Electrical Characterization of Aluminum-Oxynitride Stacked Gate Dielectrics Prepared by a Layer-by-Layer Process of Chemical Vapor Deposition and Rapid Thermal Nitridation

Hideki MURAKAMI, Wataru MIZUBAYASHI, Hirokazu YOKOI, Atsushi SUYAMA, Seiichi MIYAZAKI

Summary :

We investigated the use of AlO_x:N/SiN_y stacked gate dielectric as an alternate gate dielectric, which were prepared by alternately repeating sub-nanometer deposition of Al₂O₃ from an alkylamine-stabilized AlH₃ + N₂O gas mixture and rapid thermal nitridation in NH₃. The negative fix charges, being characteristics of almina, were as many as 3.910¹² cm^-2 in the effective net charge density. The effective dielectric constant and the breakdown field were 8.9 and 8 MV/cm, respectively, being almost the same as pure Al₂O₃. And we have demonstrated that the leakage current through the AlO_x:N/SiN_y stacked gate dielectric with a capacitance equivalent thickness (CET) of 1.9 nm is about two orders of magnitude less than that of thermally-grown SiO₂. Also, we have confirmed the dielectric degradation similar to the stress-induced leakage current (SILC) mode and subsequent soft breakdown (SBD) reported in ultrathin SiO₂ under constant current stress and a good dielectric reliability comparable to thermally-grown ultrahin SiO₂. From the analysis of n⁺poly-Si gate metal-insulator-semiconductor field effect transistor (MISFET) performance, remote coulomb scattering due to changes in the gate dielectric plays an important role on the mobility degradation of MISFET with AlON/SiON gate stack.

• Publication: IEICE TRANSACTIONS on Electronics Vol.E88-C No.4 pp.640-645
• Publication Date: 2005/04/01
• DOI: 10.1093/ietele/e88-c.4.640
• Type of Manuscript: Special Section PAPER (Special Section on Fundamental and Application of Advanced Semiconductor Devices)
• Category: Si Devices and Processes

Authors

Hideki MURAKAMI
Wataru MIZUBAYASHI
Hirokazu YOKOI
Atsushi SUYAMA
Seiichi MIYAZAKI

Keyword

high-k dielectrics,  aluminum oxide,  reliability,  MISFET