Numerical Simulation And Experimental Verification Of Thi Film Growth

With the nano-film material widely used in the field of modern technology, the study of thin films has become a hot topic, whether to improve the original performance of thin film materials or to develop a new performance of thin film are all inseparable with the microstructures of the film. In the growth process of thin film, the complex atomic motions as well as the interactions between these motions have a very significant influence on the microstructures and properties of thin films, therefore it is of great significance to study the film growth in micro-scale.This paper studies the microscopic growth structure of the NiTi film experimentally and numerically. We simulated three-dimensional growth process of the elemental Cu films on the quadrilateral substrate and studied the effects of substrate temperature, deposition rate and the coverage to the roughness and surface morphology of Cu films, then studies the NiTi alloy films growth on this basis. The model considers the three dynamic processes of two kinds of atoms in the thin film growth process as well as the interactions between the atomic motions, and analyzed the influence of substrate temperature and deposition rate on film morphology. The experiment was carry out by sputtering elemental pure Ni and pure Ti target at the same time, and the influences of different substrate temperatures and sputtering powers on the film atomic composition and surface morphology were also presented and compared with the simulation.The results showed that:the surface roughness decreases when increases the substrate temperature or lower deposition rate, at the same time, the growth mode of thin film shift from island growth to layered growth, and film surface roughness is directly related to the nucleation of sub-monolayer films. We tested the components of the prepared films, and got the nearly equiatomic NiTi films. We found a decrease of4%of Ti atoms when experiment temperature increased from room temperature to500℃. The island structure is analyzed by Scanning Electron Microscope (SEM), and we observed that with the substrate temperature going higher or deposition rate becoming lower, the average size of the island becomes bigger and the island number decreases. This conclusion is consistent with the simulation results.