A Transistor Museum Interview with Wilf Corrigan Personal Reflections on Motorola’s Pioneering 1960s Silicon Transistor Development Program
Oral History – Wilf Corrigan (Continued) What were the technical aspects of the early Motorola silicon transistors? Fairchild was first out with planar silicon, which rapidly followed the mesa silicon. Their devices 2N1613, NPN, and 2N1132 PNP, rapidly became the standards. Motorola followed a strategy of being all epitaxial, both silicon and germanium. In 1962 I was given the Silicon Transistor division Job (at Motorola). We introduced the 2N2219 and 2N2218, which were epitaxial versions of the Fairchild 2N1613.  These devices rapidly supplanted the Fairchild devices, as volume leaders. Later that year we brought out the PNP versions. Fairchild only had a Mesa PNP product.  This was accomplished using an “annular ring”. By mid 60’s Moto had passed both Fairchild and TI in silicon transistors. The 2N2218 and 2N2219 were beta sorts (Gain) - 2218 was low beta, 2219 high beta. These devices were in the TO5 package (hermetic).  As we didn’t have probe sorting at that time, they were sorted into three ranges by Lehner’s automated test machines.  The low range 2N2217 was regarded as junk. However the testers sorted to specific customer specs also. The 2N2221 and 2N2222 were the same specifications as the 2218 and 2219 in the smaller TO18 package. These devices used the STAR geometry   the PNP equivalents were the 2N2904, 2905 and in TO18 2N2906 and 2907.  There were “A” versions of all these 2N numbers, A’s were a tighter sort, and were priced higher.	Oral History – Wilf Corrigan (Continued) The early 1960s were a time of fundamental change and technological innovation in the semiconductor industry.  A premier forum for major new product introductions was the annual IRE Convention, which attracted hundreds of companies to display their latest leading edge products, and was attended by thousands of industry personnel.  Shown above is a section of the 1962 IRE Convention Record, as documented in the Proceedings of the IRE. This Motorola Booth reference is the first formal commercial announcement of the new “silicon epitaxial star planar transistors” – March 1962 marks a key date in the modern history of transistor technology, and coincides with the pioneering work done at Motorola by Wilf Corrigan and others in the Silicon Transistor Organization.   ______________ Go To Corrigan Oral History, Page 8
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