Analysis of temperature-dependent current transport mechanism in Cu/n-type Ge Schottky junction

We employed oxygen plasma treatment to improve the electrical properties in Cu/n-type Ge Schottky junctions and investigated temperature dependent current transport mechanism in the temperature range of 100–300 K. The Schottky barrier height increased commensurate with increasing temperature, which was attributed to barrier inhomogeneity. The inhomogeneity of the barrier was represented by a double Gaussian distribution, each one prevailing in a distinct temperature range: a high-temperature range from 220 to 300 K and a low-temperature range from 100 to 180 K. Modified Richardson plots revealed a Richardson constant of 160.0 Acm−2 K−2 for the high-temperature region (220–300 K), which is comparable to the theoretical value of 140.0 Acm−2 K−2 for n-type Ge. Reverse current analysis revealed that Poole–Frenkel and Schottky emissions were dominant in the lower and higher voltage regions, respectively.