Semiconductor History

The first transistors developed by Bell Labs were Point Contact versions, created using an extension of diode manufacturing, which was a further refinement of diodes in 'cat's whisker' radios.  This 2N110 is a Western Electric Point Contact transistor from the 1950s. Point Contact transistors were difficult to manufacture and were superseded by grown junction, then alloy junction versions.  Western Electric continued to manufacture them longer than any other company since they were designed into telephone Central Office systems on a large scale. In the background is a page from Walter Brattain's logbook describing the first point contact transistor. A little bit more information in this previous post :  https://spingalhistory.blogspot.com/2017/02/bell-labs-point-contact-transistor.html  

Western Electric Point Contact Transistor Developed by John Bardeen and Walter Brattain at Bell Laboratories, the first transistor was a seminal moment in history. In the main because it was part of the American Telephone and Telegraph Company, Bell Labs was very open in its sharing of the invention, including its methods of manufacture. Being a monopoly, AT&T was very aware of anti-trust pressures. Bell Labs shared its knowledge with 40 licensees in 1951. From demonstrations in 1948, a number of companies had already seen the potential impact of the transistor and had started their own developments. Those with most to lose, the vacuum tube manufacturers, were quickest off the mark including Raytheon, the biggest supplier of mini vacuum tubes. Point Contact transistors were difficult to manufacture and their reliability was poor. Superior transistor manufacturing methods developed including grown junction and alloy junction. Western Electric at its Allentown PA facility contin...