应力下LDD nMOSFET栅控产生电流退化特性研究

研究了LDD nMOSFET栅控产生电流在电子和空穴交替应力下的退化特性。电子应力后栅控产生电流减小,相继的空穴注人中和之前的陷落电子而使得产生电流曲线基本恢复到初始状态。进一步发现产生电流峰值在空穴应力对电子应力引发的退化的恢复程度与阈值电压和最大饱和漏电流不同。电子应力中陷落电子位于栅漏交叠区附近的沟道侧I区和LDD侧的II区中氧化层中。GIDL应力中,空穴注入进II区中和了陷落电子,使得产生电流的退化基本得到恢复,但这些空穴并未有效中和I区中的陷落电子,因此阈值电压和最大饱和漏电流退化恢复的程度较小,分别为20%和7%。

Degradation of Gate-controlled Generation Current under Stresses in LDD nMOSFET' s

The degradation of gate-controlled generation current IGD under hot electron stressand sequent hot hole stress in LDD nMOSFET’ s is studied. IGD decreases after the hot electronstress (EIS) and is recovered to the initial value after the sequent hot hole stress (HIS). The de-gree of the HIS recovering the degraded IGD induced by the previous HES is different from thethreshold voltage VrH and the saturation drain current IDSAT. This is because the trapped electronsduring EIS are located at I region above the end of channel and II region above LDD in the gate todrain overlap area. The holes injected in HIS neutralize the trapped electrons of II region and re-covers the IGD completely. However, these injected holes can not neutralize the trapped electronin I region. This results in the small recoveries of degradations of VTH and IDsAT and they are 20%and 7%, respectively.