EARLY GERMANIUM POWER TRANSISTOR DEVELOPMENT Neville Fletcher
Biographical Note Professor Neville Fletcher has been active in multiple areas of physics for over 50 years. He is currently a Visiting Fellow at the Australian National University, and has served as the Director of the Institute of Physical Sciences at CSIRO (the Australian National research Organization). He also held the position of Professor of Physics at the University of New England in Australia for 20 years. Professor Fletcher is a Fellow of the Australian Academy of Science and of the Australian Academy of Technological Sciences and Engineering. He has published five books and over 170 papers. Professor Fletcher’s contributions to the development of germanium power transistor technology were made in the United States in the 1950s, when he was completing his PhD at Harvard University and working for an early transistor development company which was located in the Boston Massachusetts area – that company was initially known as Transistor Products Inc (TP), and, when purchased by Clevite in the mid 1950s, was known as Clevite Transistor Products (CTP). CTP was a large-scale producer of power transistors (building on Fletcher’s work). CTP continued to expand and later acquired Shockley Transistor Laboratories from Beckman Instruments in the early 1960s. This Oral History will discuss Professor Fletcher’s pioneering work on power transistor technology at TP in the mid 1950s. Fletcher Historic Audio Recordings	Oral History – Neville Fletcher Professor Fletcher, would you briefly describe the events leading to your association with Transistor Products Inc? I came to Harvard in September 1952 on a Frank Knox Memorial Fellowship – the first time it had been awarded to an Australian. I was doing my PhD there on a theoretical treatment of energy levels in semiconductors. My PhD supervisor was Harvey Brooks, and it was he who got me the vacation job at TP. This was in Brighton Massachusetts, a suburb of Boston, and worked there over the summer vacation in 1953. That was when I developed the X-78 power transistor, essentially as an individual effort. I returned fulltime during the summer vacation in 1954, by which time TP, belonged to Clevite and had moved to Waltham Ma (in the Waltham Watch Factory building, now a heritage-listed building). I returned to Australia at the beginning of 1956 after completing my PhD. As you know, the TP X-78 was one of the first germanium power transistors sold commercially. What was your involvement with the X-78? Yes, the X-78 power transistor was my baby. The ones shown in this Oral History represent a very early experimental model that had an output of around 2.5 watts. This was much greater than the 100 milli-watts or so available from other transistors. Go To Fletcher Oral History, Page 2
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