Growth, Characterization and Device Development in Monocrystalline Diamond Films
Abstract
Surfaces of diamond and GaN have been characterized using UV photoemission spectroscopy (UPS), position dependent field emission and photo-electron emission microscopy (FEEM and PEEM). Electron affinity is a critical limiting aspect for field emission from conducting p-type diamond and Si doped GaN. Emission from p-type diamond originates from the valence band of the material; field emission from Si-doped GaN originates from electrons in the conduction band. Particle detectors for high electron flux applications have been fabricated based on highly oriented diamond (HOD) films. Relatively thick HOD films were achieved by combining the bias enhanced nucleation in a microwave plasma chemical vapor deposition reactor and high rate growth process in a low pressure combustion flame reactor. The detector performance was measured using the energy spectra of alpha-particles emitted from an Am-241 source. The HOD detector showed a three to four fold improvement in performance which was close to that obtained for single crystalline diamond detectors. Voltage-dependent field emission energy distribution and I-V measurements were performed on Mo tips coated with intrinsic c-BN to determine the origin of the field-emitted electrons. Spectra were collected from the Mo emitters under UHVconditions before and after being coated. In some instances multiple FEED peaks were observed in the collected spectra. These corresponded to multiple emission sites on the emitter. The energy of the field-emitted electrons from the c-BN-coated emitters usually depended linearly upon the applied voltage and could be explained using a simplified band-bending model. However, at higher voltages the FEED measured from the c-BN-coated emitters departed from this linear behavior. These nonlinearities were attributed to contact resistance at the Mo/c-BN interface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1998
- Accession Number
- ADA345423
Entities
People
- Robert F Davis
- Robert J. Nemanich
- Zlatko Sitar
Organizations
- North Carolina State University