In the process of sputtering, what a system operator concerns are the sputtering rate, target utilization, and substrates uniformity. All of them are influenced by variables such as electromagnetic environment, chamber temperature, and pressure. In thin film manufacturing, targets bombarded by ions will sputter atoms to the substrates in order to make thin films; therefore, when a certain target zone is extensively bombarded by ions, target surface will become thinner. In general, when certain part of the target is penetrated, it is no longer usable while utilization rate only from 30 to 50 percent. It causes considerable waste and relatively higher costs. As a result, the objective of this study is to enhance target utilization and the sputtering rate through appropriate adjustment in the structure of the existing DC Magnetron Sputtering System (MSS). Since, the magnetic field distribution in the chamber will be appropriately adjusted inside the DC MSS with extra iron annulus and active compensation magnetizations being added. However, in order to get the better structural refinement of DC MSS it needs a thorough design and management based on Taguchi Method. Then, based on such structural adjustment, electron trajectories on top surface of targets can be conveniently controlled, and target erosion patterns and the number of ions bombarding the target will be indirectly controlled. It will, as a result, achieve the objective of this study by enhancing not only the target utilization efficiency but the sputtering rate.

The DC magnetron sputtering system (MSS) is used in microelectronic industries, and is a key device in the thin film depositions manufacturing process. The major influence factors of the DC magnetron sputtering system operational performance such as operational time and target utilization, which are due to unsatisfactory interactions between electrons and electromagnetic field inside the sputter. This study hopes to improve an established DC MSS, by employing commercial finite element analysis software that will be calculated the flux density, and using three-dimensional equation of motion to estimate the behavior of electrons inside the sputter; furthermore, in the light of the influence electrons position and speed, proposed refinements that the magnetic field above the target is controlled to make the performance improvement. Results from a study showed that the operational trajectory of the electrons at different magnetic flux density levels on top of the target after an operational period, the proposed refinements can increase the sputtering efficiency by as much as 30%. Other than that, through the similarities and dissimilarities between the additional magnetic fields and the main magnetic flux direction, the target erosion profiles with the refinements are more evenly spread out; reduction in the target material consumptions can also be expected.

Co-doped ZnO (ZnO:Co) thin film with room temperature ferromagnetism and spin polarized carriers is one of the advance materials and highly applicable in future development in spintronics. When ZnO:Co films deposited by a £_ growth method in a ion sputtering system, low solubility of Co (3.75%) limits further applications such that a single-guns sputtering thin film growth technique is employed in this study to outreach this limitation. A ZnO:Co bulk with 5 at% of Co was formed by a solid reaction method and used as a target. ZnO:Co films were grown in a single-gun RF sputtering system. However, all films grown at room temperature were insulator which might because sufficient oxygen content in the target and the negative charge of oxygen ion moving toward substrate making the films of full oxygen content. In this study, the post annealing in vacuum environment and the deposition of films in hydrogenation environment are conducted to try to produce various level of oxygen vacancies in the films for understanding the interplay between the oxygen vacancies and the electric transport and magnetic coupling. The present experiment contains two parts: (1) grow films with various thicknesses by controlling deposition time and then applying post annealing process, and (2) grow the films in oxygen reduced environment by introducing hydrogen during growth and taking out partial oxygen content in the plasma and the films. In the first part, the grain sizes of the films are near constant while the crystal quality is improved with the thickness of films. The worse crystal quality of grains, the better the electric transport and the stronger the magnetic coupling after post annealing processes. This indicates that the electric transport and magnetic coupling could be improved when the thin films was formed by crystals with certain disordering and contained a certain level of oxygen vacancies. In the second part, the introduced hydrogen may combine with the oxygen sputtered out from the target before deposition on substrates. It means that the films are grown in oxygen deficient conditions and result in various degrees of oxygen vacancies. Zn clusters precipitate in films when the concentration of hydrogen is over 20%, and at the meantime, they increase the conductivity and suppress the magnetic coupling in the films. These discoveries provide new perspective in understand the electric transport and ferromagnetism mechanics in DMS materials.