Strain relaxation during heteroepitaxial growth

We have studied the kinetics of stress relaxation via dislocations in III-V compounds using wafer curvature measurements.  Highlights of this work include:

-         Enhanced relaxation during deposition: Measurement of the stress evolution show that relaxation is significantly faster during growth than during pauses in the growth (see figure). 

-         Strain-relaxed buffer growth: Measurement of stress relaxation during buffer layer growth enabled the surface lattice parameter to be monitored in real time.  This was used to reduce the layer thickness needed to obtain the desired lattice parameter.