Lateral oxidation kinetics of AlAsSb and related alloys lattice matched to InP

The lateral oxidation kinetics of AlAs0.56Sb0.44 on InP substrates have been investigated to understand the antimony segregation process during oxidation. Oxidation layers were grown between GaAsSb buffer and cap layers on InP substrates by molecular beam epitaxy. Oxidation temperatures between 325 and 500 degreesC were investigated for AlAsSb layer thicknesses between 100 and 2000 Angstrom. At low oxidation temperatures (T-ox less than or equal to 400 degreesC), the process is reaction limited with a linear dependence of oxidation depth on time. At intermediate oxidation temperatures (400 <T-ox <450 degreesC), the oxidation process becomes diffusion limited. At high oxidation temperatures, the oxidation process is termed self-limiting since at 500 degreesC the process stops entirely after oxidation times on the order of 5 min and distances of 40 mum. It is shown that the antimony float layer lags the oxidation front by a temperature-dependent distance, which suggests that the antimony may change the structure of the oxide at the front and cause self-limiting behavior. The oxidation kinetics of AlxGa1-xAsSb and AlxIn1-xAsSb have also been investigated. Antimony segregation is not suppressed during oxidation of Ga-containing layers and AlInAsSb quaternary alloys do not oxidize laterally at measurable rates in the range 400-525 degreesC. SiNx cap layers deposited after growth and before oxidation do not affect the Sb segregation or oxidation rate, but do smooth the cap surface by preventing uneven Sb metal segregation to the cap/oxide interface. (C) 2001 American Institute of Physics

Anisotropic lateral oxidation of Al-III-V semiconductors: inverse problem and circular aperture fabrication

International audienceThe lateral wet oxidation of aluminum-containing III-V-semiconductors is a technological process which converts a buried (thin) cristalline material into an amorphous insulator and, as such, tends to exhibit an anisotropic behavior. As a result, the shape of the interface between the semiconductor and the insulator, often referred as the oxide aperture, differs from the etched mesa contour from which the oxidation proceeds. This, in turn, complicates the design of the devices relying on this process especially when specific oxide patterns are needed.&#13; In this paper, we introduce a method based on a morphological dilatation to determine the shape of the mesas which will lead to a specific targetted contour upon an anisotropic oxidation over a modest extent. The approach is experimentally validated by demonstrating the fabrication of circular oxide apertures which are inherently difficult to make because of their high degree of symmetry but which also turn out to be of critical importance in obtaining efficient single-mode vertical-cavity surface-emittting laser

Second harmonic generation from a QCL in an AlGaAs waveguide

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AlGaAs guided-wave second-harmonic generation at 2.23 μm from a quantum cascade laser

International audienceWe demonstrate the frequency doubling of a quantum cascade laser in a multilayered, partially oxidized GaAs/AlOx waveguide. Using the waveguide width to fulfill the phase-matching condition, the second harmonic is generated in the wavelength range between 2.2 and 2.4 μm, where not many semiconductor sources are commercially available to date. We discuss the impact of a few fabrication and experimental parameters on the conversion efficiency, an essential step toward the improvement and practical implementation of this proof-of-principle semiconductor microsystem

High reflectivity Te-doped GaAsSb/AlAsSb Bragg mirror for 1.5~μm use

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AlGaAsSb based-on Bragg mirrors and microcavities for 1.3 μm and 1.55 μm

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Vertical cavity structures on InP and GaSb with AlGaAsSb/AlAsSb Bragg mirrors for 1.55~μm emission

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