Method of forming a gate shield in an ED-CMOS transistor and a base of a bipolar transistor using BICMOS technologies

Patent metadata

Field	Value
Publication number	US-9306013-B2
Application number	US-201414286805-A
Country	US
Kind code	B2
Filing date	May 23, 2014
Priority date	May 23, 2014
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A method of fabricating a MOSFET transistor in a SiGe BICMOS technology and resulting structure having a drain-gate feedback capacitance shield formed between a gate electrode and the drain region. The shield does not overlap the gate and thereby minimizes effect on the input capacitance of the transistor. The process does not require complex or costly processing since the shield is composed of bipolar base material commonly used in SiGe BICMOS technologies.

First claim

What is claimed is:

1. A method, comprising:
developing a bipolar transistor region on a substrate;
developing a laterally diffused metal oxide semiconductor (LDMOS) transistor region on the substrate and spaced apart from the bipolar transistor;
depositing an epitaxial polysilicon layer over the bipolar transistor region and the LDMOS transistor region; and
patterning and etching the epitaxial polysilicon layer using a single mask to form:
a base above the bipolar transistor region; and
a gate shield above the LDMOS transistor region.

Assignees

• Texas Instruments Inc

Inventors

• Babcock Jeffrey A
• Sadovnikov Alexei

Classifications

• H10P50/71

  using masks for conductive or resistive materials · CPC title

• H10D62/116

  adjoining the input or output regions of field-effect devices, e.g. adjoining source or drain regions · CPC title

• H10D84/0109

  the at least one component covered by H10D12/00 or H10D30/00 being a MOS device · CPC title

• H10D84/038

  using silicon technology, e.g. SiGe · CPC title

• H10D64/661

  the conductor comprising a layer of silicon contacting the insulator, e.g. polysilicon having vertical doping variation (having lateral variation in the gate structure H10D64/671) · CPC title