| CPC H01L 29/42356 (2013.01) [H01L 29/66666 (2013.01); H01L 29/7391 (2013.01); H01L 29/7827 (2013.01); H01L 29/78642 (2013.01); H10B 12/0335 (2023.02); H10B 12/05 (2023.02); H10B 12/30 (2023.02); H10B 12/315 (2023.02); H10B 12/482 (2023.02); H10B 41/10 (2023.02); H10B 41/27 (2023.02); H10B 41/30 (2023.02); H10B 43/10 (2023.02); H10B 43/27 (2023.02); H10B 43/30 (2023.02); H10B 51/10 (2023.02); H10B 51/20 (2023.02); H10B 51/30 (2023.02); H01L 27/1203 (2013.01)] | 15 Claims | 

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               1. A method of manufacturing a semiconductor memory device, comprising: 
            providing a stack of a sacrificial layer, a first source/drain layer, a channel layer, and a second source/drain layer on a substrate; 
                defining a plurality of pillar-shaped active regions arranged in rows and columns in the first source/drain layer, the channel layer, and the second source/drain layer; 
                after defining the plurality of pillar-shaped active regions, removing the sacrificial layer and forming a plurality of bit lines extending below the respective columns of active regions in a space left by the removal of the sacrificial layer; 
                forming gate stacks around peripheries of the channel layer in the respective active regions; and 
                forming a plurality of word lines between the respective rows of active regions, wherein each of the word lines is electrically connected to the gate stacks of the respective memory cells in a corresponding one of the rows. 
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