| Summary: | 碩士 === 國立臺南大學 === 材料科學系碩士班 === 101 === In recent years, plasma or ion etching processing on the substrate surface has been widely used in academic research and industrial manufacturing. In this study, plasma and ion etching are divided into two parts. In plasma etching experiments, parallel plate electrodes are used to produce plasma to etch the (100) surface of germanium wafer and the effects on its surface morphology are also investigated. First, the processing conditions of 200V with different substrate temperatures (87℃, 24℃) are explored, and various surface morphologies can be observed from the results of experiments. The wafer surface is flattened by increasing the temperature. As different etching voltages (200V, 400V, 600V) are applied, a rougher surface with conical nanostructures is created for a high voltage. We have also examined the characteristics of Photoluminescence (PL) for various surface morphologies of (100) germanium. In ion etching experiments, focus ion beam (FIB) is used to study the effects of the ion energy and current density on the morphological formations of germanium. We first discussed the influence of gallium ion energy (30keV, 10keV) with the same current density (3.525 × A/ ). After 30keV ion energy of gallium eroded, long fiber-like structures with nano-walls are formed. On the other hand, short fiber-like structures with nano-pillars are produced after 10 keV ion beam irradiated. With increasing current density, such as 3 times of dose rate for 10 keV irradiation, similar fiber-like structures with nano-pillars were obtained. The main impact of changing ion dose rate is increasing the etching rate. From these experiments, we had also analyzed the relations between the etching rate and different irradiation conditions. At last, we simulated these patterns on germanium successfully by numerical methods.
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