From The Lab to The Fab: Transistors to Integrated Circuits

Transistor action was experimentally observed by John Bardeen and Walter Brattain in n‐type polycrystalline germanium on December 16, 1947 (and subsequently polycrystalline silicon) as a result of the judicious placement of gold‐plated probe tips in nearby single crystal grains of the polycrystalline material (i.e., the point‐contact semiconductor amplifier, often referred to as the point‐contact transistor).The device configuration exploited the inversion layer as the channel through which most of the emitted (minority) carriers were transported from the emitter to the collector. The point‐contact transistor was manufactured for ten years starting in 1951 by the Western Electric Division of AT&T. The a priori tuning of the point‐contact transistor parameters, however, was not simple inasmuch as the device was dependent on the detailed surface structure and, therefore, very sensitive to humidity and temperature as well as exhibiting high noise levels. Accordingly, the devices differed significantly in their characteristics and electrical instabilities leading to “burnout” were not uncommon. With the implementation of crystalline semiconductor materials in the early 1950s, however, p‐n junction (bulk) transistors began replacing the point‐contact transistor, silicon began replacing germanium and the transfer of transistor technology from the lab to the lab accelerated. We shall review the historical route by which single crystalline materials were developed and the accompanying methodologies of transistor fabrication, leading to the onset of the Integrated Circuit (IC) era. Finally, highlights of the early years of the IC era will be reviewed from the 256 bit through the 4M DRAM. Elements of IC scaling and the role of Moore’s Law in setting the parameters by which the IC industry’s growth was monitored will be discussed. © 2003 American Institute of Physics