ULSI DRAM 의 Capacitor Dielectric 을 위한 Paraelectric PLT 박막의 제작과 특성에 관한 연구

초록

We fabricated the Pb1-0.28αLa0.28TiO3 (PLT(28)) thin film successfully by using the sol-gel method and characterized it to evaluate its potential for being utilized as the capacitor dielectrics of ULSI DRAMs. In our sol-gel process, the acetates were used as the starting materials. Through the TGA-DTA analysis, we established the excellent fabrication conditions of the sol-gel method for the PLT(28) thin film. We obtained the dense and crack-free PLT(28) thin film of 100% perovskite phase by drying at 350℃ after each coating and final annealing at 650℃. Its electrical properties were measured from the planar capacitors fabricated on the Pt/Ti/SiO2/Si substrate. By the P-E hysteresis measurement, its paraelectric phase was identified and its dielectric constant and leakage current density were measured as 936 and 1.1μA/cm2, respectively. Those electrical values indicates that the PLT(28) thin film is the most successful candidate for the capacitor dielectrics of ULSI DRAMs at the present.