Unusual growth modes in pulsed laser deposition of ZnSe thin films on GaAs

In about 1000A thick films of ZnSe deposited on (001) GaAs substrates by pulsed laser deposition using Q-switched Nd:YAG laser, large clusters were found to grow on the sites of the microscopic surface damage in the substrate. Films deposited at a substrate temperature of 350°C showed a preferrential growth in (111) direction. At a substrate temperature of 450°C, the film was found to grow in polycrystalline wurtzite phase. Possible mechanism and reasons for these unusual growth modes are discussed.