In this study, the current driving capability of PN diodes and field effect transistors (FETs) for phase change memory (PCM) applications is investigated. To have a fair comparison, vertical gate-all-around (GAA) MOSFETs with similar cross-section as the PN diodes are selected for comparison. Through extensive 3-D device simulations have been performed based on existing experimental data from the 90 nm to 22 nm technology node, PN diodes are found to be a better choice for delivering higher programming currents down to 22 nm technology node due to the higher effective cross-sectional area of current flow. In addition, the GAA MOSFETs are subject to serious cross-talk issues that may limit their performance in PCM applications.