Fabrication of n-Si/n-Ga2O3 heterojunctions by surface-activated bonding and their electrical properties

We studied electrical properties of n-Si/n-Ga2O3 heterojunctions fabricated by surface-activated bonding. The energy barrier heights (q phi(b)) at the Si/Ga2O3 interface for different reverse voltages (V-rev) were derived from temperature-dependent current density-voltage (J-V-T) characteristics. With shifting V-rev to the negative direction, q phi(b) gradually decreased and reached a constant value due to negatively charged interface states. The conduction band offset at the heterointerface was estimated to be 0.18 eV from the V-rev dependence of q phi(b). The q phi(b) calculated from a capacitance of the heterojunction at thermal equilibrium was larger than those derived from the J-V-T characteristics, attributing to spatially inhomogeneous q phi(b) caused by the non-uniform distribution of the charged interface states. The density of shallow interface states was also extracted from the reverse J-V-T characteristics, which was estimated to be about 6 x 10(12) cm(-2) eV(-1).

Automated summary

We studied the electrical properties of n-Si/n-Ga2O3 heterojunctions fabricated by surface-activated bonding. By analyzing temperature-dependent current density-voltage characteristics, we obtained the energy barrier heights at the Si/Ga2O3 interface for different reverse voltages. The conduction band offset at the heterointerface was estimated, and the non-uniform distribution of charged interface states was found to contribute to the spatially inhomogeneous energy barrier heights. The density of shallow interface states was also extracted from the reverse current density-voltage characteristics.