Isothermal Heteroepitaxy of Ge1–xSnx Structures for Electronic and Photonic Applications

Concepción, Omar; Søgaard, Nicolaj Brink; Bae, Jin Hee; Yamamoto, Yuji; Tiedemann, A. T.; Ikonić, Z.; Capellini, Giovanni; Zhao, Qing‐Tai; Grützmacher, Detlev; Buca, D.

doi:10.1021/acsaelm.3c00112

Cited by 9 publications

(1 citation statement)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Due to the large lattice mismatch between Sn and Si, a Ge buffer layer was grown prior to the GeSn deposition to improve the crystal quality. Details on the epitaxy can be found elsewhere. , The Sn content and the layer thickness were extracted by fitting the Rutherford backscattering spectra ,, (not shown). The layer thickness of GeSn alloys of different stoichiometries was between 250 and 300 nm, except for the 12 at.% Sn, where a set of thicknesses, between 50 and 700 nm, was grown.…”

Section: Materials and Devicesmentioning

confidence: 99%

Room Temperature Lattice Thermal Conductivity of GeSn Alloys

Concepción,

Tiscareño-Ramírez,

Chimienti

et al. 2024

ACS Appl. Energy Mater.

Self Cite

View full text Add to dashboard Cite

CMOS-compatible materials for efficient energy harvesters at temperatures characteristic for on-chip operation and body temperature are the key ingredients for sustainable green computing and ultralow power Internet of Things applications. In this context, the lattice thermal conductivity (κ) of new group IV semiconductors, namely Ge1–x Sn x alloys, are investigated. Layers featuring Sn contents up to 14 at.% are epitaxially grown by state-of-the-art chemical-vapor deposition on Ge buffered Si wafers. An abrupt decrease of the lattice thermal conductivity (κ) from 55 W/(m·K) for Ge to 4 W/(m·K) for Ge0.88Sn0.12 alloys is measured electrically by the differential 3ω-method. The thermal conductivity was verified to be independent of the layer thickness for strained relaxed alloys and confirms the Sn dependence observed by optical methods previously. The experimental κ values in conjunction with numerical estimations of the charge transport properties, able to capture the complex physics of this quasi-direct bandgap material system, are used to evaluate the thermoelectric figure of merit ZT for n- and p-type GeSn epitaxial layers. The results highlight the high potential of single-crystal GeSn alloys to achieve similar energy harvest capability as already present in SiGe alloys but in the 20 °C–100 °C temperature range where Si-compatible semiconductors are not available. This opens the possibility of monolithically integrated thermoelectric on the CMOS platform.

show abstract

Section: Materials and Devicesmentioning

confidence: 99%

Room Temperature Lattice Thermal Conductivity of GeSn Alloys

Concepción,

Tiscareño-Ramírez,

Chimienti

et al. 2024

ACS Appl. Energy Mater.

Self Cite

View full text Add to dashboard Cite

show abstract

Enhancing Device Performance with High Electron Mobility GeSn Materials

Junk,

Concepción,

Frauenrath

et al. 2024

Adv Elect Materials

View full text Add to dashboard Cite

As transistors continue to shrink, the need to replace silicon with materials of higher carrier mobilities becomes imperative. Group‐IV semiconductors, and particularly GeSn alloys, stand out for their high electron and hole mobilities, making them attractive for next‐generation electronics. While Ge p‐channel devices already possess a high hole mobility, here the focus is on enhancing n‐channel transistor performance by utilizing the superior electron mobility of GeSn as channel material. Vertical gate‐all‐around nanowire (GAA NW) transistors are fabricated using epitaxial GeSn heterostructures that leverage the material growth, in situ doping, and band engineering across source/channel/drain regions. It is demonstrated that increasing Sn content in GeSn alloys constantly improves the device performances, reaching a fivefold on‐current improvement over standard Ge devices for 11 at.% Sn content. The present results underline the real potential of the GeSn alloys to bring performance and energy efficiency to future nanoelectronics applications.

show abstract

Phase‐Coherent Transport in GeSn Alloys on Si

Kaul,

Concepción,

Wielens

et al. 2024

Adv Elect Materials

View full text Add to dashboard Cite

Germanium‐Tin (GeSn) is a novel semiconductor Group IV alloy that can be tuned from indirect to direct bandgap semiconductors by adjusting the Sn content. This property makes this alloy class attractive for integrated photonic applications and high‐mobility electronic devices. In this work, the GeSn alloy properties are investigated in the view of applications fields such as spintronics and quantum computing. Using low‐temperature magneto‐transport measurements, electron interference effects and deriving typical mesoscopic benchmark parameters such as the phase‐coherence length in GeSn‐based Hall bar structures for Sn concentrations up to 14 at.% is investigated. Furthermore, Shubnikov–de Haas oscillations provide direct access to the effective mass of the Γ‐valley electrons as well as the charge carrier mobility. This work provides a new insight into advanced group IV alloys desired for the study of spin dynamics and its quantum computing applications.

show abstract

Isothermal Heteroepitaxy of Ge_1–xSn_x Structures for Electronic and Photonic Applications

Cited by 9 publications

References 50 publications

Room Temperature Lattice Thermal Conductivity of GeSn Alloys

Room Temperature Lattice Thermal Conductivity of GeSn Alloys

Enhancing Device Performance with High Electron Mobility GeSn Materials

Phase‐Coherent Transport in GeSn Alloys on Si

Contact Info

Product

Resources

About