Symmetrical current-voltage characteristic of a metal-semiconductor-metal structure of Schottky contacts and parameter retrieval of a CdTe structure
Abstract
Symmetrical, non-linear and current-voltage (I-V) characteristics of a metal-semiconductor-metal (M-S-M) structure of two metallic Schottky contacts fabricated to a p-type semiconductor were modeled by treating the semiconductor as a resistor sandwiched between two identical head-to-head Schottky barriers. The voltage distributions along the M-S-M structure were numerically determined and found that the voltage drop across the reverse-biased Schottky barrier is dominating at the low bias voltage, and the dominant range depends on the value of the resistor of the semiconductor bulk.
The field dependence of barrier height due to the image force was proposed to be the mechanism for the current through the M-S-M structure when the voltage drop across the reverse-biased barrier is dominating. The proposed model was applied to the I-V curves measured at different temperatures on low-resistivity p-type CdTe with Au contacts and the density of the effective acceptors calculated, and the zero-field Schottky barrier height and the Richardson constant were extracted using the activation energy method.
The extracted parameters fitted well with that published for the same material structure.