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Structural development and electronic properties of hot filament low pressure chemical vapor deposited fluorocarbon polymer films

Published online by Cambridge University Press:  01 January 2006

A.C. Rastogi  and
S.B. Desu
A.C. Rastogi*
Affiliation:
Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, Massachusetts 01003
S.B. Desu
Affiliation:
Department of Electrical and Computer Engineering, University of Massachusetts, Amherst, Massachusetts 01003
*
a)Address all correspondence to this author.e-mail: [email protected]
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Abstract

Fluorocarbon polymer films in the poly(tetrafluoroethylene) (PTFE)-like structure are formed by a low-pressure chemical vapor deposition technique using the hot filament excitation of the gaseous C3F6O precursor. The filament and substrate temperatures were found to influence the structure of the deposited films. Infrared absorption and electron spectroscopy studies reveal that a PTFE-like (CF2)2n linear molecular chain structure evolves by an adsorption driven nucleation and CF2 polymerization process in the films deposited with low (450 °C) filament and high (70 °C) substrate temperatures. The films formed at a low substrate temperature (–165 °C) show a higher concentration of CF and C–CF bond defects and shorter (CF2)2n chains. A high (8–10 at.%) oxygen concentration in the films deposited at 600 °C filament temperature is attributed to the reaction of the (CF2)2n chains with COF and peroxyradicals arising from the dissociation of CF3C(O)F and affects the thermal stability of the films. Such reactions are not involved in the film growth at a low (450 °C) filament temperature. These films have much lower (<2 at.%) bonded oxygen content. The films having an ordered (CF2)2n chain structure formed at 70 °C are characterized by low leakage currents ∼7 × 10−11 A cm−2 at 0.1 MV cm−1 field. In comparison, high leakage currents ∼1 × 10−8 A cm−2 are observed for the films having a higher concentration of C–F and C–CF bonds.

Keywords

Chemical vapor deposition (CVD)DielectricX-ray photoelectron spectroscopy (XPS)
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 1 , January 2006 , pp. 242 - 254
Copyright
Copyright © Materials Research Society 2006

