Patent · US Expired

Semiconductor device to prevent out-diffusion of impurities from one conductor layer to another

US4990998A · kind A · utility

10Cited by
7References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 7, 1989
Grant dateFeb 5, 1991
Priority date
Expiry dateFeb 7, 2009

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L2924/0002
  • WIPO fieldSemiconductors
  • WIPO sectorElectrical engineering

Abstract

A semiconductor device includes a first conductor layer into which is diffused an impurity for lowering the resistance, and a second conductor layer provided on the upper side of the first conductor layer through a stopper layer which suppresses the out-diffusion of the impurity. By virtue of the existence of the stopper layer, it is possible to inhibit the above-described impurity from being diffused into the second conductor layer. In SRAM, resistance variations between high-resistance elements which correspond to the second conductor layer can be suppressed, so that it is possible to prevent the lowering of the yield with respect to the electrical reliability. In SRAM, further, the resistance of the high-resistance elements is not lowered; therefore, it is possible to reduce the power consumption.

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