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Tuning the Threshold Voltage of an Oxide Thin-Film Transistor by Electron Injection Control Using a p-n Semiconductor
Jung Hoon Han1,2, Dong Yeob Shin3, Chihun Sung1
1Flexible Electronic Device Research Division, Electronics and Telecommunications Research Institute, 218, Yuseong-gu, Daejeon 34129, Korea.
ACS Applied Materials & Interfaces
|June 10, 2024
Summary
This study introduces a novel heterojunction structure using tellurium (Te) and aluminum-doped indium-zinc-tin oxide (Al:IZTO) to precisely control the threshold voltage (VT) of thin-film transistors (TFTs). The optimized design demonstrates excellent stability and endurance for advanced semiconductor applications.
Area of Science:
- Materials Science
- Semiconductor Physics
- Device Engineering
Background:
- Oxide thin-film transistors (TFTs) are crucial for electronic displays and flexible electronics.
- Precise control over threshold voltage (VT) is essential for TFT performance and stability.
- Developing new heterojunction structures is key to enhancing TFT characteristics.
Purpose of the Study:
- To design and investigate a novel heterojunction structure for precise threshold voltage (VT) modulation in oxide TFTs.
- To explore the effects of a p-type tellurium (Te) layer integrated with n-type aluminum-doped indium-zinc-tin oxide (Al:IZTO).
- To evaluate the stability and durability of the fabricated TFTs under operational stress.
Main Methods:
- Fabrication of oxide TFTs with a heterojunction structure comprising Te and Al:IZTO layers.
- Utilizing X-ray photoelectron spectroscopy (XPS) to analyze oxygen vacancies and energy band structures.
- Modulating the Te layer's thickness and deposition methods (single/double) to optimize performance.
- Conducting positive bias stress tests to assess device stability.
Main Results:
- Achieved a significant threshold voltage (VT) shift of up to +20 V by modulating the Te heterojunction layer.
- Demonstrated excellent stability under positive bias stress (+2 MV/cm for 10,000 s) without passivation.
- Confirmed the impact of the Al:IZTO/Te interface on VT control and device endurance.
- Showcased the robustness, durability, and stability of the optimized TFTs.
Conclusions:
- The integrated Te/Al:IZTO heterojunction structure effectively modulates the threshold voltage (VT) of oxide TFTs.
- The optimized TFTs exhibit remarkable stability and endurance, suitable for demanding applications.
- This approach offers a promising pathway for developing tailored semiconductor devices with enhanced performance.
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