Electrical Characteristics of Pt/SrBi₂Ta₂O₉/Ta₂O₅/Si Using Ta₂O₅ as the Buffer Layer

Abstract

We propose the Pt/SrBi 2 Ta 2 O 9 /Ta 2 O 5 /Si structure for the application of nondestructive read-out memory. The Ta 2 O 5 films were deposited on p-type Si (100) substrates by rf-magnetron sputtering and the SrBi 2 Ta 2 O 9 films were deposited by metal organic deposition (MOD) method. Coercive field that decisively affects on the memory window becomes greater by inserting the Ta 2 O 5 buffer layer between ferroelectric thin film and silicon substrate and thus the memory window also increases with an electric field to the SrBi 2 Ta 2 O 9 . The C–V characteristics of the Pt/SrBi 2 Ta 2 O 9 (195 nm)/Ta 2 O 5 (36 nm)/Si structure show memory window of 0.5–2.7 V at the applied voltage of 3–7 V. The leakage current density is 1.7×10 -8 A/cm 2 , even at the high voltage of 10 V.