Abstract
It is found that in specific Cl2 plasma conditions, using a nickel hard mask over calcium barium niobate, CBN (a material particularly difficult to etch) significantly improves both sidewall angles and etching selectivity. This mask hardening is due to the competition between NiCl2 growth and etching during the process. For applied bias voltage higher than the Ni sputtering threshold and substrate temperatures higher than 200 °C, this competition results in net NiCl2 growth which drastically improves the etching selectivity. This mask hardening was successfully used to define an optical waveguide with 73° sidewall angle in a 1 μm-thick CBN layer. This effect can potentially be used for the etching of a very large number of complex oxides that are known to be inert and very difficult to etch.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
