We successfully demonstrated a two-deck structure selectoronly memory (SOM) based on a 16 nm half-pitch, achieving endurance exceeding 107 cycles at raw bit error rate (RBER) 200 ppm through process, structure, and design strategies. Our findings reveal that SOM endurance is not only influenced by process factors such as dual functional material (DFM) and encapsulation but also strongly depends on the spike charge. This underscores the importance of both spike charge suppression and process optimizations to enhance SOM performance.