Super-Flat Interfaces in Pseudomorphic In_xGa_1-xAs/Al_0.28Ga_0.72As Quantum Wells with High In Content (x = 0.15) Grown on (411)A GaAs Substrates by Molecular Beam Epitaxy

Abstract

Pseudomorphic In x Ga1-x As/Al0.28Ga0.72As (x = 0.085–0.15) quantum wells (QWs) with well widths of 1.2, 2.4, 3.6, 4.8, 7.2 and 12 nm have been grown on (411)A and (100) GaAs substrates at a temperature (T s) of 520°C by molecular beam epitaxy (MBE). The interface flatness of the QWs was characterized by photoluminescence (PL) at 4.2 K. PL linewidths of the narrow (411)A QWs (L w = 2.4 nm) with x = 0.085 and 0.15 were 7.3 meV which is approximately 30–40% smaller than those of the (100) QWs, indicating that extremely flat interfaces over a macroscopic area [(411)A super-flat interfaces] have been realized in the pseudomorphic In x Ga1-x As/Al0.28Ga0.72As QWs (up to x = 0.15) grown on the (411)A GaAs substrates, similar to lattice-matched GaAs/Al x Ga1-x As QWs grown on (411)A GaAs substrate previously reported.

Surface segregation of indium atoms during molecular beam epitaxy of InGaAs/GaAs superlattices on GaAs substrates

“…For example, we have reported that effectively atomically flat interfaces over a macroscopic area (''super-flat interfaces'') can be formed in GaAs/AlGaAs and pseudomorphic InGaAs/AlGaAs quantum wells (QWs) grown on (4 1 1)A-oriented GaAs substrates by molecular beam epitaxy (MBE) [1][2][3][4].…”

High-quality InAlAs layers grown on (411)A-oriented InP substrates by molecular beam epitaxy

“…1,2 Photoluminescence ͑PL͒ linewidths ͑4.2 K͒ of ͑411͒A GaAs/AlGaAs QWs are much narrower than those of QWs grown on conventional ͑100͒ substrates, and they are comparable to those of split peaks of ͑100͒ growthinterrupted QWs. 3 In our recent studies, the ͑411͒A super-flat interfaces have been also achieved in MBE grown pseudomorphic In x Ga 1Ϫx As/Al 0.3 Ga 0.7 As QWs with xϳ0.08 4 and xϳ0.15 5 and In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As QWs lattice matched to InP substrates, 6 which are important materials for ultrahigh speed devices such as high electron mobility transistors ͑HEMTs͒, resonant tunneling diodes ͑RTDs͒, and long-wavelength optical devices. In order to achieve highquality InGaAs/InAlAs heterostructures with the ͑411͒A super-flat interfaces, MBE growth of a high-quality InAlAs barrier layer is essential.…”

Al x Ga1 − x As ( 111 ) A Substrate with Atomically Flat Polished Surface

“…1 Recently, the A-face (Ga-rich face) such as (111)A and other (n11)A substrates have been tried in optical devices and 2D electron devices. [7][8][9][10] The main reason for this is obtaining a flatter interface. But there are peculiar difficulties in GaAs A-face polishing.…”