Abstract
The etching properties of HfAlO, HfO2 and silicon wafer with pattern were investigated using inductively coupled high density plasma etcher. To develop plasma etch process of high dielectric gate oxide. The effects of the experimental parameters, including ICP power, bias power, chamber pressure and etching time, on the etch rate and selectivity were studied. The ion energy and reactive species were found to significantly enhance the HfAlO etch rate and improve the etching selectivity to Si from reference. Therefore, we measured the radio frequency peak voltage and ion current by impedance meter. We measured the intensity of plasma species, including Ar(750.4 nm), Cl(725.7 nm) and BCl(271.99 nm) by optical emission spectroscopy.Plasma etching of HfAlO, HfO2 and silicon wafer with pattern was studied in BCl3/Ar plasmas. The etch rate of Si is suppressed in BCl3 plasmas, due to formation of the passivation layer and reduced Cl density. We increased etching selectivity above 10 at lower bias power and chamber pressure.