【Device Papers】Investigation of high-temperature electrical transport and current conduction mechanism in PLD deposited LaAlO₃/Sn-doped β-Ga₂O₃ (−201) MOS capacitor

      Researchers from the Manipal University Jaipur have published a dissertation titled "Investigation of high-temperature electrical transport and current conduction mechanism in PLD deposited LaAlO₃/Sn-doped β-Ga₂O₃ (−201) MOS capacitor" in Materials Science in Semiconductor Processing.

Abstract

      This study employed pulsed laser deposition (PLD) techniques to grow LaAlO₃ (LAO) thin films on n-type β-Ga₂O₃ (−201) single-crystalline substrates and thoroughly analyzed their structural, optical, morphological, and electrical properties at elevated temperatures. X-ray diffraction (XRD) and UV-Vis spectroscopy confirmed the amorphous nature of the LAO oxide layer, and excellent optical transparency with a large bandgap of approximately 5.25 eV. X-ray photoelectron spectroscopy (XPS) spectra of La 3d_5/2, La 3d_3/2, Al-2p, and O-1s confirmed the presence of La³⁺, Al³⁺, and O²⁻ ions within the amorphous LaAlO matrix. The fabricated LaAlO₃/β-Ga₂O₃ MOS capacitor exhibits stable current density-electric field (J-E) characteristics, low leakage current density, and Poole-Frenkel (PF) type emission, featuring trapped energy levels of 0.72 eV and activation energies between 0.42 eV and 0.57 eV over a broad temperature range. Noticeable variations in slope and flat-band voltage shifts in the MOSCAP device were observed in capacitance-voltage (C-V) analysis, demonstrating increasing oxide and interface trap densities with temperature. The dielectric constant (ε_r) ∼20.2 and loss (δ) ∼0.0012 of the LAO oxide layer at room temperature increase to 28.05 and 0.92 at a temperature of 573K. Overall, the work demonstrates the structural integrity and electrical dependability of PLD-grown LaAlO₃/β-Ga₂O₃ MOS capacitors, emphasizing their potential use in high-power and high-temperature electronic devices.

DOI：

https://doi.org/10.1016/j.mssp.2026.110579