A Novel Remote Reactive Sink Layer Technique for the Control of N and O Concentrations in Metal/High-k Gate Stacks

A novel technique for the control of nitrogen (N) and oxygen (O) concentrations in the metal/high-k gate stacks is proposed. By inserting a reactive metal (Ti) layer remote from work function metal and high-k insulator, N and O concentration is easily decreased. This technique effectively suppresses the EOT increase after high-temperature annealing. Moreover, improved electron mobility and decreased interfacial trap density can be obtained by this technique. We demonstrated MISFET with extremely high electron mobility and thin EOT can be easily obtained even with relaxed process of HfSiON