Silicide contacts for sub-0.25 μm devices

Low resistivity TiSi₂, CoSi₂ and NiSi are the three primary candidates for metal contacts in sub-0.25 μm devices. In the present paper, we review recent progress in the investigations of low-resistivity contacts, which include enhanced formation of C54-TiSi₂ on (001)Si by tensile stress, high temperature sputtering, and interposing Mo or TiN layer improved thermal stability of C54-TiSi₂ by the addition of N₂ during Ti sputtering or N⁺ implantation in (001)Si, self-aligned formation of CoSi₂ on the selective epitaxial growth silicon layer on (001)Si, effects of stress on the epitaxial growth of CoSi₂ on (001)Si, improvement of thermal stability of CoSi₂ by nitrogen ion implantation or high temperature sputtering, and improvement of thermal stability of NiSi by nitrogen ion implantation or compressive stress.