Texas Instruments Corporation

Samuel Zafar Nawaz

Jeffrey E Brighton

Shaofeng Yu

Song Zhao

An integrated circuit contains a transistor with a stress enhancement region on the source side only. In a DeMOS transistor, forming the stress enhancement region on the source side only and not forming a stress enhancement region in the drain extension increases the resistance of the drain extension region enabling formation of a DeMOS transistor with reduced area. In a MOS transistor, by forming the stress enhancement region on the source side only and eliminating the stress enhancement region from the drain side, transistor leakage is reduced and CHC reliability improved.

MOSFET with source side only stress

According to one embodiment of the invention, a method for manufacturing bipolar junction transistors includes disposing a first oxide layer between a semiconductor substrate and a base polysilicon layer, forming a dielectric layer outwardly from the base polysilicon layer, and forming an emitter region by removing a portion of the dielectric layer and a portion of the base polysilicon layer. The method further includes removing a portion of the first oxide layer to form undercut regions adjacent the emitter region and to enlarge the emitter region, and forming an oxide pad outwardly from the semiconductor substrate in the emitter region.

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Plano, TX, United States of America

Samuel Zafar Nawaz