Analysis of C-V and I-V data of BST thin films

Abstract

Thin films of Ba_0.7Sr_0.3TiO₃ have been fabricated using Enhanced Metal Organic Decomposition (EMOD) process on Si/SiO₂/Ti/Pt substrates. The C-V characteristics of these films reveal a relation of log(1/C_m) ∝ V_A where C_m is the measured capacitance at a frequency of 10 KHz and V_A is the applied voltage. This voltage variable capacitance is characterized by an inverse quadratic distance proportinal charge distribution at the boundary layer between metal and paraelectric material. Above a threshold voltage of 3–5 V the leakage current density exhibits a modified Schottky emission, which states that log (J_L) ∝ V ^1/4. Below this threshold voltage, the origin of the leakage current which is operative in normal circuit applications has been discussed and identified from its temperature variation.