High power junction semiconductor device

Abstract

Abstract 806,505. Transistors. GENERAL ELECTRIC CO. Aug. 25, 1955 [Aug. 30, 1954], No. 24476/55. Class 37. A junction transistor comprises a semi-conductor wafer having a collector electrode over the whole of one face, a second electrode on the opposite face comprising a plurality of contacts connected together and a third electrode covering the remainder of the opposite face, either the second or the third electrode being of the alloyed junction type so as to form emitter and base electrodes. The Figures show a transistor having a fernico or nickel collector electrode plate 3 attached to an N-type germanium or silicon wafer 2 by an acceptor containing solder which provides a PN junction 10. The base electrode comprises a fernico or nickel plate 5 having apertures 8, and held in good ohmic contact with wafer 2 by a donor containing solder. The emitter consists of a plurality of alloy junction electrodes provided in apertures 8 by fusing dots 7 of acceptor material to the surface of the wafer. The PN junction under each dot is restricted so that it lies entirely within the aperture 8, and may be formed by placing a small quantity of indium in a recess 11 in wafer 2, and heating to provide the P-type region. The emitter and base electrode constructions may be reversed, by providing a PN junction under plate 5, and arranging for dots 7 to have ohmic contacts to wafer 2. The form of the collector electrode facilitates cooling by conduction, and the close spacing between the emitter, collector and base electrodes allows operation at high power. Specification 727,900 is referred to.

Inventors

• 👤 Robert N Hall

Bibliographic Details