Formation of yttrium-silicide layers by ion-beam methods

Thesis/Dissertation · Mon Dec 31 23:00:00 EST 1990

OSTI ID:5701997

Alford, T L

In an attempt to recognize and understand the initial ion-beam interactions, the low-temperature ion-induced-mixing rates of Y-Si thin films were measured. Ion mixing of yttrium and silicon due to inert ion irradiation was clearly underestimated by both ballistic and thermal spike models. However, there are still indications that non-overlapping thermal spikes may be involved. Ion mixing at more elevated temperatures resulted in the formation of yttrium silicide phase(s), YSi{sub 1.7} and (possibly) YSi. Formation temperatures were still lower than needed for typical thermal annealing. Problems associated with the presence and the cleanliness of a yttrium-silicon interface, were avoided by implanting of yttrium ions into Si. Peak implant concentrations above a threshold of about 20 at.%, and subsequent thermal annealing at 1,000C led to the formation of a continuous YSi{sub 1.7} layer. However, completely coalesced yttrium-silicide precipitates were found in those samples were the Y peak-concentration was greater than about 37 at.%. Results from the buried silicide layer formed by ion implantation suggested that higher-energy implantation may possess advantages over the keV-energy implantation.

• Research Organization: Cornell Univ., Ithaca, NY (United States)
• OSTI ID: 5701997
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
360206 -- Ceramics
Cermets
& Refractories-- Radiation Effects
BEAMS
ELEMENTS
FILMS
ION BEAMS
ION IMPLANTATION
LAYERS
METALS
PROCESSING
SEMIMETALS
SILICIDES
SILICON
SILICON COMPOUNDS
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
TEMPERATURE RANGE 1000-4000 K
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
YTTRIUM
YTTRIUM COMPOUNDS
YTTRIUM SILICIDES