International Business Machines Corporation

William P Dumke

Jerry M Woodall

Alan B Fowler

A semiconductor processor for signals such as are conveyed by fiber optics wherein the processor structure accommodates lattice mismatch and minimizes the effect of misfit dislocations. The structure permits using materials having favorable absorption properties at the 1 micrometer wavelength of optical signals. A binary semiconductor is employed with graded regions produced by adding a different third ingredient in two places so that a wide band optically transparent emitter with a graded base and graded collector are provided. The ingredients impart a strong absorption in the optical signal wavelength together with superior semiconductor carrier transit time. A structure for a silicon and germanium oxide based optical signal fiber uses a GaAlAs emitter, a base that is graded to Ga.sub.0.25 In.sub.0.75 As at the collector and then back to GaAs at the substrate.

Semiconductor transistor with graded base and collector

The invention is a three-terminal transistor structure having five layers of materials that in combination provide conduction by high mobility carrier transport across the base in an energy valley above the conduction band. The conduction is by majority carrier tunneling injection from the emitter and transport at an upper valley level across the base. The resulting structure is capable of switching in times of 10.sup.-12 seconds.

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Chappaqua, NY, United States of America

William P Dumke