Preparation of Bi₄Ti₃O₁₂ Thin Film on Si(100) Substrate Using Bi₂SiO₅ Buffer Layer and Its Electric Characterization

Abstract

Bi4Ti3O12 thin films 100, 200 and 400 nm thick were prepared on Si(100) substrates using 30 nm Bi2SiO5 as a buffer layer, by metalorganic chemical vapor deposition (MOCVD). It was demonstrated that c-axis-oriented Bi4Ti3O12 films can be grown on Si substrates at 500°C using an a-axis-oriented Bi2SiO5 buffer layer. The dielectric constant of the Bi2SiO5 film was estimated to be about 30 from capacitance measurements. The capacitance-vs-voltage (C-V) characteristics of Pt/Bi4Ti3O12/Bi2SiO5/Si (MFIS) structures had ferroelectric switching properties, and the memory windows were about 0.8, 1.5 and 2.9 V for 100, 200 and 400 nm Bi4Ti3O12, respectively. Furthermore, it was shown that the capacitance at zero bias remains almost constant for 12 days. This suggests that Bi4Ti3O12/Bi2SiO5/Si MFIS structures have excellent memory retention properties.

Atomic Layer Deposition of Photocatalytic TiO2 Thin Films from Titanium Tetramethoxide and Water

“…[5,6] In addition, TiO 2 is a constituent of several important multicomponent oxides, such as very high permittivity (Ba,Sr)TiO 3 for dynamic random access memories (DRAM), [7] and ferroelectric Pb(Zr,Ti)O 3 and Bi 4 Ti 3 O 12 for nonvolatile ferroelectric random access memories (FeRAM). [8,9] Because of the great interest, TiO 2 thin films have been prepared by nearly all possible physical and chemical thin film deposition methods, from both gas and liquid phases. Among this variety of methods, atomic layer deposition (ALD) distinguishes itself by offering excellent conformality and large area uniformity, as well as atomic level thickness and composition control.…”

Investigation of New 2,5‐Dimethylpyrrolyl Titanium Alkylamide and Alkoxide Complexes as Precursors for the Liquid Injection MOCVD of TiO2

“…[7,8] TiO 2 is also a constituent in a number of multi-component metal oxides used in microelectronics applications, such as the high-k dielectric oxide (Ba,Sr)TiO 3 for dynamic random access memory (DRAM) applications, [9] and the ferroelectric perovskites Pb(Zr,Ti)O 3 and Bi 4 Ti 3 O 12 used in infrared detectors and non-volatile ferroelectric random access memories (NV-FeRAMs). [10,11] Various techniques have been used for the deposition of TiO 2 thin films. These include reactive sputtering, [12] ionassisted deposition, [13] sol-gel deposition, [14] MOCVD, [15][16][17] and ALD.…”

Crystal structure of lanthanum bismuth silicate Bi2−xLaxSiO5 (x∼0.1)

“…The orthorhombic Bi 2 SiO 5 form was studied as insulator buffer layer for the deposition of Bi 4 Ti 3 O 12 thin films for ferroelectric systems [14][15][16][17][18]. Its two-dimensional structure [19] is built up from an intergrowth of (SiO 3 ) 2À pyroxene files layers inserted between (Bi 2 O 2 ) 2+ layers.…”