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

Wagatsuma, Youya; Alam, Md. Mahfuz; Okada, Kazuya; Yamada, Michihiro; Hamaya, Kohei; Sawano, Kentarou

doi:10.35848/1882-0786/abd4c5

Cited by 8 publications

(7 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[43]. On top of the HT-Ge layer, a 70-nm-thick phosphorus (P)-doped n-Si 0.1 Ge 0.9 (111) layer is grown by MBE at 350 • C [47]. Finally, a 7-nm-thick P δ-doped Ge layer with a 0.3nm-thick Si layer is grown on top of the spin-transport layer for the Schottky tunnel conduction of electrons in spin-transport measurements [48].…”

Section: Resultsmentioning

confidence: 99%

Effect of Strain on Room-Temperature Spin Transport in Si0.1Ge0.9

Naitô

Yamada²,

Wagatsuma³

et al. 2022

Phys. Rev. Applied

View full text Add to dashboard Cite

We report a strain effect on spin transport in semiconductors that exhibit Ge-like conduction bands at room temperature. Using four-terminal nonlocal spin-transport measurements in lateral spin-valve devices, we experimentally estimate the spin diffusion length (λ) of Ge and strained Si 0.1 Ge 0.9 with two different carrier concentrations. Despite the Ge-like electronic band structure, the obtained λ of a strained Si 0.1 Ge 0.9 is comparable to that of a Si channel. We discuss a possible mechanism of the strain-induced enhancement of λ at room temperature. As a consequence, we demonstrate the electrical detection of 5-μm lateral spin transport in the strained Si 0.1 Ge 0.9 by applying an electric field at room temperature.

show abstract

Section: Resultsmentioning

confidence: 99%

Effect of Strain on Room-Temperature Spin Transport in Si0.1Ge0.9

Naitô

Yamada²,

Wagatsuma³

et al. 2022

Phys. Rev. Applied

View full text Add to dashboard Cite

show abstract

“…17) Next, a strained n-doped Si 0.1 Ge 0.9 layer with a thickness of 70 nm was grown at 350 °C to form a spin transport layer. 18) A Ge cap layer with phosphorus (P) delta (δ) doping and an ultrathin Si layer were further stacked on top of this layer to enable the use of Schottky tunneling conduction of electrons in the spin transport measurements. 19) To form a highly ordered Co 2 MnSi Heusler alloy on top of it, an ultra-thin iron (Fe) layer is inserted between the Co 2 MnSi and the Ge cap, 20) where Co 2 MnSi is a highly efficient ferromagnetic spin injector material for semiconductors.…”

Section: Methodsmentioning

confidence: 99%

Local strain distribution analysis in strained SiGe spintronics devices

Onabe,

Wu,

Tohei

et al. 2024

Jpn. J. Appl. Phys.

Self Cite

View full text Add to dashboard Cite

This paper reports nanobeam X-ray diffraction (nanoXRD) measurement results for strained SiGe spintronics devices grown by molecular beam epitaxy. A quantitative nanoXRD analysis verifies that in-plane strain is properly exerted on the SiGe spin channel layer in the device showing enhanced spin diffusion length, whereas overall strain relaxation and local change in crystallinity occur in the sample with unclear spin signals. Crystal defects such as dislocations and stacking faults found in cross-sectional transmission electron microscopy observations are correlated with the results of nanoXRD analysis and their influence on spin transport properties are discussed. The present results demonstrate the capability of the nanoXRD based method for quantitative nondestructive analysis of strain distribution and crystallinity in real device structures.

show abstract

“…However, there are still very few reports on experimental investigations of crack formation in tensile-strained SiGe layers. Recently, we have been studying the initial stage of defect formation for tensile-strained SiGe layers, and have experimentally determined the critical thickness for defect generation and resultant strain relaxation [17][18][19][20][21]. We have also shown that cracks and accompanying surface ridge roughness appear in tensile-strained SiGe epilayers when the thickness of the epilayer exceeds the critical thickness [18].…”

Section: Introductionmentioning

confidence: 99%

(Digital Presentation) Strain Engineering of Heteroepitaxial SiGe/Ge on Si with Various Crystal Orientations

Alam¹,

Wagatsuma²,

Okada³

et al. 2022

ECS Trans.

View full text Add to dashboard Cite

Strained SiGe layers with high Ge concentrations are grown on the Ge and Ge-on-Si substrates with various crystal orientations, and structural properties are studied. Particularly, initial stages of defect formation and related surface morphology are investigated. It is found that cracks are generated in the tensile-strained layer and surface ridge roughness is formed around the cracks although the total relaxation ratio of the SiGe layer is almost 0 %. Due to annealing the tensile strain is partially relaxed by creating additional trench-like roughness with the initially formed ridge roughness left unchanged. This comparative investigation of strain relieving defect formation provides quite useful information toward applications to strained SiGe-based optoelectronic and spintronic devices with enhanced performances.

show abstract

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

Cited by 8 publications

References 32 publications

Effect of Strain on Room-Temperature Spin Transport in Si0.1Ge0.9

Effect of Strain on Room-Temperature Spin Transport in Si0.1Ge0.9

Local strain distribution analysis in strained SiGe spintronics devices

(Digital Presentation) Strain Engineering of Heteroepitaxial SiGe/Ge on Si with Various Crystal Orientations

Contact Info

Product

Resources

About