Compact Modeling of IGZO-based CAA-FETs with Time-zero-instability and BTI Impact on Device and Capacitor-less DRAM Retention Reliability
Jingrui Guo, Ying Sun, Lingfei Wang, Xinlv Duan, Kailiang Huang, Zhaogui Wang, Junxiao Feng, Qian Chen, Shijie Huang, Lihua Xu, Di Geng, Guangfan Jiao, Shihui Yin, Zhengbo Wang, Weiliang Jing, Ling Li, Ming Liu
Abstract
This work developed a compact model of the stackable vertical Channel-All-Around (CAA) IGZO FETs, based on carrier trapping dynamics and (inner/outer) surface potential of a cylindrical channel shell. It is calibrated to fabricated devices with geometric effects (e.g., asymmetry Source/Drain (S/D) to Gate (G) overlaps) on turn-on voltage (V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> ). Besides, temperature (T) effects on V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> , leakage current and non-linear contacts were considered from 233 K to 393 K, and such degradation effects contribute to time-zero instability (TZI) on DRAM retention performance. To further understand time dependent reliability (i.e., bias-temperature-instability, BTI), an abnormal PBTI with negative V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</inf> shift is studied from the perspective of device physics and is more pronounced than NBTI. By incorporating TZI and BTI in capacitor-less DRAMs, it enables a reliability-aware design technology co-optimization flow characterizing weak cells for scalability of BEOL-compatible 3D integration.