Low contact resistance of n(+)-Si/Ti/WNx/Al submicron contact structures

Abstract

We have suggested a new n(+)-Si/Ti/WNx/Al multilayer metallization scheme. The contact resistance has been strongly related to the plasma nitridation of the Ti surface because the contact resistance of n(+)-Si/Ti/WNx/Al with contact size of 0.49 mu m(2) about 100-130 Omega, whereas without the nitridation of the Ti surface the contact resistance rises up to 200-390 Omega. F-19 (p,alpha gamma) nuclear resonance analysis and Auger electron spectroscopy reveal that F adatoms on the Ti surface are successfully removed by the 30 s nitridation and as a result, the low contact resistance can be achieved.