High-performance vacuum-processed metal oxide thin-film transistors: A review of recent developments

Since 2010, vacuum-processed oxide semiconductors have greatly improved with the publication of more than 1,300 related papers. Although the number of researches on oxide semiconductors has continued to increase year by year, the average field-effect mobility of oxide semiconductor thin-film transistors (TFTs) has not shown significant improvement; from 2010 to 2018; the average field-effect mobility of vacuum-processed n-type oxide TFTs is around 20 cm²/Vs. To investigate the obstacles for performance improvements, the latest progress and researches on vacuum-processed oxide semiconductor TFTs for high performance over the past decade are highlighted, along with the pros and cons of each technology. Finally, complementary metal oxide semiconductor (CMOS) logic circuits composed of both n- and p-type oxide semiconductor TFTs are introduced, and future prospects for this state-of-the-art research on the oxide semiconductors are presented.