The crucial component of an electronic device is a controllable valve

that lets a weak signal control a much larger flow much as a faucet
controls the flow of water. At one time the controllable valve used in
electronic circuits was the vacuum tube. The vacuum tube worked but
it was bulky and used a lot of electrical power that ended up as heat
which shortened the life of the tube itself. The transistor was a much
more elegant solution to the needs of electronics. The transistor is
small and uses much, much less power than the vacuum tube.
Because it uses so little power there is little heat to dissipate and the
transistor does not fail as quickly as does a vacuum tube.

The transistor was successfully demonstrated on December 23, 1947

at Bell Laboratories in Murray Hill, New Jersey. Bell Labs is the
research arm of American Telephone and Telegraph (AT&T). The
three individuals credited with the invention of the transistor were
William Shockley, John Bardeen and Walter Brattain. William
Shockley played a quite different role in the invention than the other
two. Shockley had been working on the theory of such a device for
more than ten years. While he could work out the theory successfully
but after eight years of trying he could not build a working model.
Bardeen and Brattain were called in to handle the engineering and
development, which they did in the relatively short time of two years,
to the consternation of Shockley. Shockley, as their supervisor,
shared in the glory. What Bardeen and Brattain had created was the
"point-contact" transistor. Shockley subsequently designed a new
type of transistor called the "bipolar" transistor which was superior to
the point- contact type and replaced it. Thus the transistor was, in
large part, Shockley's creation.

William Shockley was raised in Palo Alto, the son of a mining

engineer and his Stanford-educated wife. He did his undergraduate
work at the California Institute of Technology (Cal Tech) in Pasadena
and went on for his Ph.D. in physics at M.I.T. When he completed his
doctorate, specializing in quantum physics, he went to work for Bell
Labs.

Shockley had started working in 1936 on the solid state physics

theory that was the basis for the transistor. There was precedence for
this type of device. The early radios had signal detectors which
consisted of a fine wire, called a cat's whisker, impinging upon a
galena (lead sulfide) crystal. The radio user had to move the cat's
whisker around upon the germanium crystal to find a suitable point of
contact where a radio signal could be picked up. These early radios
worked but only imperfectly. Nevertheless the principle upon which
the crystal detector worked was the basis for the "point-contact"
transistor. Bardeen and Brattain used germanium instead of galena in
that first transistor. They also used the equivalent of cat's whiskers,
but two rather than one. Shockley's design, the bipolar transistor,
eliminated the delicate, troublesome point contacts. Later transistors
were made from silicon, a much more common element and one that
was protected from corrosion by a thin layer of silicon dioxide.
Texas Instruments of Dallas, Texas first started commercial
production of junction transistors for portable radios in 1954. The
Sony Company of Japan soon acquired the right to produce
transistors and came to dominate the market. In the 1960's Sony
began to manufacture television sets using transistors rather than
vacuum tubes. Soon afterwards vacuum tube technology became
obsolete.

In 1956 Shockley returned to Palo Alto to found his own company. He

brought talented engineers and scientists to his company but he was
a very difficult person to work with and seemed to have bazaar notion
of how to manage an enterprise. For one thing, he insisted upon
posting of the salaries of all the employees. This produced
unnecessary friction among the employees. Ultimately the top staff
joined together in leaving the company. They wanted to continue to
work together in another company and Steven Fairchild of Fairchild
Camera was induced to create Fairchild Semiconductor for the group.

https://www.sjsu.edu/faculty/watkins/transistor

History of Transistor
Since the mid-20th century, the transistor has played a vital role in
the innovation of modern technologies. While the transistor was
primarily employed for amplification in an analog circuit and
switching in a digital circuit, intensive research and development has
continued to open doors for new transistor-based applications.
Thanks to very large-scale integration (VLSI) technology, billions of
transistors can be placed on a single chip for use in
computing applications. The M1 Ultra SoC from Apple, for example, is
made up of 114 billion transistors—the largest number of transistors
ever on a chip.
Dating back to the early 20th century, engineers have used transistors
to amplify electrical signals. The first instance of this use case came
from British electrical engineer John Ambrose Fleming when he
invented the vacuum tube. However, vacuum tubes faced many
drawbacks that would only be solved by the invention of the modern
transistor.

