利用背面Ar^+轰击改善n-MOSFET饱和区特性  

Improvement of Characteristics in the Saturation Region of n-MOSFET Using Backsurface Ar^+ Bombardment

作　　者：陈平[1] 黄美浅[1] 李旭[1] 李观启[1] 

机构地区：[1]华南理工大学物理科学与技术学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2005年第2期70-74,共5页Journal of South China University of Technology(Natural Science Edition)

摘　　要：用550eV的低能量Ar+离子束轰击n MOSFET(n沟金属-氧化物-半导体场效 应晶体)芯片的背面,以改善其饱和区的直流特性(如跨导、阈值电压和表面有效迁移率) 以及低频噪声等.结果表明,随着轰击时间的增加,跨导和沟道表面有效迁移率先增大后 减小,阈值电压先减小后增大,而低频噪声在轰击后明显减小.实验证明,上述参数的变化 是硅—二氧化硅界面的陷阱密度和二氧化硅中固定电荷密度在轰击后变化的结果.Ar + ion beams with the energy of 550eV were used to bombard the backside of n-MOSFET chip to improve the direct current characteristics and overcome the low-frequency noise of the device in the saturation region. The direct current characteristics include the following aspects: the transconductance, the threshold voltage and the effective mobility of the surface inversion layer carrier. The results indicate that, as the bombardment time increases, the transconductance and the effective mobility first increase and then decrease, while the change tendency of the threshold voltage is on the contrary. The low-frequency noise obviously decreases after the bombardment. It is proved by experiments that all these changes are due to the trap density variation on the Si—SiO_2 surface and the fixed charge density variation in SiO_2.

关 键 词：背面Ar^+轰击 金属-氧化物-半导体场效应晶体管 跨导 阈值电压 噪声 

分 类 号：TN304[电子电信—物理电子学]