Process method to facilitate silicidation

Abstract

The present invention substantially removes dry etch residue from a dry plasma etch processprior to depositing a cobalt layeron silicon substrate and/or polysilicon material. Subsequently, one or more annealing processesare 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 operationand then an extended cleaning operationthat includes a suitable cleaning solution. The first cleaning operation typically removes some, but not all of the dry etch residue. The extended cleaning operationis performed at a higher temperature and/or for an extended duration and substantially removes dry etch residue remaining after the first cleaning operation