The thesis is divided into two parts. One is about the preparation of discotic liquid crystals Acid-6. The other is about the growth of Acid-6 thin film by thermal evaporation on silicon oxide surfaces and modified silicon oxide surfaces such as self-assembled monolayer(SAM) in different temperature. The surface morphology and molecular orientation of the thin film were studied by Atomic Force Microscopy(AFM) , X-ray Diffraction (XRD) , and then they were applicated to organic thin film transistor and measured properties by Semiconductor Parameter Analyzer. In the second part of our research, our expectative characteristics was not observed in different temperature and substructure. In the other side, we guessed that because discotic liquid crystals Acid-6 is negative semiconductor materials, so it is susceptible to hydrosphere, thus we can¡¦t observe the electric characteristic of OTFT in the atmosphere. In addition, due to discotic liquid crystals Acid-6 have biggish moleculer weight, thus its viscosity was so big that cause the diameter of Acid-6 crystals to be too small. Therefore, it influenced the carrier mobility. Finally, from the aspect of procedure about fabrication of the devices we can discuss whether this parameter of this device can apply to OTFT.

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.

Thesis (Ph. D.)--Lehigh University, 2000. / Includes vita. Includes bibliographical references (leaves 162-174).

Thesis (doctoral)--Helsinki University of Technology, 2009. / Includes bibliographical references. Also available on the World Wide Web.

Thesis (Ph. D.)--University of Texas at Austin, 2002. / Vita. Includes bibliographical references. Available also from UMI Company.

Thesis (Ph. D.)--School of Chemical Engineering, Georgia Institute of Technology, 2004. Directed by Clifford L. Henderson. / Includes bibliographical references (leaves 366-371).

Thesis (Ph. D.)--University of Hong Kong, 2009. / Includes bibliographical references. Also available in print.

Thesis (M.S.) in Electrical Engineering--University of Maine, 2001. / Includes vita. Includes bibliographical references (leaves 128-129).

Tungsten disulfide is a proven material as a low friction solid coating. The material is well characterized and has proven its capabilities the last century. Graphene is this centurys most promising material with electrical and mechanical properties. With it the 2D material revolution have started. In this thesis I present a feasible way to sputter tungsten disulfide on graphene as a substrate with little damage to the graphene from energetic particles and a straight forward method to quantize the damage before and after deposition. Further I investigate compositional changes in the sputtered films depending on processing pressure and how tungsten disulfide film thickness and the amount of graphene damage affects the materials low friction capabilities. It is shown that graphene is not a viable substrate for a low friction tungsten disulfide film and that tungsten disulfide is an excellent material for low friction coatings even down too a few nanometers and that the films behavior during load in the friction testing significantly depends on the processing pressure during sputtering.

Sputtering is a physical vapor deposition (PVD) process used to create thin films, i.e very thin layers of material. To form compounds, such as oxides and nitrides, it may be beneficial to add a reactive gas to the process which is known as reactive sputtering. This thesis focuses on the simulation of the reactive sputtering process and, more specifically, the effect of the process pressure. Two models have been developed. A Monte Carlo model simulates the distribution of sputtered material throughout the chamber. It is based on the binary collision model with initial conditions acquired from simulations in TRIM. The hard-sphere potential is used as interaction potential in the scattering calculations. The effect of the process pressure is studied for two different elements, sulfur and tungsten. It is found that the distribution of material is heavily influenced by the pressure. A high pressure gives a more diffusion-like distribution compared to a low pressure. As the pressure is increased the deposited material’s energy distribution is found to be shifted towards lower energies until it reaches the energy of thermalized atoms. The second model developed is an extended Berg model that incorporates the effect of redeposition of sputtered material on the target, implantation of reactive ions in the target and preferential sputtering. Using simulations the effect of these extensions is discussed. It is found that an increased pressure may eliminate the hysteresis region which has been observed experimentally. Finally an outline is presented on how the two models can be unified into a Berg-model that takes the non-uniform distribution of sputtered material into account.