Unveiling the Impact of AC PBTI on Hydrogen Formation in Oxide Semiconductor Transistors
Gan Liu, Qiwen Kong, Zuopu Zhou, Ying Xu, Chen Sun, Kaizhen Han, Yuye Kang, Dong Zhang, Xiaolin Wang, Yang Feng, Wei Shi, Bich-Yen Nguyen, N. Kai, Gengchiau Liang, Xiao Gong
Abstract
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 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(T)$</tex>. (2) In AC PBTI, both frequency <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(f)$</tex> and duty factor (DF) play a crucial role in mitigating the H formation effect. (3) DF exhibits a more influential impact than <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$f$</tex> (4) AC PBTI, particularly at 25% DF and 1 MHz, can alleviate up to 99.2% of the threshold voltage change <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\Delta V_{\text{th}})$</tex> 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.