High gain photoconductive semiconductor switch having tailored doping profile zones

• Main Authors: HOU HONG Q, ZIPPERIAN THOMAS E, LOUBRIEL GUILLERMO M, SULLIVAN CHARLES T, ALLERMAN ANDREW A, BROWN DARWIN J, O'MALLEY MARTIN W, DENISON GARY J, HJALMARSON HAROLD P, BACA ALBERT G, ZUTAVERN FRED J, HELGESON WESLEY D, MAR ALAN
• Format: Patent
• Language: English
• Published: 19.06.2001
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

A photoconductive semiconductor switch with tailored doping profile zones beneath and extending laterally from the electrical contacts to the device. The zones are of sufficient depth and lateral extent to isolate the contacts from damage caused by the high current filaments that are created in the device when it is turned on. The zones may be formed by etching depressions into the substrate, then conducting epitaxial regrowth in the depressions with material of the desired doping profile. They may be formed by surface epitaxy. They may also be formed by deep diffusion processes. The zones act to reduce the energy density at the contacts by suppressing collective impact ionization and formation of filaments near the contact and by reducing current intensity at the contact through enhanced current spreading within the zones.