The application of parallel light detection to plasma deposition processes

This thesis is concerned with the application of parallel light detection to a variety of physical processes, many of which are plasma processes. Parallel light detection is carried out using an optical multichannel analyser (OMA) coupled with a 1024channel photodiode array detector, and a spectrograph if the spectral information is required. The plasma processes investigated include a planar DC sputtering deposition system, a cathodic titanium vacuum arc and a magnetic solenoid filtered vacuum arc deposition system. An application of the optical multichannel analyser in spectrophotometry is presented. Because of parallel detection of light the OMA-base d spectrophotometer is able to collect optical reflectance and transmittance data at a rate of up to 1024 samples in 17 ms compared with a commercial spectrophotometer which normally has the highest useable rate of 10 samples per second. Using parallel light detection an in—situ monitoring system is set up on a planar DC sputtering deposition system. A number of metal thin films Cu, Ag and Au are produced and their reflectance and transmittance are measured in-situ. It is shown the percolation thickness of silver film produced by sputtering is about 4.7 nm. The optical constants of these films at thicknesses ranging from discrete island form to tens of nanometres are derived from the in-situ measured data using an inverse analysis technique. The light emission from the cathode spot of a titanium vacuum arc is studied using Fizeau interferometry combined with the OMA. The temperatures of neutrals and ions in the cathode spot are determined from Doppler broadening of the emission lines. Temperatures of -3x 105K and 3.5x 104K are assigned for titanium ions and titanium atoms present in the cathode spot respectively. The light emission from a vacuum arc deposition system which has a curved magnetic solenoid between the vacuum arc chamber and the deposition chamber is also studied. The light is detected in the region near the substrate so the effect of magnetic field, ambient gases and substrate bias to the film deposition can be investigated. It is shown that the curved magnetic solenoid effectively removes the neutral species. The introduction of substrate increases the neutral emission due to resputtering of the coated substrate. The ambient gases increase ion emission as a function of their atomic weight, and the substrate bias also increases the ion emission. Defects of optical fibres are studied by cathodoluminescence spectroscopy using the OMA and an electron microscope. The cathodoluminescence spectra obtained for various optical fibre preform samples exhibit a number of defect centres GeE', SiE' and drawing induced defects (DID). It is shown the codopant phosphorus decreases the E' defects and DID while codopants boron and fluorine decreases the DID. It is also shown the oxygen-deficient deposition enhances the GeE' centres. Finally, the optical properties of a Bicron wavelength shifting panel (BC-480) is studied using parallel light detection technique. The quantum efficiency of the panel is found for six incident UV radiation of different wavelengths. This data is crucial in studies into solar neutrinos in high energy particle physics. They range from 43% at 365 nm to 1.5% at 254 nm