Electrical properties of hafnium silicate gate dielectrics deposited directly on silicon
- 10 May 1999
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 74 (19), 2854-2856
- https://doi.org/10.1063/1.124036
Abstract
Hafnium silicate (HfSixOy) gate dielectric films with ∼6 at. % Hf exhibit significantly improved leakage properties over SiO2 in the ultrathin regime while remaining thermally stable in direct contact with Si. Capacitance–voltage measurements show an equivalent oxide thickness (tox) of less than 18 Å for a 50 Å HfSixOy film deposited directly on a Si substrate, with no significant dispersion of the capacitance for frequencies ranging from 10 kHz to 1 MHz. Current–voltage measurements show for the same film a leakage current of 1.2×10−6 A/cm2 at 1 V bias. Hysteresis in these films is measured to be less than 20 mV, the breakdown field is measured to be EBD∼10 MV/cm, and the midgap interface state density is Dit∼1011 cm−2 eV−1. Cross-sectional transmission electron microscopy shows no signs of reaction or crystallization in HfSixOy films on Si after being annealed at 800 °C for 30 min.Keywords
This publication has 12 references indexed in Scilit:
- MOS transistors with stacked SiO/sub 2/-Ta/sub 2/O/sub 5/-SiO/sub 2/ gate dielectrics for giga-scale integration of CMOS technologiesIEEE Electron Device Letters, 1998
- Transistor characteristics with Ta/sub 2/O/sub 5/ gate dielectricIEEE Electron Device Letters, 1998
- Crystalline Oxides on Silicon: The First Five MonolayersPhysical Review Letters, 1998
- Intermixing at the tantalum oxide/silicon interface in gate dielectric structuresApplied Physics Letters, 1998
- Low Temperature CVD of Crystalline Titanium Dioxide Films Using Tetranitratotitanium(IVChemical Vapor Deposition, 1998
- Surface preparation, growth, and characterization of ultrathin gate oxides for scaled CMOS applicationsPublished by SPIE-Intl Soc Optical Eng ,1997
- Thermodynamic stability of binary oxides in contact with siliconJournal of Materials Research, 1996
- Direct extraction of the electron tunneling effective mass in ultrathin SiO2Applied Physics Letters, 1996
- Reactions of Zr thin films with SiO2 substratesJournal of Applied Physics, 1988
- Thermodynamic considerations in refractory metal-silicon-oxygen systemsJournal of Applied Physics, 1984