Etching of CoSi2 in HF-based solutions

The etching of CoSi2 thin films in hydrogen fluoride (HF) based solutions has been investigated. It has been observed that the etching mechanism follows a layer-by-layer removal, with a constant etch rate. It has been found that the etch rate of cobalt disilicide in a HF 2 wt% solution is very dependent on the pH of the solution. The lower the pH value is, i.e. a more acid mixture, the higher the etch rate is. CoSi2 etching in HF-based solutions is controlled predominantly by the H+ concentration.