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A new study examines the influence of proton irradiation on an AlxHa1-xN/GaN high electron mobility transistor device.

We investigate oriented abrupt steps (OASs), a type of surface defect in InSb/AlxIn1−xSb quantum-well (QW) samples grown on GaAs (0 0 1) substrates. Previous atomic force microscopy studies have reported that the OASs are oriented along the [1 1 0] and [1¯ 1 0] directions and have an inclination angle of ∼5°–15° with respect to the sample surface. Our plan-view and cross-sectional transmission electron microscopy analyses reveal that the OASs are the terminal edges of threading micro-twins at the sample surface. Hall effect measurements indicate that the density of OASs correlates with the electron mobility in the InSb QWs. [Copyright &y& Elsevier]

The differential cross-section for forward recoiling hydrogen with 4He ions has been determined for the energy range of 1.0–12.5 MeV at a laboratory angle of 30°. Relative measurements of the cross-section were determined from a magnetron sputtered diamond-like carbon thin film deposited on a polished molybdenum substrate. Polystyrene (C8H8) thin films were used as a standard to re-normalize the relative cross-section measurements through the Rutherford cross-section of carbon. This technique allowed the determination of all data points to 5% absolute error over the entire energy range. A polynomial fit of the absolute cross section is also presented. [Copyright &y& Elsevier]

Structural defects in InSb/AlxIn1−xSb quantum-well samples grown on (0 0 1) GaAs substrates have been investigated using transmission electron microscopy. A high density of dislocations is created at the interface between the InSb nucleation layer and the substrate, while {1 1 1}-planar defects are introduced at various locations. An InSb/AlxIn1−xSb interface 920 nm above the InSb/GaAs interface acts as a trapping site for many dislocations. The majority of the {1 1 1}-planar defects are micro-twins with {1 1 1}-bilayer thickness fluctuations. The anisotropic distribution of the micro-twins correlates with the measured anisotropic electron mobility in the quantum well. [Copyright &y& Elsevier]