In the early 1960s, a fundamental change in the department's policy on teaching electronics was made. Before that time, emphasis was almost entirely on vacuum tube circuits, with little coverage of the physics of the devices. The change was to teach solid-state device circuits. At that time, all engineering students were required to take a three-course sequence of M.E. 202, Phycs. 383, and Met.E. 384, and the device physics were to be covered, in a rather perfunctory manner, in the last course of the sequence. Electronics in the Department of Electrical Engineering was still circuit oriented but with transistors as the active elements rather than vacuum tubes.
In 1965, Chih-Teng Sah received an NSF grant of approximately $54,000 to purchase equipment for a laboratory to accompany lectures specifically on semiconductor materials and solid-state devices. The experiments were heavily biased towards measurements backing up theory and covered such subjects as Hall effect, lifetime measurement, optical properties of germanium, resistivity measurements, oxidation, and diffusion. One experiment was devoted to device fabrication in which the students made alloyed tunnel diodes. The laboratory experiments were developed by Benjamin G. Streetman, Robert Pierret, George E. Anner, Frank Hielscher, and Leo Yao.
The laboratory course was first offered in 1966-67, was equipped to handle a maximum of 30 students per academic year, and as offered to graduate students only. In late 1968, Texas Instruments Incorporated donated some equipment that was essential for making diffused planar devices. The first diffused diodes made in the laboratory were of the mesa type. Photolithography was not used; the diode mesas were masked for etching with wax dots. The course originally was taught jointly by Sah, Streetman, and Anner.
In the years between 1968 and 1972, Anner gradually took over direction of the laboratory and concentrated on obtaining equipment from industry to upgrade photolithographic facilities. At that time, the semiconductor industry was changing its production lines to handle 3-in. rather than 2-in. wafers, so the laboratory actively solicited gifts of mask aligners and related equipment. Industry also donated large quantities of the 2-in. silicon wafers. These were diced into approximately 2 cm x 2 cm pieces so that each student would have a "wafer" for fabricating. Many semiconductor companies made contributions to the new laboratory, including Texas Instruments, Motorola, Delco, and Harris, but National Semiconductor was the kingpin in helping the laboratory convert to device processing.
The first devices made in the laboratory by planar processng were diodes fabricated by Raymond Bregar in 1971-72. No photomasks were available, so he made masters by pasting black circles on ruled mylar sheets, which were then photoreduced onto glass plates that fit mask aligners. This work was done as a special project using the laboratory facilities outside of scheduled class sessions, a mechanism that became widely used later. Bregar was the first undergraduate to go from the course directly into industry when he joined National Semiconductor in Danbury, Connecticut. He was followed by many graduates from the course, who strengthened the link between equipment and materials donated by industry to the laboratory.
Centennial History of the Department of ECE
University of Illinois at Urbana-Champaign
Electrical and Computer Engineering Department