Patent ID: 8912574

Claim:
A method of making a semiconductor structure, comprising: forming a shallow trench isolation (STI) structure in a substrate; forming a barrier layer on and contacting the STI structure and the substrate, wherein the barrier layer is composed of nitride or oxynitride; forming an insulator layer on and contacting the barrier layer; forming a trench through the STI structure and into the substrate; forming a liner comprising an electrical insulator material on sidewalls and a bottom of the of the trench; forming a core comprising a high thermal conductivity material in the trench and on the liner, wherein the liner is between the core and the substrate across the bottom of the trench; and forming a cap in the trench and on the core, wherein the forming the trench comprises forming the trench adjacent to a heterojunction bipolar transistor (HBT) comprising a collector, a base formed over the collector, and an emitter formed over the base; and an uppermost surface of the core is above an interface region between the collector and the base.