Recent progress and perspectives on atomic-layer-deposited semiconducting oxides for transistor applications

This paper reviews recent developments in the fabrication of high-performance n-channel metal-oxide thin-film transistors (TFTs) through atomic-layer deposition (ALD), which are now attracting attention due to their potential for use in augmented and virtual reality, ultra-high-definition organic light-emitting diodes, and flexible electronics. Recent trends in research on TFT backplanes for display applications are provided in the introduction. In the main section, ALD-derived n-type oxides serving as active layers are classified into binary, ternary, and quaternary systems, and recent developments and critical issues in n-channel oxide TFTs are described. The performance of n-channel oxide TFTs can be boosted through advanced architectures, including stacked heterojunction channels using two-dimensional electron gases, and the introduction of high-k dielectric such as ALD-derived hafnium oxide, which is highlighted in this review. Finally, progress in p-channel ALD-derived oxide TFTs is briefly addressed with respect to complementary metal-oxide-semiconductor applications.