Mt. Asom et al., MOLECULAR-BEAM EPITAXIAL-GROWTH AND PROPERTIES OF SI-DOPED GAAS ALGAAS QUANTUM-WELLS/, Journal of vacuum science & technology. B, Microelectronics and nanometer structures processing, measurement and phenomena, 12(2), 1994, pp. 1239-1241
We report on molecular beam epitaxial growth of Si doped, single and m
ultiple quantum well structures. We have examined the effects of growt
h parameters such as substrate temperature, group V/III ratio, and int
entional and unintentional impurities, on the electrical and optical p
roperties of the quantum wells structures. Capacitance-voltage and sec
ondary ion mass spectrometry analysis of the structures reveal that th
e net density of electrically active carriers in the wells is controll
ed by the number of acceptor states in the AlGaAs barrier. We have ass
igned the source of the acceptor state to the presence of oxygen in th
e AlGaAs barrier. We observe that the strength of the intersubband opt
ical absorption from the quantum wells increases linearly with the Si-
doping in the well. Photoluminescence measurements indicate that for a
given substrate temperature, a lower V/III ratio results in higher qu
ality quantum well.