Contact resistance of LPCVD W/Al and PtSi/W/Al metallization

The sensitivity of measured specific contact resistivity to surface doping concentration has been investigated for selectively deposited LPCVD W contacts to n+ and p +Si with surface concentrations from 10
¹⁸
to 10
²⁰
cm
^-3
. W contact resistance to n+ Si is about a factor of 20 lower than that of Al; W contact resistance to p +Si is comparable to that of Al. Ultralow resistance, stable contacts with self-aligned PtSi, and W to p +Si are demonstrated.