Fabrication and Analysis of AlN/GaAs(001) and AlN/Ge/GaAs(001) Metal–Insulator–Semiconductor Structures

Abstract

Using sputtering-deposited AlN insulator films, we fabricated and analyzed AlN/GaAs(001) and AlN/Ge/GaAs(001) metal–insulator–semiconductor (MIS) structures; the former is obtained by the direct deposition of AlN on GaAs, while the latter includes a Ge interlayer between AlN and GaAs. By current–voltage (I–V) measurements, we obtained similar good insulating properties for both MIS structures. On the other hand, we observed rather different frequency dispersions in the capacitance–voltage (C–V) characteristics of the MIS structures; the AlN/Ge/GaAs(001) MIS structure exhibits a significantly smaller dispersion than the AlN/GaAs(001) MIS structure, attributed to a smaller interface state density, as confirmed by analysis using the conductance method. From the X-ray photoelectron spectroscopy analysis results of the MIS interfaces, we found that, in comparison with the AlN/GaAs(001) interface, the AlN/Ge/GaAs(001) interface exhibits suppressed As deficiency and Ga–O bonding, with an indication of their relation to interface states.

Interface analysis of AlN/InAs(001) and AlN/Ge/InAs(001) by angle-resolved X-ray photoelectron spectroscopy

“…We previously investigated sputtering-deposited AlN as an important high-k insulator, with a possible high breakdown field > ∼ 10 MV/cm, a high dielectric constant ∼ 9, which are comparable to those of Al 2 O 3 , and also a high thermal conductivity, ∼ 10 times higher than that of Al 2 O 3 . As a result, we realized a low interface state density and reduction of frequency dispersion in C-V characteristics for AlN/Ge/GaAs(001) MIS structures, and analyzed their interfaces by X-ray photoelectron spectroscopy (XPS) [3]. In this work, we fabricated AlN/InAs(001) and AlN/Ge/InAs(001) MIS structures, and their insulator-semiconductor interfaces are analyzed by angle-resolved XPS (ARXPS).…”

Effect of High-Pressure Inert Gas Annealing on AlON/Ge Gate Stacks

“…In this study, we focus on AlN among several nitride candidates, because AlN has a relatively large energy band gap ($6 eV). 22,23) AlN films were prepared on p-type (100) Ge wafers. The Ge wafers were cleaned using methanol, hydrochloric acid, a mixture of hydrogen peroxide and ammonium solution, diluted hydrofluoric acid (HF) solution, and finally in deionized water (DIW).…”

Investigation of interface properties of h-BN and AlN on AlGaN/GaN heterostructures

“…Solid lines are the theoretical calculation using different AlN defect densities. Diamond symbols are single crystal samples measured by Slack et al [103] (in purple), and Rounds et al [104]. Square symbols are a poly-crystalline bulk sample [113] (in green) and various polycrystalline films (grey: Kuo et al [106], purple: Duquenne et al [105], black: Zhao et al [107], red:…”

“…Among non-oxide insulators, AlN is an attractive high-k dielectric material for III-N MISHEMTs due to its high breakdown field and high dielectric constant [103], [104]. In addition, AlN is of interest due to its high thermal conductivity (200 WK -1 m -1 ), which makes it suitable for use as a passivation layer to suppress the self-heating [52].…”