Pure spin current transport in a SiGe alloy

Naitô, Takeshi; Yamada, Michihiro; Tsukahara, Makoto; Yamada, Shinya; Sawano, Kentarou; Hamaya, Kohei

doi:10.7567/apex.11.053006

Cited by 23 publications

(23 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In terms of surface orientations, an orientation of (111) for Ge is very attractive since higher electron mobility can be obtained in Ge(111) channels than in Ge(100) channels. 22,23) Moreover, high-quality ferromagnetic materials can be epitaxially grown on Ge(111) and Ge-rich SiGe(111), [24][25][26][27][28][29] allowing us to realize Ge or SiGe channel spintronics devices. Recently, pure spin-current transport has been demonstrated in a SiGe(111) channel layer.…”

mentioning

confidence: 99%

A drastic increase in critical thickness for strained SiGe by growth on mesa-patterned Ge-on-Si

Wagatsuma

Alam

Okada

et al. 2021

Appl. Phys. Express

Self Cite

View full text Add to dashboard Cite

We demonstrate that the critical thickness for Ge-rich strained SiGe layers can be drastically increased by a factor of more then two by means of growth on mesa-patterned Ge-on-Si. The Si0.2Ge0.8 layer grown on sub-millimeter mesa Ge-on-Si is fully strained and free from ridge roughness, while the same Si0.2Ge0.8 layers grown on unpatterned Ge-on-Si and a Ge substrate are partially strain-relaxed with the surface covered by high-density ridge roughness. This demonstrates that the proposed patterning method can provide thick and stable strained SiGe films as promising templates for realization of strained SiGe-based optoelectronic and spintronic devices.

show abstract

mentioning

confidence: 99%

A drastic increase in critical thickness for strained SiGe by growth on mesa-patterned Ge-on-Si

Wagatsuma

Alam

Okada

et al. 2021

Appl. Phys. Express

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thus far, pure spin-current transport has been observed in Ge(111) and SiGe epitaxial layers even at room temperature. [15][16][17] Recently, in the strained Si 0.1 Ge 0.9 layers, we clearly observed an enhancement in the spin lifetime at room temperature, 18) meaning that the strain induced in Si 0.1 Ge 0.9 enables us to lift the degeneracy between L-valleys in the conduction bands where the intervalley spin-flip scattering occurs. Since high-quality Ge-on-Si virtual substrates have recently become available owing to the two-step growth method, [19][20][21][22][23] feasibility of employment of SiGe with high Ge concentrations has remarkably increased.…”

mentioning

confidence: 77%

Significant reduction of crack propagation in the strained SiGe/Ge(111) induced by the local growth on the depth-controlled area patterning

Wagatsuma¹,

Kanesawa²,

Alam³

et al. 2022

Appl. Phys. Express

Self Cite

View full text Add to dashboard Cite

We propose a method for obtaining crack-free fully-strained SiGe layers on Ge(111). To achieve the crack-free strained SiGe layers, we introduce patterned area with a sufficient depth (step height) of more than 1 µm on Ge(111) substrates. Because of the complete suppression of the crack propagation from the SiGe layer grown on the outside of the patterned area on Ge(111), we achieve crack-free fully strained SiGe layers on the inside of the patterned area. This approach will drastically expand applicability of the strained SiGe to the fields of Si photonics and spintronics.

show abstract

“…For n-Ge, intervalley spin-flip scattering of electrons between L valleys in the conduction band should be taken into account to increase λ SC . 51,[74][75][76][77][78] Recently, impurityand phonon-induced intervalley spin-flip scattering processes were partly suppressed by utilizing a strained n-Si 0.1 Ge 0.9 (111) layer, 102,103 where the Ge-rich Si 1−x Ge x exhibited a Ge-like electronic band structure with conduction-band minima at L points. In the future, researchers should explore the simultaneous utilization of high-quality Co 2 YZ/Fe/Ge Schottky-tunnel contacts with a large γ (≧ 0.8) and strained n-Ge-rich Si 1−x Ge x channels with a large λ SC (≧ 2.0 µm) at room temperature.…”

Section: Potential For Applicationsmentioning

confidence: 99%

Semiconductor spintronics with Co2-Heusler compounds

Hamaya

Yamada

2022

MRS Bulletin

Self Cite

View full text Add to dashboard Cite

Ferromagnetic Co2-Heusler compounds showing high spin polarization have been utilized as spin injectors and detectors for III–V and Group-IV semiconductors. In this article, we first describe the progress in the crystal growth of Co2-Heusler films on GaAs(001) and Ge(111) by low-temperature molecular beam epitaxy. Next, some examples of electrical spin injection from Co2-Heusler contacts into GaAs and Ge through Schottky-tunnel barriers are introduced. Thanks to those efforts, it was found that Co2-Heusler compounds are useful for the realization of spin injection, transport, and detection in GaAs and Ge at room temperature. However, to achieve highly efficient spin transport, it is very important to suppress the interfacial out-diffusion of GaAs or Ge into the Co2-Heusler layer near the heterojunction. Recent progress in high-quality Co2-Heusler/Ge heterojunctions has demonstrated two-terminal magnetoresistance ratios of more than 0.1% at room temperature even for semiconductor spintronic device structures. The approach using Co2-Heusler compounds provides a powerful solution to the need for simultaneous achievement of highly efficient spin injection and low electric power at the source and drain contacts in semiconductor devices such as a spin MOSFET. Graphical abstract

show abstract

Pure spin current transport in a SiGe alloy

Cited by 23 publications

References 70 publications

A drastic increase in critical thickness for strained SiGe by growth on mesa-patterned Ge-on-Si

A drastic increase in critical thickness for strained SiGe by growth on mesa-patterned Ge-on-Si

Significant reduction of crack propagation in the strained SiGe/Ge(111) induced by the local growth on the depth-controlled area patterning

Semiconductor spintronics with Co2-Heusler compounds

Contact Info

Product

Resources

About