Comparative Analysis of Hot Carrier Degradation (HCD) in 10-nm Node nMOS/pMOS FinFET Devices

Abstract

In 10-nm node core FinFETs, we analyzed the cause of higher hot carrier degradation (HCD) in pFinFETs than in nFinFETs. Self-heating effect is severe in pFinFETs because SiGe is used as the source/drain materials, which makes the device temperature higher than nFinFETs. Theoretically, because the lifetime of multiple particle (MP) mechanism decreases as temperature increases, degradation due to MP decreases. Therefore, it is difficult for the pure HCD mechanisms to occur more in pFinFETs, which has higher temperature than nFinFETs. However, in pFinFETs, unlike nFinFETs, interface traps can be generated due to negative-bias temperature instability (NBTI) that occurs by the reaction between inversion holes and electrons of Si-H bonds. Also, since NBTI deteriorates more as the temperature increases, the phenomenon of higher degradation in pFinFET than nFinFET can be explained with the NBTI mechanism. Therefore, we propose an additional NBTI mechanism that is caused by high device temperature in pFinFETs even in the HCD condition. In addition, the main components were investigated through measurements of current degradation rate in various voltage conditions, and it was found that NBTI is dominant in pFinFETs. Finally, NBTI that can occur in the HCD condition was predicted through technology computer-aided design (TCAD) simulation. As a result, degradation due to pure hot carriers without NBTI occurs more in nFinFETs than in pFinFETs.