Bipolar transistor fabrication with trench isolation

• Main Authors: BYUNG-RYUL RYUM, DEOK-HO CHO, SOO-MIN LEE, SEONG-HEARN LEE, JIN-YOUNG KANG, TAE-HYEON HAN
• Format: Patent
• Language: English
• Published: 26.06.1996
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; SEMICONDUCTOR DEVICES; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS

A bipolar transistor has a buried collector 22 on a silicon substrate 21, a collector 23 defined by trenches filled with insulating material, an intrinsic base 30 formed on the collector 23, an extrinsic base 26 electrically isolated from the silicon substrate 21 by a thermal-oxide layer 25, a conductive polysilicon layer 31 formed in self-alignment to connect the intrinsic base with the extrinsic base, and an emitter 33 formed on a portion of the intrinsic base and composed of polysilicon doped with an impurity. The trench may be defined by etching, or by a side-wall nitride layer.