Junction termination for SiC Schottky diode

US5914500A · kind A · utility

Assignee

• ABB RESEARCH LTD. · CH

Inventors

• Mietek Bakowski · Gately Drive, SE
• Ulf Gustafsson · Linköping, SE

Key dates

• Filing date: Mar 20, 1997
• Grant date: Jun 22, 1999
• Expiry date: Mar 20, 2017

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D62/117

Abstract

A semiconductor diode structure with a Schottky junction, wherein a metal contact and a silicon carbide semiconductor layer of a first conducting type form the junction and wherein the edge of the junction exhibits a junction termination divided into a transition belt (TB) having gradually increasing total charge or effective sheet charge density closest to the metal contact and a Junction Termination Extension (JTE) outside the transition belt, the JTE having a charge profile with a stepwise or uniformly deceasing total charge or effective sheet charge density from an initial value to a zero or almost zero total charge at the outermost edge of the termination following a radial direction from the center part of the JTE towards the outermost edge of the termination. The purpose of the transition belt is to reduce the electric field concentration at the edge of the metal contact of the Schottky diode, while the purpose of the junction termination extension is to control the electric field at the periphery of the diode.