Patent · US Expired

Method for tailoring oxygen precipitate particle density and distribution silicon wafers

US4437922A · kind A · utility

61Cited by
7References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 26, 1982
Grant dateMar 20, 1984
Priority date
Expiry dateMar 26, 2002

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S148/024
  • WIPO fieldSurface technology, coating
  • WIPO sectorChemistry

Abstract

A wide precipitate-free-zone (PFZ) is formed at the surface of a semiconductor substrate and at the same time a high density of oxygen precipitate particles are produced beneath at the surface PFZ by a two step annealing process involving a first cycle of very rapidly heating the wafers to a first high temperature and a second cycle of very slowly heating the wafers to a second high temperature.

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