Thermal stability of an InAlN/GaN heterostructure grown on silicon by metal-organic chemical vapor deposition

Abstract

The thermal stabilities of metal-organic chemical vapor deposition-grown lattice-matched InAlN/GaN/Si heterostructures have been reported by using slower and faster growth rates for the InAlN barrier layer in particular. The temperature-dependent surface and two-dimensional electron gas (2-DEG) properties of these heterostructures were investigated by means of atomic force microscopy, photoluminescence excitation spectroscopy, and electrical characterization. Even at the annealing temperature of 850 °C, the InAlN layer grown with a slower growth rate exhibited a smooth surface morphology that resulted in excellent 2-DEG properties for the InAlN/GaN heterostructure. As a result, maximum values for the drain current density (IDS,max) and transconductance (gm,max) of 1.5 A/mm and 346 mS/mm, respectively, were achieved for the high-electron-mobility transistor (HEMT) fabricated on this heterostructure. The InAlN layer grown with a faster growth rate, however, exhibited degradation of the surface morphology at an annealing temperature of 850 °C, which caused compositional in-homogeneities and impacted the 2-DEG properties of the InAlN/GaN heterostructure. Additionally, an HEMT fabricated on this heterostructure yielded lower IDS,max and gm,max values of 1 A/mm and 210 mS/mm, respectively.

Investigation of InAlN Layers Surface Reactivity after Thermal Annealings: A Complete XPS Study for HEMT

“…J. Palisaitis et al have done deep investigations by STEM (Scanning Transmission Electron Microscopy) characterization on InAlN thin layers during in situ thermal annealing. 41,42 Their work points out the fact that In-rich layers decompose at 750 • C, starting from the formation of metallic In clusters at grain boundaries, whereas Al-rich layers show few signs of decomposition and remain chemically stable even at 950 • C. Consequently, different approaches are considered by the community, such as operating at slower growth rate in MOVPE to increase thermal stability, 43 or processing ohmic contact at a lower annealing temperature around 600 • C. [44][45][46] Actually, the growth of a thermal oxide layer on III-V nitrides like InAlN is still hard to control and not fully understood.…”

Improved reverse recovery characteristics of inAlN/GaN schottky barrier diode using a SOI substrate

“…InAlN barrier layers have also been shown to improve the quality of the epitaxial layers and device reliability via the lattice matching of In x Al 1−x N alloys to GaN. InAlN/GaN provides greater reliability compared to AlGaN/GaN, particularly under high-voltage and high-temperature conditions [3]. GaN-based Schottky barrier diodes (SBDs) provide a high breakdown voltage, low on-resistance, and rapid reverse bias recovery [4,5].…”

NbN Capping Layer for Enhanced Thermal Processing of Group III-Nitride Semiconductor Devices

“…Inbearing alloys have similar or lower decomposition temperatures at atmospheric pressures. 6,10 z E-mail: jordan.greenlee@gmail.com There are a few approaches to solve the problem of GaN decomposition during high temperature annealing. First, III-nitrides can be annealed at high temperatures without decomposing with the use of a high nitrogen overpressure.…”