A study of temperature-related non-linearity at the metal-silicon interface

Abstract

. (2012) A study of temperature-related non-linearity at the metal-silicon interface. Journal of Applied Physics, Vol.112 . Article no. 114513 Permanent WRAP url: http://wrap.warwick.ac.uk/52407 Copyright and reuse:The Warwick Research Archive Portal (WRAP) makes the work of researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-forprofit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription.For more information, please contact the WRAP Team at: wrap@warwick.ac.uk A study of temperature-related non-linearity at the metal-silicon interface.A study of temperature-related non-linearity at the metal-silicon interface. In this paper, we investigate the temperature dependencies of metal-semiconductor interfaces in an effort to better reproduce the current-voltage-temperature (I-V-T) characteristics of any Schottky diode, regardless of homogeneity. Four silicon Schottky diodes were fabricated for this work, each displaying different degrees of inhomogeneity; a relatively homogeneous NiV/Si diode, a Ti/Si and Cr/Si diode with double bumps at only the lowest temperatures, and a Nb/Si diode displaying extensive non-linearity. The 77-300 K I-V-T responses are modelled using a semi-automated implementation of Tung's electron transport model, and each of the diodes are well reproduced. However, in achieving this, it is revealed that each of the three key fitting parameters within the model display a significant temperature dependency. In analysing these dependencies, we reveal how a rise in thermal energy "activates" exponentially more interfacial patches, the activation rate being dependent on the carrier concentration at the patch saddle point (the patch's maximum barrier height), which in turn is linked to the relative homogeneity of each diode. Finally, in a review of Tung's model, problems in the divergence of the current paths at low temperature are explained to be inherent due to the simplification of an interface that will contain competing defects and inhomogeneities.

The rectenna device: From theory to practice (a review)

“…Given the small potential size of a Schottky rectenna, the impact of such interface inhomogeneity will be the source of significant device-device variation, and an unpredictability of cut-off frequencies. Typical Schottky diodes can have good diode characteristics in terms of the FOMs mentioned in Equations 18, 19 and 20, as demonstrated by the simple example of a Cr/Si Schottky diode made in-house for [155]. The characteristics of this diode are close to ideal (i.e.…”

“…Instead, a more realistic scenario should be considered where multiple current paths exist flowing over barriers of different barrier height, so modifying this equation that has been the standard for a century or more. The papers by Tung 151,160 and others [155][156][157][158][159] pro-vide a much more rigorous understanding of the Schottky diode and its operation under this inhomogeneous regime. Given the small potential size of a Schottky rectenna, the impact of such interface inhomogeneity will be the source of significant device-device variation, and an unpredictability of cut-off frequencies.…”

Temperature dependent transport characteristics of graphene/n-Si diodes

“…At low temperatures, for inhomogeneous Gr/Si interfaces, transport is dominated by the low Schottky barrier patches while with increasing temperature, more electrons have sufficient energy to surmount the higher barriers and the extracted effective barrier increases. Although reports of such temperature dependence of φ b0 and η exist in other metal/semiconductor (M/S) interfaces [15][16][17] , no clear explanation other than the consideration of an inhomogeneous distribution of barrier heights has been proposed 18 . For Gr/Si interfaces, inhomogeneity in barrier heights arise due to local modification of graphene work function by the nonuniform interface charge distribution caused by unavoidable potential fluctuations due to ripples 9 and/or formation of graphene grain boundaries 10 etc.…”

High Voltage Graphene Nanowall Trench MOS Barrier Schottky Diode Characterization for High Temperature Applications

“…From the I-V plot in Figure 5a, we can see that the current at the forward region is linear at voltage ≤0.5 V and starts to deviate from linearity due to series resistance, R s . The double bumps that were normally due to other transport mechanisms such as generation-recombination, thermionic field emission, and field emission, were not observed in this case [26,54,55]. This is also an indication that thermionic emission starts to dominate at the temperature range tested.…”

“…Although the homogeneity of TiSi 2 is better than GNW, the lack of micro heat sink characteristic in TiSi 2 causes a much higher temperature effect on the leakage current. Another study done by Gammon [26] on metal with different homogeneity also showed that inhomogeneous metal would require a large carrier concentration to activate all the patches with low barrier height, while the homogenous interface requiring less carrier concentration to activate the patches. Therefore, the leakage current for the homogeneous interface could be higher than the inhomogeneous surface.…”