Printed indium gallium zinc oxide transistors. Self-assembled nanodielectric effects on low-temperature combustion growth and carrier mobility

Solution-processed amorphous oxide semiconductors (AOSs) are emerging as important electronic materials for displays and transparent electronics. We report here on the fabrication, microstructure, and performance characteristics of inkjet-printed, low-temperature combustion-processed, amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) grown on solution-processed hafnia self-assembled nanodielectrics (Hf-SANDs). TFT performance for devices processed below 300 C includes >4× enhancement in electron mobility (μ_FE) on Hf-SAND versus SiO₂ or ALD-HfO₂ gate dielectrics, while other metrics such as subthreshold swing (SS), current on:off ratio (I_ON:I_OFF), threshold voltage (V_th), and gate leakage current (I_g) are unchanged or enhanced. Thus, low voltage IGZO/SAND TFT operation (<2 V) is possible with I_ON:I_OFF = 10⁷, SS = 125 mV/dec, near-zero V_th, and large electron mobility, μ_FE(avg) = 20.6 ± 4.3 cm² V^-1 s^-1, μ _FE(max) = 50 cm² V^-1 s^-1. Furthermore, X-ray diffraction analysis indicates that the 300 C IGZO combustion processing leaves the underlying Hf-SAND microstructure and capacitance intact. This work establishes the compatibility and advantages of all-solution, low-temperature fabrication of inkjet-printed, combustion-derived high-mobility IGZO TFTs integrated with self-assembled hybrid organic-inorganic nanodielectrics.