Peter Trefonas

Last updated
Peter Trefonas
Born1958 (age 6566)
NationalityAmerican
Alma mater University of New Orleans, University of Wisconsin-Madison
AwardsACS Heroes of Chemistry 2014, Perkin Medal 2016
Scientific career
Fields Lithography
Institutions Dow Chemical
Doctoral advisor Robert West
External videos
Nuvola apps kaboodle.svg "Peter Trefonas: Chemistry is key player in lithography process", Micro/Nano Lithography, SPIE
Nuvola apps kaboodle.svg "Dow Chemical - Dow AR Fast Etch Organic Bottom Antireflectant Coatings", ACS

Peter Trefonas (born 1958) is a retired DuPont Fellow (a senior scientist) at DuPont, where he had worked 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. [1] [2]

Contents

Education

Peter Trefonas is a son of Louis Marco Trefonas, also a chemist, and Gail Thames. [3] He was inspired by Star Trek and the writings of Isaac Asimov, and created his own chemistry lab at home. [1] Trefonas attended the University of New Orleans, receiving his Bachelor of Science in chemistry in 1980. [4]

While an undergraduate, Trefonas earned money by writing video games for early personal computers. These included Worm, a clone of the 1976 arcade video game Blockade , and a clone of the arcade game Hustle (1977), which itself was based on Blockcade. Worm was the first of what would become many games in the snake video game genre for home computers. [5] [6] Trefonas also wrote a game based on Dungeons & Dragons . [7]

Trefonas studied at the University of Wisconsin-Madison with Robert West, [4] completing a Ph.D. in inorganic chemistry in late 1984. [1] Trefonas became interested in electronic materials after working with West and chip makers from IBM to create organosilicon bilayer photoresists. [1] His thesis topic was "Synthesis, properties and chemistry of organosilane and organogermane high polymers" (1985). [8]

Career

Trefonas joined MEMC Electronic Materials in late 1984. In 1986, he and others co-founded Aspect Systems Inc., utilizing photolithography technology acquired from MEMC. [1] 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] [1]

Trefonas has published at least 137 journal articles and technical publications. He has received 132 US patents. [12] [13]

Research

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] [2] 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". DuPont Company in 2019 recognized Trefonas with its top recognition, the Lavoisier Medal, for "commercialized electronic chemicals which enabled customers to manufacture integrated circuits with higher density and faster speeds".

Awards and honors

Related Research Articles

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MEMS is the technology of microscopic devices incorporating both electronic and moving parts. MEMS are made up of components between 1 and 100 micrometres in size, and MEMS devices generally range in size from 20 micrometres to a millimetre, although components arranged in arrays can be more than 1000 mm2. They usually consist of a central unit that processes data and several components that interact with the surroundings.

Photolithography is a process used in the manufacturing of integrated circuits. It involves using light to transfer a pattern onto a substrate, typically a silicon wafer.

<span class="mw-page-title-main">Photoresist</span> Light-sensitive material used in making electronics

A photoresist is a light-sensitive material used in several processes, such as photolithography and photoengraving, to form a patterned coating on a surface. This process is crucial in the electronics industry.

<span class="mw-page-title-main">Immersion lithography</span> Photolithography technique where there is a layer of water between a lens and a microchip

Immersion lithography is a technique used in semiconductor manufacturing to enhance the resolution and accuracy of the lithographic process. It involves using a liquid medium, typically water, between the lens and the wafer during exposure. By using a liquid with a higher refractive index than air, immersion lithography allows for smaller features to be created on the wafer.

<span class="mw-page-title-main">Electron-beam lithography</span> Lithographic technique that uses a scanning beam of electrons

Electron-beam lithography is the practice of scanning a focused beam of electrons to draw custom shapes on a surface covered with an electron-sensitive film called a resist (exposing). The electron beam changes the solubility of the resist, enabling selective removal of either the exposed or non-exposed regions of the resist by immersing it in a solvent (developing). The purpose, as with photolithography, is to create very small structures in the resist that can subsequently be transferred to the substrate material, often by etching.

Nanolithography (NL) is a growing field of techniques within nanotechnology dealing with the engineering of nanometer-scale structures on various materials.

