Accession Number:

ADA243531

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:

Annual letter rept. 1 Jan-31 Dec 91,

Corporate Author:

NORTH CAROLINA STATE UNIV AT RALEIGH

Personal Author(s):

Report Date:

1991-12-01

Pagination or Media Count:

53.0

Abstract:

Thin films of pure and A1-doped beta-SiC have been grown on 4 off- axis Si100 and c-axis oriented alpha6H-SiC in the temperature range of 1025- 1250 C using gas-source molecular-beam epitaxy. Cross-sectional TEM confirmed the epitaxial relationship between the films and the substrates. Double positioning boundaries have not been observed in the material grown on the 6H- SiC substrates. Platinum and Ti circular contacts were epitaxially deposited on alpha6H-SiC via electron beam MBE at room temperature. Leakage currents at - 10V were as low as 5 x 10-18 Acm2. The ideality factors were approximately unity. Barrier heights for the as-grown Ti and Pt contacts were determined from C-V measurements to be 0.88 eV and 1.02 eV, respectively. Theoretical investigations of the physical limitations to the RF operation of SiC IMPATT diodes has shown that good RF output power can be obtained from these devices. However, the low magnitude of the charge carrier mobility in SiC limits the magnitude of the RF voltage that can be supported, and thereby prevents efficient dc to RF power conversion. MESFETs have been fabricated with values of ft and fmax of 4.5 GHz and 3.0 GHz, respectively.

Subject Categories:

  • Electrical and Electronic Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE