Dependence of Rocking Curve for Thin In1-xGaxAs1-yPy Layer on Thickness in a Symmetric Bragg Case

The dependence of the half-width of the rocking curve and the integrated intensity for the In 1- x Ga x As 1- y P y epitaxial layer on its thickness is measured in the parallel arrangement [+(400), -(400)] in a symmetric Bragg case using double-crystal diffractometry. The half-width increases abruptly with decreasing thickness in the region thinner than 0.5 µm, while the intensity increases linearly with increasing thickness in a wide region from 0.1–10 µm. This dependence is explained by the dynamical diffraction theory in which the quaternary epitaxial layer is treated as a non-absorbing, thin, perfect crystal.