High-performance flexible oxide TFTs: optimization of a-IGZO film by modulating the voltage waveform of pulse DC magnetron sputtering without post treatment

Abstract

We propose a facile and scalable approach to fabricate high performance flexible a-IGZO thin film transistors (TFTs) by adopting the waveform modulation of pulse DC magnetron sputtering (PDCMS) to rationally optimize the film quality of semiconductors without post treatment. The voltage waveform was modulated by rationally altering the frequency and duty cycles, and, consequently, an optimum film quality of a-IGZO film was obtained that resulted in the outstanding performance of the flexile oxide TFTs. A series of characterizations (TEM, XRR AFM, XPS, μ-PCD etc.) were carried out to understand the mechanism of a-IGZO semiconductor film growth. The flexible TFT with an optimum a-IGZO film exhibited a mobility (μ_sat) of 20.9 cm² V⁻¹ s⁻¹ and good stability under bending strain. This work provides an alternative approach to fabricate high performance flexible a-IGZO TFTs on an industrial scale.