Magnetron Sputtering With Helium Titanium Film And Thin Film Deposition Monte Carlo Simulation Study

As research on helium behavior in metals is related to the material application in the national defense and energy source areas, it has been always concerned by worldwide researchers. To carry out the investigation into the influence of helium on material's macro performance, we should first explore the method to introduce helium into material. The three common methods, tritium decay, neutron irradiation or ion implantation, do not satisfy one aspect of being safe, simple and available to repeat, short-time applicable, of uniform distribution and demanded concentration or of lower damage. Our research group presents a method that helium is incorporated into the growing Ti film by DC magnetron sputtering in mixture of working gases of helium and argon, which suits most of the above demand and in which the quantity of helium can be controlled.This thesis in the first part further studies the magnetron deposition method on the basis of experiments. By emphasis on the theoretical helium introduction mechanism, this thesis founds a macro-theoretical model, that is:according to the He-Ar mixture system in the experiment, two basic micro-theories (Backscattering Neutrals Theory, BSNT and Low Energy Positive Ions Theory, LEPIT) are combined to a new model through adding the helium ions part to Hoffman's model. We consider that helium into the Ti film is from both helium atoms backscattered by the target with some energy and helium ions near the substrate under the negative bias voltage. The model is then used for the analysis of the above experimental results and the results of model analysis and of experiments fit very well.Moreover, this thesis simulates 2-dimention film deposition process using kinetic Monte Carlo method for further research on helium introduction mechanism and on the relationship between helium concentration and deposition factors and on the influence of helium introduction to micro-structure of film growth. Figures of influence by substrate temperature and deposition energy on the deposited film are showed and explored. It says that:the rising of temperature is good for density of film with voids filled and surface smoothed; while the sampling range of deposition energy is increased, it occurs that there are more vacancies, which is similar to the situation in the introduction of helium that the damage caused by high energy helium and concern of the influence of deposition energy is meaningful to further simulation work; also when the bigger the deposition rate, the more vacancies it is in the film and the more rough it is of the surface and we ascribe them to the insufficient diffusion by limited diffusion time. As the simulation work is simplified, thus many gaps should be filled to the real process, and lots of work has to continue for improving.