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Oral History – Adolph Blicher (Continued)
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The low frequency devices at
that time were made on 10 mil (1 mil = .001inch) thick Ge crystals and with
large indium alloyed emitters and collectors. To achieve a high frequency
capability (i.e., 25 MHz), it was necessary to reduce the Ge chip thickness
by 90%, to about 1 mil. The emitter and collector sizes had to be
drastically reduced as well. All this required much better control of the
indium alloying temperatures, which now had to be about 1000 deg,
plus/minus1deg C. The germanium crystals would have to be carefully grown
for proper orientation and reasonable minority carrier lifetimes.
Additional attention had to be paid to lowering the device thermal resistance
to avoid overheating during operation. The electrical measurement
equipment available had to be adapted for high frequency measurements.
Because of the very small dimensions of the three transistor regions, all
electrical connections had to be made by hand under a microscope. The
device design itself was far from straightforward, since at that time much
was unknown about acceptable current densities, crystal doping levels,etc.,
all of which affected the transistor's frequency response. These problems
were successfully addressed, and after a few months a junction type alloyed
high speed switching transistor, RR156 (2N404) was fully developed and made
ready for large scale production.
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Oral History – Adolph Blicher (Continued)
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In early 1955, Radio Receptor
Co. was charging about $25 for one single transistor (about $164 in year
2001 dollars, adjusted for inflation). Among the first customers was MIT's
Lincoln Laboratory, which was involved in the development of fully transistorized
computers. Thanks to this development success, I became personally
well-known in the semiconductor field and many companies offered me very
attractive positions. Among others approaching me was Dr. Louis Malter,
Chief Engineer of the RCA Semiconductor Division, who convinced me to
accept a managerial position with his organization. Bill Harding and Dave
DeWitt made extraordinary efforts to keep me at the Radio Receptor Co., but
to no avail since by then I had become very much aware of the company's
financial problems. In mid-1955 RCA was not yet ready with their
development of the 2N404. Interestingly, one of the reasons for the delay
was that their germanium crystals contained only a small number of
dislocations, which led to an uncontrolled spreading of the indium-doped
emitters and collectors. I.e., the problem was that the crystals were too
good.
I joined RCA in October,
1955. My first job there was not on the 2N404 device project, because
Radio Receptor threatened RCA with a lawsuit for "personnel
piracy," so I managed another big program whose final result was the
development of the 2N301 power transistor. Joel Ollendorf and Israel Kalish
reported to me at that time.
Go
To Blicher Oral History, Page 3
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