Al掺杂浓度对Hf0.5Zr0.5O2薄膜铁电性能的影响

Effect of Al Doping Concentration on Ferroelectric Properties of Hf0.5Zr0.5O2 Thin Films

采用脉冲激光沉积法(Pulsed laser deposition,PLD)在Pt/Ti/SiO 2/Si衬底上制备TiN/Al掺杂Hf0.5Zr0.5O2/TiN的MIM(金属-绝缘体-金属)结构薄膜电容器。对Al掺杂浓度为0%~4%(摩尔分数)的Al∶Hf0.5Zr0.5O2薄膜的微观结构以及电学性能进行了研究,在此基础上,还研究了退火温度对Al∶Hf0.5Zr0.5O2薄膜的影响。测试结果表明,随着Al掺杂浓度的增大和退火温度的降低,四方相更加稳定,电滞回线更加细窄,剩余极化强度减小。退火温度为500℃时,掺杂浓度为1.03%(摩尔分数)的Al∶Hf0.5Zr0.5O2薄膜中将诱导出类似反铁电薄膜具有的双电滞回线特性,储能密度更高。分析结果表明,这些变化均是由于Al∶Hf0.5Zr0.5O2薄膜内四方相与正交相之间发生的场致可逆相变以及氧空位的再分布。

Apulsed laser deposition(PLD)method was used to prepare thin-film capacitors of MIM structure with TiN/Al-doped Hf0.5Zr0.5O2/TiN on Pt/Ti/SiO2/Si substrates.The microstructure and electrical properties of Al∶Hf 0.Zr0.5O2 film with Al doping concentration of 0%to 4%(mol fraction)were studied.On this basis,the effect of annealing temperature on the Al∶Hf0.5Zr0.5O2 film was also studied.The test results show that,as the Al doping concentration increases and the annealing temperature decreases,the tetragonal phase becomes more stable,the hysteresis loop becomes narrower,and the residual polarization decreases.When the annealing temperature is 500℃,the Al∶Hf 0.5r0.5O2 film with doping concentration of 1.03%will induce a double-hysteresis loop characteristic similar to antiferroelectricity,and the energy storage density is higher.The analysis results show that these changes are due to the field-induced reversible phase transition between the tetragonal phase and the orthogonal phase and the redistribution of oxygen vacancies in the Al∶Hf0.5Zr0.5O2 film.