Thermal Oxidation of AlInN for III-Nitride Electronic and Optoelectronic Devices

Abstract

The oxidation of semiconductors is a fundamental building block of many modern electronic devices. The prime example is the oxidation of silicon into silicon dioxide, which is used as a gate dielectric, waveguides, masking layer, and a device isolation layer. The ability to form an analogous stable and insulating oxide in III-nitride semiconductors would enable a new generation of III-nitride-based electronic and optoelectronic devices. Here we present data on the conversion of thick (>100 nm) AlInN epitaxial layers into oxides with H 2 O vapor in an N 2 carrier gas (wet oxidation) at elevated temperatures (900 °C). The Al x In 1−x N layers are grown on and latticed-matched (x = 0.82) to GaN layers. The oxide can be formed over its entirety or selectively by patterning the surface. The conversion to an oxide is confirmed and characterized by atomic force microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, spectroscopic ellipsometry, and electrical measurements. The oxide is smooth and crystalline, has a low index of refraction of ∼1.8 in the visible, and exhibits very high resistivity of >10 14 Ω•cm.

Low‐to‐Mid Al Content (x = 0–0.56) AlxIn1−xN Layers Deposited on Si(100) by Radio‐Frequency Sputtering

“…[1] In particular, AlInN alloys are special candidates for power electronics, highly efficient emitters, optoelectronic devices, and solar cells. [2][3][4][5][6][7][8] In that sense, radio-frequency (RF) magnetron sputtering allows the deposition of large-area and single-phase AlInN material using this low-cost and low-temperature technology exportable to the industry.…”

“…III‐Nitride semiconductors are interesting materials for the development of novel devices due to their direct bandgap energy tunable from the infrared (0.7 eV) for InN to the UV (6.2 eV) for AlN, their strong chemical and temperature endurance, and their radiation hardness . In particular, AlInN alloys are special candidates for power electronics, highly efficient emitters, optoelectronic devices, and solar cells . In that sense, radio‐frequency (RF) magnetron sputtering allows the deposition of large‐area and single‐phase AlInN material using this low‐cost and low‐temperature technology exportable to the industry.…”

Selective wet oxidation of AlAsSb alloys on GaAs

“…Investigations 2 of the oxidation of other Al-containing III-V semiconductors have also been carried out to gain additional chemico-physical insight and to potentially expand the use of this process to make transistors or photonics devices operating in other spectral bands than the near-infrared window (800-1000 nm). So far, the studied alloys include AlIn(Ga)P 28 on GaAs, AlInAs [29][30][31][32] and AlAsSb [33][34][35] on InP, AlInN on GaN 36,37 , and AlAsSb on GaSb [38][39][40][41][42] .…”

Aperture diameter dependences in GaN-based vertical-cavity surface-emitting lasers with nano-height cylindrical waveguide formed by BCl3 dry etching

“…In the infrared GaAs-based VCSELs, selective AlGaAs oxide layers can be facilitated by a steam oxidation, and work well as the current and optical confinements. 23) A steam oxidation of an AlInN surface has been reported, 24) but so far no such selective oxide layers have been established in GaN-based materials. Under the circumstances, in 2013, Hashemi et al theoretically showed large optical loss values (40 cm −1 ) without the optical confinement, and proposed various confinement structures with a convex step mesa and/or a surrounding buried oxide layer.…”