Two Cornell University graduate students have received generous graduate fellowships from the Semiconductor Research Corp. (SRC), the microchip industry's long-term research consortium.

Leonard Harris, a second-year graduate student in chemical engineering, and Christianto Chih-Ching Liu, in his second year of study in electrical and computer engineering, each will receive complete funding for their tuition and fees and a living stipend for up to three years of study. Both are pursuing doctoral degrees at Cornell.

SRC also places students with industry mentors and internships as part of this program. Harris and Liu are among 28 graduate students from 18 universities chosen for the awards this year.

Throughout the 15-year history of the SRC fellows and scholars programs, about 70 percent of supported students have accepted full-time positions with SRC member companies, and another 10 percent have joined university faculties, SRC reported.

"These 28 young men and women are among the brightest students in the world," said Virginia Wiggins, SRC manager of student relations. "The semiconductor community looks forward to their contributions to the industry and the innovations they will impart to all of our lives."

Harris grew up in Cos Cob, Conn., then moved to Highland Ranch, Colo., where he attended Highland Ranch High School. He received his undergraduate degree from the University of Colorado – Boulder.

At Cornell he has been conducting research under Paulette Clancy, Cornell associate professor of chemical engineering, creating computer simulations of the defects that develop in silicon when doping atoms are added by ion implantation. "Doping" is part of the process of making transistors: When atoms of an impurity such as boron are inserted into silicon, they displace some of the silicon atoms in the crystal structure, creating free electrons and "holes" that can conduct electricity. However, the displaced silicon atoms may create defects elsewhere in the crystal that interfere with the working of the transistor.

"In larger structures, this isn't a problem, but as we make devices smaller and smaller, it becomes a problem," Harris explains.

Liu was born in Taiwan, but his family moved to Victoria, British Columbia, where he attended St. Michaels University School. He received his undergraduate degree from the California Institute of Technology.

His research with Sandip Tiwari, Cornell professor of electrical and computer engineering and director of the Cornell Nanofabrication Facility, concerns the investigation of three-dimensional integrated circuits. Currently most circuits consist of an array of transistors and other components on the flat surface of a semiconductor chip. One problem with this design is that the tiny wires connecting components must sometimes follow involved, winding routes to get from one place to another without crossing. A three-dimensional circuit consists of several device layers, allowing both higher circuit density and shorter vertical connections, thereby making the chip much faster and interesting new applications feasible.

Liu is using computer simulations to find out what kinds of circuits will benefit most from three-dimensional integration and is studying the problems raised by the additional heat generated in such close-packed circuits. He is building three-dimensional circuits in the Cornell Nanofabrication Facility.