The Application of an Ultrathin ALD HfSiON Cap Layer on SiON Dielectrics for Ni-FUSI CMOS Technology Targeting at Low-Power Applications

In this letter, we report that the application of a thin HfSiON cap layer (2-10 cycles via atomic layer deposition) on SiON host dielectrics in phase-controlled Ni-fully-silicide (FUSI) CMOS technology is effective to modulate the device V t and reduce the gate leakage while maintaining a similar gate capacitance equivalent thickness and a long channel device mobility (at an E eff of 0.8 MV/cm). High-V t ring oscillator with a delay of 17 ps has been demonstrated, with a much-reduced static power (~10 times) as compared to the Ni-FUSI device using the pure SiON dielectrics. It is proposed that the phase-controlled Ni-FUSI technology using the SiON dielectrics capped with thin HfSiON is promising for the 45-nm and beyond low-power CMOS applications.