Ni-SILICIDE/Si AND SiGe(C) CONTACT TECHNOLOGY FOR ULSI APPLICATIONS

摘要

We have investigated the crystalline and electrical properties of Ni silicide/Si and SiGeC contacts for ULSI applications. NiSi/Si contacts promises the contact resistivity as low as 10{sup}(-8) Ωcm{sup}2 for both n{sup}+- and p{sup}+-Si. Degradation of the sheet resistance of NiSi layers critically depends on the annealing time particularly at temperatures ranging from 650°C to 750°C. The enlargement of the Si-exposed region concomitant with the NiSi agglomeration is a dominant factor responsible for the increase in sheet resistance and the activation energy of this process is estimated to be 2.8±0.4 eV. Incorporation of Ge into Ni/Si systems is effective in raising the transformation temperature from NiSi to NiSi{sub}2. Incorporation of C into NiSi/Si system effectively suppresses the NiSi agglomeration. C introduction also causes the pile-up of B atoms at the NiSi/Si interface, which promises the reduction of the contact resistivity.