EARLY TRANSISTOR AND DIODE HISTORY

AT BELL LABS

Art Uhlir Jr.

Oral History Art Uhlir Jr.

 

Oral History Art Uhlir Jr.

(Continued)

After you completed your PhD in 1952, what were the circumstances of your accepting a position at Bell Labs?

 

I visited ten companies while doing my research and got offers from nine. At Hughes Aircraft, Harper Q. North showed me gold-bonded germanium diodes being sealed in glass. (This design became widely used in early computers.) Hughes offered me the highest salary ($960 per month for four 10-hour days a week.

 

When in New Jersey to interview at the Celanese Laboratory, I visited my aunt in Peapack. She suggested that I apply also at Bell Labs. I dropped in and was soon called back for a serious interview. They were trying to hire advanced-degree recipients who would be willing to work on odd things like transistors instead of, for example, traveling-wave tubes or basic research.

 

Bell (like most) offered $525 a month. They urged me to accept and attend a short course on transistor theory and technology in the late summer of 1951 at the Princeton Inn (for staff members and some recruits). My thesis advisor told me that one does not get an offer from Bell Labs just any time. So I agreed to join and indicated preference for Development over Research. After the short course I hurried to finish my research, defended my thesis, and sent it off to be published (thereby bypassing the famous UC "margin lady."). Then I packed my belongings in my V-12 Lincoln and drove straight through to NJ to start in December, 1951.

 

 

What was your first assignment?

 

As a way of learning facilities and services, I designed a bomb and tried to diffuse nitrogen into germanium under high pressure. That encountered "thermal conversion" (later attributed to traces of fast-diffusing copper).

The supervisory group that I was placed in was called "High-frequency Transistor Development." Dr. J. Earl Thomas was there on a one-year assignment from MIT Lincoln Lab. He set up a 100 MHz swept transmission test.

Because electron mobility is higher than hole mobility, it was thought that P-type point-contact transistors would give higher frequency response (although lower current gain) than the routine N-type. They did have gain at 100MHz. Don Thomas used them in an FM microphone demonstration.

 

Development proceeded on the assumption that point-contact transistors would be introduced into some Bell System applications where they could promptly offer savings because of small size and long life.

 

Process variables included resistivity and the strength of the electrical "forming" pulse used to enhance and stabilize the characteristics. We photographed collector characteristics with a 60Hz curve tracer, stepping the emitter current manually with a row of push buttons.

 

Go To Uhlir Oral History, Page 3

 

 

 

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