A Defects-Based Model on the Barrier Height Behavior in 3C-SiC-on-Si Schottky Barrier Diodes

Abstract

3C-Silicon Carbide (3C-SiC) Schottky Barrier Diodes on Silicon (Si) substrates (3C-SiC-on-Si) have been found to suffer of excessive sub-threshold current, despite the superior electrical properties of 3C-SiC. In turn, that is one of the factors deterring the commercialization of this technology. The forward Current-Voltage (I-V) characteristics in these devices carry considerable information about the material quality. In this context, an advanced Technology Computer Aided Design (TCAD) model is proposed and validated with measurements obtained from a fabricated and characterized Platinum/3C-SiCon-Si Schottky Barrier Diode with scope to shed light in the physical carrier transport mechanisms, the impact of traps and their characteristics on the actual device performance. The model includes defects originating from both the Schottky contact and the hetero-interface of 3C-SiC with Si, which allows the investigation of their impact on the magnification of the subthreshold current. Further, the simulation results and measured data allowed for the identification of additional distributions of interfacial states, the effect of which is linked to the observed nonuniformities of the Barrier Height value. A comprehensive characterization of the defects affecting the carrier transport mechanisms of the investigated 3C-SiC-on-Si power diode is thus achieved and the proposed TCAD model is able to accurately predict the device current both during forward and reverse bias conditions.

On the origin of the premature breakdown of thermal oxide on 3C-SiC probed by electrical scanning probe microscopy

“…Hence, the increased local electron injection accelerate the dielectric breakdown, producing extrinsic breakdown events. A similar role of charged interfacial defects has been invoked by Arvanitopoulos et al [37] to describe the anomalous experimental current behaviour through Schottky barriers on 3C-SiC. Accordingly, the charged defects at the metal/3C-SiC interface induce an electrostatic thinning of the Schottky barrier, resulting in an enhanced current conduction.…”

Impact of Stacking Faults and Domain Boundaries on the Electronic Transport in Cubic Silicon Carbide Probed by Conductive Atomic Force Microscopy

“…Recently, Arvanitopoulos et al [28] proposed a defects-based model of the 3C-SiC/Si Schottky barrier diodes behavior. As a matter of fact, the increased density of states in the conduction band for both SFs and APBs is consistent with an increased current injection from the 3C-SiC to the Pt contact under forward bias polarization of the Schottky junction.…”

Effect of hydrogen treatment on 4H-SiC Schottky barrier diodes

“…Moreover, as shown in figure 4(c), there is slightly smaller trendency in R on-sp of the most SiC SBDs after hydrogen treatment. The possible mechanism for the changes in n and Φ B may be the decrease of acceptor-like states and defects at the Schottky interface [30], the phenomenon on R on-sp may be caused by the change in the doping profile of SBDs. The acceptor-like states above Fermi level (E f ) could form a positive charge at the interface to thin the Schottky barrier, and traps at the interface would make inhomogeneous Schottky contact [31][32][33].…”