Vertical-channel charge-trap memory thin film-transistors (V-CTM TFTs) using oxide semiconductors were fabricated and characterized, in which In-Ga-Zn-O (IGZO) channels were prepared by sputtering and atomic-layer deposition (ALD) methods to elucidate the effects of deposition process. The vertical-channel gate stack of the fabricated device was verified to be well implemented on the vertical sidewall of the spacer patterns due to excellent step-coverage and self-limiting mechanisms of ALD process. The V-CTM TFTs using ALD-IGZO channel exhibited a wide memory window (MW) of 15.0 V at a VGS sweep of ±20 V and a large memory margin of 1.6 × 102 at a program pulse duration as short as 5 ms. The programmed memory margin higher than 105 did not experience any degradation with time evolution for 104 s. The mechanical durability was also evaluated after the delamination process of polyimide (PI) film. There were no marked variations in charge-trap-assisted MW even at a curvature radius of 1 mm and programmed memory margin even after repeated program operations of 104 cycles. The introduction of ALD process for the formation of IGZO active channel was suggested as a main process parameter to ensure the excellent memory device characteristics of the V-CTM TFTs.