The Point-contact Transistor: A Star is Born

The first recognized transistor was developed by Bell Labs researchers
Walter Brattain and John Bardeen in 1947. After several efforts to
make an amplifier with silicon, Bardeen and Brattain resolved to use a
slab of germanium and two gold foils to make a point-contact
transistor. They observed more holes for electrons when a gold foil
was placed in close proximity to the surface of germanium. The Bell
researchers also noticed that the current passing through the contact
was further boosted and amplified at the other contact of the gold
foil.
This discovery marked the dawn of a new transistor-led era in the
electronics industry. In 1952, the point-contact transistor became
widely accessible in commercial use and was instrumental in
manufacturing telephone systems.

From Germanium to Silicon

In an attempt to improve the transistor design of Bardeen and
Brattain, William Shockley fabricated the junction transistor from
germanium in 1951. Shockley's junction transistor was simply a
sandwich of semiconductors with three layers. The outer layers
contained many more electrons than the middle layer. Shockley
explained that this design allowed current to flow through the
sandwiched semiconductors to make an amplifier.
While the point-contact and junction transistor relied on germanium,
researchers soon thereafter noted that the component broke down at
180°F. This is because germanium introduces too many free electrons
in transistors when it is heated to a very high temperature, breaking
the whole component down.
This drawback inspired Gordon Teal, a researcher at Texas
Instruments, to invent the first-ever silicon transistor in 1954. Teal's
silicon transistor had the same working principle as the germanium
transistor, but it could withstand high temperatures. The silicon
transistor was an n-p-n structure and was fabricated via a grown-
junction process.
MOSFETs Make the Modern Era
The development of the silicon transistor led to the invention of more
silicon-based transistors, such as metal-oxide-semiconductor
transistors (MOSFETs). The first MOSFET was fabricated by Bell Labs
researcher John Atalla in 1960. The design was based on Shockley’s
field-effect theories.
Unlike the sandwich junction transistor, a MOSFET has a channel of
either n- or p-type semiconductors. An electric field, which acts like a
faucet to turn on and off the current in the transistor, is generated
when voltage is applied to the channel. To achieve a high switching
speed, manufacturers often adopt an epitaxial decomposition
process during fabrication. This process also yields high breakdown
voltages in transistors.

The Next Generation of Nano-scale Transistors

According to Moore’s law, the number of transistors per unit area in

an integrated circuit (IC) doubles every couple of years. This push for
miniaturization creates complexity for the next generation of
transistors—from microelectronics to nanoelectronics. Today,
researchers are aiming to downsize transistors to the nanometer
scale.
With silicon-based transistors now operating in nanometer sizes,
engineers face the design and fabrication challenges associated with
dwindling physical space. For instance, a 100nm-sized MOSFET might
experience short-channel effects that adversely affect the transistor’s
performance. What’s more, nano-sized silicon transistors experience
high channel leakage currents.
To address these limitations, researchers are now looking into
nanotechnology materials to fabricate transistors. Recently,
researchers have explored 2D ultrathin monolayer materials such as
molybdenum disulfide to create more reliable transistors than
miniaturized silicon transistors. Carbon nanotube and graphene are
also promising materials to replace silicon in transistors.
Additionally, a team of researchers at TU Dresden recently reported
the "world's first" efficient organic bipolar junction transistor. The
team used highly-ordered, thin organic layers based on crystalline
films of n- and p-type doped rubrene to develop organic bipolar
transistors. These transistors may increase performance for data
processing and transmission.

https://www.allaboutcircuits.com/