Methods of forming non-volatile memory devices include forming a semiconductor layer having a first impurity region of first conductivity type extending adjacent a first side thereof and a second impurity region of second conductivity type extending adjacent a second side thereof, on a substrate. A first electrically conductive layer is also provided, which is electrically coupled to the first impurity region. The semiconductor layer is converted into a plurality of semiconductor diodes having respective first terminals electrically coupled to the first electrically conductive layer. The first electrically conductive layer operates as a word line or bit line of the non-volatile memory device. The converting may include patterning the first impurity region into a plurality of cathodes or anodes of the plurality of semiconductor diodes (e.g., P-i-N diodes).