Semiconductor History

The Siemens brothers were industrialists from the mid 19th century, Siemens & Halske being one arm of several. At some point post WWII, the remaining entities merged into Siemens AG.  The patent shown in the image was filed in Germany in 1956 and in the US one year later. At the time the dominant transistor manufacturing technology was alloy junction. The method described in the patent was an early adoption of diffusion for creating the process layers with masking and etching, similar to the mesa transistor structure which emerged around the same time in the US. Depositing metal instead of attaching gold wires, embedding the diffused layers and a protective layer on the surface would be the basis of the planar process subsequently invented by Fairchild.  Siemens first established transistor manufacturing in their electron tube facility in Munich in 1952.

Telefunken in Germany had been producing semiconductor rectifiers for a number of years before they developed transistors for mass production. Launched in 1953, the OC601 and OC602 were alloy junction germanium pnp transistors. Telefunken also developed S (special) versions which had attached copper heatsinks. These work but are low gain.  hfe=26, Vf=97mV. hfe=18, Vf=100mV.

Small changes having a big impact. Introduced in 1960, Philco had by then improved their etching process to create the thin base layer of their germanium alloy junction transistors. They then replaced the indium electrodes making the emitter and collector junctions with cadmium, giving better thermal dissipation. Due to its speed and thermal performance, it became widely used in computers of the time. These were manufactured by Philco (later Philco-Ford) at their factory in Spring City, PA. One AI processor chip now has more transistors than the first 25 years at least of the semiconductor industry!  It works, hfe (gain) is 96, Vf=273mV (so germanium).

Inside the Boss HA-5 headphone guitar amplifier from 1983. It had built in chorus and delay effects. The chorus came from the Boss CE-3 guitar pedal and used the Matsushita/Panasonic MN3207 Bucket Brigade Device and the accompanying MN3102 clock generator chip. The NEC IC on the left is an analog compander device i.e. it compresses and expands a signal. The Bucket Brigade concept, developed by Philips Research Labs, had a series of on-chip capacitors between which charges moved in sequence, based on an external clock cycle. It was also a precursor to the Charge Coupled Device (CCD) that was developed as the first significant semiconductor image sensor.

Raytheon sold its semiconductor operations in Mountain View CA to Fairchild in 1997. Fairchild was then a re-incarnation, not the original Silicon Valley pioneer. Raytheon had originally purchased Mountain View's Rheem in 1959, two years after it had spun out from Fairchild, led by Ed Baldwin who had moved from Hughes Semiconductors to Fairchild. Raytheon was expanding its transistor manufacturing into California through the acquisition. Like many companies, Raytheon expanded into bipolar and MOS circuits. Cyrus Madavi, who led Burr-Brown through to acquisition by TI came from Raytheon. I worked for Hughes, Raytheon and Burr-Brown.

In 1962 Mullard (Philips) and GEC pooled their resources and facilities to create Associated Semiconductor Manufacturers. Mullard owned 2/3 of the combined business. GEC pulled out in 1969. This is a small signal diode CV7364/AAZ12, germanium, Vf=258mV.

Inside two RCA alloy junction transistors from the 1950s. The smaller one is a 40V/50mA pnp and the larger is a 40V/250mA, hence the thicker wires for lower loss at the higher current. The metal connecting the base is also larger to provide better heat dissipation. The base is a thin cut slice of pure n-type germanium which has indium pellets alloyed to each side creating the pnp junctions.  There was viscous white goo inside the cases which was difficult to remove.

TI introduced the 900 series silicon transistors in 1954 but they continued to produce germanium transistors. The germanium grown junction 2N172 was introduced in 1956, adding to their transistor portfolio for radios. TI and IDEA introduced the first all transistor radio (Regency TR-1) in 1954. TI started transistor development in Lemmon Avenue in Dallas and in 1958 moved to a 300 acre site at North Central Expressway. The Semiconductor building was the first building on the campus. The building is still there (although modified) and is now a Raytheon building following the acquisition of TI's defense business in 1997.  Working transistor, hfe=23, Vf=183mV, fairly low gain.

Germanium transistors from 1955. In the early 1950s Sylvania established transistor and diode manufacturing at their tube (valve) facility in Emporium PA. Manufacturing was transferred to the Electronics Divsions in Woburn Mass. In 1957 it was divided into two new organizations, the Semiconductor Division and Special Tube Operations. Skyworks, one of the current world leaders in RF components for smartphones has its roots in Sylvania, Woburn.