Discharge cleaning with hydrogen plasma

Traditional methods of cleaning are being gradually replaced with novel techniques due to increasing technological and ecological standards. A possible substitute for wet chemical cleaning is discharge cleaning. Oxidative impurities are effectively removed by the use of a low-pressure weakly ionized highly dissociated hydrogen plasma. The cleaning action is mainly due to potential interaction of highly reactive hydrogen particles (mainly atoms) with solid surfaces. During the treatment with hydrogen plasma, the samples are often kept close to room temperature, so the method is suitable also for cleaning of delicate samples such as archaeological artifacts. The reaction products such as H2O, H2S, HCl desorb from the surfaces and are easily pumped away. The efficiency of the method is demonstrated by showing results of the discharge cleaning of chip bases, contact strips and old coins. (C) 2001 Elsevier Science Ltd. All rights reserved.