Dielectrically isolated semiconductor device and a method for its manufacture

US5432377A · kind A · utility

Assignee

• Telefonaktiebolaget LM Ericsson (Publ) · SE

Inventor

• Andrej Litwin · Stockholm, SE

Key dates

• Filing date: Jan 24, 1994
• Grant date: Jul 11, 1995
• Expiry date: Jan 24, 2014

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S148/05

Abstract

A semiconductor device is supported by a semiconductor body which comprises a substrate, an oxide layer and a weakly doped monocrystalline wafer. Trenches for a dielectrically isolating layer which surrounds a component region are etched in the wafer. A field effect transistor in the component region has two doped wafer-line gate regions, which have been diffused in the component region with the aid of a first mask. Two heavily doped regions are diffused in the component region with the aid of a second mask, these regions forming the source region and the drain region of the transistor. The semiconductor body is easy to produce and is available commercially, which simplifies manufacture of the field effect transistor. Manufacture is also simplified because the configuration of both the component region and the parts of the transistor are determined by the simple choice of masks. The component region is weakly doped and is easy to deplete of charge carriers. The electrical field strength in the component region is weak, according to the RESURF method, and the field effect transistor withstands high voltages without risk of current breakthrough. The component region occupies only a r…