Correlation between background carrier concentration and x-ray linewidth for InGaAs/InP grown by vapor phase epitaxy

Abstract

The background carrier concentration of nominally undoped InGaAs/InP grown by the hydride process was found to correlate to the x-ray linewidth. A double crystal diffractometer was used to measure the mismatch parallel to the (100) surface as well as the more standard perpendicular mismatch. The epitaxial layers were, in general, found to be tetragonally distorted, and the linewidth was found to correlate to the parallel mismatch. Two regimes for the carrier concentration were identified, one for samples having no parallel mismatch and one for samples with parallel mismatch. In the latter case lattice defects which accommodated the misfit strain such as misfit dislocations are concluded to have been responsible for the carrier concentration.