Preparation of Barium Titanate Thin Films using Barium Acetate

Online Inquiry

Barium titanate (BaTiO₃) is not only a typical electronic material, but also the earliest developed perovskite ferroelectric. It has excellent piezoelectric, ferroelectric, dielectric, and pyroelectric properties. Therefore, BaTiO₃ thin films can be used in the development of microelectronic devices, such as thin film capacitors, non-volatile memory elements, dynamic random access devices, optoelectronic devices such as optical waveguides, optical modulators, second harmonic generators, infrared detectors, etc., and can also be combined with superconducting thin films to develop ferroelectric/superconducting devices, such as superconducting field effect transistors and ultra-high density dynamic random access memories.

Reagents

Barium acetate (Ba(CH₃COO)₂), Ti(OC₄H₉)₄, glacial acetic acid, ethylene glycol methyl ether, ethylene glycol, anhydrous ethyl alcohol, and isopropanol.

Experimental Procedure

Dissolve a certain amount of Ba(CH₃COO)₂ in hot acetic acid, add Ti(OC₄H₉)₄ with an equal molar ratio, add an appropriate amount of water in the stirring process to hydrolyze it, continue to add integral agent and surfactant, adjust the sol to a certain concentration of sol with solvent, stir for 1 hour to form a yellow transparent sol, filter, shake the filtrate on a single crystal Si (100) sheet for 50 seconds, and decompose it at a certain temperature. Finally, after annealing at about 973 K, the barium titanate thin films based on monocrystalline silicon were obtained.

Performance and Application

BaTiO₃ is one of the ferroelectric materials. When it is deposited on different substrates, the physical properties of barium titanate thin films change with the influence of substrate surface stress, dipole layer, impurities, and polycrystalline state, so there is a great difference in physical properties between barium titanate thin films and bulk materials.

Many factors must be considered in the processing and characteristic development of BaTiO₃ thin films, and the standards for selecting ferroelectric materials are not compatible with different applications. For example, in DRAM applications, materials are required to have a large dielectric constant and coercive field, but not spontaneous polarization, while NVRAM (non-volatile random access memory) requires a small dielectric constant and coercive field, as well as large residual polarization. For example, in the application of a pyroelectric detector synthetic image array, parameters such as the pyroelectric coefficient, dielectric constant, and dielectric point loss of BaTiO₃ should be balanced in order to optimize the merit value of the device.

The experimental results show that barium titanate thin film has the most potential in TFEL (thin film electroluminescence) as a dielectric layer, and it shows a high dielectric constant in thin film mixed oxides and integrated circuits.