Accession Number : AD0250119

Title :   RESEARCH IN THE PREPARATION OF HYPERPURE SINGLE CRYSTAL SILICON CARBIDE

Corporate Author : WESTINGHOUSE ELECTRIC CORP YOUNGWOOD PA

Personal Author(s) : HAMILTON, D.R. ; CHU, T.L.

Report Date : APR 1960

Pagination or Media Count : 1

Abstract : THE WORK IS CONCERNED WITH THE PREPARATION OF SIC CRYSTALS OF HIGHEST PURITY. WHILE THE TECHNIQUE USED IS BASICALLY THAT OF LELY, MUCH OF THE WORK IS CONCERNED WITH THE METHODS BY WHICH THE OVER-ALL PURITY HAS BEEN INCREASED AT LEAST AN ORDER OF MAGNITUDE. PURE SIC NOW MEANS REPRODUCIBLE SAMPLES OF THOUSANDS TO HUNDREDS OF THOUSANDS OHM CM RESISTIVITY (ROOM TEMPERATURE), WITH IMPURITY LEVELS OF THE ORDER OF 10TO THE 16TH POWER ATOMS/CC. HALL MEASUREMENTS INDICATE THAT THE DENSITY OF ELECTRICALLY ACTIVE LEVELS MAY BE AS LOW AS 10 TO THE 14TH POWER/CC. THE OVER-ALL MORPHOLOGY OF SAMPLES PREPARED IN THE LABORATORY IS DESCRIBED. A SECTION IS DEVOTED TO THE ORIGIN OF SCREW DISLOCATIONS WHICH HAVE PLAYED SUCH A PROMINENT ROLE IN RECENT STUDIES OF SPIRAL GROWTH STEPS ON SIC SURFACES, WHILE OTHER SAMPLES ARE SHOWN TO BE ATOMICALLY FLAT. PRELIMINARY STUDIES WITH THE PLASMAJET HAVE DEMONSTRATED ITS SUITABILITY FOR HIGH TEMPERATURE REACTION STUDIES.

Descriptors :   *SILICON COMPOUNDS, *SINGLE CRYSTALS, CARBIDES, CRYSTAL STRUCTURE, CRYSTALS, DEFORMATION, GROWTH(PHYSIOLOGY), PURIFICATION, SEMICONDUCTORS, SUBLIMATION.

Distribution Statement : APPROVED FOR PUBLIC RELEASE