Limits...
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 diagram of sample cooling after the thermal treatment at 925°C measured by IR pyrometer; cooling rates are as follows: ~0.17°C/s or "slow cooling" of the STM samples (1); ~0.4°C/s or "quenching" of the STM samples (2) and 2" wafers (3).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211275&req=5

Figure 1: A diagram of sample cooling after the thermal treatment at 925°C measured by IR pyrometer; cooling rates are as follows: ~0.17°C/s or "slow cooling" of the STM samples (1); ~0.4°C/s or "quenching" of the STM samples (2) and 2" wafers (3).

Mentions: Afterward, the samples were loaded into the airlock and transferred into the preliminary annealing chamber where outgassed at ~600°C and ~5 × 10-9 Torr for about 6 h. Then, the samples were moved for final treatment, and decomposition of the oxide film into the MBE chamber evacuated down to ~10-11 Torr. There were two stages of annealing in the process of sample heating: at ~600°C for ~5 min and at ~800°C for ~3 min [1,14,27]. The final annealing was carried out at ~925°C.1 Then, the temperature was rapidly lowered to ~850°C. The rates of the further cooling down to the room temperature were ~0.4°C/s (referred to as the "quenching" mode of both the STM samples and 2" wafers) or ~0.17°C/s (called the "slow cooling" mode of only the STM samples) (Figure 1). The pressure in the MBE chamber increased to ~2 × 10-9 Torr during the process.


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 diagram of sample cooling after the thermal treatment at 925°C measured by IR pyrometer; cooling rates are as follows: ~0.17°C/s or "slow cooling" of the STM samples (1); ~0.4°C/s or "quenching" of the STM samples (2) and 2" wafers (3).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: A diagram of sample cooling after the thermal treatment at 925°C measured by IR pyrometer; cooling rates are as follows: ~0.17°C/s or "slow cooling" of the STM samples (1); ~0.4°C/s or "quenching" of the STM samples (2) and 2" wafers (3).
Mentions: Afterward, the samples were loaded into the airlock and transferred into the preliminary annealing chamber where outgassed at ~600°C and ~5 × 10-9 Torr for about 6 h. Then, the samples were moved for final treatment, and decomposition of the oxide film into the MBE chamber evacuated down to ~10-11 Torr. There were two stages of annealing in the process of sample heating: at ~600°C for ~5 min and at ~800°C for ~3 min [1,14,27]. The final annealing was carried out at ~925°C.1 Then, the temperature was rapidly lowered to ~850°C. The rates of the further cooling down to the room temperature were ~0.4°C/s (referred to as the "quenching" mode of both the STM samples and 2" wafers) or ~0.17°C/s (called the "slow cooling" mode of only the STM samples) (Figure 1). The pressure in the MBE chamber increased to ~2 × 10-9 Torr during the process.

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.