New Compact Electron Cyclotron Resonance Plasma Source for Silicon Nitride Film Formation in Minimal Fab System

• Published in: IEEE Journal of the Electron Devices Society
• Main Authors: Tetsuya Goto, Kei-Ichiro Sato, Yuki Yabuta, Shigetoshi Sugawa, Shiro Hara
• Format: Article
• Language: English
• Published: IEEE 2018-01-01
• Subjects: Minimal fab system; silicon nitride; plasma damage
• Online Access: https://ieeexplore.ieee.org/document/8107492/

A compact magnetic-mirror confined electron cyclotron resonance plasma source for low-damage plasma processings was developed, especially aiming for the realization of high-quality silicon nitride film formation for the sub-micron complementary metal-oxide semiconductor device processes in the minimal fab system. The developed plasma source was installed in the minimal tool, and deposition of silicon nitride film was performed. The magnetic mirror confinement method worked well to excite the high-density plasma with low plasma excitation power of 10 W or less. By adopting the substrate position slightly apart from the core plasma region with the pressure range of 25 Pa, the silicon nitride film having the similar N/Si ratio to the ideal value of Si₃N₄ could be obtained in the room-temperature deposition. Under this condition, impurity concentration of oxygen in the film could be suppressed less than 1%, which was even smaller than that in the controlled low-pressure chemical-vapor deposited film at 750 °C.