Physics

Materials science

Physics Today

Gunter Schwuttke, professor emeritus in Arizona State University’s College of Engineering and Applied Sciences and founding director of Arizona State’s Semiconductor Materials Research Laboratory, died on 4 November 1998 in Scottsdale, Arizona, of complications following surgery.Gunter was born in Breslau, Germany, on 7 August 1922. He began his studies at the Technical University of Breslau, continuing his education in 1947 at the University of Munich. There, he earned his MS in physics in 1949 and his PhD in physics in 1952. Simultaneously, he held a research associate position at the Max Planck Institute of Physics.Gunter’s first research endeavor in industry was with Siemens in Munich. In 1956, he became a consultant for the US Department of Defense (DOD). A year later, he joined the Sylvania Research Laboratories (later GTE Laboratories) in Bayside, New York, where he studied defects in semiconductor crystals with an emphasis on silicon. At that time, defect densities were generally determined by counting etch pits on specially etched wafer surfaces. He extended this technique to a useful application in a crystal orienter for fast and precise alignment and cutting of crystals into wafers.In the early 1960s, x-ray topography made it possible to examine defects in the volume of the wafer. Gunter’s invention of the scanning oscillator technique and his development of precise topographic cameras set the stage for his later work. The stereo x-ray topographs he produced, for example, allowed scientists to view and study the distribution and shape of dislocations tubes throughout the thickness of the wafers.When Gunter joined IBM in Poughkeepsie, New York, in 1963 as a senior physicist, his colleagues already regarded him among the small cadre of the foremost x-ray topography experts as well as a preeminent solid-state physicist. He managed various development groups concerned with semiconductor materials science and processing. This research resulted in the identification of defects generated during semiconductor processing and their elimination to improve the performance of bipolar integrated circuits (ICs) and solar cells. His contributions in this area significantly influenced progress in minimizing defects in large metal-oxide semiconductor memories and complementary metal-oxide semiconductor microprocessors that are used today in computers and other electronic systems. He made other achievements in computer-controlled growth of high-quality silicon crystals and in basic studies of defects generated by radiation damage and by ion implantation. One of us (Huff) warmly remembers and welcomed the occasional visits of Gunter and his colleagues in the late 1960s, during which we discussed methodologies for the identification, characterization, and control of dislocations introduced during bipolar IC processing. Gunter’s work relating his x-ray diagnostic studies with rapid turnaround etchant diagnostic analyses was of critical importance in the early days of the IC industry. Although these concepts were known in principle, their elucidation by Gunter facilitated their rapid use for a generation of personnel working in production facilities. These concepts enabled workers to develop rapid “use tests” based on furnace thermal procedures and subsequent wafer etching to deduce the efficacy of the processes involved in controlling and, eventually, minimizing dislocation generation and macroscopic plastic deformation, which were major yield detractors for bipolar ICs. With the burgeoning of the IC industry during the late 1960s, many publications in the scientific literature could be traced to real issues involved in the production of bipolar ICs. Indeed, the discussions at scientific conferences during these early days in the development of the IC industry were truly heady times.During the 1970s at IBM, Gunter was involved with the improvements of growth techniques to produce better semiconductor materials and processes. Among these improvements were computer-controlled growth of large-diameter Czochralski silicon, growth of monocrystalline silicon ribbon, and growth of silicon carbide crystals. Even before the 1973 energy crisis, he had submitted proposals for solar energy conversion. Gunter also worked on innovative ways to produce low-cost, single-crystal silicon for photovoltaic energy generation. He was a member of the Department of Energy/Jet Propulsion Laboratory advisory group on high-performance, low-cost solar cells; in the early 1980s, this group studied the state-of-the-art poly-silicon properties and devices. These low-cost poly-silicon solar cells are currently produced widely and used as energy converters.In 1982, Gunter retired from IBM and dedicated his efforts to building an academic laboratory, Arizona State’s Semiconductor Materials Research Laboratory. He established a crystal growth laboratory with support from several government agencies. The expert crystal growth system developed by Gunter and his group achieved the growth of the largest gallium arsenide crystals grown at a university at that time. The system was an autonomous artificial intelligence system that not only automated the single-crystal growth process, but also used real-time feedback from the collected crystal growth parameter data. Gunter retired in 1988 from Arizona State and became a professor emeritus of the college of engineering and applied sciences.During his career, Gunter was also active in advising the NSF and the Advanced Research Project Agency. As a DOD consultant, he successfully oversaw research programs that addressed the leading issues of the day in IC manufacturing and related defect studies. He received more than 56 US patents. Gunter also supported scientific exchange programs with postdoctoral fellows from European and South African universities.The most advanced and precise scanning oscillator topographic cameras were manufactured from 1982 to 1992 by Gunter’s instrument corporation, the GHS Corp in Scottsdale, Arizona. By a serendipitous event, the Schwuttke family donated three of these cameras to the SUNY Stony Brook materials science department; the department chair, Michael Dudley, had, as a graduate student, met Gunter at a conference in Paris. He had admired Gunter’s research, but had just become aware that Gunter had manufactured those wonderfully machined and highly crafted precision instruments with the unique capability of oscillation. The cameras will expand research capabilities and will be invaluable tools for students and faculty. The department has designated the section of the laboratory with the x-ray cameras as the Gunter H. Schwuttke Topography Facility.Gunter not only loved science but also had a balanced view of the relationship among science, technology, and manufacturing as it influences the economy and society as a whole. Following his interests, when he could no longer focus his eyes well enough, his daughter Ursula, a distinguished scientist in her own right, sat beside him in the hospital and read to him the latest news in physics and about cosmology. His friends, colleagues, and students will miss him, because they valued his enthusiasm and high work standards. His extensive knowledge and strong character set the standard for his many colleagues to emulate. Gunter Schwuttke PPT|High resolution© 2001 American Institute of Physics.