Removal of Gold Oxide by Low-Temperature Hydrogen Annealing for Microelectromechanical System Device Fabrication

A technique for cleaning a gold surface with a dry process is described for the fabrication of microelectromechanical system (MEMS) devices. Thermal desorption spectroscopy (TDS) analysis of a gold surface exposed to reactive oxygen revealed that annealing causes oxygen to desorb from the gold oxide. To examine the effectiveness of dry-process surface cleaning, the surfaces were annealed in a vacuum, with nitrogen as an inert ambient, and hydrogen as a reductive ambient. For the annealing in a vacuum and nitrogen ambient, a temperature of over 260 degrees C is necessary for the oxide removal. Annealing in hydrogen ambient drastically lowers the cleaning temperature from 260 to 60 degrees C. (C) 2012 The Japan Society of Applied Physics