Surface and interface structure formation in III-V compound semiconductors grown by metal-organic vapor phase epitaxy

The influence of impurity incorporation on the formation of microscopic growth-front morphology during metal-organic vapor phase epitaxy (MOVPE) was quantitatively evaluated. The impact of different doping chemistry on growth front morphology was initially studied at first, by using different carbon doping precursors. A model was developed in which surface-adsorbed methyl groups can inhibit further adsorption of Ga species and impede the lateral motion of surface atomic steps and thus lead to the change in surface morphology.; Different types of doping materials belonging to group II, IV, and VI in periodic table were used to study the interaction between impurity elements and growth front structure. Systematic trends of the impact of different impurities on surface morphology were observed. Oxygen and magnesium have the largest influence on the surface morphology of the dopants studied. Several factors, including the impurity valence state, the impurity-host atom bond strength and length, surface step structure, and the surface reaction chemistry play important roles in determining the influence of the impurity atoms on the surface morphology. Models incorporating both surface chemistry and structures were developed in order to predict and explain the details of the different types of impurity incorporation processes.; The effect of interface roughness on the resonant tunneling diode (RTD) device performance was quantitatively examined. A methodology of quantitatively evaluating interface roughness in device structures was demonstrated. The quantitative impact of substrate misorientation and growth interruption at the In{dollar}sb{lcub}0.3{rcub}{dollar}Ga{dollar}sb{lcub}0.7{rcub}{dollar}As/Al{dollar}sb{lcub}0.8{rcub}{dollar}Ga{dollar}sb{lcub}0.2{rcub}{dollar}As interface on the formation of the microscopic interfacial structures was determined. A simulation was used to quantitatively correlate the interface roughness to the I-V characteristics and subsequent device performance.