Selectivity investigation of HfO/sub 2/ to oxide using wet etching

Experiments indicate that higher HfO/sub 2//oxide etching selectivity in IPA/HF solution as compared to DI water/HF solution. Although DI water/HF solution is acceptable for some HfO/sub 2/ and CVD oxide films, from an integration point of view, the process window is smaller than IPA/HF solution. It is believed that adequately damaged HfO/sub 2/ and annealed CVD oxides will result in considerably high HfO/sub 2//CVD oxide etching selectivity in IPA/HF solution.