Advertisement

Journal of Materials Science

, Volume 25, Issue 12, pp 4965–4971 | Cite as

The dielectric properties of aluminium nitride substrates for microelectronics packaging

  • J. S. Thorp
  • D. Evans
  • M. Al-Naief
  • M. Akhtaruzzaman
Papers

Abstract

The dielectric behaviour of sintered polycrystalline aluminium nitride substrates has been examined over the frequency range 500 Hz to 10 MHz and correlated with composition and microstructure. For pure, white AlN at 20 ° C both the permittivity (ɛ′) and dielectric loss (ɛ″) are frequency independent giving ɛ′ = 9.2±0.05 and tan δ = (2.1±0.1) × 10−3. The permittivity is less than for pure alumina substrates (ɛ′ = 10.2) but tan δ compares favourably, with that (1.4 × 10−3) of alumina, which though used more widely has a thermal conductivity some eight times less than that of AlN. The addition of impurities, particularly iron, to give opaque black AlN causes large, frequency dependent increases in ɛ″; at 500 Hz the loss is seven times that of pure white AlN and is two times greater above 100 kHz. The temperature coefficient of permittivity [(ɛ′ − 1)(ɛ′ + 2)]−1 [∂ɛ/∂T]p between −180 and +180 ° C for pure white AlN is 1.05×10−5 K−1 which is similar to the value of 9×10−6 K−1 for pure Al2O3. For impure black AlN the coefficient below 20 ° C is the same but above 20 ° C there is a rapid, non-linear increase of ɛ′ with temperature. Below 180 ° C for pure white AlN and 20 ° C for impure black AlN the values of temperature coefficient are frequency independent at least up to 200 kHz.

Keywords

Iron Microstructure Thermal Conductivity Al2O3 Nitride 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    R. Berman, “Thermal Conduction in Solids” (Clarendon, Oxford, 1978).Google Scholar
  2. 2.
    J. S. Thorp, M. Akhtaruzzaman andD. Evans,J. Mater. Sci., in press.Google Scholar
  3. 3.
    J. S. Thorp andN. E. Rad,ibid. 16 (1981) 255.Google Scholar
  4. 4.
    J. S. Thorp, M. E. Rad, D. Evans andC. D. H. Williams,ibid. 21 (1986) 3091.Google Scholar
  5. 5.
    Md. Akhtaruzzaman, PhD thesis, University of Durham (1989).Google Scholar
  6. 6.
    F. Ott,Z. Physik 22 (1924) 201.Google Scholar
  7. 7.
    M. AL-Naief, PhD thesis, University of Durham (1988).Google Scholar
  8. 8.
    S. Bhagat, L. L. Hirst andJ. R. Anderson,J. Appl. Phys. 37 (1966) 1.Google Scholar
  9. 9.
    B. Bleaney andK. W. H. Stevens,Rep. Prog. Phys. 18 (1955) 304.Google Scholar
  10. 10.
    S. Bhagat andP. Lublitz,Phys. Rev. B 10 (1974) 179.Google Scholar
  11. 11.
    S. Bhagat, J. R. Anderson andN. Wu,Phys. Rev. 155 (1967) 510.Google Scholar
  12. 12.
    J. S. Thorp, A. P. Johnson andC. Savage,J. Mater. Sci. Lett. 4 (1985) 221.Google Scholar
  13. 13.
    C. D. H. Williams, S. R. Hoon andJ. S. Thorp,ibid. 5 (1986) 832.Google Scholar
  14. 14.
    R. C. Weast, “Handbook of Chemistry and Physics”, 57th edn. (CRC, Cleveland, Ohio, 1976) p. E120.Google Scholar
  15. 15.
    R. M. Bozorth, “Ferromagnetism” (Van Nostrand, London, 1951).Google Scholar
  16. 16.
    H. Looyenga Physica 31 (1965) 401.Google Scholar
  17. 17.
    D. C. Dube,J. Phys. D. 3 (1979) 1648.Google Scholar
  18. 18.
    H. D. Wirzke,Phys. Status Solidi 2 (1962) 1109.Google Scholar
  19. 19.
    J. Pastrnak andL. Roskovcova,Phys. Status Solidi 7 (1964) 331.Google Scholar
  20. 20.
    A. T. Collins, E. C. Lightowlers andP. J. Dean,Phys. Rev. 158 (1967) 833.Google Scholar
  21. 21.
    T. L. Chu andR. W. Kelm,J. Electrochem. Soc. 122 (1975) 995.Google Scholar
  22. 22.
    K. M. Taylor andC. Lenie,ibid. 107 (1960) 308.Google Scholar
  23. 23.
    A. J. Bosman andE. E. Havinga,Phys. Rev. 127 (1963) 1593.Google Scholar

Copyright information

© Chapman and Hall Ltd. 1990

Authors and Affiliations

  • J. S. Thorp
    • 1
  • D. Evans
    • 2
  • M. Al-Naief
    • 1
  • M. Akhtaruzzaman
    • 2
  1. 1.School of Engineering and Applied ScienceUniversity of DurhamDurhamUK
  2. 2.Department of PhysicsUniversity of DurhamDurhamUK

Personalised recommendations