ISOLATION STRUCTURE FOR INTEGRATED CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a method for fabricating and electrically isolating bipolar, CMOS and DMOS transistors, and passive components in a semiconductor chip monolithically at high densities without the need for epitaxial layers or high temperature fabrication processing steps.SOLUTION: A variety of isolation structures for semiconductor substrates include a trench formed in a substrate. The trench is filled with a dielectric material or filled with a conductive material, and lined with a dielectric layer along the walls of the trench. The trench may be used in combination with doped sidewall isolation regions. Both the trench and the sidewall isolation regions may be annular and enclose an isolated pocket of the substrate. The isolation structures are formed by modular implant and etch processes that do not include significant thermal processing or diffusion of dopants, so that the resulting structures are compact and may be tightly packed in the surface of the substrate.