Unveiling the Impact of AC PBTI on Hydrogen Formation in Oxide Semiconductor Transistors

For the first time, we elucidate the impact of both alternating current (AC) and direct current (DC) positive bias temperature instability (PBTI) on hydrogen (H) formation of oxide semiconductor FETs (OSFET). Our investigation employs a systematic and holistic analysis on the highly stable co-sputtered Indium-Gallium-Zinc-Tin-oxide (IGZTO) FETs. Key discoveries include: (1) There are distinctive variations between AC and DC PBTI results at high temperatures
$(T)$
. (2) In AC PBTI, both frequency
$(f)$
and duty factor (DF) play a crucial role in mitigating the H formation effect. (3) DF exhibits a more influential impact than
$f$
(4) AC PBTI, particularly at 25% DF and 1 MHz, can alleviate up to 99.2% of the threshold voltage change
$(\Delta V_{\text{th}})$
induced by H formation from DC PBTI. These findings contribute significant insights into the H formation mechanism, providing a more relevant and accurate understanding of PBTI reliability across diverse real-world applications. The results also offer valuable guidance for device optimization and circuit design in the pursuit of enhanced performance and reliability.