Limits...
Effect of annealing treatments on photoluminescence and charge storage mechanism in silicon-rich SiNx:H films.

Sahu BS, Delachat F, Slaoui A, Carrada M, Ferblantier G, Muller D - Nanoscale Res Lett (2011)

Bottom Line: The silicon-rich a-SiNx:H films (SRSN) were sandwiched between a bottom thermal SiO2 and a top Si3N4 layer, and subsequently annealed within the temperature range of 500-1100°C in N2 to study the effect of annealing temperature on light-emitting and charge storage properties.A strong visible photoluminescence (PL) at room temperature has been observed for the as-deposited SRSN films as well as for films annealed up to 1100°C.A significant memory window of 4.45 V was obtained at a low operating voltage of ± 8 V for the sample containing 25% excess silicon and annealed at 1000°C, indicating its utility in low-power memory devices.

View Article: PubMed Central - HTML - PubMed

Affiliation: InESS-UdS-CNRS, 23 Rue du Loess, 67037 Strasbourg, France. sahu.bhabani@iness.c-strasbourg.fr.

ABSTRACT
In this study, a wide range of a-SiNx:H films with an excess of silicon (20 to 50%) were prepared with an electron-cyclotron resonance plasma-enhanced chemical vapor deposition system under the flows of NH3 and SiH4. The silicon-rich a-SiNx:H films (SRSN) were sandwiched between a bottom thermal SiO2 and a top Si3N4 layer, and subsequently annealed within the temperature range of 500-1100°C in N2 to study the effect of annealing temperature on light-emitting and charge storage properties. A strong visible photoluminescence (PL) at room temperature has been observed for the as-deposited SRSN films as well as for films annealed up to 1100°C. The possible origins of the PL are briefly discussed. The authors have succeeded in the formation of amorphous Si quantum dots with an average size of about 3 to 3.6 nm by varying excess amount of Si and annealing temperature. Electrical properties have been investigated on Al/Si3N4/SRSN/SiO2/Si structures by capacitance-voltage and conductance-voltage analysis techniques. A significant memory window of 4.45 V was obtained at a low operating voltage of ± 8 V for the sample containing 25% excess silicon and annealed at 1000°C, indicating its utility in low-power memory devices.

No MeSH data available.


(Color online) Frequency-dependent G-V characteristics of Al/Si3N4/SRSN/SiO2/Si (MNNOS) structure containing 25 at.% of Si excess in the range 10-500 kHz.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211231&req=5

Figure 7: (Color online) Frequency-dependent G-V characteristics of Al/Si3N4/SRSN/SiO2/Si (MNNOS) structure containing 25 at.% of Si excess in the range 10-500 kHz.

Mentions: For a better understanding of the results obtained from C-V measurements, frequency-dependent G-V measurements were further carried out in the frequency range of 10-500 kHz. Frequency-dependent G-V curves for the sample S2 are shown in Figure 7. G-V measurement is considered to be a more sensitive approach than C-V measurement technique, and provides the dynamic information related to trap density. In fact, conductance is related directly to the energy loss in response to the applied ac signal during the capture and emission of charge carriers by interface states. This method is quite effective even at high frequencies. The G-V curves exhibit a small parallel shift of 0.2 V along the voltage axis on decreasing the frequency from 500 to 10 kHz. This negligible shift of G-V curves can be due to the presence of a small quantity of fast traps in the memory capacitor. However, our frequency-dependent C-V curves remain almost constant with a change in measurement frequency (not shown here). Moreover, no distortion in C-V characteristics due to slow traps and/or large surface density (flat step) was observed in the samples with a change in frequency. It was noticed that the full width at half maxima (FWHM) of the conductance peak is small and almost constant in the frequency range of 10-500 kHz, indicating that the hysteresis and conductance peak are of the same origin. Furthermore, the conductance peak, where energy loss is maximum, increases with measurement frequency as more interface states at higher frequency could not respond to the change in ac signal resulting in a greater loss. From the above discussions, it can be ascertained that the charge storage is predominantly in deep traps inside the SRSN matrix and at SiO2/SRSN interface.


