低温生长SiO<sub>2</sub>膜的性质及其在SiGe/Si HBT研制中的应用

低温生长SiO₂膜的性质及其在SiGe/Si HBT研制中的应用

摘要: 用磁控溅射SiO₂膜作为台面SiGe/SiHBT的表面保护纯化膜和光刻掩膜.测试分析了溅射工艺对SiO₂膜的性质和SiGe/SiHBT性能的影响.研究发现,较高的衬底温度(200℃)有得于改善SiO₂膜的质量.用溅射SiO₂方法制备的HBT的电流增益明显高于用热分解正硅酸乙脂方法淀积SiO₂制备的HBT.这说明溅射法避免了高温引起SiGe层应变驰豫所造成的HBT性能变差.

Abstract: SiO₂ films used for passivation in the fabrication of mesa SiGe/Si HBTs were deposited by sputtering. The influence of the sputtering procedure on the propenties of the films and the performance of the HBTs was discussed. As it turned out that higher substrate temperature is favorable to the quality of the films. The electric current gain of the HBT with SiO₂ deposited by sputtering is much higher than those deposited by thermal decomposition owing to that the former approach avoids the strain relaxation caused by high temperature procedure which would result in the degradation of the HBT performance.