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Structural and optical properties of germanium nanostructures on Si(100) and embedded in high-k oxides.

Ray SK, Das S, Singha RK, Manna S, Dhar A - Nanoscale Res Lett (2011)

Bottom Line: The structural and optical properties of Ge quantum dots (QDs) grown on Si(001) for mid-infrared photodetector and Ge nanocrystals embedded in oxide matrices for floating gate memory devices are presented.The temperature- and bias-dependent photocurrent spectra of a capped Si/SiGe/Si(001) QDs infrared photodetector device are presented.The properties of Ge nanocrystals of different size and density embedded in high-k matrices grown using radio frequency magnetron sputtering have been studied.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Meteorology, Indian Institute of Technology Kharagpur 721302, India. physkr@phy.iitkgp.ernet.in.

ABSTRACT
The structural and optical properties of Ge quantum dots (QDs) grown on Si(001) for mid-infrared photodetector and Ge nanocrystals embedded in oxide matrices for floating gate memory devices are presented. The infrared photoluminescence (PL) signal from Ge islands has been studied at a low temperature. The temperature- and bias-dependent photocurrent spectra of a capped Si/SiGe/Si(001) QDs infrared photodetector device are presented. The properties of Ge nanocrystals of different size and density embedded in high-k matrices grown using radio frequency magnetron sputtering have been studied. Transmission electron micrographs have revealed the formation of isolated spherical Ge nanocrystals in high-k oxide matrix of sizes ranging from 4 to 18 nm. Embedded nanocrystals in high band gap oxides have been found to act as discrete trapping sites for exchanging charge carriers with the conduction channel by direct tunneling that is desired for applications in floating gate memory devices.

No MeSH data available.


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Frequency-dependent C-V characteristics at room temperature for the samples (a) A-900 and (b) F-900.
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Figure 8: Frequency-dependent C-V characteristics at room temperature for the samples (a) A-900 and (b) F-900.

Mentions: The origin of C-V hysteresis can be accredited either to injected charges mainly in nanocrystals or at the interfaces between the NCs and the surrounding oxides. To understand the contribution of trapped charges in detail, the frequency-dependent capacitance-voltage measurement has been carried out for the samples annealed at 900°C. Figure 8a, b shows the frequency dependent C-V curves for the samples A-900 and F-900 for ± 10 and ± 6 V sweep voltages, respectively. Almost similar anti-clockwise C-V hysteresis in the frequency range from 10 kHz to 1 MHz was observed with no stretch-out along the gate voltage axis for the entire experimental frequency range at room temperature. This indicates that the hysteresis is not due to interface traps, as they generally give rise to frequency-dependent flat-band shift and stretching of C-V characteristics [24].


Structural and optical properties of germanium nanostructures on Si(100) and embedded in high-k oxides.

Ray SK, Das S, Singha RK, Manna S, Dhar A - Nanoscale Res Lett (2011)

Frequency-dependent C-V characteristics at room temperature for the samples (a) A-900 and (b) F-900.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211282&req=5

Figure 8: Frequency-dependent C-V characteristics at room temperature for the samples (a) A-900 and (b) F-900.
Mentions: The origin of C-V hysteresis can be accredited either to injected charges mainly in nanocrystals or at the interfaces between the NCs and the surrounding oxides. To understand the contribution of trapped charges in detail, the frequency-dependent capacitance-voltage measurement has been carried out for the samples annealed at 900°C. Figure 8a, b shows the frequency dependent C-V curves for the samples A-900 and F-900 for ± 10 and ± 6 V sweep voltages, respectively. Almost similar anti-clockwise C-V hysteresis in the frequency range from 10 kHz to 1 MHz was observed with no stretch-out along the gate voltage axis for the entire experimental frequency range at room temperature. This indicates that the hysteresis is not due to interface traps, as they generally give rise to frequency-dependent flat-band shift and stretching of C-V characteristics [24].

Bottom Line: The structural and optical properties of Ge quantum dots (QDs) grown on Si(001) for mid-infrared photodetector and Ge nanocrystals embedded in oxide matrices for floating gate memory devices are presented.The temperature- and bias-dependent photocurrent spectra of a capped Si/SiGe/Si(001) QDs infrared photodetector device are presented.The properties of Ge nanocrystals of different size and density embedded in high-k matrices grown using radio frequency magnetron sputtering have been studied.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Physics and Meteorology, Indian Institute of Technology Kharagpur 721302, India. physkr@phy.iitkgp.ernet.in.

ABSTRACT
The structural and optical properties of Ge quantum dots (QDs) grown on Si(001) for mid-infrared photodetector and Ge nanocrystals embedded in oxide matrices for floating gate memory devices are presented. The infrared photoluminescence (PL) signal from Ge islands has been studied at a low temperature. The temperature- and bias-dependent photocurrent spectra of a capped Si/SiGe/Si(001) QDs infrared photodetector device are presented. The properties of Ge nanocrystals of different size and density embedded in high-k matrices grown using radio frequency magnetron sputtering have been studied. Transmission electron micrographs have revealed the formation of isolated spherical Ge nanocrystals in high-k oxide matrix of sizes ranging from 4 to 18 nm. Embedded nanocrystals in high band gap oxides have been found to act as discrete trapping sites for exchanging charge carriers with the conduction channel by direct tunneling that is desired for applications in floating gate memory devices.

No MeSH data available.


Related in: MedlinePlus