Metal-insulator-semiconductor capacitors were fabricated using atomic vapor deposition HfO 2 dielectric with sputtered copper (Cu) and aluminum (Al) gate electrodes. The counterparts with SiO 2 dielectric were also fabricated for comparison. Bias-temperature stress and charge-to-breakdown (Q BD ) test were conducted to examine the stability and reliability of these capacitors. In contrast with the high Cu drift rate in an SiO 2 dielectric, Cu in contact with HfO 2 seems to be very stable. The HfO 2 capacitors with a Cu-gate also depict higher capacitance without showing any reliability degradation, compared to the Al-gate counterparts. These results indicate that HfO 2 with its considerably high density of 9.68 g/cm 3 is acting as a good barrier to Cu diffusion, and it thus appears feasible to integrate Cu metal with the post-gate-dielectric ultralarge-scale integration manufacturing processes.
- Bias-temperature stress
- Copper-gate (Cu-gate) electrode
- Hafnium dioxide (HfO)