Ideal barrier metal arrangements in tungsten dual poly-metal (W/barrier metals/dual poly-Si) gates were developed for high performance, low-power and high density-memory devices. An additional metallic amorphous layer, such as TiN/WSix/WN, inserted at the diffusion barrier metals of Ti/WN resulted in both a low gate contact (Rc) and sheet resistance (Rs), which may result in superior improvement of the ring oscillator delay characteristics. (c) 2011 Elsevier Ltd. All rights reserved.