High voltage integrated circuit devices electrically isolated from an integrated circuit substrate

US4868921A · kind A · utility

Assignee

• General Electric Company · US

Inventor

• Michael Adler · Bel Air, US

Key dates

• Filing date: Feb 5, 1988
• Grant date: Sep 19, 1989
• Expiry date: Feb 5, 2008

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/157

Abstract

An integrated circuit with a substrate of one conductivity type and a drift layer on the substrate of opposite conductivity type includes a high voltage semiconductor device, such as a P-N diode, with a first main device region of the opposite conductivity type adjoining the drift layer and a second main device region of the same conductivity type as the substrate adjoining the drift layer. The high voltage semiconductor device is electrically isolated from other devices through the incorporation into the integrated circuit of an isolation region adjoining the substrate and surrounding the high voltage device. Electrical isolation of the high voltage device from the substrate is achieved by interposing a highly-doped buried layer of the opposite conductivity type between the second main device region and the substrate so as to prevent current carrier injection from the second main device region into the substrate. A field gate is included in the high voltage device, being insulatingly spaced from the drift layer, situated between the buried layer and the first main device region, and electrically shorted to the second main device region. The field gate prevents the buried layer fro…