A Family of Semiconductor Devices for Microelectronic Applications

A variety of approaches to microminiaturization is now being widely explored by electronic systems designers. Among the approaches taken, continued reliance is being placed upon discrete active components that can be used in module, welded, thin-film, or hybrid types of microcircuits. By the use of discrete elements, maximum circuit flexibility is retained, tight component tolerances are possible, and production shrinkage of complete circuit functions is minimized, as compared with the solid-state circuit approach. Moreover, ``throw-away'' maintenance costs are low. A series of microminiature silicon diodes and transistors has been developed and produced for use in applications where stringent size and weight limitations, and high reliability requirements, exist. Through the use of extremely simple mechanical constructions, surface passivation techniques and impervious glass-like coatings, low cost can be achieved in mass production without sacrificing reliability. By use of appropriate fabrication processes, alloyed or diffused diodes and transistors can be formed in mesa or planar configurations, and an extension to epitaxial structures can be employed. Electrical characteristics are comparable to, or better than those of existing conventional types of diodes and transistors. At 25°C, failure rates below 0.01 per cent per thousand hours have been substantiated. This paper begins with an outline of the theory underlying surface protection techniques used, describes the construction and characteristics of several devices in the family, and presents test information proving a high degree of reliability.