InSb MQW - X-Ray Diffraction

X-Ray Diffraction provides essential crystallographic information on the InSb quantum well structures. Rocking curves taken along the (004) axis, shown below, allow the evaluation of barrier layer thickness, Al compostion of the barrier layers and strain on the InSb well. Extending the evaluation along a non-perpendicular axis such as the (115) the strain relative to the GaAs substrate may also be evaluated.

(click on image to enlarge)

X-Ray rocking curves of InSb MQW samples: The left half of each image is the attributed to the InSb wells and the right half is the rocking curve from the Al_xIn_1-xSb barrier and buffer layers. Simulations of the QW structures show that the oscillations in the InSb section of the rocking curves is due to the periodic structure of the quantum wells and give the thickness of the barrier layer. Further by varying the lattice constant (Al content) of the barrier layer, the strain on the InSb lattice is alter which produces a shiftof the simulation, the