A method for forming a FET device is provided, the method including: forming a fin structure; while masking the fin structure from a second side of the fin structure opposite a first side of the fin structure: etching each of first and second fin parts laterally from the first side such that a set of source cavities and a set of drain cavities is formed in first non-channel layers in the first fin part and the second fin part, and subsequently, forming a source body and a drain body, each comprising a respective common body portion along the first side and a set of prongs protruding from the respective common body portion into the source and drain cavities, respectively, and abutting the channel layers; and while masking the fin structure from the first side: etching the third fin part laterally from the second side such that a set of gate cavities extending through the third fin part is formed in second non-channel layers, and subsequently, forming a gate body comprising a common gate body portion along the second side and a set of gate prongs protruding from the common gate body portion into the gate cavities.