Atomic Hydrogen as a Reducing Agent

T h e removal of surface oxides is an important step in the manufacture of electron devices. The objective of this process is usually to facilitate the wetting of solid surfaces by molten metals or to improve some electrical properties of the device by changing the surface properties of certain components. Oxide-free surfaces can be obtained by wet chemical treatments, by bombardment with accelerated particles or by reduction in a gaseous ambient. Each of these processes exhibits certain limitations. Liquid reagents leave residues and require additional cleaning, electron or ion bombardment is vulnerable to shielding effects, and the high temperatures necessary for gaseous reduction restrict its application on most assembled electron devices. A powerful gaseous reducing agent capable of removing oxygen at relatively low temperatures combines the virtues of all these methods.1 A study was undertaken, therefore, with such a reagent, atomic hydrogen, to establish the feasibility of its use. T h e following discussion gives our findings on the following three questions: (1) how to produce and transfer atomic species, (2) how much decrease in reduction temperature can be expected compared 261