The invention of the transistor can be traced back to 1929, when engineer Lilienfeld had patented a transistor. However, due to the technical level at the time, the materials used to make such devices were not pure enough, making it impossible to manufacture such transistors.
Because the effect of vacuum tubes in processing high-frequency signals is not ideal, people try to improve the mineral whisker detector used in mineral radios. In this kind of detector, there is a metal wire (as thin as a hair and can form a detection contact) in contact with the surface of the ore (semiconductor). It can not only allow the signal current to flow in one direction, but also prevent the signal current from flowing in the opposite direction. direction flow. On the eve of the outbreak of World War II, Bell Laboratories was looking for a detection material with better performance than the early galena crystal. It was discovered that the performance of germanium crystal mixed with a very small amount of impurities was not only better than that of ore crystal, but also Better than tube rectifiers in some ways.
During the Second World War, many laboratories also made many achievements in the manufacturing and theoretical research of silicon and germanium materials, which laid the foundation for the invention of the transistor.
In order to overcome the limitations of electron tubes, after the end of World War II, Bell Labs stepped up basic research on solid electronic devices. Shockley and others decided to focus on research on semiconductor materials such as silicon and germanium, and explore the possibility of using semiconductor materials to make amplifier devices.
Bratton and others also came up with effective ways to achieve this amplification effect. They input a weak signal between the emitter and the base, and it is amplified into a strong signal at the output between the collector and the base. In modern electronic products, the amplification effect of the above-mentioned transistor is widely used.
The magnification of the solid-state device originally made by Bardeen and Bratton was about 50. Soon after, they used two very close (0.05 mm apart) whisker contacts to replace the gold foil contacts and created a "point contact transistor". In December 1947, the world's earliest practical semiconductor device finally came out. In the first test, it could amplify audio signals 100 times. Its appearance was shorter than a matchstick, but thicker.
When naming this device, Bratton thought of its resistance conversion characteristics, that is, it works by transferring current from a "low resistance input" to a "high resistance output". So it was named trans-resister (conversion resistor), which was later abbreviated to transister. The Chinese translation is transistor.
Due to the complex manufacturing process of point contact transistors, many products have failed. It also has shortcomings such as high noise, difficulty in controlling when the power is high, and narrow application range. In order to overcome these shortcomings, Shockley proposed a bold idea of ??using a "rectifier junction" to replace the metal semiconductor contacts. The semiconductor research team has proposed the working principle of this semiconductor device.
In 1950, the first "junction transistor" came out, and its performance was exactly as Shockley originally envisioned. Most of today's transistors are still junction transistors.
In 1956, Shockley, Bardeen, and Brattain simultaneously won the Nobel Prize in Physics for their invention of the transistor.