Molecular beam epitaxy of GaAs/AlxGa1−xAs/InyGa1−yAs heterostructures for opto-electronic devices: control of growth parameters

The growth of heterostructures for opto-electronic devices by molecular beam epitaxy is described. As this first of approximately one hundred process steps determines the threshold voltages of transistors as well as the threshold currents of lasers it needs very close control. The basic structure consists of aGaAs/AlxGa1−xAsquantum well laser grown on top of a two sided δ-doped quantum well HEMT structure for depletion and enhancement FETs. Growth parameters are first controlled by RHEED, Hall effect and photoluminescence. Further control is done by measuring electrical parameters on separate HEMT and laser structures. Finally, control is done before and after the growth of the opto-electronic structure. There is no control of parameters during epitaxy.