A Novel, Single-Step 3D-Printed Shadow Mask Fabrication Method for TFTs

This work presents a low-cost and scalable method for fabricating thin-film transistors (TFTs) using a single-step, 3D-printed shadow mask approach. Room temperature growth of both aluminum-doped zinc oxide (AZO) thin film was used as the semiconductor channel, and zirconium oxide (ZrO2) as the high-k dielectric, and the films were never exposed to any post-annealing treatment. Structural and morphological characterization confirmed smooth, compact films with stable dielectric behavior. Electrical measurements revealed a field-effect mobility of 13.1 cm2/V·s, a threshold voltage of ~4.1 V, and an on/off ratio of ~104, validating effective gate modulation and drain current saturation. The off-state current, estimated from AZO conductivity measurements, was ~10−10 A, while the on-state current reached ~10−6 A. Benchmarking against state-of-the-art devices shows that these transistors rival ALD-processed IGZO TFTs and significantly outperform reported indium-free ZnO/AZO devices, while avoiding scarce indium and costly high-temperature or photolithographic processing. These findings establish 3D-printed shadow masks as a practical alternative to conventional lithography for oxide TFT fabrication. The method offers high device performance with simplified, indium-free, and room-temperature processing, underscoring its potential for scalable, transparent, and flexible electronics.