The thermal stability of ∼50 nm CoSi2 and TiSi2 thin films after BF2+ implantation was investigated. The electrical characteristics of silicide films were evaluated after high temperature annealing as a function of implanted BF2+ energy. It was observed that implantation with a projected range near the silicide/silicon interface produced the most stable films. The silicide/silicon interface morphology was investigated using scanning tunneling microscopy, where with appropriate BF2 implantation conditions, smoother interfaces were seen after high temperature annealing. The stabilizing effect is attributed to fluorine segregation into the silicide grain boundaries and at the silicide/silicon interface.

The thermal stability of thin CoSi2 submicrometer lines on Si substrate was investigated using electrical evaluation, in situ transmission electron microscopy observations, Rutherford backscattering, and scanning electron microscopy measurements. Heat-treatments were performed at temperatures ranging from 800~ up to ll00~ for 10 s in N2 or Ar ambients. It was found that as-formed silicide was thinner at the edges of features giving rise to an apparent difference between the electrically equivalent line width and its physical size. The ~45 nm silicide films started to degrade above 1000~ Arsenic implantation into the silicide exacerbated its degradation at high temperatures, which resulted in an apparent higher sheet resistance. Narrower lines exhibited a greater relative degradation in resistance than wider ones, and the electrically measured line width decreased after annealing. However, no line width dependence of this line width reduction was observed up to 1000~ for line widths down to 0.45 pro. Pull back of CoSi2 from the edges of submicrometer lines and the formation of islands were observed after annealing at 1000~ for about 300 s. A model was proposed to explain the degradation of submicrometer lines of CoSi2 based on the observed thinner edge phenomenon. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.192.114.19ABSTRACT When HF/H20 vapor derived from an azeotropic solution of HF/H20 was used to etch various oxides of silicon, the etch rates were found to have qualitatively similar dependence on the wafer temperature. However, the sensitivites of the dependence were found to vary greatly among the different oxides. Consequently, the etch selectivities among different oxides could be controlled by changing the wafer temperature. In particular, the phosphosilicate glass to thermal oxide etch selectivity increased from about 18:1 to at least 2900:1, when the temperature was raised from around 25~ to around ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 128.192.114.19 Downloaded on 2015-06-18 to IP

A new version of the PREDICT process model has been developed which updates many of the existing models with new data describing metal silicide formation and dopant redistribution. The new program also incorporates several novel features, not previously included as part of a process modeling program: (i) silicide resistivity as formed, after ion implantation, and after agglomeration, (ii) roughening of the silicide/silicon interface, and (iii) profile convolution routines to account for secondary ion mass spectroscopy cascade mixing and silicide roughening. The latter algorithms provide a bridge so that experimental data can be compared to model predictions.