TIN FOIL RECONSTRUCTION IN A HYDROGEN PLASMA

As part of a continuing effort to characterize the influence of plasma environments on metals, tin foil reconstruction in argon, oxygen, and hydrogen plasma afterglows, created with a low power (< 250 W) microwave system, was studied. It was found that neither oxygen nor argon plasmas had any apparent impact on the foil morphology. Hydrogen plasma treatments led to a dramatic reconstruction of the foils. Whereas originally the foil samples consisted of large, oriented crystals, following treatment in hydrogen plasmas the foil surfaces became a network of large pores and strings of small randomly oriented crystallites. No weight loss (etching) was observed. Detailed study and modeling work suggested that the reconstruction was the result of the formation of metastable tin hydride and subsequent short range metal transport. In contrast to the etching of other metals, ions, and electrons were found to play no role in the process. © 1990, American Vacuum Society. All rights reserved.