Advertisement

Junctions and Contacts

A junction is formed when two dissimilar materials come in contact with each other. The junction between a p-type and n-type semiconductor is called a pn junction. A heterojunction is formed when the semiconductors on both sides of a pn junction are not the same. An example of a heterojunction is when one side is made of silicon and the other of a silicon–germanium alloy. A junction formed between a metal, or a material of metallic character, and a semiconductor is called a contact. The contact is ohmic if it exhibits no barrier to majority carriers in either direction, resulting in a symmetrical current–voltage characteristic with respect to the zero origin. A rectifying contact is asymmetrical, the resistance to current being much larger in one direction than in the other.

The pn junction is the fundamental building block for other silicon devices. The junction shape, profile and characteristics have a direct impact on device parameters. A thorough understanding of the properties of pn junctions is therefore essential to the understanding of the operation of transistors and integrated circuits.

Keywords

Contact Resistance Breakdown Voltage Minority Carrier Depletion Region Forward Bias 
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. W. Dutton and Z. Yu, Technology CAD, Computer Simulation of IC Process and Devices, Kluwer Academic Publishers, 1993.Google Scholar
  2. 2.
    S. M. Sze, Physics of Semiconductors, John Wiley & Sons, 1981.Google Scholar
  3. 3.
    H. Armstrong, “A theory of voltage breakdown of cylindrical P–N junctions, with applications,” IRE Trans. Electron Dev., ED-4, 15–16, 1957.CrossRefGoogle Scholar
  4. 4.
    A. B. Phillips, Transistor Engineering, McGraw-Hill, New York, 1962.Google Scholar
  5. 5.
    W. Shockley, and W. T. Read, “Statistics of recombination of holes and electrons,” Phys. Rev. 87, 835, 1952.MATHCrossRefGoogle Scholar
  6. 6.
    R. N. Hall, “Electron-hole recombination in Germanium,” Phys. Rev., 87, 387, 1952.CrossRefGoogle Scholar
  7. 7.
    A. K. Jonscher, Principles of Semiconductor Device Operation, John Wiley & Sons, New York, 1960.MATHGoogle Scholar
  8. 8.
    J. L. Moll, Physics of Semiconductors, McGraw-Hill, New York, 1964.MATHGoogle Scholar
  9. 9.
    A. G. Chynoweth, “Ionization rates for electrons and holes in silicon,” Phys. Rev., 109 (5), 1537–1540, 1958.CrossRefGoogle Scholar
  10. 10.
    G. A. Baraff, “Distribution functions and ionization rates for hot electrons in silicon,” Phys. Rev., 128 (6), 2507–2517, 1962.MATHCrossRefGoogle Scholar
  11. 11.
    R. Van Overstraeten and H. DeMan, “Measurement of the ionization rates in diffused silicon p-n junctions,” Solid State Electron., 13 (5), 583–608, 1970.CrossRefGoogle Scholar
  12. 12.
    W. N. Grant,“Electron and hole ionization rates in epitaxial silicon at high electric fields,” Solid State Electron., 16, 1189–1203, New York 1973.Google Scholar
  13. 13.
    A. D. Sutherland, “An improved empirical fit to Baraff's universal curves for the ionization coefficients of electron and hole multiplication in semiconductors,” IEEE Trans. Electron. Dev., ED-27 (7), 1299–1300, 1980.CrossRefGoogle Scholar
  14. 14.
    C. R. Crowell and S. M. Sze, “Temperature dependence of avalanche multiplication in semiconductors,” Appl. Phys. Lett., 9 (6), 242–244, 1966.CrossRefGoogle Scholar
  15. 15.
    S. Reggiani, E, Gnani, M. Rudan, G. Baccarani, C. Corvasce, D. Barlini, M. Ciappa, W. Fichtner, M. Denison, N. Jensen, G. Groos, and M. Stecher, “Measurement and modeling of the electron impact-ionization coefficient in silicon up to very high temperature,” IEEE Trans. Electron. Dev., 52 (10), 2290–2299, 2005.CrossRefGoogle Scholar
  16. 16.
    S. M. Sze and G. Gibbons, “Avalanche breakdown voltage of abrupt and linearly graded p-n junctions in Ge, Si, GaAs and GaP,” Appl. Phys. Lett., 8, 111, 1966.CrossRefGoogle Scholar
  17. 17.
    K. G. McKay, “Avalanche breakdown in silicon,” Phys. Rev., 94, 877–884, 1954.CrossRefGoogle Scholar
  18. 18.
    R. M. Warner, “Avalanche breakdown in silicon diffused junctions,” Solid State Electron., 15, 1303, 1972.CrossRefGoogle Scholar
  19. 19.
    J. H. He, X. Zhang, and Y. Wang, “Equivalent doping profile transformation: a semi-empirical analytical method for predicting breakdown characteristics of an approximate single-diffused parallel-plane junction,” IEEE Trans. Electron. Dev., 48 (12), 2763–2768, 2001.CrossRefGoogle Scholar
  20. 20.
    S. M. Sze and G. Gibbons, “Effect of junction curvature on breakdown voltages in semiconductors,” Solid State Electron., 9, 831–840, 1966.CrossRefGoogle Scholar
  21. 21.
