Perfornance Enhancement for Strained HfO2 nMOSFET with Contact Etch Stop Layer (CESL) under Pulsed-IV Measurement

High-performance CESL strained nMOSFET with HfO₂ gate dielectrics has been successfully demonstrated in this work. It is found that, the transconductance (g_m) and driving current (I_on) of the nMOSFETs increase 70% and 90%, respectively, of the increase of devices with a 300 nm capping nitride layer. A superior HfO₂/Si interface for CESL-devices is observed, demonstrated by an obvious interface state density reduction (6.56times10¹¹ to 9.85times10¹⁰ cm^-2). Further, a roughly 50% and 60% increase of g_m and I_on, respectively, can be achieved for the 300 nm SiN-capped HfO₂ nMOSFET without considering charge trapping under pulsed-IV measurement.