SOI器件的kink效应研究

Research on Kink Effect of SOI Transistors

研究了SOI器件中的kink效应,主要包括不同器件类型、不同体接触结构、沟道长度以及栅氧厚度对kink效应的影响。研究发现NMOS器件由于能够产生较多的电子空穴对,在输出特性曲线中呈现明显的kink效应,而PMOS器件由于空穴的电离率较低,碰撞电离产生的电子-空穴对远低于NMOS器件,它的kink效应不明显。对源体短接、H型栅和T型栅三种不同结构的NMOS器件进行研究,发现T型栅器件kink效应最明显。比较了不同沟道长度对kink效应的影响,发现沟道越短,kink效应越明显。比较了栅氧厚度对kink效应的影响,发现随着栅氧厚度减小,kink效应越明显,这主要是由于隧穿电流引起的。

The kink effect of SOI transistors was studied,included effects of different device types,body contacts,channel lengths and gate oxide thickness. The results show that more electrons and holes can generate in NMOS transistors,so the kink effect will present in output characteristics curve. PMOS transistors do not present obvious kink effect due to low ionization rates and the electron hole pairs generated by impact ionization are much less than that compared with NMOS transistors.Then different SOI transistors included source and body shorted,H-type and T-type NMOS devices were studied. The T-type NMOS device present kink effect most obviously. The influence of different channel lengths on kink effect was also studied. The kink effect of shorter channel length device is more obvious. At last,the influence of gate oxide thickness on kink effect was studied. With the decreasing of gate oxide thickness,kink effect is more obvious,which is mainly caused by tunneling currents.