Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5365294 | Applied Surface Science | 2007 | 6 Pages |
Abstract
The forward bias current-voltage (I-V) characteristics of Al/p-Si (MS) Schottky diodes with native insulator layer were measured in the temperature range of 80-300 K. The obtained zero bias barrier height ΦB0(I-V), ideality factor (n) and series resistance (Rs) determined by using thermionic emission (TE) mechanism show strong temperature dependence. There is a linear correlation between the ΦB0(I-V) and n because of the inhomogeneties in the barrier heights (BHs). Calculated values from temperature dependent I-V data reveal an unusual behaviour such that the ΦB0 decreases, as the n and Rs values are increasing with decreasing absolute temperature, and these changes are more pronounced especially at low temperatures. Such temperature dependence of BH is contradictory with the reported negative temperature coefficient of the barrier height. In order to explain this behaviour we have reported a modification in the expression reverse saturation current Io including the n and the tunnelling factor (αΧ1/2δ) estimated to be 15.5. Therefore, corrected effective barrier height Φbef.(I-V) versus temperature has a negative temperature coefficients (α = â2.66 Ã 10â4 eV/K) and it is in good agreement with negative temperature coefficients (α = â4.73 Ã 10â4 eV/K) of Si band gap. In addition, the temperature dependent energy distribution of interface states density Nss profiles was obtained from the forward bias I-V measurements by taking into account the bias dependence of the Φe and n. The forward bias I-V characteristics confirm that the distribution of Nss, Rs and interfacial insulator layer are important parameters that the current conduction mechanism of MS Schottky diodes.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Å. Altındal, H. Kanbur, D.E. Yıldız, M. Parlak,