PREPARATION OF CHEMICAL VAPOR-DEPOSITED MATERIALS FOR USE IN FIELD-ENHANCED ELECTRON EMISSION STUDIES.
Abstract
The general principles of chemical vapor deposition (CVD) are described and specific experimental results on the deposition of pyrolytic graphite, of CVD boron nitride, and of CVD tungsten on tungsten substrates are discussed. In order to obtain uniform anisotropic, thin films of pyrolytic graphite and CVD boron nitride, the deposition parameters such as deposition temperature, concentration of the gaseous reactants, and gas flow pattern were varied, and their influence on the deposits was studied. It was found that the uniformity of pyrolytic graphite can be increased by using high total gas flow rates and low methane concentrations. The most uniform CVD-boron nitride deposits were obtained under the following conditions: Temperature: 1600C; Gas flow rate (cc/min): ammonia 10, boron trichloride 6, nitrogen 4. The deposits of pyrolytic graphite and CVD boron nitride exhibited a high degree of anisotropy. Thin-film sandwich structures of pyrolytic graphite and CVD boron nitride were successfully produced. Preliminary tests have been performed with CVD tungsten. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1966
- Accession Number
- AD0631515
Entities
People
- David G. Mcmaster
Organizations
- United States Army Communications-Electronics Command