Effect of Device Dimensions, Layout and Pre-Gate Carbon Implant on Hot Carrier Induced Degradation in HKMG nMOS Transistors

The hot carrier (HC) induced degradation has become a major concern in advanced CMOS technologies because of non-scalable V _DD . In this work, we have shown that the HC induced degradation in gate-first HKMG nMOS transistors can be modulated by optimizing the device width, lanthanum capping layer thickness, and pre-gate carbon (C) implant. The physics responsible for these observations are investigated and attributed to the reduction in the number of defects (traps) in hafnium oxide (HfO ₂ ) and reduction in carrier injection into these defects. It is also shown that the HC performance of these transistors could be further improved by increasing the active-to-active spacing.