Formation of In_xGa_1-xAs/GaAs heteroepitaxial layers using a pulsed laser driven rapid melt-solidification process

Heteroepitaxial In_xGa_1-xAs/GaAs structures have been formed for the first time by pulsed laser induced mixing of molecular beam epitaxy deposited In films (∼200 Å) on GaAs (100) substrates. The process occurs by a melt-induced, rapid-mixing and solidification process driven by a XeCl pulsed excimer laser. The laser has a 27 ns full width at half maximum pulse width at 308 nm with its energy density of 0.28-0.61 J cm ^-2 homogenized into a 4×4 mm square area which is stepped across the wafer. In_xGa_1-xAs layers with x values, as determined by both x-ray diffraction and Rutherford backscattering spectrometry simulation ranging from x=0.21-0.26 and thicknesses of 77-94 nm, have been formed. The formation of single-crystal layers has been verified by ⁴He ion channeling and cross-section transmission electron microscopy.