Temperature dependence of high-performance, wide bandgap diode reveals barrier characteristics

For their ability to generate high power with low conduction loss, power semiconductor devices have been used for nearly a century in a variety of applications, including communications and consumer electronics. While silicon semiconductors are the most common material for these devices, higher demands on wide bandgap performance are pushing researchers to look beyond silicon for these devices. Gallium oxide (Ga₂O₃) may point in this direction for a new generation of power semiconductor applications.

In a study detailed in AIP Advances, authors describe the effects of temperature changes on a beta gallium oxide device and its electron transport characteristics from 125 K to 350 K. They constructed a platinum/beta gallium oxide Schottky barrier diode whose parameters were derived from thermionic emission theory and measured its current-voltage and capacitance-voltage characteristics at various temperatures. The current density of the device increased, while series- and on-resistance decreased with increasing temperature.

Analysis drawing on thermionic emission theory shed light on different features of the high-performance diode, including its barrier height and ideality factor. Results indicated that the device exhibited inhomogeneous barrier behavior.

After finding that the inhomogeneity could be explained by the standard deviation associated the Gaussian distribution and associated temperature coefficient, the group attributed this inhomogeneous behavior to the spatial variation of the barrier height. Factoring in Gaussian distributions also allowed the modified Richardson plot, a graph relating the current density of electrons leaving a heated conductor to the conductor’s temperature, to produce a more accurate Richardson constant for the diode.

Having revealed the Gaussian distribution of barrier height inhomogeneity, the group’s next steps will be to use ballistic electron emission spectroscopy to further explore ways to reduce these features.

Source: “Characterization of the inhomogeneous barrier distribution in a Pt/(100)β-Ga₂O₃ Schottky diode via its temperature-dependent electrical properties,” by Guangzhong Jian, Qiming He, Wenxiang Mu, Bo Fu, Hang Dong, Yuan Qin, Ying Zhang, Huiwen Xue, Shibing Long, Zhitai Jia, Hangbing Lv, Qi Liu, Xutang Tao, and Ming Liu, AIP Advances (2017). The article can be accessed at https://doi.org/10.1063/1.5007197 .