US 9,812,447 B2
Bipolar junction transistors with extrinsic device regions free of trench isolation
Ramana Malladi, Essex Junction, VT (US); and Renata Camillo-Castillo, Essex Junction, VT (US)
Assigned to GLOBALFOUNDRIES INC., Grand Cayman (KY)
Filed by GLOBALFOUNDRIES INC., Grand Cayman (KY)
Filed on Feb. 2, 2016, as Appl. No. 15/13,393.
Prior Publication US 2017/0221887 A1, Aug. 3, 2017
Int. Cl. H01L 29/737 (2006.01); H01L 27/082 (2006.01); H01L 21/8228 (2006.01); H01L 29/66 (2006.01); H01L 29/161 (2006.01); H01L 29/165 (2006.01); H01L 23/66 (2006.01)
CPC H01L 27/0826 (2013.01) [H01L 21/82285 (2013.01); H01L 23/66 (2013.01); H01L 29/161 (2013.01); H01L 29/165 (2013.01); H01L 29/66242 (2013.01); H01L 29/7378 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A device structure formed using a substrate, the device structure comprising:
one or more trench isolation regions in the substrate, the one or more trench isolation structures surrounding a device region having a portion;
a base layer on the device region, the base layer including an intrinsic base and an extrinsic base on the portion of the device region, and the extrinsic base having a higher electrical conductivity than the intrinsic base;
a plurality of contacts extending to a section of the extrinsic base on the portion of the device region; and
a first emitter finger and a second emitter finger in a spaced relationship on the base layer,
wherein the intrinsic base has a first section beneath the first emitter finger and a second section beneath the second emitter finger, the section of the extrinsic base is located laterally in the base layer between the first section of the intrinsic base and the second section of the intrinsic base, the portion of the device region extends from the first emitter finger to the second emitter finger, and the portion of the device region is free of a dielectric material.