Unraveling the Influence of Surface Contaminants and Cleaning Protocols on Charge States of SiO₂ Dielectrics and the Performance of Organic Field-Effect Transistors.

Authors

Zhenxin Yang, Fushun Li, Yuanju Zhao, Delong Yang, Juntao Hu, Tao Zhang, Deng-Ke Wang, Qiang Zhu, Zheng-Hong Lu

Published in

Langmuir : the ACS journal of surfaces and colloids. Aug 16, 2025. Epub Aug 16, 2025.

Abstract

Organic field-effect transistors (OFETs) fabricated on SiO₂/Si wafers represent a crucial avenue for the development of organic-on-silicon technology and serve as a platform for materials science to characterize carrier mobility. The surface cleaning treatment of wafers is critical because OFETs are highly sensitive to surface states. In this study, the effects of intrinsic organic contaminants on wafers, as well as the functions of commonly used cleaning solvents and treatments on the surface states, electronic structure of SiO₂, and the performance of OFETs were systematically investigated. The intrinsic organic contaminants on the wafer surface were identified as being in positively charged states, which led to high operational voltages of OFETs and degraded bias-stress stability. However, their impact on field-effect mobility was found to be minimal following any surface cleaning process. The conventional ultrasonic cleaning using acetone and isopropanol only partially removed contaminants, which provides limited improvement in reducing operational voltages and enhancing bias-stress stability. The subsequent ultrasonic cleaning with deionized water and UV-ozone treatment further removed contaminants. More importantly, these processes anchor hydroxyl species on the SiO₂ surface, which impart negative charges for the neutralization of surface charge states, thereby comprehensively enhancing operational performance of devices. By leveraging the distinct properties of various solvents and treatments, an optimized surface cleaning protocol was proposed, in which the threshold voltage of OFETs was reduced to nearly 0 V, and the bias-stress stability was enhanced by approximately 300%.

PMID:
40817871
Bibliographic data and abstract were imported from PubMed on 16 Aug 2025.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.