Reliability of low-temperature-processing hafnium oxide gate dielectrics prepared by cost-effective nitric acid oxidation technique
Journal
IEEE Transactions on Device and Materials Reliability
Journal Volume
7
Journal Issue
4
Pages
611-616
Date Issued
2007
Author(s)
Abstract
In this paper, the physical and electrical characteristics of low-temperature-processing hafnium oxide (HfO 2 ) films are studied. A simple cost-effective room-temperature process was introduced to prepare high-k HfO 2 dielectrics. A novel technique of direct oxidation of an ultrathin Hf metal by nitric acid, followed by rapid thermal annealing in N 2 is demonstrated. The prepared HfO 2 gate dielectrics show good uniformity, low leakage currents, high breakdown field, and superior reliability under electrical stressing. The long-term ten-year lifetime was also evaluated by a time-dependent-dielectric-breakdown analysis to project the maximum operation voltage of -1.8 V for HfO 2 gate stacks. This low-temperature oxidation technology for preparing high-quality high-k HfO 2 dielectrics is promising for flat-panel-display applications.
Type
journal article