Bipolar transistor and manufacture thereof

Abstract

Abstract PURPOSE:To form both a base region and an emitter region so as to be selfaligned with a first window, so that the base region and the emitter region are made small in area by a method wherein a sidewall is formed inside a first window opened through a lithography technique. CONSTITUTION:A first polycrystalline silicon 6 and a first insulating 5, which are formed on a semiconductor substrate that comprises an n<+>-type buried layer 2 and an n-type epitaxial layer 3 formed on a p-type semiconductor substrate 1, are successively subjected to an anisotropic etching for the opening of a first window 9. The exposed surface of the n-type epitaxial layer 3 is oxidized and a silicon nitride film is subjected to etching so as to remove a first side wall 9a. Next, a second polycrystalline silicon film 12 is made to grow. A sixth insulating film 17 formed of the same silicon nitride film as a second side wall 14 is made to grow to be excellent in a step coverage, thereafter a third polycrystalline silicon film 19 is made to grow, and an emitter is formed through the ion-implantation of arsenic. The polycrystalline silicon film 19 is selectively etched, so that a collector contact opening 20, a base contact opening 21, or the like are provided.

Inventors

• 👤 Junzo Shimizu

Bibliographic Details