Cluster particle's deposition on rough surfaces; Effects of diffusion and cluster's shape

The significance role of thin films in manufacturing electronic, magnetic and optical devices has led to technological advances in surface growth under none equilibrium conditions. To fabricate the desired surfaces, various... [ view full abstract ]

The significance role of thin films in manufacturing electronic, magnetic and optical devices has led to technological advances in surface growth under none equilibrium conditions. To fabricate the desired surfaces, various techniques have been introduced to manage the rate of involved mechanisms such as deposition, evaporation, and diffusion of particles. In recent years, increasing the application of surfaces deposited by clusters in magnetic storage and solar cells has brought about new methods of producing cluster particles and depositing them on surfaces. The controllability of parameters in cluster sources such as, the kinetic energy of particle beam; particle size distribution function and density of clusters in the presence of substrates with specified properties have led to produce a wide variety of thin films. Researches show that deposition of particles with low kinetic energy does not change shapes of particles and substrate, which consequently leads to porous media. In the other hands, deposition of clusters with higher kinetic energy can lead to the deformation of particles and surfaces which can construct smoother surfaces.
We use Monte Carlo simulation to study the spatial-temporal behavior of thin films generated by low kinetic energy cluster particles. To this end, two models are considered in order to investigate the effects of clusters' shapes and their diffusion ability on the surface. In the first model, clusters are considered as a string of particles with unit height and non-unit length. The growth process in this model is implemented based on Random Deposition with Surface Relaxation (RDSR) model where particles can diffuse on the surface until reaching the minimum state of energy. In the RDSR model for particles with unit size, the model with specific critical exponents is categorized in Edward- Wilkinson (EW) universality class. The second model studies deposition of porous clusters with different shapes according to Random Deposition (RD) model. Our results reveal that using cluster particles with non-unit size leads to a non-Markovian process with a porous medium which changes the universality class of models to Kardar-Parizi-Zhang (KPZ) by scaling exponents B = 0:3 and a = 0:5.