High Resistivity Buffer Layers by Oxygen Doping
Abstract
The goal of this project was to study the effects of GaAs doping with dimethylaluminum methoxide during OMVPE growth. Incorporation of both aluminum and oxygen was analyzed as a function of growth conditions (growth temperature, V/III ratio, reactor pressure, growth rate, and DMAIMO mole fraction) by Secondary Ion Mass Spectroscopy. The aluminum content changed only slightly with deposition parameters but oxygen incorporation exhibited thermally activated behavior with the activation energy of 2.0 eV. At temperatures below 500 deg C oxygen content approached that of aluminum indicating that Al-O is incorporated as a pair into GaAs. The oxygen concentrations were as high as 5x10 to the l9 cu cm without degrading surface morphology. Layers with high oxygen content exhibited short carrier lifetime (very weak near-band-edge photoluminescence) and high resistivity as determined by C-V profiles and Hall effect measurements. Localized Vibrational Mode spectroscopy proved that aluminum and oxygen atoms remain bonded as pairs in the volume of the epilayer. This is the first successful attempt at controlled introduction of Impurity complexes into semiconductors. GaAs, Oxygen, MDCVP, Growth, Buffer layer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 31, 1993
- Accession Number
- ADA274986
Entities
People
- Marek Skowronski
Organizations
- Carnegie Mellon University