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References

REFERENCES

1.Castner, D.G. and Ratner, B.D.: Biomedical surface science: Foundations to frontiers. Surf. Sci. 500, 28 (2002).CrossRefGoogle Scholar
2.Guidoin, R., Chakfe, N., Maurel, S., Haw, T., Batt, M., Marois, M. and Gosselin, C.: Expanded polytetrafluoroethylene arterial prostheses in humans—Histopathological study of 298 surgically excised grafts. Biomaterials 14, 678 (1993).CrossRefGoogle ScholarPubMed
3.Luginbuhl, R., Garrison, M.D., Overney, R.M., Weiss, L., Schieferdecker, H., Hild, S., and Ratner, B.D.: Chemical and contact mechanical characterization of thin plasma-deposited hexafluoropropylene films, in Fluorinated Surfaces, Coatings and Films, edited by Castner, D.G. and Grainger, D.W. (ACS Symposium Ser. 787, ACS, Washington, DC 2001), p. 187.CrossRefGoogle Scholar
4.Man, P.F., Gogoi, B.P. and Mastrangelo, C.H.: Elimination of post release adhesion in microstructures using the conformal fluorocarbon coatings. J. Microelectromech. Syst. 6, 25 (1997).CrossRefGoogle Scholar
5.Nason, T.C., Moore, J.A. and Lu, T-M.: Deposition of amorphous fluoropolymer thin films by thermolysis of Teflon amorphous fluoropolymer. Appl. Phys. Lett. 60, 1866 (1992).CrossRefGoogle Scholar
6.Li, S.T., Arenholz, E., Heitz, J. and Bauerle, D.: Pulsed laser deposition of crystalline Teflon (PTFE) films. Appl. Surf. Sci. 125, 17 (1998).CrossRefGoogle Scholar
7.Goulb, M.A. and Wydeven, T.: Fluoropolymer films deposited by rf plasma sputtering of polytetrafluoroethylene using inert gases, in Fluorinated Surfaces, Coatings and Films, edited by Castner, D.G. and Grainger, D.W. (ACS Symposium Ser. 787, ACS, Washington, DC, 2001), p. 203.CrossRefGoogle Scholar
8.Limb, S.J., Gleason, K.K., Edell, D.J. and Gleason, E.F.: Flexible fluorocarbon wire coatings by pulsed plasma enhanced chemical vapor deposition. J. Vac. Sci. Technol. A 15, 1814 (1997).CrossRefGoogle Scholar
9.Jansen, H.V., Gardeniers, J.G.E., Elders, J.E., Tilmans, H.A.C. and Elwenspoek, M.: Application of fluoropolymers in micromechanics and micro machining. Sens. Actuators A 41–42, 136 (1994).CrossRefGoogle Scholar
10.Smith, B.K., Brown, C.D., Vigne, G. La and Sniegowski, J.J. Thin Teflon like films for MEMS: Film properties and reliability studies, in Micromachining and Microfabrication Process Technology IV, edited by Smith, J.H. (Proc. SPIE, 3511 SPIE-The International Society for Optical Engineering, Bellingham, WA, 1998), p. 114.CrossRefGoogle Scholar
11.Mackie, N.M., Capps, N.E., Butoi, C.I., and Fisher, E.R.: Surface interactions of CF2 radicals during deposition of amorphous fluorocarbon films, in Fluorinated Surfaces, Coatings and Films, edited by Castner, D.G. and Grainger, D.W. (ACS Symposium Ser. 787, ACS, Washington, DC, 2001), p. 168.CrossRefGoogle Scholar
12.Butoi, C.I., Mackie, N.M., Barnd, J.L., Fisher, E.R., Gamble, L.J. and Castner, D.G.: Control of surface film composition and orientation with down stream PECVD of hexafluoropropylene oxide. Chem. Mater. 11, 862 (1999).CrossRefGoogle Scholar
13.Limb, S.J., Edell, D.J., Gleason, E.F. and Gleason, K.K.: Pulsed plasma-enhanced chemical vapor deposition from hexafluoropropylene oxide: film compositions study. J. Appl. Polym. Sci. 67, 1489 (1998).3.0.CO;2-X>CrossRefGoogle Scholar
14.Savage, C.R., Timmons, R.B. and Lin, J.W.: Spectroscopic characterization of films obtained in pulsed radio-frequency plasma discharges of fluorocarbon monomers. Adv. Chem. Ser. 236, 745 (1993).CrossRefGoogle Scholar
15.d’Agostino, R.: Plasma Deposition, Treatment and Etching of Polymers (Academic Press, Boston, MA, 1990).Google Scholar
16.Limb, S.J., Labelle, C.B., Gleason, K.K., Edell, D.J. and Gleason, E.F.: Growth of fluorocarbon polymer thin films with high CF2 fractions and low dangling bond concentrations by thermal chemical vapor deposition. Appl. Phys. Lett. 68, 2810 (1996).CrossRefGoogle Scholar
17.Lau, K.K.S., Caulfield, J.A. and Gleason, K.K.: Structure and morphology of fluorocarbon films grown by hot filament chemical vapor deposition. Chem. Mater. 12, 3032 (2000).CrossRefGoogle Scholar
18.Lau, K.K.S. and Gleason, K.K. Low-dielectric constant fluorocarbon films, in Plasma Deposition and Treatment of Polymers, edited by Lee, W.W., R. d’Agostino, and Wertheimer, M.R. (Mater. Res. Soc. Symp. Proc. 544 Warrendale, PA 1999), p. 209.Google Scholar
19.Lau, K.K.S., Caulfield, J.A. and Gleason, K.K.: Variable angle ellipsometry of fluorocarbon films from hot filament chemical vapor deposition. J. Vac. Sci. Technol. A 18, 2404 (2000).CrossRefGoogle Scholar
20.Lau, K.K.S., Gleason, K.K. and Trout, B.L.: Thermochemistry of gas phase CF2 reactions: A density-functional theory study. J. Chem. Phys. 113, 4103 (2000).CrossRefGoogle Scholar
