Back to results
US 4,900,689 AGranted
Method of fabrication of isolated islands for complementary bipolar devices
AssigneeHarris Corporation
InventorsGeorge Bajor, Hugh C. Nicolay
Life of this patent
Estimating the term…
Abstract
A process includes selectively forming laterally adjacent complementary doped epitaxial layers over low resistive buried regions of a horizontally isolated substrate. Self-aligned oxide mask are used for the epitaxial deposition. Lateral dielectric isolation trenches at the complementary doped epitaxial boundary complete the isolation of the islands. Base and emitter regions are formed in the epitaxial collector layers.
Claims17
A process for fabricating complementary isolated islands on a substrate having at least first and second semiconductor regions isolated by horizontal isolation comprising:
- forming a first buried region of a first conductivity type and impurity concentration in said first region of said substrate;
- forming a second buried region of a second conductivity type and impurity concentration in said second region of said substrate;
- epitaxially forming a third region of said first conductivity type having a smaller impurity concentration than said first buried region and having a first thickness at least on said first region;
- forming a first mask over said third region and exposing said second region;
- epitaxially forming a fourth region of said second conductivity type, having a smaller impurity concentration than said second buried region and having a thickness equal to said third region;
- and
- forming a dielectric isolation region at adjacent lateral portions of said third and fourth regions and said first and second buried regions.
4 more elements
Dependencies are inferred from the claim text.