One of the many recent millennial TV programs highlighted the
20 greatest minds of the 20th century. What caught my attention
was the choice of William Shockley as one of those twenty. In an
earlier column, I mentioned that when I came to Bell Labs in
1952, I was taken immediately to meet Bill Shockley who, with
Walter Brattain and John Bardeen, was later awarded the 1956
Nobel Prize for the invention of the transistor. Bardeen, who had
left by the time I arrived, shared a second Nobel Prize for his
work on superconductivity, a remarkable achievement. All three
were fascinating individuals and I recommend the book “Crystal
Fire. The Birth of the Information Age” by Michael Riordan and
Lillian Hoddeson for an equally fascinating account of the lives of
these and other key players who formed the technological world
we live in today.
Brattain was a rather gruff, curmudgeonly character who with
Bardeen first demonstrated amplification of power and voltage
with the so-called “point contact” transistor. This was a device
that simply involved putting a couple of wires in contact with a
piece of an element called germanium. Shockley was the leader
of the group and was chagrined that, in spite of some earlier
efforts of his own to achieve amplification, he had not contributed
to this momentous discovery. He spent the next couple of
months feverishly working on the theory and on others forms the
transistor might take (the point contact transistor was an
unwieldy, rather erratic device). Shockley came up with the idea
for a “built-in” pn junction that forms the basis of today”s
transistors. However, it took a couple more years before his
theoretical ideas were demonstrated in an actual device.
Indeed, the achievement involved as a key ingredient the
purification of germanium to a degree unheard of for any solid
material. It was another interesting character, Bill Pfann, to come
up with a purification process that was pure elegance in its
simplicity. This process is called “zone refining” and is based on a
very simple principle. Say you have a liquid, for example, water
containing an impurity such as blue ink. Now suppose you start
freezing the water. As the water freezes to form ice, the ice will
typically be colorless while the remaining liquid water will
become a deeper blue. Why? The ink is more soluble in the
liquid water than in the solid water. So, as the water freezes the
ink piles up in the remaining liquid. We call the ratio of the
impurity in the solid to that in the liquid the “distribution
coefficient”. For the ink in water this distribution coefficient is
less than 1, i.e., it prefers to remain in the liquid. I myself spent a
fair number of years determining distribution coefficients of
various impurities in germanium and silicon.
Now suppose that we have a long ingot of silicon or germanium
containing impurities such as copper, a particularly bad actor.
Almost every impurity has a distribution coefficient less than 1,
often much less than 1. In zone refining, you take the ingot and
pass it through a heating coil of some sort, melting a little zone of
material within the coil. Moving either the ingot or the coil, this
zone travels through the whole ingot. The impurities concentrate
in the liquid zone and the frozen material left behind is
significantly purer, while the last-to-freeze germanium or silicon is
more impure than it was originally. By repeating this process
several times, the first-to freeze material gets purer and purer and
the copper can be reduced to parts per billion or even lower. To
speed things up, just make your setup with several coils and one
pass through the apparatus gives you multiple purifications. If an
impurity has a distribution coefficient greater than 1, the first to
freeze material is less pure and the last-to-freeze is the pure stuff.
Today, this zone refining technique is used extensively to purify
all kinds of materials, not just germanium and silicon.
With Pfann”s invention and the extremely pure germanium, the
grown-in pn junctions theorized by Shockley became a reality and
soon replaced the point contact transistors. Shockley reportedly
was a very abrasive person in a supervisory role (see also below)
and both Brattain and Bardeen had fallings out with him, Bardeen
leaving Bell Labs for the University of Illinois. A couple years
ago, I talked with two former technicians and a machinist who
had worked closely with Shockley in the 1940s and they were
unanimous in their very favorable evaluation of Shockley. All
three said that he was a very easy person to work with who could
explain his ideas at a technical level that was comfortable for them
and without any appearance of talking down to them. Indeed,
they resented the later criticisms of Shockley as being an
arrogant, egotistical individual. In the few meetings I sat in on
where he was present, I found him to be relatively soft spoken
and confident, but not overbearing.
Brattain, as I mentioned, was a gruff individual. I was in a large
meeting room in New York at an American Physical Society
meeting and Brattain was sitting down front in the audience. As
is common in these large meetings with simultaneous sessions,
people drift in and out of the various venues to hear particular
papers of interest. At one point, Brattain, bothered by the noise
in the back of the room, interrupted the speaker in his loud nasal
tone, “Will you cut out the noise back there!”. Later, my
colleague Bob and one or two other Bell Labs types came to this
same room and tried one door but found it seemed to be locked.
They went to another door and found it too was very hard to
open. Indeed, when Bob pulled extra hard on the door, out
popped Brattain, who had been holding the other end. Bob was
rather surprised to see Brattain but even more surprised when
Brattain punched him in the jaw! Bob never received an apology
from Brattain, though he suggested to management that one
would seem quite in order! Apparently, the Nobel Prize carries
with it certain prerogatives other than prestige and money.
Back to Shockley. He eventually became restless, divorced his
wife, left Bell Labs and eventually moved to California, where he
had grown up in the about-to-become Silicon Valley. There he
set up his own company backed financially by Arnold Beckman,
well known in the scientific community for his Beckman
Instrument Company, maker of many of the analytical instruments
used in chemistry. Shockley hired a first rate crew of individuals
for his company but was disappointed that he was unable to lure
some of the Bell Labs luminaries. He turned out to be a terrible
manager and soon a group of his staff known as the “traitorous
eight” went to Beckman to try to get him to ease Shockley out in
some manner. Beckman refused and the eight left to join
Fairchild. Later, two of them, Robert Noyce and Gordon Moore,
left Fairchild to form Intel and the rest is history.
Shockley ended up going to Stanford University, where he gained
notoriety for his politically incorrect and inflammatory views on
race and intelligence. His view of his own intelligence and the
possibility of transmitting it to following generations led him to a
well publicized donation to a sperm bank to accomplish that
mission. To my knowledge, it isn”t known whether there
ever was a recipient of that sperm with exceptionally brilliant
offspring. I”m writing this on the Saturday before the Sunday
“Saturday Night Live” 25th anniversary retrospective on NBC in
prime time. I no longer have the stamina or desire to stay up late
enough to watch the show but to my mind Shockley”s sperm
inspired one of its funniest episodes. This episode featured
Rodney Dangerfield, finally getting so much respect he just
couldn”t handle it. Specifically, his sperm was so popular that he
was overwhelmed trying to fill the demand. His suggestion that
various movie or sports stars could provide equally desirable
genetic material was rebuffed; they all wanted Rodney”s!
Shockley”s idea of intelligence propagation is apparently still alive
and kicking, in China of all places! There was recently a brief
report in the journal Science about the “Notables Sperm Bank” of
the Chengdu Municipal Family Planning Technical Guidance
Agency. According to the report, sperm donors are grouped into
three categories namely, intellectuals with at least a masters
degree, top businessmen and a third category lumping successful
artists, entertainers and athletes (a strange category!). Most
donors to date are reportedly in the intellectual category but it
wasn”t clear whether this corresponded to the demand or just to
self-appraisals of the donors. All this while the media publicizes
debates in this country over the “Mozart effect” and the influence,
or almost total lack of influence, of the type of parenting on the
fate of one”s offspring. The nature versus nurture debate still
rages!
Allen F. Bortrum
