Electrical characteristics of MOS capacitors with HfTiON as gate dielectric

Abstract

HfTiN film was deposited by co-reactive sputtering and then was annealed in different gas ambients at temperature of 650 °C for 2 min to form HfTiON film. Capacitance-voltage and gate-leakage characteristics were investigated. The N₂O-annealed sample exhibited small interface-state and oxide-charge densities, and enhanced reliability, which was attributed to the fact that nitridation could create strong Si⊀N bonds to passivate dangling Si bonds and replaced strained Si-O bonds, thus forming a hardened dielectric/Si interface with high reliability. As a result, it is possible to prepare high-quality HfTiON gate dielectric of small-scaling CMOS devices in the industry-preferred N₂O environment.

Keywords

high-k gate dielectric / HfTiON / co-reactive sputter / gate-leakage current

References

[1] Gusev E. P., Carier E., Buchanan D. A. Ultrathin High-K Metal Oxides on Silicon: Processing, Characterization and Integration Issues[J]. Microelectron. Eng., 2001, 59: 341-349.

[2] Wilk G. D., Wallace R. M. Electrical Properties of Hafnium Silicate Gate Dielectrics Deposited Directly on Silicon[J]. Appl. Phys. Lett., 1999, 74: 2 854-2 856.

[3] Wilk G. D., Wallace R. M., Anthony J. M. High-k Gate Dielectrics: Current Status and Materials Properties Considerations[J]. J. Appl. Phys., 2001, 89(10): 5 243-5 275.

[4] Lee B. H., Kang L., Nieh R. Thermal Stability and Electrical Characteristics of Ultrathin Hafnium Oxide Gate Dielectric Reoxidized with Rapid Thermal Annealing[J]. Appl. Phys. Lett., 2000, 76: 1 926-1 928.

[5] Yamamoto K., Hayashi S., Niwa M. Electrical and Physical Properties of HfO₂ Films Prepared by Remote Plasma Oxidation of Hf Metal[J]. Appl. Phys. Lett., 2003, 83(11): 2 229-2 231.

[6] Sayan S., Aravamudhan S., Busch B. W. Chemical Vapor Deposition of HfO₂ Film on Si(100)[J]. J. Vac. Sci. Technol. A, 2002, 20(2): 507-512.

[7] Campbell S. A., Ma T. Z., Smith R. High Mobility HfO₂ n- and p-channel Transistors[J]. Microelectronic Engineering, 2001, 59: 361-365.

[8] W Zhu, T P Ma, T Tamagawa. HfO₂ and HfAlO for CMOS: Thermal Stability and Current Transport[J]. IEDM Tech Digest, 2001: 463–466

[9] Shang G., Peacock P. W., Robertson J. Stability and Band Offsets of Nitrogenated High-dielectric-constant Gate Oxides[J]. App. Phys. Lett., 2004, 84(1): 106-108.

[10] A Shanware, M R Visokay, J J Chambers. Reliability Evalution of HfSiON Gate Dielectric Film with 12.8 A SiO₂ Equivalent Thickness[J]. IEDM Tech Digest, 2001: 137–140

[11] S J Rhee, C S Kang, C H Choi. Improved Electrical and Material Characteristics of Hafnium Titanate Multi-metal Oxide n-MOSFETs with Ultra-thin EOT(∼8 Å) Gate Dielectric Application[J]. IEDM Tech Digest, 2004: 837–840

[12] Fang Q., Zhang J. Y., Wang Z. M. Investigation of TiO₂-doped HfO₂ Thin Films Deposited by Photo-CVD[J]. Thin Solid Films, 2003, 428: 263-268.

[13] Honda K., Skaki A., Sakashita M. Pulsed Laser Deposition and Analysis for Structural and Electrical Properties of HfO₂-TiO₂ Composite Films[J]. Japanese Journal of Applied Physics, 2004, 43(4A): 1 571-1 576.

[14] Terman L. M. An Investigation of Surface States at a Silicon/Silicon Oxide Interface Employing Metal-oxide-silicon Diodes[J]. Solid-State Electron, 1962, 5: 285-299.

[15] Bhat M., Kim J., Yan J. MOS Characteristic of Ultrathin NO-Grown Oxynitrides[J]. IEEE Transaction, Electron Devices Letters, 1994, 15: 421-423.