AVS 49th International Symposium
    Thin Films Tuesday Sessions
       Session TF-TuP

Paper TF-TuP2
Structural and Electrical Characteristics of ZrO@sub 2@ as a Gate Dielectric and Buffer Layer Grown by RF Magnetron Sputtering

Tuesday, November 5, 2002, 5:30 pm, Room Exhibit Hall B2

Session: Poster Session
Presenter: G.S. Lim, Korea University
Authors: G.S. Lim, Korea University
H.S. Choi, Korea University
J.H. Lee, Korea University
Y.T. Kim, Korea Institute of Science and Technology
S.I. Kim, Korea Institute of Science and Technology
I.H. Choi, Korea University
Correspondent: Click to Email
The zirconium oxide (ZrO@sub 2@) layer has been reported to have a relatively high dielectric constant and a strong barrier property against diffusion. Therefore, the buffer layer combined with SiO@sub 2@ is expected to have a good interface with silicon and a strong barrier property against interdiffusion. The emphasis of the results is twofold: the first is the high quality of the investigated films as evidenced by the small measured values of loss factor, flatband voltages, and surface states density as well as the low dispersion of the relative dielectric constants. This work examines the structural and electrical properties of ZrO@sub 2@ thin films deposited by rf magnetron sputtering using a Zr target. The ZrO@sub 2@ /ZrSi@sub x@O@sub y@ /SiO@sub 2@ layer is stoichiometric, uniform, amorphous, and has an equivalent oxide thickness of ~1 nm and a dielectric constant range from 15 to 18 depending upon process conditions and very small C-V hysteresis and low leakage current. The second is that Metal-ferroelectric-insulator-semiconductor (MFIS) structures using zirconium oxide (ZrO@sub 2@) layers as an insulating barrier against interdiffusion have been investigated. Strong barrier effect of ZrO@sub 2@ layer is demonstrated by both High-resolution transmission electron microscopy (HRTEM) and analysis of Auger Electron Spectroscopy (AES). Coercive field that decisively affects the memory window becomes greater by inserting the ZrO@sub 2@ buffer layer between ferroelectric thin film and silicon substrate and thus the memory window also increases with an electric field to the SrBi@sub 2@Nb@sub 2@O@sub 9@ (SBN). The memory windows of the MFIS structure were in the range of 0.7 ~ 3.6 V for gate voltages form 3 to 9 V. The maximum memory window was observed in the MFIS with a 12-nm-thick ZrO@sub 2@ layer. And the leakage current density was 4.74x10@super -8@ A/cm@super 2@ at an applied voltage of 3 V.