Elastic properties of AlAs-like and InSb-like strained interfaces in [InAs/AlSb] heterostructures

Abstract

Elastic properties of [InAs/AlSb] heterostructures coherently grown on a (001) InAs substrate are investigated by the density functional theory and compared to the prediction of the linear elasticity theory. The stress-strain curves of the four involved binaries (InAs, AlAs, AlSb, and InSb) are first studied: a significant deviation to the linear elasticity theory is observed for strain above 2.5% (in absolute value). Nevertheless, the relationship between the out-of-plane and in-plane strains is in a good agreement with the prediction of the linear elasticity theory. In the heterostructures, highly strained perfect AlAs-like and InSb-like interfaces are examined. The interfacial strains calculated using the density functional theory are in a surprisingly good agreement with the prediction of the linear elasticity theory. The reduction of the layer thickness to the thinnest possible InAs or AlSb layers while keeping perfect interfaces does not change these conclusions.

Unintentional As incorporation into AlSb and interfacial layers within InAs/AlSb superlattices

“…Later in 2016, Claveau et al from A. Ponchet's group studied the InAs/AlSb interface elastic strain properties using Density Functional Theory (DFT). Their calculations of strain via DFT agreed with the prediction of structures with predominately Al-As interfaces [45].…”

“…Al-As bonds were suspected to be the primary cause of interfacial strains in InAs/AlSb heterostructures [5][6][7] [45]. Excess As at the interfaces may cause Al-As bonds outnumber In-Sb bonds.…”

Investigation of band alignment between InAlAs and atomic-layer-deposited HfO2/Al2O3 by X-ray photoelectron spectroscopy

“…nAs/AlSb high-electron-mobility transistors (HEMTs) are strong candidates for applications in low-power highspeed radio-frequency circuits, 1,2) by virtue of their high electron velocity (4 × 10 7 cm s −1 ) and high electron mobility (30000 cm 2 V −1 s −1 at 300 K). 3,4) In addition, a big conduction band offset between InAs and AlSb (ΔE c = 1.35 eV) provides deeper quantum wells available for any other latticematched III-V heterostructure.…”