TY - JOUR

T1 - Local droplet etching on InAlAs/InP surfaces with InAl droplets

AU - Cao, Xin

AU - Zhang, Yiteng

AU - Ma, Chenxi

AU - Wang, Yinan

AU - Brechtken, Benedikt

AU - Haug, Rolf J.

AU - Rugeramigabo, Eddy P.

AU - Zopf, Michael

AU - Ding, Fei

N1 - Funding Information: The authors acknowledge the funding by the German Federal Ministry of Education and Research (BMBF) within the project Q.Link.X (Grant No. 16KIS0869) and QR.X (Grant No. 16KISQ015), the European Research Council (Grant No. QD-NOMS GA715770), and the German Research Foundation under Germany’s Excellence Strategy—EXC-2123, Quantum Frontiers—Grant Nos. 390837967 and 454635269. Y. Zhang acknowledges the China Scholarship Council (Grant No. CSC201908370225).

PY - 2022/5/2

Y1 - 2022/5/2

N2 - GaAs quantum dots (QDs) grown by local droplet etching (LDE) have been studied extensively in recent years. The LDE method allows for high crystallinity, as well as precise control of the density, morphology, and size of QDs. These properties make GaAs QDs an ideal candidate as single photon and entangled photon sources at short wavelengths (<800 nm). For technologically important telecom wavelengths, however, it is still unclear whether LDE grown QDs can be realized. Controlling the growth conditions does not enable shifting the wavelength of GaAs QDs to the telecom region. New recipes will have to be established. In this work, we study Indium-Aluminum (InAl) droplet etching on ultra-smooth In0.55Al0.45As surfaces on InP substrates, with a goal to lay the foundation for growing symmetrical and strain-free telecom QDs using the LDE method. We report that both droplets start to etch nanoholes at a substrate temperature above 415 °C, showing varying nanohole morphology and rapidly changing density (by more than one order of magnitude) at different temperatures. Al and In droplets are found to not intermix during etching, and instead etch nanoholes individually. The obtained nanoholes show a symmetric profile and very low densities, enabling infilling of lattice-matched InGaAs QDs on InxAl1-xAs/InP surfaces in further works.

AB - GaAs quantum dots (QDs) grown by local droplet etching (LDE) have been studied extensively in recent years. The LDE method allows for high crystallinity, as well as precise control of the density, morphology, and size of QDs. These properties make GaAs QDs an ideal candidate as single photon and entangled photon sources at short wavelengths (<800 nm). For technologically important telecom wavelengths, however, it is still unclear whether LDE grown QDs can be realized. Controlling the growth conditions does not enable shifting the wavelength of GaAs QDs to the telecom region. New recipes will have to be established. In this work, we study Indium-Aluminum (InAl) droplet etching on ultra-smooth In0.55Al0.45As surfaces on InP substrates, with a goal to lay the foundation for growing symmetrical and strain-free telecom QDs using the LDE method. We report that both droplets start to etch nanoholes at a substrate temperature above 415 °C, showing varying nanohole morphology and rapidly changing density (by more than one order of magnitude) at different temperatures. Al and In droplets are found to not intermix during etching, and instead etch nanoholes individually. The obtained nanoholes show a symmetric profile and very low densities, enabling infilling of lattice-matched InGaAs QDs on InxAl1-xAs/InP surfaces in further works.

UR - http://www.scopus.com/inward/record.url?scp=85129892665&partnerID=8YFLogxK

U2 - 10.1063/5.0088012

DO - 10.1063/5.0088012

M3 - Article

AN - SCOPUS:85129892665

VL - 12

JO - AIP Advances

JF - AIP Advances

SN - 2158-3226

IS - 5

M1 - 055302

ER -