Characterization of the inhomogeneous barrier distribution in a Pt/(100)β-Ga2O3 Schottky diode via its temperature-dependent electrical properties

Abstract

β-Ga2O3 is an ultra-wide bandgap semiconductor with applications in power electronic devices. Revealing the transport characteristics of β-Ga2O3 devices at various temperatures is important for improving device performance and reliability. In this study, we fabricated a Pt/β-Ga2O3 Schottky barrier diode with good performance characteristics, such as a low ON-resistance, high forward current, and a large rectification ratio. Its temperature-dependent current–voltage and capacitance–voltage characteristics were measured at various temperatures. The characteristic diode parameters were derived using thermionic emission theory. The ideality factor n was found to decrease from 2.57 to 1.16 while the zero-bias barrier height Φb0 increased from 0.47 V to 1.00 V when the temperature was increased from 125 K to 350 K. This was explained by the Gaussian distribution of barrier height inhomogeneity. The mean barrier height Φ¯b0 = 1.27 V and zero-bias standard deviation σ0 = 0.13 V were obtained. A modified Richardson plot gave a Richardson constant A* of 36.02 A·cm−2·K−2, which is close to the theoretical value of 41.11 A·cm−2·K−2. The differences between the barrier heights determined using the capacitance–voltage and current–voltage curves were also in line with the Gaussian distribution of barrier height inhomogeneity.

TCAD-Machine Learning Framework for Device Variation and Operating Temperature Analysis With Experimental Demonstration

“…The WF variation is mainly produced by various surface treatment mentioned in Section II. The consideration of the WF variation is essential to mimic the barrier height inhomogeneity widely reported in Ga2O3 SBDs [13][22] [23].…”

An Overview of the Ultrawide Bandgap Ga2O3 Semiconductor-Based Schottky Barrier Diode for Power Electronics Application

“…The most important part in SBD is the Schottky junction, so in the early research works on Ga 2 O 3 SBD, there are a substantial numbers of ones focusing on the study on the Schottky junction, mainly including the contact between Ga 2 O 3 and different Schottky electrodes (Ni、Cu、Au、Pt、TiN) [57–59], the electron transport mechanism of the Schottky junction, the issues of interface states, barrier inhomogeneity and image force existing in the Schottky contact, and the methods of how to acquire perfect ohmic contact in the cathode interface [60, 61]. …”

“…With the increase of temperature, R on and J @2V became better, demonstrating that the device could work well at high temperature. In their following work, they further deeply investigated the temperature dependence of ideality factor and Schottky barrier height and found that this kind of temperature characteristics can be explained by the Gaussian distribution of barrier height inhomogeneity [61]. In 2018, they further optimized crystal growth parameters and improved the Sn doping concentration ( N d  −  N a  = 2.3 × 10 14  cm −3 ).…”

Conduction mechanisms of the reverse leakage current of β-Ga2O3 Schottky barrier diodes

“…The Schottky barrier diodes (SBDs) based on β-Ga 2 O 3 material are being conducted early-stage research by several authors. Few studies have dealt with the electrical behavior of β-Ga 2 O 3 SBDs using β-Ga 2 O 3 single crystal grown using the several growth methods with different crystal orientations [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. In these works, the most of the authors investigated the electrical conduction in β-Ga 2 O 3 SBDs under forward bias conditions where the thermionic emission current dominates the forward total current.…”