Patent ID: 8372723

Claim:
A method of manufacturing a semiconductor device, comprising: forming a collector for a bipolar transistor within a semiconductor substrate, wherein the collector excludes a collector tub; forming an isolation region under the collector; forming a contact trench within the collector; forming a diffusion buried contact region within the trench, at least a portion of the diffusion buried contact region located within the trench and extending along sidewalls of the trench, the diffusion buried contact region extending into the collector to a depth sufficient to contact and make electrical connection with the collector forming a base within the collector; forming at least first and second bipolar transistor emitter structures on a surface of the semiconductor substrate and over the base and the collector and having a common base contact region located in the base and between the at least first and second bipolar transistors; and forming a contact plug that extends into the collector to the depth to contact the diffusion buried contact region within the trench.