Determination of the characteristic parameters of Sn/n-GaAs/Al-Ge Schottky diodes by a barrier height inhomogeneity model

TÜRÜT A., Doğan H.

SEMICONDUCTOR SCIENCE AND TECHNOLOGY, vol.21, no.6, pp.822-828, 2006 (Peer-Reviewed Journal) identifier

  • Publication Type: Article / Article
  • Volume: 21 Issue: 6
  • Publication Date: 2006
  • Doi Number: 10.1088/0268-1242/21/6/021
  • Journal Indexes: Science Citation Index Expanded, Scopus
  • Page Numbers: pp.822-828


A study on parameters of the Sn/n-GaAs Schottky barrier diode (SBD) fabricated on an n-type GaAs substrate has been made. The Sn/n-GaAs SBD has shown a nearly ideal behaviour with ideality factor and barrier height (BH) values of 1.081 and 0.642 eV, respectively, from the experimental forward-bias current-voltage (I-V) characteristics. A BH value of 0.724 eV has been obtained from the experimental reverse-bias capacitance-voltage (C-V) characteristics. An accurate theoretical modelling of the effect of the presence of inhomogeneities on the electron transport across the metal-semiconductor interface has been applied. This model attempts to explain abnormal experimental results obtained on 'real' Schottky diodes. Our results clearly demonstrate that the electron transport at the metal-semiconductor interface is significantly affected by low-barrier regions (patches). When the experimental data are described by the thermionic emission theory of inhomogeneous Schottky contacts, it has been concluded that both the experimental forward and reverse I-V characteristics and the difference between the values of the experimental I-V and C-V SBHs should be considered. An experimental BH difference of Delta = 0.082 V has been obtained for the Sn/n-GaAs SBD that is less than the critical value; therefore, it has been seen that the potential in front of the patch is not pinched off.