Nano-Scale Ga₂O₃ Interface Engineering for High-Performance of ZnO-Based Thin-Film Transistors

Abstract

Thin-film transistor (TFT) is a essential device for future electronics driving the next level of digital transformation. The development of metal-oxide-semiconductor (MOS) TFTs is considered one of the most advantageous devices for next-generation, large-area flexible electronics. This study demonstrates the systematic study of the amorphous gallium oxide (a-Ga2O3) and its application to nanocrystalline ZnO TFTs. The TFT with a-Ga2O3/c-ZnO-stack channel exhibits a field-effect mobility of ∼41 cm2 V–1 s–1 and excellent stability under positive-bias-temperature stress. The a-Ga2O3/c-ZnO-stack TFT on polyimide (PI) substrate exhibits a negligible threshold voltage shift upon 100k bending cycles with a radius of 3 mm and is very stable under environmental test. The smooth morphology with tiny grains of ∼12 nm diameter with fewer grain boundary states improves the charge transport in Ga2O3/ZnO-stack TFT. The existence of amorphous a-Ga2O3 in between very thin ZnO layers helps to enhance the heterointerfaces and reduce the defect density in Ga2O3/ZnO interface. Therefore, integrating a-Ga2O3 in the ZnO channel in stacked TFT can increase mobility and enhance stability for next-generation flexible TFT electronics.

Deep Ultraviolet Detector Based on Low-Temperature Fabricated ZnO/Ga2O3 Heterojunction

“…To address this issue, researchers have composed Ga 2 O 3 with other metal compounds to form heterojunction devices, achieving promising results [15][16][17] . Among them, ZnO, with its high electron mobility, low preparation temperature, and good response to the day-blind wavelength range, has shown good results in Ga 2 O 3 /ZnO heterojunction devices [18] .…”

As-Grown Crystalline InGaZnO by Spray Pyrolysis on a Flexible Substrate for a Thin-Film Transistor with Excellent Stability

“…Therefore, extensive research has been conducted on solution-processed MOS TFTs. The popular methods for the solution process are spray pyrolysis, spin coating, and inkjet printing. − Among them, the spray pyrolysis method is promising because of the advantage of large-area uniformity . Note that the spray pyrolysis method eliminates the need for additional thermal annealing for crystallization.…”

High‐performance, coplanar amorphous InGaZnO thin‐film transistors by spray pyrolysis on polyimide substrate for low‐cost manufacturing of foldable active‐matrix organic light emitting diode display

“…There is of increasing interest in high mobility with excellent stability, thin‐film transistors (TFTs) for high‐resolution and large‐area flexible active‐matrix organic light emitting diode (AMOLED) display 1 . As an active layer of TFT, metal oxide semiconductors such as InGaZnO (IGZO), InZnSnO (IZTO), and ZnO are widely used 2–4 . Among them, amorphous IGZO (a‐IGZO) TFT is the most popular for display backplane 5 …”

“…1 As an active layer of TFT, metal oxide semiconductors such as InGaZnO (IGZO), InZnSnO (IZTO), and ZnO are widely used. [2][3][4] Among them, amorphous IGZO (a-IGZO) TFT is the most popular for display backplane. 5 The reactive sputtering, atomic layer deposition (ALD), spin coating, and spray pyrolysis are popular deposition techniques for a-IGZO for display TFT backplanes.…”