Interface formation of Al₂O₃ on n‐GaN(0001): Photoelectron spectroscopy studies

Abstract

Al 2 O 3 insulator layers were deposited step by step by the physical vapor deposition (PVD) method onto gallium nitride in the wurtzite form, n-type and (0001)-oriented. The substrate surface and the early stages of Al 2 O 3 /n-GaN(0001) interface formation were characterized in situ under ultra-high vacuum conditions by X-ray and ultraviolet photoelectron spectroscopy (XPS, UPS). The electron affinity (EA) of the substrate cleaned by annealing was 3.6 eV. Binding energies of the Al 2p (76.0 eV) and the O 1s (532.9 eV) confirmed the creation of the Al 2 O 3 compound in the deposited film for which the EA was 1.6 eV. The Al 2 O 3 film was found to be amorphous with a bandgap of 6.9 eV determined from the O 1s loss feature. As a result, the calculated Al 2 O 3 /n-GaN(0001) valence band offset (VBO) is −1.3 eV and the corresponding conduction band offset (CBO) 2.2 eV.

X‐ray photoelectron spectroscopy characterization of band offsets of MgO/Mg2Si and SiO2/Mg2Si heterojunctions

“…Thin film transistor (TFT) is an important electron device in integrated circuit domain, and its essence is field effect transistor. [1][2][3][4][5] High performance, low power consumption, and small characteristic size are the inevitable trend of integrated circuit development. In order to obtain higher performance and smaller size of TFT, the key is to choose the appropriate channel (semiconductor) material and gate dielectric material.…”

Investigation of a memory effect in a Au/(Ti–Cu)Ox-gradient thin film/TiAlV structure

“…Taking into consideration the bandgap energy of the thin films equal to 2.80 eV, the thin film surface exhibits p-type conduction. The electron affinity (χ) of the thin film surface was equal to 2.41 eV and was calculated based on the relationship [ 51 – 52 ]:…”

“…Taking into consideration the bandgap energy of the thin films equal to 2.80 eV, the thin film surface exhibits p-type conduction. The electron affinity (χ) of the thin film surface was equal to 2.41 eV and was calculated based on the relationship [51,52]: (1) where hν = 21.22 eV is the He (I) photon energy, W = 16.01 eV is the width of the spectrum, that is, the energy difference between the VBM and the photoemission cutoff energy, and E g = 2.80 eV is the bandgap energy calculated from the transmission spectrum. The work function (W f ) was determined to be equal to 4.01 eV and was calculated as the difference between the photon energy of the He (I) line and the position of the cutoff energy of the photoemission (17.21 eV).…”

Lattice-aligned gallium oxynitride nanolayer for GaN surface enhancement and function extension

“…After 40 s, the fraction of Ga-O bonds keeps around a negligible value, suggesting that the GaON nanolayer has been completely sputtered. The rise of the Ga-Ga bond intensity is because of the preferential sputtering of the light atoms (O and N), leaving a thin layer of metallic Ga on the surface [27,28].…”