Auger Electron Spectroscopy of Cleanup‐Related Contamination on Silicon Surfaces

Auger electron spectroscopy has been used to evaluate the chemical state of silicon (111) surfaces cleaned by various liquid reagents, ion sputtering, and plasma treatment. The two most common impurities observed were carbon and oxygen. Results indicated that liquid reagent cleaning produced surfaces which were heavily contaminated with carbon, and that when oxidizing reagents were used, carbon contamination could be kept to a minimum. Sputtering was found to be an unsatisfactory method of cleaning because slices became activated after sputtering and adsorbed impurities from the atmosphere when removed from the vacuum system. Plasma treatment was the most effective of the three types of cleanups used, producing surfaces with the lowest carbon concentrations. One exception was plasma which was shown to deposit carbon on the surface.