Design of Atomic Layer Deposited Oxide Channel Transistor for High-Performance, High-Pixel Density AMOLED

Abstract

Metal oxide thin-film transistors (TFTs) are used as switches for AMOLED screen of the state-of-art smart phones where the pixel driver is driven by low-temperature polycrystalline silicon TFTs. So-called low-temperature-polysilicon-oxide (LTPO) in the high-end mobile AMOLED benefits the low-power-consumption operation because the extremely small leakage current of oxide TFTs allows the frame-rate variable operation depending on the picture content. However, the three-dimensional structural complexity and, thus, high panel cost of LTPO backplane are a major concern. High-performance metal oxide TFTs can be a strongly backplane candidate for such high-end mobile AMOLED. In this paper, the design of oxide semiconductor on basis of atomic layer deposition for high-performance, high-pixel density AMOLED was described. The 2DEG concept can be demonstrated in ALD-based oxide TFTs, which renders the exceptional high field-effect mobility (>70 cm2/Vs) and excellent PBTS/NBTS stability.