VARIATION OF ELECTRICAL-CONDUCTION PHENOMENA OF PT (BA, SR)TIO3/PT CAPACITORS BY DIFFERENT TOP ELECTRODE FORMATION PROCESSES/

Electrical conduction behaviors of Pt/(Ba, Sr)TiO3/Pt thin him capacit ors having top Pt electrodes with different deposition powers are inve stigated. The capacitors having top Pt electrode with deposition power of 0.2kW show Schottky emission behavior at both top and bottom elect rode interfaces with potential barrier heights of 1.24-1.48 eV and 1.8 8-2.08 eV, respectively. However, the capacitor having top Pt electrod e with larger deposition power of 0.5kW shows Schottky emission behavi or only at bottom electrode interface with barrier of 1.61-1.89eV. Int erface with top electrode appears to have very low resistance, and a p ositive temperature coefficient of resistivity (PTCR) effect is observ ed when the electrons are injected ham the top electrode to bottom ele ctrode through BST film. Tap Pt electrode becomes very rough by grain growth during postannealing when the top Pt is deposited with powers o f larger than 0.5kW. Roughening of the top Pt results in the low-resis tance contact behavior at the interface between top Pt and BST, which results in PTCR effect.