Effect of annealing treatments on photoluminescence and charge storage mechanism in silicon-rich SiNx:H films.

Sahu BS, Delachat F, Slaoui A, Carrada M, Ferblantier G, Muller D - Nanoscale Res Lett (2011)

(Color online) Frequency-dependent G-V characteristics of Al/Si3N4/SRSN/SiO2/Si (MNNOS) structure containing 25 at.% of Si excess in the range 10-500 kHz.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211231&req=5

Figure 7: (Color online) Frequency-dependent G-V characteristics of Al/Si3N4/SRSN/SiO2/Si (MNNOS) structure containing 25 at.% of Si excess in the range 10-500 kHz.
Mentions: For a better understanding of the results obtained from C-V measurements, frequency-dependent G-V measurements were further carried out in the frequency range of 10-500 kHz. Frequency-dependent G-V curves for the sample S2 are shown in Figure 7. G-V measurement is considered to be a more sensitive approach than C-V measurement technique, and provides the dynamic information related to trap density. In fact, conductance is related directly to the energy loss in response to the applied ac signal during the capture and emission of charge carriers by interface states. This method is quite effective even at high frequencies. The G-V curves exhibit a small parallel shift of 0.2 V along the voltage axis on decreasing the frequency from 500 to 10 kHz. This negligible shift of G-V curves can be due to the presence of a small quantity of fast traps in the memory capacitor. However, our frequency-dependent C-V curves remain almost constant with a change in measurement frequency (not shown here). Moreover, no distortion in C-V characteristics due to slow traps and/or large surface density (flat step) was observed in the samples with a change in frequency. It was noticed that the full width at half maxima (FWHM) of the conductance peak is small and almost constant in the frequency range of 10-500 kHz, indicating that the hysteresis and conductance peak are of the same origin. Furthermore, the conductance peak, where energy loss is maximum, increases with measurement frequency as more interface states at higher frequency could not respond to the change in ac signal resulting in a greater loss. From the above discussions, it can be ascertained that the charge storage is predominantly in deep traps inside the SRSN matrix and at SiO2/SRSN interface.

Bottom Line: The silicon-rich a-SiNx:H films (SRSN) were sandwiched between a bottom thermal SiO2 and a top Si3N4 layer, and subsequently annealed within the temperature range of 500-1100°C in N2 to study the effect of annealing temperature on light-emitting and charge storage properties.A strong visible photoluminescence (PL) at room temperature has been observed for the as-deposited SRSN films as well as for films annealed up to 1100°C.A significant memory window of 4.45 V was obtained at a low operating voltage of ± 8 V for the sample containing 25% excess silicon and annealed at 1000°C, indicating its utility in low-power memory devices.

View Article: PubMed Central - HTML - PubMed

Affiliation: InESS-UdS-CNRS, 23 Rue du Loess, 67037 Strasbourg, France. sahu.bhabani@iness.c-strasbourg.fr.

ABSTRACT
In this study, a wide range of a-SiNx:H films with an excess of silicon (20 to 50%) were prepared with an electron-cyclotron resonance plasma-enhanced chemical vapor deposition system under the flows of NH3 and SiH4. The silicon-rich a-SiNx:H films (SRSN) were sandwiched between a bottom thermal SiO2 and a top Si3N4 layer, and subsequently annealed within the temperature range of 500-1100°C in N2 to study the effect of annealing temperature on light-emitting and charge storage properties. A strong visible photoluminescence (PL) at room temperature has been observed for the as-deposited SRSN films as well as for films annealed up to 1100°C. The possible origins of the PL are briefly discussed. The authors have succeeded in the formation of amorphous Si quantum dots with an average size of about 3 to 3.6 nm by varying excess amount of Si and annealing temperature. Electrical properties have been investigated on Al/Si3N4/SRSN/SiO2/Si structures by capacitance-voltage and conductance-voltage analysis techniques. A significant memory window of 4.45 V was obtained at a low operating voltage of ± 8 V for the sample containing 25% excess silicon and annealed at 1000°C, indicating its utility in low-power memory devices.

No MeSH data available.