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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.


STM images of the same region on the Si(001) surface: (a) empty states (+2.0 V, 100 pA) and (b) filled states (-2.0 V, 100 pA); an inset at (b) shows the image of the (2 × 1) surface between the rows of "rectangles".
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Figure 6: STM images of the same region on the Si(001) surface: (a) empty states (+2.0 V, 100 pA) and (b) filled states (-2.0 V, 100 pA); an inset at (b) shows the image of the (2 × 1) surface between the rows of "rectangles".

Mentions: Figure 6 presents the STM images obtained for the samples cooled in the quenching mode but containing areas free of "rectangles". The images (a) and (b) of the same place on the surface were obtained serially one by one. We managed to image the surface structure between the areas occupied by the "rectangle" rows, but only in the filled-state mode (see the inset at Figure 6b). Similar to as shown in Figure 5b, this structure is seen to be formed by parallel dimer rows going 2a apart. The direction of these rows is perpendicular to the direction of the rows of "rectangles". The height difference of the rows of "rectangles" and the (2 × 1) rows is 1 monoatomic step (~1.4Å). We did not succeed to obtain a good enough image of these subjacent dimer rows in the empty-state mode. It should be noted also that positions of the "rectangles" are always strictly fixed relative to the dimer rows of the lower layer: they occupy exactly three subjacent dimer rows. It also may be seen in the STM images presented in refs. [5,10].


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)

STM images of the same region on the Si(001) surface: (a) empty states (+2.0 V, 100 pA) and (b) filled states (-2.0 V, 100 pA); an inset at (b) shows the image of the (2 × 1) surface between the rows of "rectangles".
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 6: STM images of the same region on the Si(001) surface: (a) empty states (+2.0 V, 100 pA) and (b) filled states (-2.0 V, 100 pA); an inset at (b) shows the image of the (2 × 1) surface between the rows of "rectangles".
Mentions: Figure 6 presents the STM images obtained for the samples cooled in the quenching mode but containing areas free of "rectangles". The images (a) and (b) of the same place on the surface were obtained serially one by one. We managed to image the surface structure between the areas occupied by the "rectangle" rows, but only in the filled-state mode (see the inset at Figure 6b). Similar to as shown in Figure 5b, this structure is seen to be formed by parallel dimer rows going 2a apart. The direction of these rows is perpendicular to the direction of the rows of "rectangles". The height difference of the rows of "rectangles" and the (2 × 1) rows is 1 monoatomic step (~1.4Å). We did not succeed to obtain a good enough image of these subjacent dimer rows in the empty-state mode. It should be noted also that positions of the "rectangles" are always strictly fixed relative to the dimer rows of the lower layer: they occupy exactly three subjacent dimer rows. It also may be seen in the STM images presented in refs. [5,10].

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.