Patent · US Expired

Neutral pH silicon etchant for etching silicon in the presence of phosphosilicate glass

US4171242A · kind A · utility

32Cited by
7References
14Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 8, 1978
Grant dateOct 16, 1979
Priority date
Expiry dateMar 8, 1998

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L21/31111
  • WIPO fieldSemiconductors
  • WIPO sectorElectrical engineering

Abstract

A silicon etchant is disclosed composed of an aqueous solution of a fluoride ion and oxygen maintained at a substantially neutral pH. The etchant eliminates the problems of stripping organic photoresists, maintaining silicon/phosphosilicate glass selectively, silicon surface pitting, oxide residues, and insoluble reaction products.

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