<span class="mw-page-title-main">Extreme ultraviolet lithography</span> Lithography using 13.5 nm UV light

Extreme ultraviolet lithography is a technology used in the semiconductor industry for manufacturing integrated circuits (ICs). It is a type of photolithography that uses 13.5 nm extreme ultraviolet (EUV) light from a laser-pulsed tin (Sn) plasma to create intricate patterns on semiconductor substrates.

In semiconductor fabrication, a resist is a thin layer used to transfer a circuit pattern to the semiconductor substrate which it is deposited upon. A resist can be patterned via lithography to form a (sub)micrometer-scale, temporary mask that protects selected areas of the underlying substrate during subsequent processing steps. The material used to prepare said thin layer is typically a viscous solution. Resists are generally proprietary mixtures of a polymer or its precursor and other small molecules that have been specially formulated for a given lithography technology. Resists used during photolithography are called photoresists.

<span class="mw-page-title-main">Stepper</span> Photolithographic Tool

A stepper or wafer stepper is a device used in the manufacture of integrated circuits (ICs). It is an essential part of the process of photolithography, which creates millions of microscopic circuit elements on the surface of silicon wafers out of which chips are made. It is similar in operation to a slide projector or a photographic enlarger. The ICs that are made form the heart of computer processors, memory chips, and many other electronic devices.

<span class="mw-page-title-main">Nanoimprint lithography</span> Method of fabricating nanometer scale patterns using a special stamp

Nanoimprint lithography (NIL) is a method of fabricating nanometer-scale patterns. It is a simple nanolithography process with low cost, high throughput and high resolution. It creates patterns by mechanical deformation of imprint resist and subsequent processes. The imprint resist is typically a monomer or polymer formulation that is cured by heat or UV light during the imprinting. Adhesion between the resist and the template is controlled to allow proper release.

<span class="mw-page-title-main">Optical proximity correction</span> Photolithography enhancement technique

Optical proximity correction (OPC) is a photolithography enhancement technique commonly used to compensate for image errors due to diffraction or process effects. The need for OPC is seen mainly in the making of semiconductor devices and is due to the limitations of light to maintain the edge placement integrity of the original design, after processing, into the etched image on the silicon wafer. These projected images appear with irregularities such as line widths that are narrower or wider than designed, these are amenable to compensation by changing the pattern on the photomask used for imaging. Other distortions such as rounded corners are driven by the resolution of the optical imaging tool and are harder to compensate for. Such distortions, if not corrected for, may significantly alter the electrical properties of what was being fabricated. Optical proximity correction corrects these errors by moving edges or adding extra polygons to the pattern written on the photomask. This may be driven by pre-computed look-up tables based on width and spacing between features or by using compact models to dynamically simulate the final pattern and thereby drive the movement of edges, typically broken into sections, to find the best solution,. The objective is to reproduce the original layout drawn by the designer on the semiconductor wafer as well as possible.

<span class="mw-page-title-main">SU-8 photoresist</span> Epoxy-based polymer

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<span class="mw-page-title-main">Multiple patterning</span> Technique used to increase the number of structures a microchip may contain

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<span class="mw-page-title-main">Diazonaphthoquinone</span> Chemical compound

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References

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  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. Bibcode:1999SPIE.3678..702T. doi:10.1117/12.350257. S2CID   138376696.
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  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. Bibcode:1987SPIE..771..194T. doi:10.1117/12.940326. S2CID   96668019.
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  21. Han, Yu-Kai; Reiser, Arnost (June 11, 1999). "Mechanism of the Trefonas effect (Polyphotolysis) in dissolution inhibition resists". In Conley, Will (ed.). Advances in Resist Technology and Processing XVI. Vol. 3678. p. 360. Bibcode:1999SPIE.3678..360H. doi:10.1117/12.350219. S2CID   95748950 . Retrieved 30 May 2017.{{cite book}}: |journal= ignored (help)
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  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. Bibcode:2013JMM&M..12d3006T. doi:10.1117/1.JMM.12.4.043006. S2CID   123535313 . Retrieved 12 April 2017.