ETCHING OF COSI2 IN HF-BASED SOLUTIONS

The etching of CoSi2 thin films in hydrogen fluoride (HF) based soluti ons has been investigated. It has been observed that the etching mecha nism follows a layer-by-layer removal, with a constant etch rate. It h as been found that the etch rate of cobalt disilicide in a HF 2 wt% so lution is very dependent on the pH of the solution. The lower the pH v alue 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+ co ncentration.