Carrier mobility in advanced CMOS devices with metal gate and HfO2 gate dielectric

Advanced channel N and P MOSFETs with HfO2 gate dielectric and metal gate have been fabricated and exhibit high performance. The effective mobility has been characterized at various temperatures for NMOS and PMOS devices. The electron mobility is lower than in SiO2, whereas the hole mobility is relatively unaffected at room temperature but also degraded at low temperatures. The mobility degradation after constant voltage stress suggests a more important Coulomb scattering contribution to mobility as compared to SiO2. (C) 2003 Elsevier Ltd. All rights reserved.