At&t Bell Laboratories

Yiu H Wong

Robert Charles Frye

Harry T Weston

Joseph E Griffith

McDonald Robinson

A semiconductor structure including a pair of single-crystal semiconductor bulk regions (10.3, 12.2) of differing first and second bulk conductivities, respectively, for forming semiconductor circuits therein, is fabricated whereby each such region is electrically isolated from the other and from a rigid body (20) supporting these regions. The structure is formed by forming at a major surface of a single crystal semiconductor water (10) having the first bulk conductivity a bulk zone (12.1) having the second bulk conductivity, followed by the steps of (1) forming in the wafer (10) at the major surface (10.6) thereof a V-shaped groove (10.2) at the boundary of the bulk zone (12.1) using a crystallographic orientation dependent etch, in order to define the regions (10.3, 12.2) of differing conductivities, (2) forming a dielectric layer (15.1, 15.2) upon the walls of the V-groove and upon the exposed portion of the major surface, (3) forming a rigid body layer (20), such as polysilicon, upon the dielectric layer (15.1, 15.2), and (4) planarizing the exposed, opposed major surface of the single crystal medium down to the vertices of the V-grooves. The semiconductor circuits themselves can then be fabricated in the resulting mutually dielectrically isolated regions (10.3, 12.2).

Isolation process for high-voltage semiconductor devices

Dielectrically isolated single crystal silicon of high quality is produced by an extremely convenient process. This process involves the fusing of two silicon bodies where at least one of these bodies has a region of silicon oxide. The bodies are contacted so that the silicon oxide is at an interface between the two bodies. The bodies are then heated to an elevated temperature while applying a nominal electrical potential across the interface. This combination of applied potential and temperature permanently fuses the two bodies without producing any significant damage to the crystal quality of these bodies.

Growing community of inventors

Berkeley Heights, NJ, United States of America

Yiu H Wong