Accession Number:

ADA218211

Title:

Growth, Characterization and Device Development in Monocrystalline Diamond Films

Descriptive Note:

Annual rept. 1 Jun 1988-31 May 1989

Corporate Author:

NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATERIALS SCIENCE AND ENGINEERING

Report Date:

1990-02-01

Pagination or Media Count:

138.0

Abstract:

Two chemical vapor deposition CVD systems hot filament and microwave plasma and a multitechnique analysis system have been designed, constructed and characterized. The effects of surface steps, substrate material and substratefilament bias have been examined. Diamond films from outside sources have been analyzed by a variety of techniques. Most notably, numerous defects, especially 111 twins, have been identified by TEM and are similar to those found in natural diamond. Certain diamond particles were in a twinned epitaxial relationship with the Silicon substrate. It has also been found that a thin Silicon carbide layer forms immediately i.e. 5 min upon exposure to the Methane Hydrogen plasma, followed by the slow formation of the diamond crystallites. Large-Signal, nonlinear device models for both microwave diamond power MESFETs and mm-wave diamond IMPATT diodes have been developed. Diamond power MESFETs operating in X-band are found to be capable of producing approximately 25 Wunit gate width of RF power with a power-added efficiency of greater than 40. A diamond IMPATT oscillator should produce about 2 W RF power with an efficiency of 10 at 100 GHz. Keywords Thin films.

Subject Categories:

  • Electrical and Electronic Equipment
  • Crystallography
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE