Degradation Characteristics by Hot Carrier Injection of nchannel MOSFET with Gate- $n^{-}$S/D Overlapped Structure

게이트와 $n^{-}$소스/드레인 중첩구조를 갖는 n 채널 MOSFET의 핫캐리어 주입에의한 소화특성

The n-channel MOSFETs with gate-$n^{-}$S/D overlapped structure have been fabricated by ITLDD(inverse-T gate lightly doped drain) technology. The gate length(L$_{mask}$) was 0.8$\mu$m. The degradation effects of hot carriers injected into the gate oxide were analyzed in terms of threshold voltage, transconductance and drain current variations. The degradation dependences on the gate voltage and drain voltage were characterized. The devices with higher n-concentration showed higher resistivity against the hot carrier injection. As the results of investigating the lifetime of the device, the lifetime showed longer than 10 years at V$_{d}$ = 5V for the overlapped devices with the implantation of an phosphorus dose of 5$\times$10$^{13}$ cm$^{-2}$ and an energy of 80 keV in the n$^{-}$resion.