Fabrication and Characterization of Pb-Rich Lead Strontium Titanate Films by RF Magnetron Sputtering

摘要

Lead strontium titanate (PST) films were fabricated by RF magnetron sputtering. Pb-rich PST films on Ir(111)/SiO_2/Si and Pt(111)/Ti/SiO_2/Si substrates showed perovskite structure. Dielectric loss of the PST film on Pt(111)/Ti/SiO_2/Si substrate showed smaller value compared to that on Ir(111)/SiO_2/Si substrate. This results might be originated from the grain size and suiface roughness of the PST films; PST films fabricated on Pt(111)/Ti/SiO_2/Si substrate showed small grain and smooth surface. Ir electrode is advantageous to reduction of fatigue properties in Pb(Zr,Ti)O_3 ferroelectric random access memory, however, Pt/Ti bottom electrode is favorable in case of PST films because of a small lattice mismatch between metal and PST films.