Formation and reduction of pyramidal hillocks on InGaAs/InP(111)A.

The formation and reduction of pyramidal hillocks on InGaAs/InP(111)A grown by metal organic chemical vapor deposition were investigated. The triangular pyramidal hillocks were observed on the InGaAs surface on on-axis InP (111)A grown at 650 °C. The hillocks disappeared when the vicinal InP (111)A substrates with an off-axis angle >0.4° were applied. The step and terrace surface of InGaAs on 4.0°-off InP (111)A were obtained. InGaAs on on-axis InP (111)A exhibited a hole concentration, mobility of Hall effect measurement, and full width at half-maximum of X-ray diffraction as 1.0 × 1017 cm−3, 56 cm2/V s, and 140 arcsec, respectively. In contrast, InGaAs on 2.0°-off InP (111)A exhibited 2.3-1017 cm−3, 142 cm2/V s, and 63 arcsec, respectively. We suggest that off-axis substrates enable a reduction of stacking faults, which leads to considerable improvement of crystallinity. [ABSTRACT FROM AUTHOR]