Schottky barrier height of InxAl1−xAs epitaxial and strained layers

Abstract

The Schottky barrier height of n-type semiconducting and semi-insulating InxAl1−xAs grown by molecular beam epitaxy has been determined on the lattice-matched composition, x=0.523, in tension and in compression relative to their (110) oriented InP substrates. For the semiconducting material in the composition range 0.43<x<0.62, the barrier height is φbn=0.62±0.05 eV while the anomalous rise and saturation of φbn at 1.2 eV of the semi-insulating material, within the same composition range, is attributed to the presence of AlAs clusters within an InxAl1−xAs matrix.

Schottky contacts on ternary compound semiconductors: Compositional variations of barrier heights

“…Their data supplement results previously published by Lin et al 3 and Chu and co-workers. 4 They varied the compositional parameter x between 0.45 and 0.55. Figure 1 displays these data and also shows barrier heights reported by Best 5 for Au/AlAs and by Sadwick et al 6 and Gueissaz et al 7 for Al/Al 0.48 In 0.52 As contacts.…”

Subnanometer analysis of molecular beam epitaxy grown ternary arsenides

“…When the cluster shape is approximated with a sphere, these binary clusters have been found to have diameters of less than 10 nm. Chu et al 2 concluded that AlAs clusters were present at certain growth conditions from observations of Schottky barrier heights at 1.2 eV in InAlAs. Using cross-sectional transmission electron microscopy ͑XTEM͒, McDevitt et al 3 found the average periodicity of the compositional fluctuations was on the order of 3-7 nm for a lattice matched ternary on indium phosphide ͑InP͒.…”

InP-based enhancement-mode pseudomorphic HEMT with strained In/sub 0.45/Al/sub 0.55/As barrier and In/sub 0.75/Ga/sub 0.25/As channel layers

“…Compared with that of In Al As lattice-matched to InP, Schottky barrier height of strained Al-rich In Al As lattice-mismatched to InP has been verified to rise anomalously with the increase of fractional Al concentration and saturated at 1.2 eV [7], showing the possibility for this material used as Schottky contact material in E-HEMT's. In this paper, we demonstrate InAlAs/InGaAs E-PHEMT by introducing strained In Al As as barrier layer and titanium still as Schottky contact.…”