EARLY GERMANIUM

POWER TRANSISTOR DEVELOPMENT

Neville Fletcher

 

Oral History Neville Fletcher (Continued)

 

Can you provide a summary of the papers you published to document your work on the X-78 and other early power transistors?

 

The power transistor development I did at TP was described in two papers I wrote:

 

1. "Some aspects of the design of power transistors" Proc. I.R.E. 43, 551-559 (1955).

 

2. "Self-bias cutoff effect in power transistors" Proc. I.R.E. 43, 1669 (1955).

 

These led to a US Patent "Power Transistor" with me as sole inventor, assigned to Clevite TP in 1955. I am afraid I do not have any detailed reference to this. I also included a substantial section on the design of power transistors in my PhD thesis at Harvard (the first part of the thesis was called "Impurity levels in semiconductors" -- you can probably see it in the Harvard library if you are interested. The second part on transistor design basically repeats material in the Proc IRE publications rather than presenting anything new.) After I returned to Australia at the beginning of 1956, I worked for our national research organisation CSIRO. For two years I continued working on semiconductor devices and wrote 5 more papers, before being transferred to work on cloud physics. After two more years I took a university position. These papers were:

 

3. "Note on the variation of junction transistor current amplification factor with emitter current" Proc. I.R.E. 44, 1475-1476 (1956).

 

Oral History Neville Fletcher (Continued)

 

4. "A junction transistor for kilowatt pulses" Proc. I.R.E. 45, 544 (1957).

 

5. "General semiconductor junction relations" J. Electronics 2, 609-610

(1957).

 

6. "The high current limit for semiconductor devices" Proc. I.R.E. 45,

862-872 (1957)

 

7. "Power transistors" Proc. I.R.E. Aust. 19, 311-315 (1958).

 

From the point of view of history, you would find papers 1 and 4 the most interesting - both have photos of the power transistor element.

 

 

Transistor Products Inc was one of the original Bell Labs licensees of transistor technology. Can you provide any other recollections about this pioneering company?

 

There is, indeed, a great deal I remember about the place (or rather both places, since I worked in both the Boston site and then the Waltham site). You may be interested to know that TP did the whole process from beginning to end, starting with germanium dioxide, reducing it to germanium, zone refining, and crystal growing -

 

 

Go To Fletcher Oral History, Page 4

 

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