Transient and End Silicide Phase Formation in Thin Film Ni/polycrystalline-Si Reactions for Fully Silicided Gate Applications

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.2799247· OSTI ID:959624

Kittl, J; Pawlak, M; Torregiani, C; Lauwers, A; Demeurisse, C; Vrancken, C; Absil, P; Biesemans, S; Coia, C; al, et

The Ni/polycrystalline-Si thin film reaction was monitored by in situ x-ray diffraction during ramp annealings, obtaining a detailed view of the formation and evolution of silicide phases in stacks of interest for fully silicided gate applications. Samples consisted of Ni (30-170 nm)/polycrystalline-Si (100 nm)/SiO2 (10-30 nm) stacks deposited on (100) Si. The dominant end phase (after full silicidation) was found to be well controlled by the deposited Ni to polycrystalline-Si thickness ratio (tNi/tSi), with formation of NiSi2 ( {approx} 600 C), NiSi ( {approx} 400 C), Ni3Si2 ( {approx} 500 C), Ni2Si, Ni31Si12 ( {approx} 420 C), and Ni3Si ( {approx} 600 C) in stacks with tNi/tSi of 0.3, 0.6, 0.9, 1.2, 1.4, and 1.7, respectively. NiSi and Ni31Si12 were observed to precede formation of NiSi2 and Ni3Si, respectively, as expected for the phase sequence conventionally reported. Formation of Ni2Si was observed at early stages of the reaction. These studies revealed, in addition, the formation of transient phases that appeared and disappeared in narrow temperature ranges, competing with formation of the phases expected in the conventional phase sequence. These included the transient formation of NiSi and Ni31Si12 in stacks in which these phases are not expected to form (e.g., tNi/tSi of 1.7 and 0.9, respectively), at temperatures similar to those in which these phases normally grow.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 959624
• Report Number(s): BNL--82610-2009-JA
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 17 Vol. 91; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SILICIDES
THICKNESS
THIN FILMS
TRANSIENTS
X-RAY DIFFRACTION
national synchrotron light source