Compensation of shallow impurities in oxygen-doped metalorganic vapor phase epitaxy grown GaAs

Abstract

Intentional oxygen incorporation, using diethyl aluminum ethoxide ͓(C 2 H 5 ͒ 2 AlOC 2 H 5 ͔ during metalorganic vapor phase epitaxy GaAs was found to compensate C and Zn shallow acceptors as well as Si and Se shallow donors, due to the oxygen-related multiple deep levels within the GaAs band gap. Deep level transient spectroscopy ͑DLTS͒ was used to characterize the energy levels associated with these oxygen deep centers. The total measured trap concentration from DLTS can account for the observed compensation in n-type GaAs:O. The total trap concentration in p-type GaAs:O, however, was found to be lower than the observed compensation by a factor of ϳ100. These oxygen deep centers exhibit multiple electronic states which have been associated with the local number of Al nearest neighbors and the microscopic structure of the defect. The concentration and nature of these deep levels were not influenced by the chemical identity of the shallow dopants.

Heavily doped p-type AlGaInP grown by metalorganic chemical vapor deposition

“…In MOCVD, oxygen contaminations built into the layer through reactions with aluminium form the strong Al-O bond [8]. Recently, it was shown by Huang et al [9] that intentionally added oxygen in the form of diethyl aluminium ethoxide gives rise to multiple deep donor and acceptor levels in the band gap of GaAs. Oxygen related deep donor levels are also found in AlGaInP, but in this material oxygen does not form a deep acceptor level [1].…”

Improved performance of laterally oxidized GaInP/AlGaInP lasers by thermal annealing

“…There is little data in the literature concerning oxygen in AlGaInP; however data exists on oxygen in AlGaAs and in particular, controlled amounts of O and Al in GaAs and InP. 12,13 It has been found that the deep levels which compensate p-type doping are related to Al-O bonds. Because of the strength of such bonds, it is expected that the moderate temperature used in this experiment would break up few of the Al-O bonds in the cladding region, but would easily break up the acceptor-hydrogen complexes.…”

Epitaxy and characterization of AlGaInP-based LEDs on Si substrates for visible-spectrum light emission

“…Oxygen impurities can deactivate both n-type and p-type dopants. In this case, the p-type cladding layer could be fully compensated by oxygen impurities [113]. This proposed mechanism of oxygen compensation supports the J-V characteristics of the newly grown p-i-n LED, and it also explains the early turn-on voltage of the newly grown n-i-p LED.…”