On the nitrogen and oxygen incorporation in plasma-enhanced chemical vapor deposition (PECVD) SiOxNy films

Silicon oxynitride films were deposited by plasma-enhanced chemical vapor deposition at low temperatures using nitrous oxide (N2O) and silane (SiH4) as gas precursors. The influence of the N2O/SiH4 flow ratio (varied from 0.25 up to 5) and the thickness of the films on the optical and structural properties of the material was analyzed. The films were characterized by ellipsometry, Fourier-transform infrared spectroscopy, Rutherford backscattering spectroscopy and optical absorption. Two distinct types of material were obtained, silicon dioxide-like oxynitrides SiO2−xNx and silicon-rich oxynitrides SiOxNy (x+y<2). The results demonstrate that in silicon dioxide-like material, the nitrogen concentration can be adequately controlled (within the range 0–15 at.%) with total hydrogen incorporation below 5 at.% and no appreciable SiH bonds. It is also shown that the composition remains uniform through the entire thickness of the films. Furthermore, a linear relation between the refractive index and the nitrogen concentration is observed, which makes this material very attractive for optoelectronic applications. On the other hand, silicon-rich material is similar to amorphous silicon, and presents an increasing concentration of SiH bonds, increasing refractive index and decreasing optical gap, which makes it promising for applications in light-emitting devices.

[1]  U. Hilleringmann,et al.  Results of Monolithic Integration of Optical Waveguides, Photodiodes and CMOS Circuits on Silicon , 1992, ESSDERC '92: 22nd European Solid State Device Research conference.

[2]  Carlos Domínguez,et al.  Plasma enhanced CVD silicon oxide films for integrated optic applications , 1999 .

[3]  W. Brown,et al.  Post-deposition processing of low temperature PECVD silicon dioxide films for enhanced stress stability , 1997 .

[4]  S. Burton,et al.  The Variation of Physical Properties of Plasma‐Deposited Silicon Nitride and Oxynitride with Their Compositions , 1984 .

[5]  W. Lanford,et al.  The hydrogen content of plasma‐deposited silicon nitride , 1978 .

[6]  Process Optimization of Plasma-Enhanced Chemical Vapor Deposited Passivation Thin Films for Improving Nonvolatile Memory IC Performance , 1998 .

[7]  K. Worhoff,et al.  Plasma enhanced chemical vapor deposition silicon oxynitride optimized for application in integrated optics , 1999 .

[8]  I. Boyd,et al.  Characteristic photoluminescence band in Si+-implanted SiO2 grown on Si wafer , 2000 .

[9]  M. I. Alayo,et al.  Thick SiOxNy and SiO2 films obtained by PECVD technique at low temperatures , 1998 .

[10]  B. Tweed,et al.  Fabrication of waveguides using low‐temperature plasma processing techniques , 1993 .

[11]  David V. Tsu,et al.  Atomic structure in SiO2 thin films deposited by remote plasma‐enhanced chemical vapor deposition , 1989 .

[12]  W. Windbracke,et al.  Thermal Annealing Effects on the Mechanical Properties of Plasma‐Enhanced Chemical Vapor Deposited Silicon Oxide Films , 1992 .

[13]  M. Estrada,et al.  Influence of low-temperature annealing on the dielectric characteristics and final parameters of SiO2 MIS thin film transistors , 1997 .

[14]  B. Pivac,et al.  SiH bonding configuration in SiOx: N,H films deposited by chemical vapor deposition , 1996 .

[15]  C. Denisse,et al.  Plasma‐enhanced growth and composition of silicon oxynitride films , 1986 .

[16]  G. Lucovsky,et al.  Infrared spectroscopic study of SiOx films produced by plasma enhanced chemical vapor deposition , 1986 .

[17]  M. Tabasky,et al.  Investigation of thick, low‐temperature plasma deposited silica films for waveguide fabrication , 1994 .

[18]  Minoru Nakamura,et al.  Infrared, Raman, and X‐Ray Diffraction Studies of Silicon Oxide Films Formed from SiH4 and N 2 O Chemical Vapor Deposition , 1985 .

[19]  N. Morimoto,et al.  Deposition of thick TEOS PECVD silicon oxide layers for integrated optical waveguide applications , 1998 .

[20]  W. Brown,et al.  Characterization of High Rate Deposited PECVD Silicon Dioxide Films for MCM Applications , 1995 .

[21]  The preparation of photoluminescent Si nanocrystal SiOX films by reactive evaporation , 1998 .

[22]  R. Berjoan,et al.  Composition-density and refractive index relations in PECVD silicon oxynitrides thin films , 1997 .

[23]  M. I. Alayo,et al.  High quality low temperature DPECVD silicon dioxide , 1997 .

[24]  D. Della Sala,et al.  Structural Analysis by Infrared and X‐Ray Photoelectron Spectroscopy of Amorphous Silicon Produced by Plasma‐Deposition , 1990 .

[25]  A. Kuiper,et al.  Characterization of Silicon‐Oxynitride Films Deposited by Plasma‐Enhanced CVD , 1986 .

[26]  Adele Sassella,et al.  Infrared study of Si-rich silicon oxide films deposited by plasma-enhanced chemical vapor deposition , 1997 .

[27]  C. Domínguez,et al.  An integrated silicon ARROW Mach-Zehnder interferometer for sensing applications , 1996 .

[28]  I. Pereyra,et al.  Low temperature plasma enhanced chemical vapour deposition boron nitride , 1997 .