Successful Cleaning and Study of Contamination of Si(001) in Ultrahigh Vacuum

Journal Article · Mon Oct 03 00:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3647078· OSTI ID:21611731

Gheorghe, N G; Lungu, G A; Husanu, M A; Costescu, R M ^[1]

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1. National Institute of Materials Physics, Atomistilor 105bis, P.O. Box MG-7, 077125 Magurele - Ilfov (Romania)

This paper presents the very first surface physics experiment performed in ultrahigh vacuum (UHV) in Romania, using a new molecular beam epitaxy (MBE) installation. Cleaning of a Si(001) wafer was achieved by using a very simple technique: sequences of annealing at 900-1000 deg. C in ultrahigh vacuum: low 10{sup -8} mbar, with a base pressure of 1.5x10{sup -10} mbar. The preparation procedure is quite reproducible and allows repeated cleaning of the Si(001) after contamination in ultrahigh vacuum. The Si(001) single crystal surface is characterized by low energy electron diffraction (LEED), reflection high energy electron diffraction (RHEED), and Auger electron spectroscopy (AES). The latter technique is utilized in order to investigate the sample contamination by the residual gas in the UHV chamber, as determined by a residual gas analyzer (RGA). Unambiguous assignment of oxidized and unoxidized silicon is provided; also, an important feature is that the LVV Auger peak at 90-92 eV cannot be solely attributed to clean Si (i.e. Si surrounded only by Si), but also to silicon atoms bounded with carbon. Even with a sum of partial pressures of oxygen and carbon containing molecules in the range of 5x10{sup -10} mbar, the sample is contaminated very quickly, having a (1/e) lifetime of about 76 minutes.

• OSTI ID: 21611731
• Journal Information: AIP Conference Proceedings, Vol. 1387, Issue 1; Conference: TIM-10: Physics conference, Timisoara (Romania), 25-27 Nov 2010; Other Information: DOI: 10.1063/1.3647078; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
AUGER ELECTRON SPECTROSCOPY
CARBON
ELECTRON DIFFRACTION
EV RANGE
LIFETIME
MOLECULAR BEAM EPITAXY
MONOCRYSTALS
OXIDATION
OXYGEN
PRESSURE RANGE NANO PA
REFLECTION
SILICON
SURFACES
CHEMICAL REACTIONS
COHERENT SCATTERING
CRYSTAL GROWTH METHODS
CRYSTALS
DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY RANGE
EPITAXY
HEAT TREATMENTS
NONMETALS
PRESSURE RANGE
SCATTERING
SEMIMETALS
SPECTROSCOPY