Ultraviolet-Assisted Low-Thermal-Budget-Driven α-InGaZnO Thin Films for High-Performance Transistors and Logic Circuits

Developing a low-temperature fabrication strategy of an amorphous InGaZnO (alpha-IGZO) channel layer is a prerequisite for high-performance oxide-based thin film transistor (TFT) flexible device applications. Herein, an ultraviolet-assisted oxygen ambient rapid thermal annealing method (UV-ORTA), which combines ultraviolet irradiation with rapid annealing treatment in an oxygen atmosphere, was proposed to realize the achievement of high-performance alpha-IGZO TFTs at low temperature. Experimental results have confirmed that UV-ORTA treatment has the ability to suppress defects and obtain high-quality films similar to high-temperature-annealing-treated samples. alpha-IGZO/HfAIO TFTs with high-performance and low-voltage operating have been achieved at a low temperature of 180 degrees C for 200 s, including a high mu(sat) of 23.12 cm(2) V-1 S-1, large I-on/off of 1.1 x 10(8), small subthreshold swing of 0.08 V/decade, and reliable stability under bias stress, respectively. As a demonstration of complex logic applications, a low-voltage resistor-loaded unipolar inverter based on an alpha-IGZO/HfAIO TFT has been built, demonstrating full swing characteristics and a high gain of 13.8. Low-frequency noise (LFN) characteristics of alpha-IGZO/HfAIO TFTs have been presented and concluded that the noise source tended to a carrier number fluctuation (Delta N) model from a carrier number and correlated mobility fluctuation (Delta N-Delta mu) model. As a result, it can be inferred that the low-temperature UV-ORTA technique to improve alpha-IGZO thin film quality provides a facile and designable process for the integration of alpha-IGZO TFTs into a flexible electronic system.

Automated summary

This study proposes a low-temperature fabrication strategy for high-performance alpha-IGZO TFTs using an ultraviolet-assisted oxygen ambient rapid thermal annealing method (UV-ORTA). The experimental results show that the UV-ORTA treatment effectively suppresses defects and produces high-quality films similar to those treated at high temperatures. The alpha-IGZO/HfAIO TFTs fabricated using this method exhibit high-performance and low-voltage operation at a low temperature of 180 degrees C. A low-voltage resistor-loaded unipolar inverter based on the alpha-IGZO/HfAIO TFT demonstrates full swing characteristics and a high gain of 13.8.