Electrical and reliability characteristics of HfO2 gate dielectric treated in N2 and NH3 plasma atmosphere

Abstract As-grown HfO 2 films by plasma-enhanced chemical vapor deposition (PECVD) were treated by N 2 and NH 3 plasma at 70 W and 300 ° C. The films treated by either N 2 or NH 3 plasma were crystallized at annealing temperature above 800 ° C, resulting in 200 ° C higher crystallization temperature than that of HfO 2 films without plasma treatment. The capacitors treated at the bottom side of HfO 2 by NH 3 plasma exhibited the lowest leakage current density, but the highest interface trap density. The capacitors treated at the bottom side of HfO 2 by N 2 plasma showed a comparable leakage current density to samples treated by NH 3 plasma and the lowest interface trap density. The N 2 plasma-treatment instead of NH 3 is a suitable method to improve the reliable characteristics of HfO 2 gate dielectric.