LATERAL AND VERTICAL COMPOSITION CONTROL IN MOCVD-GROWN INP/GAINAS(P) STRUCTURES

Optimisation of the MOCVD process to give very uniform InGaAs and GaInAsP is discussed together with techniques for achieving monolayer interfaces in InP/InGaAs quantum wells. Standard deviations (sigma-78) in the PL wavelength of less than 5 nm have been achieved over 2 inch wafers for all the alloys studied, while that for the lattice mismatch has been in the 200-300 ppm range. A standard deviation (sigma-78) in layer thickness for 2 inch wafers of less than 3% has been measured by XRD measurements on MQW stacks.