Facilitated C54-TiSi2 Formation with Elevated Deposition Temperature: A Study of Co-deposited Layers

TiSi sub 2 is one of the most widely used self-aligned silicides (salicides) in ULSI CMOS devices, because of its low electrical resistivity and high thermal stability. The formation of the low resistivity C54-TiSi sub 2 phase on narrow silicon lines, however, remains a serious issue. Recently, a significant reduction in the formation temperature of the C54-TiSi sub 2 phase was demonstrated by using Mo implanted substrates and by using thin Mo interlayers. In this work, the C49 to C54 TiSi sub 2 phase transformation is further investigated using Mo interlayer, Mo implantation, and co-deposited TiSi sub x thin films. Various profiles of TiSi sub x (x = 0 ~ 3.0) / MoSi sub y layers were artificially created by co-deposition under UHV conditions on the surfaces of crystalline or amorphized Si substrates at temperatures up to 400C.