A New Metal--Insulator--Metal Capacitor with Nickel Fully Silicided Polycrystalline Silicon Electrodes

• Published in: Japanese Journal of Applied Physics 2010-09, Vol.49 (9), p.091503-091503-5
• Main Authors: Lee, Jung-Hsiang, Tsai, Zheng-Ye, Lin, Yi-Chang, Zhu, Yi-Yun, Chen, Bo-Han
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.49.091503

A novel low-cost metal--insulator--metal (MIM) capacitor with a high capacitance density of ${\sim}10.2$ fF/\mbox{$\mu$m} 2 has been developed by using nickel fully silicided (Ni-FUSI) polycrystalline silicon electrodes. The low resistivities of Ni 3 Si, Ni 2 Si, and NiSi electrodes have been achieved and determined to be around 106, 39, and 21 \mbox{$\mu$}$\Omega$$\cdot$cm without requiring noble metal materials. At room temperature, this MIM capacitor also displays a good leakage current density of $3.9\times 10^{-6}$ A/cm 2 at 1 V and a quadratic voltage coefficient ($\alpha$) of 2266 ppm/V 2 . Experiments demonstrated that Schottky emission is the dominant conduction mechanism at high temperatures and low fields under top electrode injection. The Schottky barrier heights ($\varPhi_{\text{B}}$) at the Ni 3 Si/ZrO 2 , Ni 2 Si/ZrO 2 , and NiSi/ZrO 2 interfaces were extracted firstly to be 1.15, 1.05, and 0.8 eV, respectively. Material characterization further reveals this structure highly appropriate for advanced MIM capacitors.