Br. Bennett et Ja. Delalamo, OPTIMAL EPILAYER THICKNESS FOR INXGA1-XAS AND INYAL1-YAS COMPOSITION MEASUREMENT BY HIGH-RESOLUTION X-RAY-DIFFRACTION, Journal of applied physics, 73(12), 1993, pp. 8304-8308
The composition of InxGa1-xAs and InyAl1-yAs epitaxial layers on InP s
ubstrates can be measured by high-resolution x-ray diffraction (HRXRD)
in many cases. If layers are too thick, however, substantial lattice
relaxation will occur, requiring multiple asymmetric scans to determin
e composition. If layers are too thin, they will not produce a distinc
t Bragg peak. Based upon measurements of both coherent and relaxed lay
ers as well as simulations, we have determined the range of epilayer t
hickness over which a single HRXRD scan yields the composition of InxG
a1-xAs and InyAl1-yAs layers to within 1%. Calibration layers grown wi
thin this range allow fast and accurate characterization.