Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To obtain BJT whose switching speed is high, by making uniform and thin inner and outer bases by utilizing a molecular beam epitaxial method, by providing base metal electrodes at every small distances from an emitter so that they are in ohmic contact with the outer base, and by providing the emitter on the inner base. CONSTITUTION:An n<+> buried layer 22 and an n<-> epitaxial layer 23 are superposed on a p<-> type Si substrate 1, and a p<-> thin layer 24 is superposed thereon by a molecular beam epitaxial method. An n<+> collector take-out layer 27 is formed by separating said layer by a channel cut 26 and an oxide film 25. Next, an Au film 28 is connected thereon by the molecular beam epitaxial method, and, an SiO2 mask 29 being provided, the p<-> base layer 24 is etched with aqua regia, whereby a cavity is made therein. Then, an n type emitter 31 and a collector 32 are prepared selectively by the molecular beam epitaxial method, whereby single crystals are formed only on the substrate 21. Electrodes 33-35 are attached after a base electrode window is provided. According to this constitution, both parasitic capacity and base resistance can be held to be small, and thus a switching speed can be improved.

Inventors

• 👤 Hiroshi Goto
• 👤 広志 後藤

Bibliographic Details