MOCVD/MOVPE epitaxy of group III-V nitride with atomistic Prospective & cost Effectiveness

The present study deals with the comparison between two procedures of AlN epitaxy: the Si (111) surface without and with a predose of TMAl. The variation in growth temperature is examined in the samples of both procedures. The use of the pulsed atomic-layer epitaxy (PALE) technique has also been demonstrated successfully to justify the experimental evidence. It was found that PALE is one of the most promising techniques to address the issues associated with the perplexing and controversial question of the initial nucleation process-TMAl or NH3-first, with the capability to overcome the parasitic gas phase chemical kinetics. The reproduction of the MOCVD/MOVPE experimental growth processes pertaining to AlN buffer layer growth on Si (111) substrate is done through simulation. The work also reviews the previously reported modeling approaches of MOCVD reactor, geometry dependent gas phase chemical kinetics and surface diffusion processes involved in growing films. Synergistic use of different aspects to model an entire film's growth is carried out within the framework of the TNL-EpiGrow simulator software. Additionally, the simulation results have been matched with the experimental results, and good agreement has been achieved among them, indicating the reliability of the simulations. The TNL-EpiGrow simulator helps in better understanding the MOCVD/MOVPE growth mechanism at atomistic scale and to achieve the optimum growth conditions of group III-V nitrides, thus, helps in reduction of the epitaxy experimentation cost. The simulation studies of different AlN MOCVD growth processes provide valuable and deeper insight, which is generally not available. The simulation studies used MOCVD AIXTRON 200/4 RF-S horizontal flow reactor geometry architecture in all the cases. The major issue of gas phase parasitic reactions, the impact of variations in temperature, and the V/III ratio on the crystal quality of the film has been examined in details. The pulsed atomic-layer epitaxy (PALE) technique implemented in the TNL-EpiGrow simulator was exploited to examine the improvement in the crystal quality. The TNL-Chemical Kinetics utility package is exploited to simulate gas and surface phase chemical reactions. The adsorption, hopping, and desorption mechanism rates are computed using kinetic Monte Carlo (kMC) algorithms implemented in the TNL-EpiGrow simulator to reproduce the real MOCVD reactor based deposition experiments.