Methods of forming capacitor-free DRAM cells include forming a field effect transistor by forming a first semiconductor wafer having a channel region protrusion extending therefrom and surrounding the channel region protrusion by an electrical isolation region. A portion of a backside of the first semiconductor wafer is then removed to define a semiconductor layer having a primary surface extending opposite the channel region protrusion and the electrical isolation region. A gate electrode is formed on the primary surface. The gate electrode extends opposite the channel region protrusion. The source and drain regions are formed in the semiconductor layer, on opposite sides of the gate electrode.