Effects of Deposition and Annealing Parameters on Ohmic Behavior of Indium Contacts to GaAs

Many studies have reported prospective methods of forming ohmic contacts to semiconductors and measuring their quality in terms of electrical characterization via I-V curves and transmission line measurements, surface/depth chemical analysis using techniques like X-ray photoelectron spectroscopy, and structural analysis via cross-section TEM. In this project, the process of forming annealed indium-gallium arsenide contacts is drawn from the literature and modified such that the quality of the resulting In-GaAs interfaces can be investigated to assess the validity of the method. To create the contacts, indium is deposited onto GaAs wafers with mesa-patterned structures via DC magnetron sputtering. Different annealing and deposition conditions will be considered, and the effects of the variation on the quality of the interface will be evaluated in terms of the electrical, chemical, and crystallographic properties of the interface. Ultimately, results are intended to inform whether the proposed methodology is proper for fabricating low-resistance ohmic contacts to gallium arsenide, according to the benchmark set by the established literature.