Designing buried-gate InGaZnO transistors for high-yield and reliable switching characteristics

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2024-04, Vol.12 (15), p.5347-5354
• Main Authors: Kim, Do Hyeong, Oh, Seyoung, Kwon, Ojun, Jeong, Soo-Hong, Seo, Hyun Young, Cho, Eunjeong, Kim, Min Jeong, Seo, Wondeok, Kwon, Jung-Dae, Kim, Yonghun, Park, Woojin, Cho, Byungjin
• Format: Article
• Language: English
• Subjects: Control equipment; Electrical properties; Gallium; Indium gallium zinc oxide; Reliability; Semiconductor devices; Thin film transistors; Transistors
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/d3tc04531e

The indium-gallium-zinc-oxide (IGZO) transistor has consistently encountered reliability issues and has intrinsic material limitations that limit its electrical performance. In this study, we demonstrate a device concept containing a buried back gate in the IGZO transistor that offers a practical solution, enhancing device reliability and significantly improving transistor performance. Buried-gate transistors that apply a uniform gating field effect to the effective channel region outperform control-gate transistor devices with respect to the on-current, hysteresis window, subthreshold swing, and μ FE . The device yield is also substantially increased (∼81% even higher than ∼54% of the control device) by mitigating the non-uniform gating field effect arising from the protruding gate structure of the control device. Furthermore, the reduced series resistance and decreased interface trap density of the buried-gate transistor substantiate the geometrical optimization of the original transistor device with intrinsically bending stacked-layers (IGZO/A 2 O 3 ). These results provide a feasible approach for enhancing the reliability and electrical properties of oxide thin film transistors, potentially paving a way toward the development of a highly reliable transistor for commercial gadgets. The study emphasizes the benefits of buried gate IGZO transistor devices, showcasing enhanced electrical performance and reliability.