Back to results
US 5,399,509 AGranted
Method of manufacturing a bipolar transistor
AssigneeNational Semiconductor Corporation
InventorAli A. Iranmanesh
Life of this patent
Estimating the term…
Abstract
A semiconductor device and method to reduce the size of bipolar transistors and decrease the number of steps required to fabricate the bipolar transistor by using a unitary contiguous oxide sidewall to separate a collector contact from the base, emitter and emitter contact. The device and method may also be used during the fabrication of BiCMOS devices.
Claims10
A method of manufacturing a bipolar transistor comprising the steps of:
- a) forming a collector region having a first conductivity type;
- b) forming a base having a second conductivity type over the collector region;
- c) forming an emitter contact having a first conductivity type over the emitter and an emitter having a first conductivity type over the base;
- d) forming an etching mask over a portion of said emitter;
- e) etching the surface of the transistor not covered by the etching mask to a depth below the base thereby providing a trench, wherein the step of forming an emitter contact is performed prior to etching the trench;
- f) forming an oxide layer over at least the trench;
- g) anisotropically etching the oxide layer without a mask to expose a portion of said collector region, thereby providing an oxide sidewall extending from below the upper surface of the collector region to the emitter;
- and
- h) forming a collector contact to said exposed portion of said collector region.
6 more elements
Dependencies are inferred from the claim text.