Kinetics of formation of the midgap donor EL2 in neutron irradiated GaAs materials
Fast neutron irradiation of n-GaAs mainly induces two deep electron traps in the band gap. The first of these is referred to as EL6 and has an energy level at E/sub c/ -0.35 eV, where E/sub c/ is the conduction band minimum; the second one has a wide energy distribution around E/sub c/ -0.5 V and is referred to as the U band. The annealing kinetics of these two levels is studied, and it is found that EL6 vanishes by a pair-defect (short-range) type recombination while the U band anneals by a long range migration process. Both annealing processes can be observed between 400 and 500 /sup 0/C. In this annealing temperature range, the concentration of deep donor level EL2 (E/sub c/ -0.75 eV) increases with temperature. It is suggested that the defect giving rise to the EL2 level is created during irradiation but that medium range (tens to hundreds of A) interactions with other neighboring defects strongly influence the electric properties of the overall defect, which is then detected as the U band. Due to long range migration, annealing reduces medium range interaction and the U band disappears in favor of the well-defined EL2 level (E/sub c/ -0.75 eV). This allows us to reconcile the apparent contradiction between DLTS (deep level transient spectroscopy) and EPR (electron paramagnetic resonance) and to identify the EL2 level with the EPR signal attributed to the As/sub Ga/ defect.
- Research Organization:
- Laboratoires d'Electronique et de Physique Appliquee 3, avenue Descartes, 94450 Limeil-Brevannes, France
- OSTI ID:
- 6140790
- Journal Information:
- J. Appl. Phys.; (United States), Vol. 56:10
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GALLIUM ARSENIDES
ANNEALING
ENERGY GAP
PHYSICAL RADIATION EFFECTS
ENERGY LEVELS
EXPERIMENTAL DATA
IMPURITIES
NEUTRON FLUX
RECOMBINATION
TRAPS
ARSENIC COMPOUNDS
ARSENIDES
DATA
GALLIUM COMPOUNDS
HEAT TREATMENTS
INFORMATION
NUMERICAL DATA
PNICTIDES
RADIATION EFFECTS
RADIATION FLUX
360605* - Materials- Radiation Effects