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Effect of film chemistry on refractive index of plasma-enhanced chemical vapor deposited silicon oxynitride films: A correlative study

Published online by Cambridge University Press:  31 January 2011

S. Naskar
Affiliation:
RTI International, Center for Materials & Electronic Technologies, Research Triangle Park, North Carolina 27709; and Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708
S.D. Wolter*
Affiliation:
Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708
C.A. Bower
Affiliation:
RTI International, Center for Materials & Electronic Technologies, Research Triangle Park, North Carolina 27709
B.R. Stoner
Affiliation:
RTI International, Center for Materials & Electronic Technologies, Research Triangle Park, North Carolina 27709; and Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708
J.T. Glass
Affiliation:
Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Thick SiOxNy films were deposited by radiofrequency (rf) plasma chemical vapor deposition using silane (SiH4) and nitrous oxide (N2O) source gases. The influence of deposition conditions of gas flow ratio, rf plasma mixed-frequency ratio (100 kHz, 13.56 MHz), and rf power on the refractive index were examined. It was observed that the refractive index of the SiOxNy films increased with N and Si concentration as measured via x-ray photoelectron spectroscopy. Interestingly, a variation of refractive index with N2O:SiH4 flow ratio for the two drive frequencies was observed, suggesting that oxynitride bonding plays an important role in determining the optical properties. The two drive frequencies also led to differences in hydrogen concentration that were found to be correlated with refractive index. Hydrogen concentration has been linked to significant optical absorption losses above index values of ∼1.6, which we identified as a saturation level in our films.

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Articles
Copyright
Copyright © Materials Research Society 2008

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References

REFERENCES

1Germann, R., Salemink, H.W.M., Beyeler, R., Bona, G.L., Horst, F., Massarek, I.Offrein, B.J.: Silicon oxynitride layers for optical waveguide applications. J. Electrochem. Soc. 147(6), 2237 2000CrossRefGoogle Scholar
2Mattsson, K.E.: Plasma enhanced growth, composition and refractive index of silicon oxynitride films. J. Appl. Phys. 77(12), 6616 1995CrossRefGoogle Scholar
3Alayo, M.I., Pereyra, I.Carreno, M.N.P.: Thick SiOxNy and SiO2 films obtained by PECVD technique at low temperatures. Thin Solid Films 332, 40 1998CrossRefGoogle Scholar
4Alayo, M.I., Pereyra, I., Scopel, W.L.Fantini, M.C.A.: On the nitrogen and oxygen incorporation in plasma-enhanced chemical vapor deposition (PECVD) SiOxNy films. Thin Solid Films 402, 154 2002CrossRefGoogle Scholar
5Ay, F., Aydinli, A., Roeloffzen, C.Driessen, A.: Structural and loss characterization of SiON layers for optical waveguide applications,IEEE Lasers and Electro-Optics Society (LEOS) 2000 Annual Meeting, Vol. 2, IEEE Piscataway, NJ 2000 760Google Scholar
6Worhoff, K., Hilderink, L.T.H., Driessen, A.Lambeck, P.V.: Silicon oxynitride—A versatile material for integrated optics application. J. Electrochem. Soc. 149(8), F85 2002Google Scholar
7Worhoff, K., Driessen, A., Lambeck, P.V., Hilderink, L.T.H., Linders, P.W.C.Popma, Th.J.A.: Plasma enhanced chemical vapor deposition silicon oxynitride optimized for application in integrated optics. Sens. Actuators 74, 9 1999CrossRefGoogle Scholar
8Worhoff, K., Lambeck, P.V.Driessen, A.: Design, tolerance analysis and fabrication of silicon oxynitride based planar optical waveguides for communication devices. J. Light-wave Technol. 17(8), 1401 1999CrossRefGoogle Scholar
9Tsu, D.V., Lucovsky, G., Mantini, M.J.Chao, S.S.: Deposition of silicon oxynitride thin films by remote plasma enhanced chemical vapor deposition. J. Vac. Sci. Technol., A 5, 1998 1987CrossRefGoogle Scholar
10Lucovsky, G., Richard, P.D., Tsu, D.V., Lin, S.Y.Markunas, R.J.: Deposition of silicon dioxide and silicon nitride by remote plasma enhanced chemical vapor deposition. J. Vac. Sci. Technol., A 4, 681 1986CrossRefGoogle Scholar
11Chao, S.S., Tyler, J.E., Tsu, D.V., Lucovsky, G.Mantini, M.J.: Auger electron spectroscopy studies of silicon nitride, oxide, and oxynitride thin films: Minimization of surface damage by argon and electron beams. J. Vac. Sci. Technol., A 5, 1283 1987CrossRefGoogle Scholar
12Green, M.L., Gusev, E.P., Degraeve, R.Garfunkel, E.L.: Ultrathin (<4 nm) SiO2 and Si–O–N gate dielectric layers for silicon microelectronics: Understanding the processing, structure, and physical and electrical limits. J. Appl. Phys. 90, 2057 2001CrossRefGoogle Scholar
13Gusev, E.P., Lu, H.C., Garfunkel, E., Gustafsson, T., Green, M.L., Brasen, D.Lennard, W.N.: Nitrogen engineering of ultrathin oxynitrides by a thermal NO/O2/NO process. J. Appl. Phys. 84, 2980 1998CrossRefGoogle Scholar
14Gusev, E.P., Lu, H.C., Gustafsson, T., Garfunkel, E., Green, M.L.Brasen, D.: The composition of ultrathin silicon oxynitrides thermally grown in nitric oxide. J. Appl. Phys. 82, 896 1997CrossRefGoogle Scholar
15Lu, H.C., Gusev, E.P., Gustafsson, T.Garfunkel, E.: Effect of near-interfacial nitrogen on the oxidation behavior of ultrathin silicon oxynitrides. J. Appl. Phys. 81, 6992 1997CrossRefGoogle Scholar
16Augustine, B.H., Irene, E.A., He, Y.J., Price, K.J., McNeil, L.E., Kristensen, K.N.Maher, D.M.: Visible light emission from thin films containing Si, O, N, and H. J. Appl. Phys. 78(6), 4020 1995CrossRefGoogle Scholar
17Wagner, C.D., Naumkin, A.V., Kraut-Vass, A., Allison, J.W., Powell, C.J., Rumble, J.R. Jr.: NIST X-Ray Photoelectron Spectroscopy Database, NIST Standard Reference Database 20, version 3.4 (Web version), available online at: http://srdata.nist.gov/xps.Google Scholar
18Naskar, S.: Deposition and characterization of silicon oxynitride material for the fabrication of optical waveguides. Ph.D. Dissertation, Case Western Reserve University, Cleveland, OH, 2006Google Scholar
19Smith, D.L.: A.S. Alimonda, C-C. Chen, S.E. Ready, and B. Wacker: Mechanism of SiNxHy deposition from NH3–SiH4 plasma. J. Electrochem. Soc. 137, 614 1990CrossRefGoogle Scholar
20Smith, D.L., Alimonda, A.S.Von Preissig, F.J.: Mechanism of SiNxHy deposition from N2–SiH4 plasma. J. Vac. Sci. Technol., B 8, 551 1990CrossRefGoogle Scholar
21Naskar, S., Bower, C.A., Wolter, S.D., Stoner, B.R.Glass, J.T.: Verification of the O–Si–N complex in plasma-enhanced chemical vapor deposition silicon oxynitride films. Appl. Phys. Lett. 87, 261,907 2005CrossRefGoogle Scholar