Investigation of Galvanic Corrosion Characteristics between Tantalum Nitride and Poly Silicon in Dilute HF Solutions

摘要

Galvanic corrosion characteristics between poly-Si and tantalum nitride (TaN) (area ratio 1:1 and 1:4) have been investigated in very dilute HF solutions (0.01 to 0.05%) containing controlled levels of dissolved oxygen. The increase in exposed cathode (metal) area as well as aeration results in higher corrosion of poly-Si. In de-aerated HF solutions (less than 0.5 ppm of O_2), irrespective of the area ratio, there appears to be no silicon loss. Morphological changes on poly-Si due to galvanic corrosion have been characterized using Scanning Electron Microscopy.