This article is cited in 7 papers

Semiconductor structures, low-dimensional systems, quantum phenomena

The effect of the periphery of metal-semiconductor Schottky-barrier contacts on their electrical characteristics

N. A. Torkhov^a, V. A. Novikov<sup>b

a</sup> Scientific-Research Institute of Semiconductor Devices, Tomsk
^b Tomsk State University

Abstract: During the formation of the metal-semiconductor contact with a Schottky barrier (as a gold film on the $p$- or $n$-type gallium arsenide surface), an electric field $E_l$ built into the electric contact is induced, which propagates around the contact to the distance $l$ (halo) tens of times larger than space-charge region sizes. This field reduces the electrostatic potential of the $\varphi_{\mathrm{Au}}$ contact by a significant value $\varphi^*$. In the general case, the halo size l and the decrease $\varphi^*$ in the electrostatic potential are controlled by the charge value and sign in the space-charge region, which depend on the contact diameter $D$, semiconductor concentration and conductivity type. For Au/$n$-GaAs Schottky-barrier contacts, a decrease in $D$ results in the increasing role of periphery, which manifests itself in increasing $\varphi^*$ and decreasing $\varphi_{\mathrm{Au}}$ and $l$. For Au/$p$-GaAs contacts, a decrease in $D$ results in the decreasing effect of periphery, which appears in decreasing $\varphi^*$ and increasing $\varphi_{\mathrm{Au}}$ and $l$. The absence of the space-charge region in metal-insulator-semiconductor contacts results in the fact that the halo size $l$ and $\varphi^*$ are independent of their diameters.

Received: 26.02.2010
Accepted: 15.03.2010

 English version: Semiconductors, 2011, 45:1, 69–84

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