화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.159, No.6, H595-H598, 2012
Memory Functions of Nanocrystalline ITO Embedded Zirconium-Doped Hafnium Oxide High-k Capacitor with ITO Gate
Memory functions of MOS capacitors with the nanocrystalline ITO embedded zirconium-doped hafnium oxide high-k gate dielectric thin film and the ITO gate electrode have been studied. Compared with the capacitor of the same dielectric stack but an aluminum gate, the ITO gated sample has a larger charge storing density. The primary memory mechanism of this device is based on hole injection and trapping to the embedded nanocrystalline ITO layer supplied from the substrate under a negative gate bias condition. The large work function of the ITO gate makes it difficult to transfer electrons from the gate to the embedded nanocrystalline ITO site, which favors the hole storage. Under the positive gate bias condition, all positive charges stored in the ITO gated capacitor are erased while those stored in the aluminum gated capacitor are partially erased.