Inductively coupled plasma etching of LiTaO₃ in CHF₃/Ar plasmas

CHF3/Ar plasma was used to etch LiTaO3 crystal by inductively coupled plasma technology. The etched crystals under different process parameters were analyzed by surface profilometer and characterized by atomic force microscopy and scanning electron microscope. It was shown that ICP power, RIE power, and total gas flow rate had similar effects on etching rate and selectivity, while Ar/(Ar + CHF3) gas ratio had opposite effects on etching rate and selectivity, with better etching rate and selectivity at the ratio of 0.2. Our work gives a fundamental instruction for the fabrication of LiTaO3 based devices.