Metal Oxide Semiconductor Field Effect Transistor Characteristics with Iridium Gate Electrode on Atomic Layer Deposited ZrO2 High-$k$ Dielectrics

概要

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We have investigated metal oxide semiconductor (MOS) characteristics with Ir gate on ZrO2 high-$k$ dielectrics gate structure. The ZrO2 films are grown with atomic layer deposition method using O2 and tetrakis (diethyl amino) zirconium (TDEAZ) as a Zr precursor. Some ZrO2 films are also grown with oxygen plasma along with TDEAZ. The ZrO2 grown with oxygen plasma shows the EOT value of 1.39 nm, high $k$ of 18.2 and little hysteresis of 20 mV, whereas EOT and $k$ values of the ZrO2 films grown with O2 are 1.52 nm, 13.34 nm, respectively. This is due to dense and well-matched stoichiometric ZrO2 and interfacial reaction through the diffusion of oxygen in the oxygen plasma. Metal oxide semiconductor field effect transistor (MOSFET) characteristics of Ir/ZrO2 grown with oxygen plasma/Si gate structured transistor reveals that the effective mobility is 226 cm2/Vs at $V_{\text{GS}}=1.5$ V, which is slightly smaller than the saturation mobility of 250 cm2/Vs. The interface trap density in the ZrO2 grown with oxygen plasma is also lower than that in the ZrO2 grown with O2.
Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physicsの論文
2003-08-15