Patent · US Expired

Process for producing crystalline silicon nitride powder

US4929432A · kind A · utility

5Cited by
7References
18Claims
0Family size

Assignee

Inventor

Key dates

Filing dateOct 19, 1988
Grant dateMay 29, 1990
Priority date
Expiry dateOct 19, 2008

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC01P2006/80
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

A process for producing crystalline silicon nitride powder by a gas phase reaction of ammonia (NH.sub.3) and silane (SiH.sub.4) with a molar ratio of 7:1 or above at a temperature of 900.degree. C. or above and the heating the as-reacted amorphous powders at a temperature of 1350.degree. C. to 1800.degree. C. to convert the powders to a highly pure and submicron crystalline silicon nitride powder comprising at least a 90% .alpha.-Si.sub.3 N.sub.4 phase.

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