Accession Number:

ADA239223

Title:

Research and Development on Advanced Silicon Carbide Thin Film Growth Techniques and Fabrication of High Power and Microwave Frequency Silicon Carbide-Based Device Structures.

Descriptive Note:

Semiannual letter rept. 1 Jan-30 Jun 91,

Corporate Author:

NORTH CAROLINA STATE UNIV AT RALEIGH

Personal Author(s):

Report Date:

1991-06-01

Pagination or Media Count:

40.0

Abstract:

A gas source molecular beam epitaxy system has been designed, constructed and commissioned for the growth and doping of silicon carbide thin films at low temperatures. Monocrystalline films of beta silicon carbide on 3 deg off-axis 100 silicon substrates have been obtained at 1075 C, as shown by Auger profiles and reflection high energy electron diffraction. The heteroepitaxial growth on titanium rectifying contacts on n-type alpha6H-SiC has also been achieved at room temperature via ultra high vacuum electron beam evaporation. I-V measurements revealed low leakage currents approx. 6nA at - 10V and the lowest ideality factors ever reported for contacts on SiC. Theoretical simulation has shown that SiC IMPATTs are capable of good RF output power in the 30-100 GHz range. However, the dc-RF conversion is fundamentally low and may restrict development. High frequency 6H-SiC MESFETs have been fabricated with the highest values of Ft and Fmax being 2.9 GHz and 1.9 GHz, respectively. Methods to reduce the source and gate resistances were pursued. Avalanche characteristics in alpha 6H-SiC p-n junction IMPATT diode were observed for the first time. This device structure appears promising for high power microwave operation.

Subject Categories:

  • Electrical and Electronic Equipment
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE