Compact modeling of thin film transistors for flexible hybrid IoT design

Flexible Electronics (FE) is emerging for low-cost, light-weight wearable electronics, artificial skins and IoT nodes, benefiting from its low-cost fabrication and mechanical flexibility. Combining FE with thinned silicon chips, known as flexible hybrid electronics (FHE), can take advantages of both low-cost printed electronics and high performance silicon chips, which brings together flexible form factors and IoT innovations. Thin film transistors (TFTs), as a critical component for FHE applications, have achieved tremendous improvements in charge carrier mobility, device stability and scalability; however, an accurate compact model for TFTs which can capture fundamental behaviors of TFTs and be broadly applicable to multiple flexible technologies is still missing for circuit and system design. Such a model is crucial for designing flexible hybrid IoT (Flex-IoT) in order to enable design explorations and technology evaluations. In this paper, we present a SPICE-compatible unified compact model covering DC, AC and technology scaling of TFTs for Flex-IoT designs. We validated the presented model for three different types of TFT technologies and performed circuits-level investigations based on fabricated Pseudo-CMOS circuits. We demonstrate that the presented TFT model can provide accurate and trustworthy predictions for circuit evaluation and Flex-IoT system design.Peer reviewed: YesNRC publication: Ye