Reactive ion beam etching of HfO_2 film using Ar/CHF_3 gas chemistries

摘要

A number of current and future optical and optoelectronic devices require the creation of structure in HfO_2 film. The reactive ion beam etching of HfO_2 film and photoresist mask in Ar/CHF_3 gas mixture was examined as a function of ion energy, discharge composition and ion beam incident angle. The details of etch rate have been interpreted in terms of mechanism of etching. The etch rate has shown a square root dependence on ion energy and variation versus incidence angle. The CHF_3- plasma produced some chemical enhancement in HfO_2 film etching. Compared with pure argon etching, better selectivity and higher fidelity pattern transfer were achieved with Ar/CHF_3 for HfO2 film over photoresisit mask. The AFM scans of etched HfO_2 film by tapping mode showed good surface quality.