Probing Interface Trapping Characteristics of Au/β-Ga2O3 Schottky Barrier Diode on Si (100)

Gallium Oxide (Ga2O3) and Sapphire have been a preferred choice of substrates for fabricating β-Ga2O3 Schottky barrier diodes (SBDs). However, Si (100) substrate with low cost and relatively high thermal conductivity has been explored as a platform in this work for the growth of β-Ga2O3 using the pulsed laser deposition (PLD) technique. X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) results confirm the good crystalline quality and uniformity of the Ga2O3 film, respectively. The roughness (RMS) of 1.44 nm of the film surface is confirmed by the atomic force microscope (AFM) technique. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics are employed for investigating the electrical and interface trap properties of the SBDs. The Schottky barrier height measured at room temperature from I-V and C-V characteristics are 0.78 eV and 1.17 eV, respectively and the ideality factor turns out to be 1.95. The charge transport mechanism of SBD has been investigated using the log-log plot of I-V characteristics. The Schottky metal (Au)/β-Ga2O3 interface trap density (Dit) which is obtained on the order of 10 cm-2 eV-1 using the conventional conductance method. In the energy range of Ec-0.27 eV to Ec-1.57 eV, the density of interface states changes from 3.72×10 eV-1cm-2 to 3.10×10 eV-1cm-2, respectively. The maximum value of Dit is found to be 4.38 ×10 eV-1cm-2 at Ec-0.68 eV. The value of Dit can be further reduced for potential and reliable integration of β-Ga2O3 with Si electronics.