摘要 |
There is provided a method of fabricating a semiconductor device, including the steps of (a) forming impurity-diffused layers at a surface of a silicon semiconductor substrate in selected regions, (b) forming a refractory metal film over the impurity-diffused layers, (c) carrying out first thermal annealing in nitrogen atmosphere to convert the refractory metal film into a refractory metal silicide layer, (d) causing damage to a denaturated layer having been formed over the refractory metal film due to the first thermal annealing, (e) etching both the denaturated layer and non-reacted portions of the refractory metal film with a solution containing ammonia and hydrogen peroxide therein, and (f) carrying out second thermal annealing in nitrogen atmosphere to reduce resistance of the refractory metal silicide layer. For instance, the damage is caused to the denaturated layer by arsenic (As) ion implantation. The damage may be caused to the denaturated layer by exposing to oxygen plasma. As an alternative, the damage may be caused to the denaturated layer by carrying out third thermal annealing in oxygen atmosphere at a lower temperature than a temperature at which the second thermal annealing is to be carried out. The above mentioned method makes it possible to prevent occurrence of current leakage which would be accompanied with silicidation, without increasing the number of photoresist steps.
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