Minimizing hydrogen content in silicon oxynitride by thermal oxidation of silicon-rich silicon nitride

✍ Scribed by C.K. Wong; H. Wong; M. Chan; C.W. Kok; H.P. Chan

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 519 KB
• Volume: 46
• Category: Article
• ISSN: 0026-2714
• DOI: 10.1016/j.microrel.2006.01.006

✦ Synopsis

This work reports a detailed study of the re-oxidation effects on the hydrogen content and optical properties of silicon oxynitride films grown by plasma enhanced chemical vapor deposition (PECVD) with N 2 O, NH 3 and SiH 4 as the precursors. Results showed that the silicon oxynitride deposited with gas flow rates of NH 3 /N 2 O/SiH 4 = 20/500/20 (sccm) has favorable properties for integrated waveguide applications. The refractive index of this layer is about 1.57 at 632.8 nm wavelength and the layer has a comparative low density of NAH bonds. With a high temperature re-oxidation of the as-deposited film, the hydrogen content of the oxynitride film was reduced from 2.255 • 10 22 to 6.98 • 10 20 cm À3 which is attributed to the removal of excess silicon oxidation and hydrogen bonds.