1. A method of fabricating a variable-resistance random access memory device, comprising: forming a vertical stack of bit lines on a substrate; forming a first word line on a first sidewall of the vertical stack of bit lines by: depositing an electrically conductive layer on the vertical stack of bit lines; and patterning the electrically conductive layer to define the first word line on the first sidewall and a second word line on a second sidewall of the vertical stack of bit lines; and forming a variable resistance thin-film between the first sidewall and the first word line.