分段退火工艺对PZT薄膜结晶和铁电性能的影响

摘要

快速退火(RTA，rapid thermal annealing)工艺的升温速率高，可以在很短的时间(1 min)内升到PZT薄膜的晶化温度，缩短薄膜的晶化时间，有利于降低升温过程中氧化铅的挥发损失，减少过渡层Ti原子的扩散。但是因为热处理时间太短，RTA在控制薄膜残余应力和薄膜的取向生长方面存在着不足。设计分段RTA工艺来控制薄膜生长的结晶取向，采用XRD和SEM对PZT薄膜微观结构进行分析，结果表明：分段RTA工艺能够获得结晶性能和铁电性能良好的（111）择优取向的PZT薄膜，650℃是形核阶段最佳退火温度，600℃是晶粒生长阶段最佳温度，二次退火工艺可以促进薄膜晶化完全。%Rapid thermal annealing (RTA) process of high heating rate can be up to the crystallization temperature of PZT thin films in a very short period of time (1 min), so RTA can reduce the volatilization loss during the heating process of lead oxide, and reduce the diffusion transition layer of Ti atoms. However, because of the short heat treatment time, it is too hard to control orientation and residual stress of films. By using the subsection annealing process to control the crystal orientation of the thin film, the microstructure of PZT thin film was analyzed by SEM and XRD. The experimental results show that this annealing process can obtain the (111) preferred orientation PZT films with good crystalline properties and ferroelectric properties. 650℃ is the optimum temperature for nucleation. 600℃ is the optimum temperature for grain growth. The second annealing process can promote the crystallization of the films.