Wet etching characteristics of cubic GaN (c GaN) thin films grown on GaAs(001) by metalorganic vapor phase epitaxy (MOVPE) are investigated.The samples are etched in HCl,H 3PO 4,KOH aqueous solutions,and molten KOH...Wet etching characteristics of cubic GaN (c GaN) thin films grown on GaAs(001) by metalorganic vapor phase epitaxy (MOVPE) are investigated.The samples are etched in HCl,H 3PO 4,KOH aqueous solutions,and molten KOH at temperatures in the range of 90～300℃.It is found that different solution produces different etch figure on the surfaces of a sample.KOH based solutions produce rectangular pits rather than square pits.The etch pits elongate in 1 0] direction,indicating asymmetric etching behavior in the two orthogonal <110> directions.An explanation based on relative reactivity of the various crystallographic planes is employed to interpret qualitatively the asymmetric etching behavior.In addition,it is found that KOH aqueous solution would be more suitable than molten KOH and the two acids for the evaluation of stacking faults in c GaN epilayers. direction,indicating asymmetric etching behavior in the two orthogonal <110> directions.An explanation based on relative reactivity of the various crystallographic planes is employed to interpret qualitatively the asymmetric etching behavior.In addition,it is found that KOH aqueous solution would be more suitable than molten KOH and the two acids for the evaluation of stacking faults in c GaN epilayers.展开更多
The wide stripe (15μm) selective area growth (SAG) of InGaAsP by low pressure MOVPE is systematically investigated.The characteristics of the growth ratios,thickness enhancement factors,bandgap modulation,and composi...The wide stripe (15μm) selective area growth (SAG) of InGaAsP by low pressure MOVPE is systematically investigated.The characteristics of the growth ratios,thickness enhancement factors,bandgap modulation,and composition modulation vary with the growth conditions such as mask width,growth pressure.Flux of Ⅲ group precursors are outlined and the rational mechanism behind SAG MOVPE is explained.In addition,the surface spike of the SAG InGaAsP is shown and the course of it is given by the variation of Ⅴ/Ⅲ.展开更多
文摘Wet etching characteristics of cubic GaN (c GaN) thin films grown on GaAs(001) by metalorganic vapor phase epitaxy (MOVPE) are investigated.The samples are etched in HCl,H 3PO 4,KOH aqueous solutions,and molten KOH at temperatures in the range of 90～300℃.It is found that different solution produces different etch figure on the surfaces of a sample.KOH based solutions produce rectangular pits rather than square pits.The etch pits elongate in 1 0] direction,indicating asymmetric etching behavior in the two orthogonal <110> directions.An explanation based on relative reactivity of the various crystallographic planes is employed to interpret qualitatively the asymmetric etching behavior.In addition,it is found that KOH aqueous solution would be more suitable than molten KOH and the two acids for the evaluation of stacking faults in c GaN epilayers. direction,indicating asymmetric etching behavior in the two orthogonal <110> directions.An explanation based on relative reactivity of the various crystallographic planes is employed to interpret qualitatively the asymmetric etching behavior.In addition,it is found that KOH aqueous solution would be more suitable than molten KOH and the two acids for the evaluation of stacking faults in c GaN epilayers.
文摘The wide stripe (15μm) selective area growth (SAG) of InGaAsP by low pressure MOVPE is systematically investigated.The characteristics of the growth ratios,thickness enhancement factors,bandgap modulation,and composition modulation vary with the growth conditions such as mask width,growth pressure.Flux of Ⅲ group precursors are outlined and the rational mechanism behind SAG MOVPE is explained.In addition,the surface spike of the SAG InGaAsP is shown and the course of it is given by the variation of Ⅴ/Ⅲ.
