Seminarium Fizyki Materii Skondensowanej

Formation of various geometric patterns during crystal growth remains asubject of continuous interests of many researchers. It is important as aninteresting example of far from equilibrium, stationary process andbecause of practical applications in the crystal growth technology. Kinetic Monte Carlo simulation method of analysis is based on a simplemodel of particles jumping between well-defined crystal site positions.The main aim of the extended kMC study is to find proper model parameters– coupling constants between particles, energy barriers for each type ofparticle jump, such that describe the main characteristics of the studiedsystem. The simplicity of the model and small number of control parametersallows studying systems of large particle numbers, performing long timesimulations and describing the model behavior in various conditions. Twodifferent systems were analyzed: GaN(0001) surface model in N-richconditions represented by lattice of Ga atoms only and full, two componentmodel of 4H SiC(0001). For both surfaces we can find such regimes ofparameters where straight steps move uniformly during crystal growth orsublimation processes. However within wide parameter range differentinstability phenomena are observed. Step bunching and step meandering arethe most characteristic ones. Both processes were studied as a functionof time, temperature or misorientation angle.