Doping dependence of the mobility enhancement in surface-channel strained-Si layers

In this paper we present simulation results for the doping dependence of the mobility enhancement in surface-channel strained-Si layers grown on relaxed Si1-xGex buffers. Our numerical results show that there is a significant reduction of the mobility enhancement with increasing substrate doping. At first, this result questioned the performance increase in devices based on these novel Si-based heteroepitaxy concepts when scaled to deep-submicron dimensions. However, we find that this is not really a problem since in devices with non-uniform doping profiles, representative of the state-of-the-art technology, significant mobility enhancement is still observed.