SILICON CARBIDE, 500C POWER RECTIFIERS.
Abstract
The preparation of 500C SiC rectifiers having a forward current capability of 10A (half wave average) while sustaining a peak reverse voltage of 150 volts has been shown practicable. During the program, several crystal growth techniques were investigated for the fabrication of power rectifiers. These include the sublimation, thermal reduction and modified Czochralski methods. Methods for obtaining larger crystals and controlling nucleation have been extensively studied in the sublimation method. Crystals of high purity up to 15 mm across have been grown. The thermal reduction and modified Czochralski methods essentially investigated the feasibility of growing SiC ribbon or sheets using a hexagonal SiC platelet as a seed. Although some growth along the adirection occurred, the amount and quality was not sufficient for device studies. Junctions were formed in SiC by sublimation, diffusion and epitaxial growth techniques. The sublimation-grown junction method was successful in preparing crystals for high current capacity rectifiers. Device fabrication techniques, such as lapping, etching, contracting and encapsulation have been developed for 10A rectifiers. Initial experiments on a non-hermetic encapsulation have been promising. The use of a new type of tungsten backing plate with grain texture parallel to the direction of heat flow has reduced the thermal impedance of the device. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1964
- Accession Number
- AD0608623
Entities
People
- J. R. Davis Jr.
- L. J. Kroko
- R. B. Campbell