Advances in selective wet oxidation of AlGaAs alloys

Choquette, Kent D.; Geib, K.M.; Ashby, Carol I. H.; Twesten, R. D.; Blum, O.; Hou, H.Q.; Follstaedt, D. M.; Hammons, B. E.; Mathes, David T.; Hull, R.

doi:10.1109/2944.640645

Cited by 266 publications

(163 citation statements)

References 52 publications

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“…At the lowest dipole resonances, the resonators have side dimensions that are roughly /n, where  is the free space wavelength and n the refractive index. Our nonlinear metasurface comprises a square lattice of GaAs nanodisk resonators lying on a low refractive index (Al x Ga 1-x ) 2 O 3 native oxide spacer layer that is formed by selectively oxidizing high-Al content Al x Ga 1-x As layers [28][29][30][31] . The resonator array pitch is designed to minimize the interaction between neighboring GaAs resonators.…”

Section: Design and Fabrication Of Gaas Dielectric Metasurfacesmentioning

confidence: 99%

Resonantly Enhanced Second-Harmonic Generation Using III–V Semiconductor All-Dielectric Metasurfaces

et al. 2016

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Abstract:Nonlinear optical phenomena in nanostructured materials have been challenging our perceptions of nonlinear optical processes that have been explored since the invention of lasers. For example, the ability to control optical field confinement, enhancement, and scattering almost independently, allows nonlinear frequency conversion efficiencies to be enhanced by many orders of magnitude compared to bulk materials. Also, the subwavelength length scale renders phase matching issues irrelevant. Compared with plasmonic nanostructures, dielectric resonator metamaterials show great promise for enhanced nonlinear optical processes due to their larger mode volumes. Here, we present, for the first time, resonantly enhanced second-harmonic generation (SHG) using Gallium Arsenide (GaAs) based dielectric metasurfaces. Using arrays of cylindrical resonators we observe SHG enhancement factors as large as 10 4 relative to 2 unpatterned GaAs. At the magnetic dipole resonance we measure an absolute nonlinear conversion efficiency of ~2 × 10 −5 with ~3.4 GW/cm 2 pump intensity. The polarization properties of the SHG reveal that both bulk and surface nonlinearities play important roles in the observed nonlinear process.

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Section: Design and Fabrication Of Gaas Dielectric Metasurfacesmentioning

confidence: 99%

Resonantly Enhanced Second-Harmonic Generation Using III–V Semiconductor All-Dielectric Metasurfaces

et al. 2016

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“…1͑f͔͒. 5 This robust layer of Al 2 O 3 is the final mask for pattern amplification in the perpendicular direction into the GaAs substrate by using further CAIBE ͓Fig. 1͑g͔͒.…”

Section: Methodsmentioning

confidence: 99%

Fabrication and characterization of high aspect ratio perpendicular patterned information storage media in an Al2O3/GaAs substrate

Wong

Scherer

Todorovic

et al. 1999

Journal of Applied Physics

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In a new approach, we have fabricated 6:1 aspect ratio magnetic nanocolumns, 60-250 nm in diameter, embedded in a hard aluminum-oxide/gallium-arsenide (Al 2 O 3 /GaAs) substrate. The fabrication technique uses the highly selective etching properties of GaAs and AlAs, and highly efficient masking properties of Al 2 O 3 to create small diameter, high aspect ratio holes. Nickel ͑Ni͒ is subsequently electroplated into the holes, followed by polishing, which creates a smooth and hard surface appropriate for future reading and writing of the columns as individual bits for high density information storage. We have used magnetic force microscopy and scanning magneto-resistance microscopy to characterize the resulting magnets. We find the columns more magnetically stable than previously achieved with magnets embedded in a SiO 2 substrate. Such stability is necessary before further writing of perpendicular patterned media can be demonstrated.

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“…To accomplish substantially vertical oxidation, the Al-content of an AlGaAs layer is graded, with the higher Al-content closer to the substrate. The exponential dependence of the oxidation rate on the Al-content [39] then drives the reaction downwards in an anisotropic fashion. For masking, we have used a thin (50 nm) layer of GaAs, which was either removed locally by wet etching or damaged by exposure to an RIE-generated plasma of CHF .…”

Section: Vertical Selective Oxidationmentioning

confidence: 99%

“…Another problem is the volume shrinkage of up to 13% [39] which can lead to strain, microcracks or structural problems such as delamination of the layer structure if the oxide is too thick. Careful process control is also required, as illustrated by the overshoot seen in Fig.…”

Section: Vertical Selective Oxidationmentioning

confidence: 99%

“…We have observed an erosion rate of only 3 nm/min for a layer of oxidised 80% x-fraction AlGaAs, which is a considerable improvement over externally deposited dielectrics. The oxidation is carried out at 400}4503C in a wet steam atmosphere, a process that has been widely studied, mainly for current aperturing in vertical cavity surface-emitting lasers (VCSELs) [39,40]. Despite this obvious improvement in erosion rate, AlO V masks have not been widely used, in part because they have to be designed into the epitaxial material structure.…”

Section: Maskingmentioning

confidence: 99%

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Photonic crystals in the optical regime â past, present and future

Krauss

Rue

1999

Progress in Quantum Electronics

445

141

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During the last decade, photonic crystals, also known as photonic microstructures or photonic bandgap structures, have matured from an intellectual curiosity concerning electromagnetic waves to a "eld with real applications in both the microwave and optical regime. In this review, we shall focus on progress and the prospects for semiconductor structures that mainly involve guided modes interacting with periodic structures, but we also evaluate alternative material systems and fabrication methods, e.g. those based on self-organisation. We shall go from basic concepts, via a discussion of the state of the art, to device applications. Naturally, the discussion of the applications will be more speculative, but we attempt to evaluate the real prospects o!ered by photonic crystals at optical frequencies while considering practical limitations. In doing so, we identify a variety of areas such as the combination of quantum dot light emitters with photonic crystals that seem particularly promising. We discuss the prospects for enhanced light}matter interactions in photonic crystals and the related material and design issues. Overall, the aim of this review is to introduce the reader to the concepts of photonic crystals, describe the state of the art and attempt to answer the question of what uses these peculiar structures may have.

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Advances in selective wet oxidation of AlGaAs alloys

Cited by 266 publications

References 52 publications

Resonantly Enhanced Second-Harmonic Generation Using III–V Semiconductor All-Dielectric Metasurfaces

Resonantly Enhanced Second-Harmonic Generation Using III–V Semiconductor All-Dielectric Metasurfaces

Fabrication and characterization of high aspect ratio perpendicular patterned information storage media in an Al2O3/GaAs substrate

Photonic crystals in the optical regime â past, present and future

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Advances in selective wet oxidation of AlGaAs alloys

Cited by 266 publications

References 52 publications

Resonantly Enhanced Second-Harmonic Generation Using III–V Semiconductor All-Dielectric Metasurfaces

Resonantly Enhanced Second-Harmonic Generation Using III–V Semiconductor All-Dielectric Metasurfaces

Fabrication and characterization of high aspect ratio perpendicular patterned information storage media in an Al2O3/GaAs substrate

Photonic crystals in the optical regime â past, present and future

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Photonic crystals in the optical regime â past, present and future