ABSTRACT
We demonstrate the use of closed loop-loop feedback control of MBE by in-situ spectroscopic ellipsometry to grow reproducible AlAs/GaAs Fabry Perot vertical cavity surface emitting laser cavities and 4 periods of thin (25Å) AlAs/GaAs quantum wells. Sample to sample reproducibility of the Fahry Perot cavity mode position was better than 0.2% among six samples grown at different times. Control of thin (25Å) quantum wells shows a variation of less than 0.5 ML in quantum well thickness. These results show the possibility of using bulk material optical constants in closed-loop feedback control with spectroscopic ellipsometry to increase the reproducibility of complex multilayer structures and thin quantum wells.