21.Lau, K.K.S. and Gleason, K.K.: Thermal annealing of fluorocarbon films grown by hot filament chemical vapor deposition. J. Phys. Chem. B 105, 2303 (2001).CrossRefGoogle Scholar
22.Lau, K.K.S. and Gleason, K.K.: Pulsed plasma enhanced and hot filament chemical vapor deposition of fluorocarbon films. J. Fluorine Chem. 104, 119 (2000).CrossRefGoogle Scholar
23.Pierson, H.O.: Handbook of Chemical Vapor Deposition (Noyes Publications, Norwich, NY, 1999).Google Scholar
24.Lewis, H.G.P., Weibel, G.L., Ober, C.K. and Gleason, K.K.: E-beam patterning of hot filament CVD fluorocarbon films using supercritical CO2 as a developer. Chem. Vap. Deposition. 7, 195 (2001).3.0.CO;2-E>CrossRefGoogle Scholar
25.Vedula, R., Kaza, S. and Desu, S.B. Chemical vapor deposition of polymers: Principles, materials, and applications, in Chemical Vapor Deposition, Surface Engineering Series, Vol. 2, edited by Park, J-H. and Sudershan, T.S. (ASM International, Materials Park, OH, 2001), p. 243.Google Scholar
26.Millard, M.M. and Pavlath, A.E.: Surface analysis of plasma-polymerized fluorocarbon films by x-ray photoelectron spectrometry. J. Macromol, Sci. Chem. A10, 579 (1976).CrossRefGoogle Scholar
27.Yang, Y.W.C., Chen, C.W., Tseng, S.C., Huang, J. and Wu, Y.Z.: Surface modification of bi-axially expanded poly(tetrafluoroethylene) by plasma polymerization of ethylene. Surf. Coat. Technol. 176, 148 (2004).CrossRefGoogle Scholar
28.d’Agostino, R., Cramarossa, F., Fracassi, F. and Illuzzi, F. Plasma polymerization of fluorocarbons, in Plasma Deposition, Treatment and Etching of Polymers, edited by d’Agostino, R. (Academic Press, San Diego, CA, 1990), p. 95.CrossRefGoogle Scholar
29.Briggs, D. and Beamson, G.: XPS studies of the oxygen 1s and 2s levels in a wide range of functional polymers. Anal. Chem. 65, 1517 (1993).CrossRefGoogle Scholar
30.Clark, D.T. and Abrahman, M.Z.: Plasma polymerization. A comparative study of the plasma polymers produced from inductively coupled plasma excited in the fluorobenzens. J. Poly. Sci. 20, 1729 (1982).Google Scholar
31.Calthrup, N.P., Daly, L.H. and Wiberley, S.E.: Introduction to Infrared and Raman Spectroscopy (Academic Press, New York, 1990).Google Scholar
32.O’Kane, D.F. and Rice, D.W.: Preparation and characterization of glow discharge fluorocarbon–type polymers. J. Macromol. Sci. Chem. A10, 567 (1976).CrossRefGoogle Scholar
33.Mackie, N.M., Dalleska, N.F., Castner, D.G. and Fisher, E.R.: Comparison of pulsed and continuous-wave deposition of thin films from saturated fluorocarbon/H2 inductively coupled rf plasmas. Chem. Mater. 9, 349 (1997).CrossRefGoogle Scholar
34.Rastogi, A.C. and Desu, S.B.: Thermal chemical vapor deposition of fluorocarbon polymer thin films in a hot filament reactor. Polym. 46, 3440 (2005).CrossRefGoogle Scholar
35.Lambert, J.B., Shurvell, H.F., Cooks, R.G. and Lightner, D.: Introduction to Organic Spectroscopy (Prentice Hall, Upper Saddle River, NJ, 1987), p. 315.Google Scholar
36.Dolphin, D. and Wick, A.: Tabulation of Infrared Spectra Data (Wiley Interscience, New York, 1977).Google Scholar
37.Banerjee, I., Harker, M., Wong, L., Coon, P.A. and Gleason, K.K.: Characterization of chemical vapor deposited amorphous fluorocarbons for low-dielectric-constant interlayer dielectric. J. Electrochem. Soc. 146, 2219 (1999).CrossRefGoogle Scholar
38.Kuptsov, A.K. and Zhizhi, G.M.: Handbook of Fourier Transform Raman and IR Spectra of Polymers, Physical Science Data 45 (Elsevier, Amsterdam, The Netherlands, 1998).Google Scholar
39.Lampert, M.A. and Mark, P.: Current Injection in Solids (Academic Press, New York, NY, 1970), p. 21.Google Scholar
40.Sze, S.M.: Physics of Semiconductor Devices (Wiley, New York, 1981), p. 402.Google Scholar
41.Rastogi, A.C. and Desu, S.B.: Characterization of low pressure chemical vapor deposited polymeric fluorinated carbon M(C:FX) in thin films with low dielectric constant. Appl. Phys. A: Materials Science and Processing (in press).Google Scholar
42.Han, S-S. and Bae, B-S.: Thermal stability of fluorinated amorphous carbon films with low-dielectric constant. J. Electrochem. Soc. 148, F67 (2001).CrossRefGoogle Scholar
43.Kennedy, R.C. and Levy, J.B.: Pyrolysis of hexafluoropropylene oxide. J. Fluorine Chem. 7, 101 (1976).CrossRefGoogle Scholar
44.Cramer, C.J. and Hillmyer, M.A.: Perfluorocarbenes produced by thermal cracking. Barriers to generation and rearrangement. J. Org. Chem. 64, 4850 (1999).CrossRefGoogle ScholarPubMed
45.Aslanidi, E.B., Zarubin, V. and Turischchev, Y.S.: The investigation of dissociation of trifluoroacetyl fluoride in the field of pulsed CO2 laser. Laser Chem. 6, 373 (1986).CrossRefGoogle Scholar
46.George, C.H., Saison, J.Y., Ponche, J.L. and Mirabel, P.H.: Kinetics of mass transfer of carbonyl fluoride, trifluoroacetyl fluoride, and trifluoroacetyl chloride at the air/water interface. J. Phys. Chem. 98, 10857 (1994).CrossRefGoogle Scholar