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 VDD. 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 (HfO2) 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.