Magnetic Resonance of Defects in Heteroepitaxial Semiconductor Structures
Abstract
Investigations of magnetic resonance of defects in epitaxial semiconductors resulted in a pioneering study of the defects present in thin film GaAs grown by MBE at temperatures between 190 and 300 C These novel epitaxial semiconductor thin films are of great technological interest, e.g., as buffer layers to avoid sidegating of FETs or in ultrafast detectors with response times in the femtosecond range. A comprehensive analysis by magnetic resonance, infrared absorption, Hall effect, x-ray diffraction, and particle- induced X-ray emission showed that the transport in these very As-rich layers is dominated by a hitherto unknown kind of hopping conduction between localized arsenic antisite defects present in concentrations up to l0e20/cm3 that are partly compensated by up to l0el8/cm3 acceptors. The total concentration of excess As reached values of 6xl0e20/cm3, corresponding to As/Ga = 1.03. This was found together with a lattice expansion of up to 0.15%. Thermal annealing to temperatures higher than 500 C resulted in disappearance of the lattice expansion, a reduction of the antisite defect concentration by at least two orders of magnitude, and the disappearance of hopping conduction. A new superconducting phase with a transition temperature of 10K was discovered after In diffusion into GaAs.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 11, 1992
- Accession Number
- ADA251918
Entities
People
- Eicke R. Weber
Organizations
- University of California, Berkeley