Memory devices and methods of forming the same are provided. A memory device of the present disclosure includes a bottom dielectric layer, a gate structure extending vertically from the bottom dielectric layer, a stack structure, and a dielectric layer extending between the gate structure and the stack structure. The stack structure includes a first silicide layer, a second silicide layer, an oxide layer extending between the first and second silicide layers, a channel region over the oxide layer and extending between the first and second silicide layers, and an isolation layer over the second silicide layer. The first and second silicide layers include cobalt, titanium, tungsten, or palladium.