The effect of thermal treatment on the thin-film reaction of La, Ce, and Nd on silicon surfaces

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Journal of Vacuum Science and Technology, A: Vacuum, Surfaces, and Films; (USA)

DOI:https://doi.org/10.1116/1.576309· OSTI ID:5526075

Hsu, C C; Wang, Y X; Hu, J; Ho, J; Qian, J J ^[1]

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1. Institute of Semiconductors, Academia Sinica, P.O. Box 912, Beijing, People's Republic of China and Laboratory for Surface Physics, Academia Sinica, P.O. Box 603, Beijing, People's Republic of China (CN)

The formation of rare-earth metal (REM) silicides prepared by dual electron beam evaporating La, Ce, and Nd under UHV on Si(111) and Si(100) has been studied using Auger electron spectroscopy depth profile, Rutherford backscattering spectroscopy, x-ray diffraction and transmission electron microscopy (TEM) techniques. Each sample had an additional thin layer of either Si, Mo, or Nb deposited on top of the REM layer to protect the REM layer from oxidation. Isothermal, rapid thermal, and laser annealing have been used to react REM overlayers. With the isothermal annealing, REMs reacted and intermixed with Si at temperatures as low as 200 {degree}C for 60 min, but the disilicide phase confirmed by the x-ray diffraction did not emerge until the annealing temperature was raised to 600 {degree}C for 60 min. Therefore, an intermediate stage of formation existed for samples annealed at 200--600 {degree}C before the formation of the disilicide final reaction product (REM Si{sub 2{minus}{ital x}}) occurred above 600 {degree}C. The experimental data show that the thermal processing can influence strongly the formation of REM silicides, the interface chemical reaction and interdiffusion. Cross-sectional TEM micrographs of interfaces formed by isothermal, rapid thermal, or laser annealing clearly identify these differences. The rapid thermal annealed and laser annealed interfaces are both flat and uniform, while the isothermal annealed interface is rough and exhibits a wavelike variation in interface plane location.

• OSTI ID: 5526075
• Journal Information: Journal of Vacuum Science and Technology, A: Vacuum, Surfaces, and Films; (USA), Journal Name: Journal of Vacuum Science and Technology, A: Vacuum, Surfaces, and Films; (USA) Vol. 7:5; ISSN JVTAD; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
AUGER ELECTRON SPECTROSCOPY
CERIUM
CHEMICAL REACTIONS
COATINGS
COHERENT SCATTERING
CRYSTAL GROWTH
DIFFRACTION
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
EPITAXY
FILMS
HEAT TREATMENTS
INTERFACES
LANTHANUM
METALS
MICROSCOPY
NEODYMIUM
RARE EARTHS
SCATTERING
SEMIMETALS
SILICON
SPECTROSCOPY
STABILITY
SUBSTRATES
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
VAPOR PHASE EPITAXY
X-RAY DIFFRACTION