Die optiese eienskappe van opgedampte silikon dunlagies

M.Sc. (Physics)Silicon thin films can be manufactured with the aid of various deposition techniques, each with its own unique properties. In this study the optical properties of silicon manufactured with physical vapour deposition from an electron beam source were studied as a function of layer thickness, deposition rate and substrate temperature. The index of refraction (n and k) as well as optical gap eg. were determined with the aid of characterization models derived specific for optical techniques. These models are covered extensively in the thesis. It was found that the layers were homogeneous and stable, but that the deposition rate and substrate temperature did have a large influence on the properties of the layers. The results show that structural changes, first from the collumnar structure to an amorphous structure and with a further increase in substrate temperature, also a transition from the amorphous to a microcrystalline structure do occure at temperatures considerably lower than what was previously anticipated. With variations in deposition rate it was found that the disorder in the coating will increase with an increase in rate resulting in a reverse transition from the microcrystalline structure to the amorphous structure. Optical gaps in the range 1. 12eV to approximately 1. 38eV were found to be possible with the correct choice of deposition parameters..