X-ray CTR scattering measurement of InPrInGaAsrInP interface structures fabricated by different growth processes

Hetero-interfaces of InPrInGaAs three monolayers ML..rInP samples grown by organometallic vapor phase epitaxy OMVPE.were investigated using X-ray crystal truncation rod CTR.measurement. The samples were prepared with three different source-gas flow-sequences: a. conventional sequence, b. growth interruption, and c. Ga and In source-gas pulse injection. The results of the X-ray CTR measurement showed that the interfaces between InP cap and InGaAs layers of b. and c. were sharper than that of a. as intended. However, the amount of As in b. was less than that designed since As atoms desorbed even from the InGaAs layer during the growth interruption. Surprisingly, the Ga atoms distributed wider and peak compositions of Ga were smaller than those designed for all the samples. It means that the quantum well structures are far from those designed and expected. It suggests that more efforts are necessary to control the distribution of group-III atoms after we solved the problem of group-V atom distributions. q2000 Elsevier Science B.V. All rights reserved