Richard Sandstrom: The 2024 SPIE Frits Zernike Award for Microlithography
Richard Sandstrom, who retired in 2015, is a co-founder of Cymer Inc., (now a subsidiary of ASML), a semiconductor capital equipment manufacturer of light sources for lithography. Sandstrom was instrumental in developing Cymer’s line of excimer lasers used by lithographic-equipment manufacturers on the most advanced deep ultraviolet (DUV) lithography tools. This technology was not just groundbreaking but a proverbial gamechanger: prior to the availability of these lasers from Cymer, the excimer lasers used in microlithography were highly unreliable. Sandstrom also served as the company’s chief technology officer from 1986-2005, and as its chief technical advisor from 2005-2015, as well as serving on the Cymer Science Advisory Board. He remained an active contributor to research across his career, working in metrology; laser design and control; pulse power; compaction and damage in DUV optical materials; and spectral shaping and control. He has also made significant contributions to the development of the EUV light source, working on the seed laser, beam isolation and delivery, and general metrology for the CO2 drive-laser system.
Sandstrom holds 155 patents related to excimer laser design, EUV light-source design, and metrology. Besides his technical talents, Sandstrom is also recognized as a great mentor and teacher who shared his wisdom and ingenuity openly with his team members and with outside partners, laying solid ground for the continued success of the semiconductor industry. He is highly regarded in the lithography community and has authored or co-authored many papers in SPIE journals and conference proceedings.
“One example of Dr. Sandstrom’s technical leadership is illustrated by the following anecdote,” notes SPIE Fellow and recipient of the 2022 SPIE Frits Zernike Award for Microlithography Harry Levinson. “When he was giving a presentation on the latest generation of excimer lasers from Cymer, he told me that reflections of the shock waves generated by the plasma discharge in the lasers would cause degradation of laser performance at high-repetition rates. He had previously seen indications of this problem on lower-repetition rate lasers, where the reflections were not yet serious enough to degrade performance. Nevertheless, Dr. Sandstrom had studied the phenomenon and was therefore able to anticipate the need to design chambers for high-repetition rate lasers that addressed these reflections. As a consequence, we were able to purchase exposure tools much earlier with higher-repetition rate lasers, leading to significantly improved productivity and lower chip prices. All this resulted from Dr. Sandstrom’s great skills as a laser technologist. His contributions to laser technology and lithography were truly transformative, something I experienced directly. I worked on one of the first development pilot lines using DUV exposure tools with excimer laser light sources, and the laser, which was based on technology preceding that introduced by Dr. Sandstrom, was our number one problem. Given the other many significant challenges that needed to be overcome in order to establish HVM-worthy DUV lithography, that is saying something! All of us who not only worked in semiconductor technology, but used the cell phones, computers, and internet technology enabled by DUV lithography benefited from Dr. Sandstrom’s contributions.”
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Read more about Richard Sandstrom and the SPIE Frits Zernike Award for Microlithography.
