IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Dielectrics Monday Sessions
       Session DI1-MoP

Paper DI1-MoP10
Material and Electrical Characteristics of ZrO@sub 2@ Film Obtained by Electron Cyclotron Resonance Plasma Enhanced Chemical Vapor Deposition (ECR-PECVD)

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: High K Dielectrics Poster Session
Presenter: J. Wang, University of California, Los Angeles
Authors: B.O. Cho, University of California, Los Angeles
J. Wang, University of California, Los Angeles
S.X. Lao, University of California, Los Angeles
J.P. Chang, University of California, Los Angeles
Correspondent: Click to Email
ZrO@sub 2@ is investigated in this work to replace SiO@sub 2@ as the dielectric material in metal-oxide-metal (MOM) capacitors in dynamic random memory (DRAM) devices for its high dielectric constant, good thermal stability, excellent conformality, and large bandgap. ZrO@sub 2@ films were deposited on p-Si (100) wafers by ECR-PECVD method using zirconium tetra-tert-butoxide (Zr(OC@sub 4@H@sub 9@)@sub 4@) as an organometallic precursor, Ar as a carrier of the precursor vapor, and O@sub 2@ as an oxidant. X-ray photoelectron spectroscopy and secondary ion mass spectrometry indicated that stoichiometric ZrO@sub 2@ film was obtained with various amount of carbon incorporation depending upon the electron temperature and the O@sub 2@/Ar flow rate ratio. X-ray diffraction showed that the films deposited without substrate heating were amorphous. By manipulating the negative substrate bias and raised the deposition temperature to around 400 °C, carbon-free amorphous ZrO@sub 2@ was obtained. High resolution transmission electron microscopy was used to observe the interfacial thin film formation between the deposited ZrO@sub 2@ and the substrate Si. The electrical property of the as deposited ZrO@sub 2@ was assessed by forming Al/ZrO@sub 2@/Si capacitor structures. Good capacitance-voltage and current-voltage characteristics were obtained with k=22 at 1 MHz and J=4x10@super -5@ A/cm@super 2@ at -1.5 V, respectively. The C-V response showed a small hysteresis of <60 mV and an interfacial state density of 2x10@super 11@ cm@super -2@ eV@super -1@ based on capacitance measurement at various frequencies. The influences of carbon incorporation, substrate heating and biasing, and post-annealing on the bulk and the interfacial trap formation were investigated by photoconductivity measurement, which enables the determination of leakage conduction mechanism.