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including The Conductor, a special section of the Spectrum printed 4 times a year

New Tech technologies licensed

By Susan Trulove

Spectrum Volume 18 Issue 19 - February 1, 1996

Two new technologies from Virginia Tech have been licensed for further development by Triad Investors Corp., a technology-development organization with offices in the Virginia Tech Corporate Research Center. The technologies are a robotic wrist and an improvement to the semiconductor production process.

Charles Reinholtz, professor of mechanical engineering, has developed a unique design for a robotic wrist. Called the "carpal wrist," it has an open cavity through the center so that cables, tubes, and electric connections can be placed safely inside the wrist, to convey paint if the wrist is used in spray painting, for example, or wire and shielding gas for welding applications.

Just as the human wrist has eight carpal bones, the robotic carpal wrist has eight primary links or mechanical connections with joints at each end, Reinholtz explains. The carpal wrist has a higher payload (weight-bearing) capacity, and is free from "singularities"-voids in the workspace where many other wrists are unable to reach. This allows the wrist to produce a full-range of desired motions.

Drawings for the components have already gone to the shop and Reinholtz expects to begin building the prototype soon. He is being assisted by Tony Ganino, master's degree student from Pasadena, Calif., and Steve Canfield, Ph.D. student from Newport. Triad is providing $65,000 over one year for the project development.

Guo-Quan Lu, assistant professor of materials science and engineering, will receive $80,000 from Triad Investors to further develop a material-processing technology for coating ceramic films on metal substrates; the coated substrates will be used as electrostatic chucks (ESC's) for holding semiconductor wafers in place during production of integrated-circuit chips.

With the rising demand for semiconductor devices, the market for semiconductor-processing equipment has grown rapidly in recent years; it now exceeds $12 billion annually world-wide. In most of the current wafer-processing equipment, mechanical chucks are used to hold the wafers, resulting in wafer bowing, non-uniform temperature distribution, contamination, and waste. Thus, electrostatic chucks (ESC's) are being introduced to replace the mechanical chucks. ESC's are electromechanical plates that hold the wafers in place using static electricity.

Lu has developed a low-cost processing technology for laying down superior ceramic films on metal substrates that can serve as ESC's for both low- and high-temperature processes. The ceramic films have high electrical resistivity at high temperatures up to 500 degrees Celsius, high toughness and thermal shock resistance, and excellent wafer-holding properties.

A team of researchers has been helping Lu on the project. Virginia Tech doctoral students JaeCheol Bang of Seoul, South Korea, and Jess Calata of Quezon City, the Philippines, and Ave Amith, adjunct professor in the MSE department, will help Lu develop prototype ceramic-coated chucks. Graduate students Thomas Kuhr of Chesapeake and undergraduate Allen Matthys of Dale City have made significant contributions to the project.

The properties were licensed from Virginia Tech Intellectual Properties Inc. Triad's investment funds prototype development in Virginia Tech's labs. Triad will use the prototypes to market the technologies. "We welcome the opportunity to look at other technologies that are generated within the university," said Stefan Strein of Triad.