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Memory properties and charge effect study in Si nanocrystals by scanning capacitance microscopy and spectroscopy.

Lin Z, Bremond G, Bassani F - Nanoscale Res Lett (2011)

Bottom Line: Scanning capacitance microscopy and spectroscopy were used to study the memory properties and charge effect in the Si nanocrystal in ambient temperature.The DC spectra curve shift direction and distance was observed differently for quantitative measurements.Holes or electrons can be separately injected into these Si-ncs and the capacitance changes caused by these trapped charges can be easily detected by scanning capacitance microscopy/spectroscopy at the nanometer scale.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institut des Nanotechnologies de Lyon, UMR 5270, Institut National des Sciences Appliquées de Lyon, Université de Lyon, Bât, Blaise Pascal, 20, avenue Albert Einstein - 69621 Villeurbanne Cedex, France. zhen.lin@insa-lyon.fr.

ABSTRACT
In this letter, isolated Si nanocrystal has been formed by dewetting process with a thin silicon dioxide layer on top. Scanning capacitance microscopy and spectroscopy were used to study the memory properties and charge effect in the Si nanocrystal in ambient temperature. The retention time of trapped charges injected by different direct current (DC) bias were evaluated and compared. By ramp process, strong hysteresis window was observed. The DC spectra curve shift direction and distance was observed differently for quantitative measurements. Holes or electrons can be separately injected into these Si-ncs and the capacitance changes caused by these trapped charges can be easily detected by scanning capacitance microscopy/spectroscopy at the nanometer scale. This study is very useful for nanocrystal charge trap memory application.

No MeSH data available.


Related in: MedlinePlus

Charge and discharge with different DC bias.
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Figure 5: Charge and discharge with different DC bias.

Mentions: Charge injection was done by separately applying (0.5, 1.0, 2.0, and 3.0 V) to the tip during the contact SCM scan. Then DC bias was set back to -0.5 V which was the best as we chose for our signal. As the SCM signal is dependent on the quantity of injected charges, it was monitored for charge retention time study. The non-linear function between the retention time and the DC bias is shown in Figure 5. The higher the DC bias (charging voltage) was, the longer its discharge time was, which means more carriers were injected into the Si-nc. Holes are much easier to be injected than electrons as the retention time of positive charging was longer than the negative charging with respect to the same DC charging intensity. When charge injection was done by more than 7 V, the charging process can't be detected in several minutes. This indicates that the charges were trapped by the Si-nc which made the retention time much longer.


Memory properties and charge effect study in Si nanocrystals by scanning capacitance microscopy and spectroscopy.

Lin Z, Bremond G, Bassani F - Nanoscale Res Lett (2011)

Charge and discharge with different DC bias.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211215&req=5

Figure 5: Charge and discharge with different DC bias.
Mentions: Charge injection was done by separately applying (0.5, 1.0, 2.0, and 3.0 V) to the tip during the contact SCM scan. Then DC bias was set back to -0.5 V which was the best as we chose for our signal. As the SCM signal is dependent on the quantity of injected charges, it was monitored for charge retention time study. The non-linear function between the retention time and the DC bias is shown in Figure 5. The higher the DC bias (charging voltage) was, the longer its discharge time was, which means more carriers were injected into the Si-nc. Holes are much easier to be injected than electrons as the retention time of positive charging was longer than the negative charging with respect to the same DC charging intensity. When charge injection was done by more than 7 V, the charging process can't be detected in several minutes. This indicates that the charges were trapped by the Si-nc which made the retention time much longer.

Bottom Line: Scanning capacitance microscopy and spectroscopy were used to study the memory properties and charge effect in the Si nanocrystal in ambient temperature.The DC spectra curve shift direction and distance was observed differently for quantitative measurements.Holes or electrons can be separately injected into these Si-ncs and the capacitance changes caused by these trapped charges can be easily detected by scanning capacitance microscopy/spectroscopy at the nanometer scale.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institut des Nanotechnologies de Lyon, UMR 5270, Institut National des Sciences Appliquées de Lyon, Université de Lyon, Bât, Blaise Pascal, 20, avenue Albert Einstein - 69621 Villeurbanne Cedex, France. zhen.lin@insa-lyon.fr.

ABSTRACT
In this letter, isolated Si nanocrystal has been formed by dewetting process with a thin silicon dioxide layer on top. Scanning capacitance microscopy and spectroscopy were used to study the memory properties and charge effect in the Si nanocrystal in ambient temperature. The retention time of trapped charges injected by different direct current (DC) bias were evaluated and compared. By ramp process, strong hysteresis window was observed. The DC spectra curve shift direction and distance was observed differently for quantitative measurements. Holes or electrons can be separately injected into these Si-ncs and the capacitance changes caused by these trapped charges can be easily detected by scanning capacitance microscopy/spectroscopy at the nanometer scale. This study is very useful for nanocrystal charge trap memory application.

No MeSH data available.


Related in: MedlinePlus