Process method to facilitate silicidation

摘要

The present invention substantially removes dry etch residue from a dry plasma etch process 110 prior to depositing a cobalt layer 124 on silicon substrate and/or polysilicon material. Subsequently, one or more annealing processes 128 are performed that cause the cobalt to react with the silicon thereby forming cobalt silicide regions. The lack of dry etch residue remaining between the deposited cobalt and the underlying silicon permits the cobalt silicide regions to be formed substantially uniform with a desired silicide sheet and contact resistance. The dry etch residue is substantially removed by performing a first cleaning operation 112 and then an extended cleaning operation 114 that includes a suitable cleaning solution. The first cleaning operation typically removes some, but not all of the dry etch residue. The extended cleaning operation 114 is performed at a higher temperature and/or for an extended duration and substantially removes dry etch residue remaining after the first cleaning operation 112.