MOVPE-grown Al_xGa_1-xAs_yP_1-y strain compensating layers on GaAs

Published in:
J. Cryst. Growth, vol. 370, pp. 150-153 (2013).
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Abstract:
We demonstrate the substitution of Al0.85GaAs layers, used as claddings in edge-emitting diode lasers, with tensile strained Al_0.85GaAs_0.96P layers to reduce the room temperature wafer bow. Monitoring of the in-situ curvature change during growth and cool down is used for optimization of strain compensation. The onset of partial relaxation during growth caused by too high accumulated tensile strain is seen in in-situ transients of the wafer curvature and thus thickness and composition of the AlGaAsP layer can be optimized. Knowing the limits we finally propose and demonstrate a strain-compensation scheme for a two-stage diode laser which reduces room temperature curvature by Δ_κ = 38 km^-1.

Keywords:
A1. High resolution X-ray diffraction; A1. In-situ curvature measurements; A3. Metalorganic vapor phase epitaxy; B3. Laser diodes

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