Abstract
There are two parts in this thesis. Part I focuses on the transient effect in InGaP/GaAs hetero-junction bipolar transistors (HBTs). Part II focuses on the P memory effect and buffer-layer-quality determination using C-V measurement in AlGaAs/GaAs pseudomorphic high-electron-mobility transistors (pHEMTs). The characterization of hydrogen passivation for InGaP HBTs grown on semi-insulating GaAs substrates is studied. The transient effect caused by hydrogen passivation results the current gain (□) increase. The calculation of the hydrogen passivation ratio in the base layer is proposed to compare with the results using the secondary ion mass spectrometry (SIMS) measurement. The transient effect can be eliminated after three or more cycles of thermal annealing. The phosphorus concentration profiles were obtained by SIMS measurement for the analysis of the memory effect. The memory effect of phosphorus is observed during the epitaxial growth. The background phosphorus concentration can be improved about two order magnitudes using the group-V elements of tertiarybutylphosphine (TBP) instead of phosphine (PH3). A comparison of samples grown by molecular-beam epitaxy (MBE) reactor and metal-organic vapor-phase epitaxy (MOVPE) is also demonstrated. Capacitance-voltage (C-V) measurements are introduced to monitor and improve the epitaxial buffer layers in pHEMTs.