Aspects of the present disclosure provide a method of fabricating a semiconductor device. For example, the method can include providing a substrate. The substrate can include a first type region and a second type region. The method can also include forming a multilayer stack on the substrate. The multilayer stack can include alternate metal layers and dielectric layers. The method can also include forming first and second openings through the multilayer stack to uncover the first and second type regions, respectively. The method can also include forming first and second vertical channel structures within the first and second openings, respectively. Each of the first and second vertical channel structures can have source, gate and drain regions being in contact with vertical sidewalls of the metal layers of the multilayer stack uncovered by a respective one of the first and second openings.