横向尺寸的变化对SiGe HBT高频噪声的影响

Impact of geometrical scaling on high-frequency noise in SiGe HBTs

摘要: 从发射极条宽、发射极条长、基极条数、发射极与基极间距四个方面分析了横向尺寸变化对SiGe HBT高频噪声的影响。结果表明增加发射极条长、基极条数和减小发射极与基极间距可以较为有效地减小晶体管噪声,而减小发射极与基极间距对噪声的改善效果比较显著。发射极与基极间距从1μm减小到0.5μm,2GHz工作频率下最小噪声系数可减小9dB,在0.5GHz工作频率下最小噪声系数可降至1.5dB,2GHz工作频率下最小噪声系数为3dB。

Abstract: Width scaling,length scaling,base stripe-number scaling and distance between emitter and base scaling ebbect on high-frequency noise in SiGe HBTs are quantified from an experimental perspective.Results show that the increase of emitter length,base stripe number,and the decrease of distance between emitter and base are proved to be effective ways to improve noise performance of SiGe HBTs.Particularly,the effect of the last method is remarkably good.As the distance reduces from 1μm to 0.5μm,the minimum noise figure can be reduced by 9dB at 2GHz and reaches 1.5dB at 0.5GHz and 3dB at 2GHz.