Details
| Original language | English |
|---|---|
| Article number | 32LT01 |
| Journal | Journal of Physics D: Applied Physics |
| Volume | 51 |
| Issue number | 32 |
| Publication status | Published - 19 Jul 2018 |
Abstract
In this letter, fabrication of all-epitaxial GeSn-on-insulator (GeSnOI) heterostructures is investigated, wherein both the GeSn epilayer and the Gd2O3 insulator are grown on Si(1 1 1) substrates by conventional molecular beam epitaxy. Analysis of the crystal and surface quality by high-resolution x-ray diffraction, cross-sectional transmission electron microscopy, and atomic force microscopy reveals the formation of a continuous and fully-relaxed single-crystalline GeSn epilayer (with a root-mean-square surface roughness of 3.5 nm), albeit GeSn epitaxy on Gd2O3 initiates in the Volmer-Weber growth mode. The defect structure of the GeSn epilayers is dominated by stacking faults and reflection microtwins, which are formed during the coalescence of the initially-formed islands. The concentration and mobility of holes, introduced by un-intentional p-type doping of the GeSn epilayers, were estimated to cm-3 and cm-2 V-1 s-1, respectively. In metal-semiconductor-metal Schottky diodes, fabricated with these GeSnOI heterostructures, the dark current was observed to be lower by a decade, when compared to similar diodes fabricated with GeSn/Ge/Si(0 0 1) heterostructures. The results presented here are thus promising for the development of these engineered substrates for (opto-)electronic applications.
Keywords
- Epitaxy, gadolinium oxide, GeSn-on-insulator, group IV photonics
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Acoustics and Ultrasonics
- Materials Science(all)
- Surfaces, Coatings and Films
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In: Journal of Physics D: Applied Physics, Vol. 51, No. 32, 32LT01, 19.07.2018.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Wafer-scale all-epitaxial GeSn-on-insulator on Si(1 1 1) by molecular beam epitaxy
AU - Khiangte, Krista R.
AU - Rathore, Jaswant S.
AU - Schmidt, Jan
AU - Osten, Hans-Jörg
AU - Laha, A.
AU - Mahapatra, S.
N1 - © 2018 IOP Publishing Ltd
PY - 2018/7/19
Y1 - 2018/7/19
N2 - In this letter, fabrication of all-epitaxial GeSn-on-insulator (GeSnOI) heterostructures is investigated, wherein both the GeSn epilayer and the Gd2O3 insulator are grown on Si(1 1 1) substrates by conventional molecular beam epitaxy. Analysis of the crystal and surface quality by high-resolution x-ray diffraction, cross-sectional transmission electron microscopy, and atomic force microscopy reveals the formation of a continuous and fully-relaxed single-crystalline GeSn epilayer (with a root-mean-square surface roughness of 3.5 nm), albeit GeSn epitaxy on Gd2O3 initiates in the Volmer-Weber growth mode. The defect structure of the GeSn epilayers is dominated by stacking faults and reflection microtwins, which are formed during the coalescence of the initially-formed islands. The concentration and mobility of holes, introduced by un-intentional p-type doping of the GeSn epilayers, were estimated to cm-3 and cm-2 V-1 s-1, respectively. In metal-semiconductor-metal Schottky diodes, fabricated with these GeSnOI heterostructures, the dark current was observed to be lower by a decade, when compared to similar diodes fabricated with GeSn/Ge/Si(0 0 1) heterostructures. The results presented here are thus promising for the development of these engineered substrates for (opto-)electronic applications.
AB - In this letter, fabrication of all-epitaxial GeSn-on-insulator (GeSnOI) heterostructures is investigated, wherein both the GeSn epilayer and the Gd2O3 insulator are grown on Si(1 1 1) substrates by conventional molecular beam epitaxy. Analysis of the crystal and surface quality by high-resolution x-ray diffraction, cross-sectional transmission electron microscopy, and atomic force microscopy reveals the formation of a continuous and fully-relaxed single-crystalline GeSn epilayer (with a root-mean-square surface roughness of 3.5 nm), albeit GeSn epitaxy on Gd2O3 initiates in the Volmer-Weber growth mode. The defect structure of the GeSn epilayers is dominated by stacking faults and reflection microtwins, which are formed during the coalescence of the initially-formed islands. The concentration and mobility of holes, introduced by un-intentional p-type doping of the GeSn epilayers, were estimated to cm-3 and cm-2 V-1 s-1, respectively. In metal-semiconductor-metal Schottky diodes, fabricated with these GeSnOI heterostructures, the dark current was observed to be lower by a decade, when compared to similar diodes fabricated with GeSn/Ge/Si(0 0 1) heterostructures. The results presented here are thus promising for the development of these engineered substrates for (opto-)electronic applications.
KW - Epitaxy
KW - gadolinium oxide
KW - GeSn-on-insulator
KW - group IV photonics
UR - http://www.scopus.com/inward/record.url?scp=85050807141&partnerID=8YFLogxK
U2 - 10.48550/arXiv.1802.03150
DO - 10.48550/arXiv.1802.03150
M3 - Article
AN - SCOPUS:85050807141
VL - 51
JO - Journal of Physics D: Applied Physics
JF - Journal of Physics D: Applied Physics
SN - 0022-3727
IS - 32
M1 - 32LT01
ER -