Ultra-high vacuum deposition and characterization of silicon nitride thin films

作者:Katzer D S*; Meyer D J; Storm D F; Mittereder J A; Bermudez V M; Cheng S F; Jernigan G G; Binari S C
来源:JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B, 2012, 30(2): 02B129.
DOI:10.1116/1.3675835

摘要

Silicon nitride thin films were deposited on (100) Si wafers in an ultra-high vacuum system using a Si effusion cell and reactive nitrogen from a radio-frequency plasma source. The films were characterized using infrared transmission spectroscopy, infrared reflectance, Rutherford backscattering spectrometry, spectroscopic ellipsometry, specular x-ray reflectivity, wet etching in a buffered-oxide etch solution, and the electrical characterization of metal-insulator-semiconductor capacitors. High-quality, stoichiometric silicon nitride films with a refractive index of 2.05 at 632.8 nm are produced when the deposition temperature is 750 degrees C. Lower deposition temperatures produce nitrogen-rich silicon nitride films with lower refractive index, lower density, greater tendency toward oxidation in ambient air, faster etching in a buffered oxide etch solution, and greater electrical leakage. A deposition model involving thermal evolution of weakly-bonded excess N is proposed to explain our observations.

  • 出版日期2012-3