Patent · US Expired

Semiconductor device with impurity layer as channel stopper immediately under silicon oxide film

US5994190A · kind A · utility

6Cited by
8References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 10, 1998
Grant dateNov 30, 1999
Priority date
Expiry dateSep 10, 2018

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH10D84/038
  • WIPO fieldSemiconductors
  • WIPO sectorElectrical engineering

Abstract

A semiconductor device includes a first conductivity type low concentration impurity layer provided around a thick silicon oxide film, which is formed for element isolation in a first conductivity type element region as a surface region in a semiconductor substrate, and a second conductivity type impurity layer which is provided immediately under at least the thick silicon oxide film. The second conductivity type impurity layer constitutes a channel stopper to enhance the effect of element isolation. The first conductivity type low concentration impurity layer has an effect of improving the P-N junction breakdown voltage of an active region in the first conductivity type element region, and suppresses the narrow channel effect of a MOS transistor in the first conductivity type element region.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.