Process for the determination of the boron contents of pure halogensilanes

US4042331A · kind A · utility

Assignee

• Wacker-Chemitronic Gesellschaft fur Elektronik Grundstoffe mbH · DE

Inventors

• Dietrich Schmidt · Camp Hill, US
• Johann Hofer · Grettstadt, DE
• Winfried Lang · Burghausen, DE
• Erich Bildl · Tittmoning, DE

Key dates

• Filing date: Nov 1, 1976
• Grant date: Aug 16, 1977
• Expiry date: Nov 1, 1996

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/041
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Process for the determination of the boron content of pure halogensilanes pecially silicon tetrachloride and trichlorosilane, which contain up to 0.1% of atoms of acceptors and donors, which comprises the steps of converting the halogen silanes into the gaseous state in a testing apparatus by contacting said halogensilanes with an evaporator surface heated to a temperature ranging from 80.degree. C to 350.degree. C, passing the generated gases to a support heated to the decomposition temperature of the gases whereby the released silicon is deposited on the support, removing the support and the deposit thereon from the testing apparatus and determining the boron content by calculation from the measured value of the specific resistance of the support plus the deposited silicon. It should be understood that all parts of the testing apparatus which come into contact with the generated gas, with the exception of the support heated to the required deposition temperature, should be at the temperature above 80.degree. C, but below the decomposition temperature of the halogensilane.