    S. K. Ghandhi, Semiconductor Power Devices, John Wiley, New York, 1977.Google Scholar
  22. 22.
    D. Krizaj and S. Amon, “Breakdown voltage of elliptic pn junctions,” Fifth European Conference on Power Electronics and Applications, Vol. 2, pp. 293–296, Sept. 13–16, 1993.Google Scholar
  23. 23.
    R. B. Fair and W. W. Hayden, “Zener and Avalanche Breakdown in As-implanted low-voltage Si n-p junctions,” IEEE Trans. Electron. Dev., ED-23(5), 512–518, 1976.CrossRefGoogle Scholar
  24. 24.
    C. Zener, “A theory of electrical breakdown voltages of solid dielectrics,” Proc. Roy. Soc. London, A145, 523–529, 1934.CrossRefGoogle Scholar
  25. 25.
    F. Braun, “Ueber die Stromleitung durch Schwefelmetalle,” Ann. Phys. J. C. Poggendorff. Phys. Chem., 153, 556–563, 1874.Google Scholar
  26. 26.
    F. Braun, “Ueber Abweichungen vom Ohm'schen Gesetz in metallisch leitenden Koerpern,” Ann. Phys. G. Wiedemann, 1, 95–110, 1877.Google Scholar
  27. 27.
    C. A. Mead, “Physics of interfaces,” in Ohmic Contacts to Semiconductors (B. Schwartz, ed.), Electrochem. Soc., New York, 3–16, 1969.Google Scholar
  28. 28.
    W. Schottky, “Halbleitertheorie der Sperrschicht,” Naturwissenschaften, 26, 843, 1938; Z. Phys. 113, 367, 1939; 118, 539, 1942.CrossRefGoogle Scholar
  29. 29.
    H. K. Henisch, “Rectifying Semiconductor Contacts,” Clarendon, Oxford, 1957.Google Scholar
  30. 30.
    M. M. Atalla, “Metal-semiconductor Schottky barriers, devices and applications,” Proc. Munich Symp. Microelectronics, pp. 123–157, October 1966.Google Scholar
  31. 31.
    J. Bardeen, “Surface states and rectification at a metal semi-conductor contact,” Phys. Rev., 71 (10), 717–727, 1947.CrossRefMathSciNetGoogle Scholar
  32. 32.
    W. Shockley, “On the surface states associated with a periodic potential,” Phys. Rev., 56 (4), 317–323, 1939.MATHCrossRefGoogle Scholar
  33. 33.
    W. H. Brattain and W. Shockley, “Density of surface states on silicon deduced from contact potential measurements,” Phys. Rev., 72, 345, 1947.Google Scholar
  34. 34.
    A. M. Cowley and S. M. Sze, “Surface sates and barrier height of metal-semiconductor systems,” J. Appl. Phys., 36, 3212, 1965.CrossRefGoogle Scholar
  35. 35.
    E. H. Rhoderick, “The physics of Schottky barriers,” Third Solid-State Device Conf., pp. 1153–1168, Exeter, 1969.Google Scholar
  36. 36.
    A. J. Dekker, Solid State Physics, Prentice-Hall, New Jersey, USA, 1965.Google Scholar
  37. 37.
    V. L. Rideout and C. R. Crowell, “Effects of image force and tunneling on current transport in metal-semiconductor (Schottky barrier) contacts,” Solid-State Electron., 13, 993–1009, 1970.CrossRefGoogle Scholar
  38. 38.
    H. A. Bethe, “Theory of boundary layer of crystal rectifiers,” MIT Radiation Lab. Rept., 43/12, 1942.Google Scholar
  39. 39.
    C. R. Crowell, “The Richardson constant for thermionic emission in Schottky barrier diodes,” Solid-State Electron., 8, 395–399, 1965.CrossRefGoogle Scholar
  40. 40.
    A. M. Cowley, “Titanium-Silicon Schottky barrier diodes,” Solid-State Electron., 12, 403”414, 1970.CrossRefGoogle Scholar
  41. 41.
    D. L. Scharfetter, “Minority carrier injection and charge storage in epitaxial Schottky barrier diodes,” Solid-State Electron., 8, 299–211, 1965.CrossRefGoogle Scholar
  42. 42.
    A. Y. C. Yu, “Electron tunneling and contact resistance of metal-silicon contact barriers,” Solid-State Electron., 13, 239–247, 1970.CrossRefGoogle Scholar
  43. 43.
    F. A. Padovani and R. Stratton, “Field and thermionic-field emission in Schottky barriers,” Solid-State Electron., 9, 695”707, 1966.CrossRefGoogle Scholar
  44. 44.
    D. K. Schroeder and D. L. Meier, “Solar cell contact resistance: A review,” IEEE Trans. Electron. Dev., ED-31 (5), 637–647, 1984.CrossRefGoogle Scholar
  45. 45.
    D. P. Kennedy and P. C. Murley, “A two-dimensional mathematical analysis of the diffused semiconductor resistor,” IBM J. Res. Dev., 12, 242–250, 1968.MATHCrossRefGoogle Scholar
  46. 46.
    H. Murrmann and D. Widmann, “Current crowding on metal contacts to planar devices,” IEEE Trans. Electron. Dev., ED-16, 1022–1024, 1969.CrossRefGoogle Scholar
  47. 47.
    H. Murrmann and D. Widmann, “Messung des Uebergangswiderstandes zwischen Metall und Diffusionsschichet in Si Planarelementen,” Solid-State Electron., 12, 879–886, 1969.CrossRefGoogle Scholar
  48. 48.
    H. Murrmann and D. Widmann, “Current crowding on metal contacts to planar devices,” IEEE Trans. Electron. Dev., ED-16, 1022–1024, 1969.CrossRefGoogle Scholar
  49. 49.
    H. H. Berger, “Models for contacts to planar devices,” Solid-State Electron., 15, 145–158, 1972.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Personalised recommendations