Real-time measurement of rocking curves during MOVPE growth of GaxIn1−xP/GaAs

Measurement of real-time rocking curves of semiconductor heterostructures at various stages of metal organic vapor epitaxy (MOVPE) process may provide useful informations about the composition, thickness and in-built strain in the growing epilayer. In this study, we have used a previously grown lattice-matched GaInP/GaAs heterostructure as the reference substrate on which GaxIn1−xP epilayers of different composition and thickness were successively grown by MOVPE while recording rocking curves of each layer in real-time during the growth by using synchrotron X-ray source. Strain redistribution at the interface of the GaInP/GaAs substrate due to the different linear thermal expansion coefficients of GaInP and GaAs was determined from rocking curve of the heterostructure measured at 570 °C. We could detect the change in rocking curve due to the growth of as thin as 16 nm of In-rich Ga0.42In0.58P epilayer at the initial stage of growth. Data from the simulation of each intermediate rocking curve during growth was systematically used to grow a lattice-matched GaInP epilayer. We believe, this is the first report of measurement of rocking curves at high temperature and during MOVPE growth of GaxIn1−xP.