Bi_4Ti_3O_(12)薄膜的取向生长及其电性能研究

c-axis Oriented Growth and Electrical Properties of Bi_4Ti_3O_(12) Thin Films Deposited on p-Si

采用Sol-Gel工艺,在快速退火的工艺条件下制备了Bi4Ti3O12铁电薄膜,研究了退火温度及时间、薄膜厚度对Bi4Ti3O12薄膜的取向生长行为及其铁电性能、漏电流的影响,探讨了Bi4Ti3O12薄膜取向生长的微观机制.结果表明:退火温度显著影响薄膜的c轴取向生长,其(00l)晶面的取向度F=(P-P0)/(1-P0)由550℃的0.081增加到850℃的0.827,退火时间对其(00l)晶面的取向度也有较大影响;经750℃以上温度退火处理的Bi4Ti3O12薄膜呈高度c轴取向,对铁电性能有较明显的削弱作用;薄膜的漏电流密度随退火温度升高而增大,但薄膜的c轴取向生长有利于减缓漏电流密度的增长.

Polycrystalline Bi4Ti3O12 thin films were successfully produced on p-Si substrates by sol-gel technique. Effects of annealing temperature, annealing time, film thickness on the c-axis-oriented growth behavior, ferroelectric properties and leakage current were studied. The results indicate that annealing temperatures have remarkable influence on c-axis-oriented growth behavior with an orientation factor of (00l) (F = (P - P-0)/(1 - P-0)) from 0.081 at 550degreesC to 0.827 at 850degreesC, and the annealing time has also influence on it. Bi4Ti3O12 thin films are highly c-axis-oriented over 750degreesC of annealing temperature and the remanent polarization decreases with the increase of the orientation factor of (001). The leakage current densities of Bi4Ti3O12 films increase with the ascending annealing temperature, but the c-axise-oriented behavior helps to slow down the increase of the leakage current densities of Bi4Ti3O12 films.