Self‐Alignment Embedded Thin‐Film Transistor with High Transparency and Optimized Performance

Abstract

Amorphous oxide semiconductor thin‐film transistors (AOS TFTs) have shown significant potential in the applications of increasingly advanced transparent and flexible electronic devices, where high speed, high transparency, and low power consumption are highly demanded. Yet, typical back‐channel etch (BCE) configuration used in the majority of TFTs still suffers from poor gate controllability, severe electrical field dispersion, relatively large parasitic capacitance and contact resistance. Here, a new embedded structure for TFTs with self‐alignment and even simpler fabrication process, outperforming conventional BCE counterpart in above aspects, is proposed in this work. More concentrated electrical field, improved gate control ability accompanied with lower contact resistance are achieved in the embedded TFTs. Consequently, superior electrical characteristics with subthreshold swing of 106.7 mV dec−1 and mobility as high as 32.10 cm2 V−1 s−1 are obtained. In addition, leakage current as well as contact resistance evidently decline compared to that in traditional BCE TFTs. By the assistance of Silvaco TCAD simulation, the performance and mechanism behind are cross‐validated from another perspective. Overall, such embedded configuration has equipped TFTs with appealing performance and it is also possible to enable other devices exploiting such structure with new possibility and thus a broader application.

Ultraflexible, High-Performance Transistors and Logic Circuits on Biocompatible Polylactic Acid (PLA) Substrate

“…Figure a,b illustrates the typical transfer curve ( I d – V g ) and output curve ( I d – V d ) of the thin-film transistor, respectively. Based on these curves, the device’s basic electrical parameters were derived, revealing a subthreshold swing (SS) of 162.8 mV/dec, an on/off current ratio of approximately 10 6 , a charge-carrier mobility of 27.81 cm 2 /(V s), and a threshold voltage ( V th ) of 1.22 V. In order to obtain high-performance devices, we have drawn upon previous work and addressed the drawbacks of the BCE TFT structure by enabling direct contact between the source–drain electrode and the low-resistance IGZO channel layer. In contrast, in the BCE TFT, the source layer and the drain layer can make contact only with the upper part of the IGZO and cannot directly contact the channel layer.…”

Effect of Tunable Sub-Source and Sub-Drain Device Behavior in Four-Terminal Operation Using Metal-Capping Thin-Film Transistors

“…Research on the application of AOSs in transparent displays, functional devices on flexible substrates, various sensors, neuromorphic devices, photodetectors, and other electronic devices has demonstrated promise for future electronic devices. TFTs based on AOSs are extensively studied for their good characteristics and integration capability through various structures. − To apply TFTs based on AOSs with various structures to next-generation applications, it is crucial to conduct research on their mechanism analysis and characterization.…”