InP/Al2O3堆栈在退火过程中的热稳定性研究

Thermal Stability of InP/Al_2O_3 Stacks upon Post Deposition Annealing

源于其高电荷迁移率,III-V族半导体材料有望在10nm技术节点以下的低功耗晶体管上得到采用。采用角分辨X射线光电子能谱(ARXPS),表征了InP/Al_2O_3堆栈退火前后的界面化学,元素扩散与脱吸附。InP/Al_2O_3堆栈在退火前后均存在In氧化物,在退火温度增加到500℃时In氧化物有脱吸附现象。在500℃退火后,P氧化物的扩散现象被角分辨XPS观察到。界面元素扩散和脱吸附会大大影响界面态密度及器件的电学性能,并直接影响其稳定性和可靠性。本文显示InP器件在制造过程中应该进行有效的界面钝化,避免高温工艺。

Group III-V semiconductors are promising to be applied in low power transistors at sub-10 nm technology node for their high charge mobility.The interfacial chemistry,elemental diffusion and desorption of the InP/Al_2O_3 stacks before and after post deposition annealing(PDA)process are investigated by using angle-resolved X-ray photoelectron spectroscopy(ARXPS).Indium oxides are detected before and after PDA process,and indium oxides desorption is seen upon PDA temperature increasing to 500 ℃.After being annealed at 500 ℃,phosphorus oxides diffusion is detected by ARXPS.Interface elemental diffusion and desorption can significantly affect interface trap density and electrical properties of the devices,which directly influence stability and reliability of devices.Interface passivation should be taken and high temperature process should be avoided in InP devices fabrication.