Semiconductor apparatus

A semiconductor apparatus includes a bit line extending in a first horizontal direction on a substrate; a channel layer on the bit line, the channel layer extending in a vertical direction, including a first oxide semiconductor material that includes indium, and having a first side wall and a second side wall; a word line on the first side wall of the channel layer; a contact forming region on a top surface and an upper portion of the second side wall of the channel layer, the contact forming region including a second oxide semiconductor material that includes indium and having a resistivity lower than a resistivity of the channel layer; a contact layer on the contact forming region; and a capacitor structure on a top surface of the contact layer.