Thermal and Electrical Properties of TaN Electrode on HfO Gate Dielectric

Abstract
Ultra-thin hafnium-oxide gate dielectric film and TaN electrode film were deposited by using atomic layer deposition and DC magnetron sputter, respectively, and the thermal and electrical properties were investigated. In this article, it is shown that TaN on ALD-HfO$_2$ has a midgap work function of $sim$ 4.67 eV and no interaction occurs between gate and dielectric. Capacitance-voltage measurements show equivalent oxide thickness of about 1.5 nm for 5.0 nm HfO$_2$ with TaN electrode. Also, the dielectric constant and the leakage current density of ALD-HfO$_2$ film are 13.3 $sim$ 16.3 and 1 $imes$ 10$^{-6}$ A/cm$^2$ at 1.0 V from flatband voltage, respectively. TEM showed that the interfaces of HfO$_2$/Si and TaN/HfO$_2$ are stable at least up to 600 $^circ$C.

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