in a single molecule, led to a better feature contrast, with better resolution and miniaturization.[16] These modified DNQs became known as "polyfunctional photoactive components" (PACs). This approach, which they termed polyphotolysis,[17][18] [19] has also been referred to as the "Trefonas Effect."[14][20] The technology of trifunctional diazonaphthoquinone PACs has become the industry standard in positive photoresists.[20] Their mechanism has been elucidated and relates to a cooperative behavior of each of the three DNQ units in the new trifunctional dissolution inhibitor molecule. Phenolic strings from the acceptor groups of PACs that are severed from their anchors may reconnect to living strings, replacing two shorter polarized strings with one longer polarized string.[21]

Trefonas has also been a leader in the development of fast etch organic Bottom Antireflective Coating (BARC)[22] BARC technology minimizes the reflection of light from the substrate when imaging the photoresist. Light that is used to form the latent image in the photoresist film can reflect back from the substrate and compromise feature contrast and profile shape. Controlling interference from reflected light results in the formation of a sharper pattern with less variability and a larger process window.[23]

In 2014, Trefonas and others at Dow were named Heroes of Chemistry by the American Chemical Society, for the development of Fast Etch Organic Bottom Antireflective Coatings (BARCs).[22] In 2016, Trefonas was recognized with The SCI Perkin Medal for outstanding contributions to industrial chemistry. In 2018, Trefonas was named as a Fellow of the SPIE for "achievements in design for manufacturing & compact modeling." Peter Trefonas was elected to the National Academy of Engineering in 2018 for the "invention of photoresist materials and microlithography methods underpinning multiple generations of microelectronics".

Awards and honors


  1. ^ a b c d "SCI Perkin Medal". Science History Institute. 2016-05-31. Retrieved 24 March 2018.
  2. ^ a b c d e f Reisch, Marc S. (September 12, 2016). "C&EN talks with Peter Trefonas, photolithography innovator". Chemical & Engineering News. 94 (36): 27–28. Note Correction, published in October: 'Sept. 12, page 27: A feature story profiling Dow Chemical's Peter Trefonas incorrectly identified when Dow acquired Rohm and Haas. The acquisition occurred in 2009, not 2001.'
  3. ^ a b "Perkin Medal". SCI. Retrieved 12 April 2017.
  4. ^ "Dr. Louis Marco Trefonas". Orlando Sentinel. Retrieved 20 April 2017.
  5. ^ Gerard Goggin (2010), Global Mobile Media, Taylor & Francis, p. 101, ISBN 978-0-415-46917-3, retrieved 2011-04-07
  6. ^ "Retro Corner: 'Snake'". Digital Spy. 2011-04-09. Retrieved 12 April 2017.
  7. ^ "CLOAD Magazine" (PDF). Gametronik. May 1980.
  8. ^ Trefonas, Peter (1985). Synthesis, properties and chemistry of organosilane and organogermane high polymers. UW Madison. [publisher not identified]. Retrieved 11 April 2017.
  9. ^ "Alumni: Peter Trefonas". University of New Orleans. Retrieved 12 April 2017.
  10. ^ Rocha, Euan; Daily, Matt (July 10, 2008). "Dow Chemical to buy Rohm and Haas for $15.3 bln". Reuters. Retrieved 12 April 2017.
  11. ^ Campoy, Ana (April 2, 2009). "Dow Chemical Closes Rohm & Haas Deal". The Wall Street Journal. Retrieved 20 April 2017.
  12. ^ a b SPIE (22 August 2016). "Peter Trefonas: Chemistry is key player in lithography process". SPIE Newsroom. doi:10.1117/2.201608.02.
  13. ^ a b c "SCI Awards Perkin Medal To Dow's Peter Trefonas By Chemical Processing Staff". Chemical Processing. May 10, 2016. Retrieved 12 April 2017.
  14. ^ a b "Peter Trefonas, 2016 Perkin Medal Recipient, Credits Chemistry for Enabling the Information Age". DOW Electronic Materials. Retrieved September 26, 2016.
  15. ^ Trefonas III, Peter; Blacksmith, Robert F.; Szmanda, Charles R.; Kavanagh, Robert J.; Adams, Timothy G. (June 11, 1999). "Organic antireflective coatings for 193-nm lithography". Proc. SPIE 3678, Advances in Resist Technology and Processing. Advances in Resist Technology and Processing XVI. XVI (702): 702. doi:10.1117/12.350257.
  16. ^ US 5128230 A, Michael K. Templeton; Anthony Zampini & Peter Trefonas III et al., "Quinone diazide containing photoresist composition utilizing mixed solvent of ethyl lactate, anisole and amyl acetate", published July 7, 1992 
  17. ^ Levy, R. A. (1989). Microelectronic materials and processes : [proceedings of the NATO Advanced Study Institute on Microelectronic Materials and Processes, Il Ciocco, Castelvecchio Pascoli, Italy, June 30-July 11, 1986]. Dordrecht: Kluwer Academic. pp. 333–334. ISBN 9780792301479. Retrieved 12 April 2017.
  18. ^ Suzuki, Kazuaki; Smith, Bruce W. (2007). Microlithography science and technology (2nd ed.). Boca Raton: CRC Press. p. 130. ISBN 9780824790240. Retrieved 13 April 2017.
  19. ^ Trefonas III, P.; Daniels, B. K. (August 25, 1987). "New Principle for Image Enhancement in Single Layer Positive Photoresists". SPIE Advances in Resist Technology and Processing. IV (771): 194–210.
  20. ^ a b Han, Yu-Kai; Yan, Zhenglin; Reiser, Arnost (December 1999). "Mechanism of the Trefonas Effect (Polyphotolysis) in Novolak−Diazonaphthoquinone Resists". Macromolecules. 32 (25): 8421–8426. doi:10.1021/ma990686j.
  21. ^ Han, Yu-Kai; Reiser, Arnost (June 11, 1999). "Mechanism of the Trefonas effect (polyphotolysis) in dissolution inhibition resists". SPIE Proceedings: Advances in Resist Technology and Processing XVI. Advances in Resist Technology and Processing XVI. 3678: 360. doi:10.1117/12.350219. Retrieved 30 May 2017.
  22. ^ a b c "2014 Heroes of Chemistry". ACS Chemistry for Life. Retrieved 12 April 2017.
  23. ^ Cameron, Jim (November 18, 2015). "Litho University℠: DBARC Technology 101". Dow Electronic Materials. Retrieved 30 May 2017.
  24. ^ "National Academy of Engineering Elects 83 Members and 16 Foreign Members". NAE Website. Retrieved 2018-02-17.
  25. ^ "2017 SPIE Fellows". Retrieved 2018-02-17.
  26. ^ "Dow Electronic Materials and Texas A&M University Win SPIE's 2013 Willson Award for Best Technical Paper". Dow Electronic Materials News. Retrieved March 20, 2014.
  27. ^ Trefonas, Peter; Thackeray, James W.; Sun, Guorong; Cho, Sangho; Clark, Corrie; Verkhoturov, Stanislav V.; Eller, Michael J.; Li, Ang; Pavia-Sanders, Adriana; Schweikert, Emile A.; Wooley, Karen L. (16 December 2013). "Bottom-up/top-down, high-resolution, high-throughput lithography using vertically assembled block bottle brush polymers". Journal of Micro/Nanolithography, MEMS, and MOEMS. 12 (4): 043006. doi:10.1117/1.JMM.12.4.043006. Retrieved 12 April 2017.

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