High density plasma etching of ultrananocrystalline diamond films in O2/CF4 and O2/SF6 inductively coupled plasmas

Inductively coupled plasma etching of ultrananocrystalline diamond (UNCD) films was performed in O₂/CF₄ and O₂/SF₆ discharges. Higher etch rates were produced for the O₂/SF₆ discharges and the films etched in the 10O₂/5CF₄ discharges retained smooth surface morphology similar to the unetched control sample. Al mask showed a good etch selectivity to the UNCD for both plasma chemistries and highly anisotropic pattern transfer with a vertical sidewall profile was achieved.