Abstract

Self-limiting reactions of ammonium salt in CHF3/O2 downstream plasma were demonstrated for thermal-cyclic atomic layer etching (ALE) of Si3N4. In situ x-ray photoelectron spectroscopy analysis shows that an (NH4)2SiF6 by-product of the same thickness forms on Si3N4 in a wide gas composition range. The (NH4)2SiF6 layer prevents etching of Si3N4 during continuous plasma exposure in that wide range. The (NH4)2SiF6 layer was sublimated by heating, which was consistent with the result of the thermodynamic calculation. The reactions of the (NH4)2SiF6 layer in CHF3/O2 downstream plasma are used for thermal-cyclic ALE of Si3N4 with a newly developed 300-mm tool equipped with an in situ ellipsometer. It was confirmed that the amount etched per cycle saturates with respect to both plasma exposure time and infrared irradiation time.

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 call

Disclaimer: 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.