Effect of Sn atoms on incorporation of vacancies in epitaxial Ge1−xSnxfilm grown at low temperature

Kamiyama, Eiji; Nakagawa, Shoichi; Sueoka, Koji; Ohmura, Takuma; Asano, Tanemasa; Nakatsuka, Osamu; Taoka, Noriyuki; Zaima, Shigeaki; Izunome, Koji; Kashima, Katsunori

doi:10.7567/apex.7.021302

Cited by 12 publications

(10 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Note that the larger x is, the larger the existence probabilities are, due to the larger energy gains. A similar phenomenon will occur between a vacancy and a Sn atom during Ge1-xSnx film growth.The increase of incorporated vacancies in the Ge matrix was actually observed during epitaxial Ge1-xSnx film growth at lower temperatures[26].…”

mentioning

confidence: 79%

The Hakoniwa method, an approach to predict material properties based on statistical thermodynamics and ab initio calculations

Kamiyama

Matsutani

Suwa

et al. 2016

Materials Science in Semiconductor Processing

Self Cite

View full text Add to dashboard Cite

An approach based on statistical thermodynamics and ab initio calculations to predict properties of materials composed of different types of atoms is presented. The key point of what the authors called the "Hakoniwa" method, is to take into account all possible structural supercells constructed by the fixed number of atoms of each species according to the composition of the target material. The conservation of the total number of atoms enables calculating the average value of a material property for a given temperature by applying statistical thermodynamics to the material property values obtained for each of

show abstract

mentioning

confidence: 79%

The Hakoniwa method, an approach to predict material properties based on statistical thermodynamics and ab initio calculations

Kamiyama

Matsutani

Suwa

et al. 2016

Materials Science in Semiconductor Processing

Self Cite

View full text Add to dashboard Cite

show abstract

“…Both GeVS and GeSn epilayers are undoped with p-type carrier concentrations ranging 10 16 to 10 17 1/cm³ depending on the Sn-content. The unintentional acceptor concentration in GeSn is presumably due to vacancies such as point defects in this compressively strained layers and increases with Sn-content 9,10 . Details regarding growth have been reported elsewhere 8,11 .…”

Section: Methodsmentioning

confidence: 99%

“…Both GeVS and GeSn epilayers are undoped with p-type carrier concentrations ranging from 10 16 to 10 17 1/cm 3 depending on the Sn-content. The unintentional acceptor concentration in GeSn is presumably due to vacancies such as point defects in this compressively strained layers and increases with Sn-content. , Details regarding growth have been reported elsewhere. , After sample cleaning with organic solvents, oxygen plasma and HF-HCl wet chemistry, the (Si)GeSn samples were loaded into an atomic layer deposition tool where 6 nm thick HfO 2 layers were deposited at T = 300 °C using tetrakis ethylmethylamino hafnium (TEMAH), Hf[N(CH 3 )(C 2 H 5 )] 4 and Ozone precursors. Subsequently, 60 nm thick TiN was deposited by reactive RF-sputtering.…”

Section: Methodsmentioning

confidence: 99%

Correlation of Bandgap Reduction with Inversion Response in (Si)GeSn/High-k/Metal Stacks

Schulte-Braucks

Narimani

Glass

et al. 2017

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

The bandgap tunability of (Si)GeSn group IV semiconductors opens a new era in Si-technology. Depending on the Si/Sn contents, direct and indirect bandgaps in the range of 0.4-0.8 eV can be obtained, offering a broad spectrum of both photonic and low power electronic applications. In this work, we systematically studied capacitance-voltage characteristics of high-k/metal gate stacks formed on GeSn and SiGeSn alloys with Sn-contents ranging from 0 to 14 at. % and Si-contents from 0 to 10 at. % particularly focusing on the minority carrier inversion response. A clear correlation between the Sn-induced shrinkage of the bandgap energy and enhanced minority carrier response was confirmed using temperature and frequency dependent capacitance voltage-measurements, in good agreement with k.p theory predictions and photoluminescence measurements of the analyzed epilayers as reported earlier. The enhanced minority generation rate for higher Sn-contents can be firmly linked to the bandgap reduction in the GeSn epilayer without significant influence of substrate/interface effects. It thus offers a unique possibility to analyze intrinsic defects in (Si)GeSn epilayers. The extracted dominant defect level for minority carrier inversion lies approximately 0.4 eV above the valence band edge in the studied Sn-content range (0-12.5 at. %). This finding is of critical importance since it shows that the presence of Sn by itself does not impair the minority carrier lifetime. Therefore, the continuous improvement of (Si)GeSn material quality should yield longer nonradiative recombination times which are required for the fabrication of efficient light detectors and to obtain room temperature lasing action.

show abstract

“…It is known that the number of point defects (e.g., vacancies) in GeSn increases with the Sn content. 41 Since As diffuses via vacancies in Ge 42 (and thus probably also in GeSn), this might result in stronger diffusion of As explaining the enhanced SGIDS 43 effect.…”

Section: E Stanogermanidation Induced Dopant Segregation (Sgids)mentioning

confidence: 99%

Schottky barrier tuning via dopant segregation in NiGeSn-GeSn contacts

Schulte-Braucks

Hofmann

Glass

et al. 2017

Journal of Applied Physics

View full text Add to dashboard Cite

We present a comprehensive study on the formation and tuning of the Schottky barrier of NiGeSn metallic alloys on Ge 1-x Sn x semiconductors. First, the Ni metallization of GeSn is investigated for a wide range of Sn contents (x ¼ 0-0.125). Structural analysis reveals the existence of different poly-crystalline NiGeSn and Ni 3 (GeSn) 5 phases depending on the Sn content. Electrical measurements confirm a low NiGeSn sheet resistance of 12 X/(almost independent of the Sn content. We extracted from Schottky barrier height measurements in NiGeSn/GeSn/NiGeSn metal-semiconductor-metal diodes Schottky barriers for the holes below 0.15 eV. They decrease with the Sn content, thereby confirming NiGeSn as an ideal metal alloy for p-type contacts. Dopant segregation for both p-and n-type dopants is investigated as a technique to effectively modify the Schottky barrier of NiGeSn/GeSn contacts. Secondary ion mass spectroscopy is employed to analyze dopant segregation and reveal its dependence on both the Sn content and biaxial layer strain.

show abstract

Effect of Sn atoms on incorporation of vacancies in epitaxial Ge₁₋_xSn_xfilm grown at low temperature

Cited by 12 publications

References 19 publications

The Hakoniwa method, an approach to predict material properties based on statistical thermodynamics and ab initio calculations

The Hakoniwa method, an approach to predict material properties based on statistical thermodynamics and ab initio calculations

Correlation of Bandgap Reduction with Inversion Response in (Si)GeSn/High-k/Metal Stacks

Schottky barrier tuning via dopant segregation in NiGeSn-GeSn contacts

Contact Info

Product

Resources

About