Options
1993
Journal Article
Titel
Electronic study of plasma-induced damage in GaAs heterostructures.
Alternative
Elektronische Untersuchung von plasma-induzierter Zerstörung in GaAs-Heterostrukturen
Abstract
Electrical damage produced during dry-etch processing of GaAs/AlGaAs-based heterostructures has been investigated by electric microwave absorption, a non-destructive, contact-free electrical measurement technique. The mobilities and carrier concentrations, both of bulk (3-dimensional) as well as 2-dimensional electron distributions, are measurable with this approach and have been seen to be sensitively dependent upon surface reactive ion etch treatments. Physical sputter (Ar) was found to be considerably more damaging than more chemically-based (CClsub2Fsub2) dry etch processes used to etch GaAs and AlGaAs. The plasma techniques used to remove oxynitride passivation (CFsub4 and CHFsub3 plus Osub2) were also examined and seen to affect the electrical properties of the semiconductor for high etch biases. Hydrogenic ambients were noted to cause greater electrical degradation due to donor passivation with H. Rapid thermal annealing was not always effective, and long (40 minute) high-temper ature steps were often seen to be necessary to restore electrical integrity; ion milling at high voltages (above 200 V) produced damage not removbable by annealing.