N. Manikanthababu , Subrata Karmakar , Ishtiaq Firoz Shiam , Injamamul Hoque Emu , Ariful Haque , Ravi Droopad
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引用次数: 0
Abstract
In this study, GeO2 thin films were grown by pulsed laser deposition (PLD) on β-Ga2O3, () single crystal substrates to fabricate metal-oxide-semiconductor capacitors (MOSCAPs) to investigate their properties using current-voltage (I-V) and capacitance-voltage (C-V) measurements at elevated temperatures. The amorphous nature, an ultrawide bandgap of ∼5.11 eV and the elemental compositions with their corresponding chemical states of the GeO2 thin films were confirmed by X-ray diffraction (XRD), UV–Vis spectrometery and the x-ray photoelectron spectroscopy (XPS), respectively. The Ge-3d deconvoluted peak at 32.4 eV confirms the elemental bonding in GeO2, with an additional peak found at 30.9 eV that can be attributed to a small portion of GeO2-x. The Au/GeO2/Ga2O3 MOSCAPs were fabricated to study its high-temperature performance from room temperature (RT) to 300 °C. The reverse leakage current was increased from 1.19 × 10−7 A to 3.66 × 10−4 A (nearly four orders of magnitude) as the temperature rises from RT to 300 °C. Due to the presence of oxygen vacancy in GeO2-x, the Poole-Frenkel current conduction mechanism was utilized to determine a trap level of 0.8 V (below the conduction band of GeO2) with an activation energy of 0.55 eV. The C–V measurements also show a significant contribution from defects in the flat-band voltage shift and the changes of the slopes indicates an increase in the oxide and interface-trapped charges. The density of oxide-trapped charges increased from 3.9 × 1012 cm−2 to 1.3 × 1013 cm−2, as the temperature reached 300 °C. Similarly, the density of interface-trapped charges increased from 3.4 × 1012 cm−2 at RT to 1.1 × 1013 cm−2 at 300 °C. The flat-band voltage shift and density of interface-trapped charges of GeO2/Ga2O3 MOSCAPs exhibit exciting materials characteristics for next-generation high-power and high-temperature electronic devices.
期刊介绍:
Materials Science in Semiconductor Processing provides a unique forum for the discussion of novel processing, applications and theoretical studies of functional materials and devices for (opto)electronics, sensors, detectors, biotechnology and green energy.
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