Defect reductions and strain relaxation mechanisms in InP grown on patterned Si(001)

We report metal organic chemical vapour deposition of InP directly on Si substrates patterned with V-grooves. The shape of the epilayer is investigated as a function of pitch of the corrugation. For the first time, growth of InP on sub μm patterned Si substrates is reported. We find complete planarization of the sawtooth structure and a reduction of dislocation density by a factor of 5. Freestanding InP mesas for V-groove pitch of 3.5 μm show enhanced luminescence efficiency on the defect-free top of the structure as well as in the groove near the heterointerface. A finite element analysis is applied to model the relaxation of thermal strain of InP-mesas on Si and is compared quantitatively with the lateral band gap variations as obtained by scanning cathodoluminescence