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Phase transition on the Si(001) clean surface prepared in UHV MBE chamber: a study by high-resolution STM and in situ RHEED.

Arapkina LV, Yuryev VA, Chizh KV, Shevlyuga VM, Storojevyh MS, Krylova LA - Nanoscale Res Lett (2011)

Bottom Line: A fraction of the surface area covered by the c(8 × 8) structure decreased, as the sample cooling rate was reduced.A model of the c(8 × 8) structure formation has been built on the basis of the STM data.Origin of the high-order structure on the Si(001) surface and its connection with the epinucleation phenomenon are discussed.PACS 68.35.B-·68.37.Ef·68.49.Jk·68.47.Fg.

View Article: PubMed Central - HTML - PubMed

Affiliation: A, M, Prokhorov General Physics Institute of RAS, 38 Vavilov Street, Moscow, 119991, Russia. arapkina@kapella.gpi.ru.

ABSTRACT
The Si(001) surface deoxidized by short annealing at T ~ 925°C in the ultrahigh vacuum molecuar beam epitaxy chamber has been in situ investigated using high-resolution scanning tunneling microscopy (STM)and redegreesected high-energy electron diffraction (RHEED. RHEED patterns corresponding to (2 × 1) and (4 × 4) structures were observed during sample treatment. The (4 × 4) reconstruction arose at T ≲ 600°C after annealing. The reconstruction was observed to be reversible: the (4 × 4) structure turned into the (2 × 1) one at T ≳ 600°C, the (4 × 4) structure appeared again at recurring cooling. The c(8 × 8) reconstruction was revealed by STM at room temperature on the same samples. A fraction of the surface area covered by the c(8 × 8) structure decreased, as the sample cooling rate was reduced. The (2 × 1) structure was observed on the surface free of the c(8 × 8) one. The c(8 × 8) structure has been evidenced to manifest itself as the (4 × 4) one in the RHEED patterns. A model of the c(8 × 8) structure formation has been built on the basis of the STM data. Origin of the high-order structure on the Si(001) surface and its connection with the epinucleation phenomenon are discussed.PACS 68.35.B-·68.37.Ef·68.49.Jk·68.47.Fg.

No MeSH data available.


A schematic drawing of the c(8 × n) structure: (a) c(8 × 8) with the short blocks, a unit cell is outlined; (b) the same structure with the long block; (c) c(8 × 6) structure.
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Figure 9: A schematic drawing of the c(8 × n) structure: (a) c(8 × 8) with the short blocks, a unit cell is outlined; (b) the same structure with the long block; (c) c(8 × 6) structure.

Mentions: Figure 9a shows a schematic drawing of the c(8 × 8) structure (a unit cell is outlined). This structure is a basic one for the model brought forward. The elementary structural unit is a short rectangle. These blocks form raised rows running vertically (shown by empty circles). Smaller shaded circles show horizontal dimer rows of the lower terrace. The remaining black circles show bulk atoms. Each "rectangle" consists of two dimer pairs separated with a dimer vacancy. The structures on the Si(001) surface composed of close ad-dimers are believed to be stable [6,13] or at least metastable [43]. In our model, a position of the "rectangles" is governed by the location of the dimer rows of the (2 × 1) structure of the underlying layer. The rows of blocks are always normal to the dimer rows in the underlying layer to form a correct epiorientation [43]. Every rectangular block is bounded by the dimer rows of the underlying layer from both short sides. Short sides of blocks form non-rebonded SB steps [3] with the underlying substrate (see Figure 5b, and three vertically running (the very left) rows of "rectangles" in Figure 7a).


Phase transition on the Si(001) clean surface prepared in UHV MBE chamber: a study by high-resolution STM and in situ RHEED.

Arapkina LV, Yuryev VA, Chizh KV, Shevlyuga VM, Storojevyh MS, Krylova LA - Nanoscale Res Lett (2011)

A schematic drawing of the c(8 × n) structure: (a) c(8 × 8) with the short blocks, a unit cell is outlined; (b) the same structure with the long block; (c) c(8 × 6) structure.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211275&req=5

Figure 9: A schematic drawing of the c(8 × n) structure: (a) c(8 × 8) with the short blocks, a unit cell is outlined; (b) the same structure with the long block; (c) c(8 × 6) structure.
Mentions: Figure 9a shows a schematic drawing of the c(8 × 8) structure (a unit cell is outlined). This structure is a basic one for the model brought forward. The elementary structural unit is a short rectangle. These blocks form raised rows running vertically (shown by empty circles). Smaller shaded circles show horizontal dimer rows of the lower terrace. The remaining black circles show bulk atoms. Each "rectangle" consists of two dimer pairs separated with a dimer vacancy. The structures on the Si(001) surface composed of close ad-dimers are believed to be stable [6,13] or at least metastable [43]. In our model, a position of the "rectangles" is governed by the location of the dimer rows of the (2 × 1) structure of the underlying layer. The rows of blocks are always normal to the dimer rows in the underlying layer to form a correct epiorientation [43]. Every rectangular block is bounded by the dimer rows of the underlying layer from both short sides. Short sides of blocks form non-rebonded SB steps [3] with the underlying substrate (see Figure 5b, and three vertically running (the very left) rows of "rectangles" in Figure 7a).

Bottom Line: A fraction of the surface area covered by the c(8 × 8) structure decreased, as the sample cooling rate was reduced.A model of the c(8 × 8) structure formation has been built on the basis of the STM data.Origin of the high-order structure on the Si(001) surface and its connection with the epinucleation phenomenon are discussed.PACS 68.35.B-·68.37.Ef·68.49.Jk·68.47.Fg.

View Article: PubMed Central - HTML - PubMed

Affiliation: A, M, Prokhorov General Physics Institute of RAS, 38 Vavilov Street, Moscow, 119991, Russia. arapkina@kapella.gpi.ru.

ABSTRACT
The Si(001) surface deoxidized by short annealing at T ~ 925°C in the ultrahigh vacuum molecuar beam epitaxy chamber has been in situ investigated using high-resolution scanning tunneling microscopy (STM)and redegreesected high-energy electron diffraction (RHEED. RHEED patterns corresponding to (2 × 1) and (4 × 4) structures were observed during sample treatment. The (4 × 4) reconstruction arose at T ≲ 600°C after annealing. The reconstruction was observed to be reversible: the (4 × 4) structure turned into the (2 × 1) one at T ≳ 600°C, the (4 × 4) structure appeared again at recurring cooling. The c(8 × 8) reconstruction was revealed by STM at room temperature on the same samples. A fraction of the surface area covered by the c(8 × 8) structure decreased, as the sample cooling rate was reduced. The (2 × 1) structure was observed on the surface free of the c(8 × 8) one. The c(8 × 8) structure has been evidenced to manifest itself as the (4 × 4) one in the RHEED patterns. A model of the c(8 × 8) structure formation has been built on the basis of the STM data. Origin of the high-order structure on the Si(001) surface and its connection with the epinucleation phenomenon are discussed.PACS 68.35.B-·68.37.Ef·68.49.Jk·68.47.Fg.

No MeSH data available.