Limits...
Impact of AFM-induced nano-pits in a-Si:H films on silicon crystal growth.

Verveniotis E, Rezek B, Sípek E, Stuchlík J, Ledinský M, Kočka J - Nanoscale Res Lett (2011)

Bottom Line: In this article, the authors show that such local modifications can be used to selectively induce further localized growth of silicon nanocrystals.First, a-Si:H films by plasma-enhanced chemical vapor deposition on nickel/glass substrates are prepared.This is also supported by micro-Raman spectroscopy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Physics ASCR, Cukrovarnicka 10, 16253, Prague 6, Czech Republic. verven@fzu.cz.

ABSTRACT
Conductive tips in atomic force microscopy (AFM) can be used to localize field-enhanced metal-induced solid-phase crystallization (FE-MISPC) of amorphous silicon (a-Si:H) at room temperature down to nanoscale dimensions. In this article, the authors show that such local modifications can be used to selectively induce further localized growth of silicon nanocrystals. First, a-Si:H films by plasma-enhanced chemical vapor deposition on nickel/glass substrates are prepared. After the FE-MISPC process, yielding both conductive and non-conductive nano-pits in the films, the second silicon layer at the boundary condition of amorphous and microcrystalline growth is deposited. Comparing AFM morphology and current-sensing AFM data on the first and second layers, it is observed that the second deposition changes the morphology and increases the local conductivity of FE-MISPC-induced pits by up to an order of magnitude irrespective of their prior conductivity. This is attributed to the silicon nanocrystals (<100 nm) that tend to nucleate and grow inside the pits. This is also supported by micro-Raman spectroscopy.

No MeSH data available.


Related in: MedlinePlus

Local morphology images after FE-MISPC resulting in non-conductive pits. (a) AFM topography; (e) CS-AFM of the same spot, and their corresponding cross sections (c, g); (b) AFM topography of the same area after the second deposition; (f) CS-AFM and the respective cross sections (d, h). The cross sections are indicated by arrows next to the AFM images.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211195&req=5

Figure 2: Local morphology images after FE-MISPC resulting in non-conductive pits. (a) AFM topography; (e) CS-AFM of the same spot, and their corresponding cross sections (c, g); (b) AFM topography of the same area after the second deposition; (f) CS-AFM and the respective cross sections (d, h). The cross sections are indicated by arrows next to the AFM images.

Mentions: Figure 1c,g, shows the local topography and conductivity map obtained at the sample bias voltage of -25 V in exactly the same area as in Figure 1a,e after the second layer was deposited. AFM topography shows an accumulation of typical silicon micro- and nano-crystals [15] around the pit. CS-AFM shows conductive regions localized within the pit. Note that the individual silicon crystals present due to the second deposition do not appear conductive because the current pre-amplifier setting (sensitivity = 1 nA/V) was adjusted to the magnitude of the current in the pit. Scanning the same area with higher current sensitivity (1 pA/V) showed conductivity on every single crystal seen in the topography. Cross sections plotted in Figure 2d,h, respectively, show that the pit depth is now 175 nm (FWHM is 200 nm) and that the conductive region exhibits an electrical current peak of 670 pA (FWHM is 30 nm).


Impact of AFM-induced nano-pits in a-Si:H films on silicon crystal growth.

Verveniotis E, Rezek B, Sípek E, Stuchlík J, Ledinský M, Kočka J - Nanoscale Res Lett (2011)

Local morphology images after FE-MISPC resulting in non-conductive pits. (a) AFM topography; (e) CS-AFM of the same spot, and their corresponding cross sections (c, g); (b) AFM topography of the same area after the second deposition; (f) CS-AFM and the respective cross sections (d, h). The cross sections are indicated by arrows next to the AFM images.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211195&req=5

Figure 2: Local morphology images after FE-MISPC resulting in non-conductive pits. (a) AFM topography; (e) CS-AFM of the same spot, and their corresponding cross sections (c, g); (b) AFM topography of the same area after the second deposition; (f) CS-AFM and the respective cross sections (d, h). The cross sections are indicated by arrows next to the AFM images.
Mentions: Figure 1c,g, shows the local topography and conductivity map obtained at the sample bias voltage of -25 V in exactly the same area as in Figure 1a,e after the second layer was deposited. AFM topography shows an accumulation of typical silicon micro- and nano-crystals [15] around the pit. CS-AFM shows conductive regions localized within the pit. Note that the individual silicon crystals present due to the second deposition do not appear conductive because the current pre-amplifier setting (sensitivity = 1 nA/V) was adjusted to the magnitude of the current in the pit. Scanning the same area with higher current sensitivity (1 pA/V) showed conductivity on every single crystal seen in the topography. Cross sections plotted in Figure 2d,h, respectively, show that the pit depth is now 175 nm (FWHM is 200 nm) and that the conductive region exhibits an electrical current peak of 670 pA (FWHM is 30 nm).

Bottom Line: In this article, the authors show that such local modifications can be used to selectively induce further localized growth of silicon nanocrystals.First, a-Si:H films by plasma-enhanced chemical vapor deposition on nickel/glass substrates are prepared.This is also supported by micro-Raman spectroscopy.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Physics ASCR, Cukrovarnicka 10, 16253, Prague 6, Czech Republic. verven@fzu.cz.

ABSTRACT
Conductive tips in atomic force microscopy (AFM) can be used to localize field-enhanced metal-induced solid-phase crystallization (FE-MISPC) of amorphous silicon (a-Si:H) at room temperature down to nanoscale dimensions. In this article, the authors show that such local modifications can be used to selectively induce further localized growth of silicon nanocrystals. First, a-Si:H films by plasma-enhanced chemical vapor deposition on nickel/glass substrates are prepared. After the FE-MISPC process, yielding both conductive and non-conductive nano-pits in the films, the second silicon layer at the boundary condition of amorphous and microcrystalline growth is deposited. Comparing AFM morphology and current-sensing AFM data on the first and second layers, it is observed that the second deposition changes the morphology and increases the local conductivity of FE-MISPC-induced pits by up to an order of magnitude irrespective of their prior conductivity. This is attributed to the silicon nanocrystals (<100 nm) that tend to nucleate and grow inside the pits. This is also supported by micro-Raman spectroscopy.

No MeSH data available.


Related in: MedlinePlus