Method for forming a fet device

Abstract

A method for forming a FET device is provided. The method includes: forming a fin structure comprising a layer stack comprising channel layers and non-channel layers alternating the channel layers; etching each of first and second fin parts from each of first and second opposite sides of the fin structure such that a set of source cavities extending through the first fin part is formed in a first set of layers of the layer stack, and such that a set of drain cavities extending through the second fin part is formed in the first set of layers of the layer stack; filling the source and drain cavities with a dummy material; while masking the fin structure from the second side: removing the dummy material by etching from the first side, and subsequently, forming a source body and a drain body, each comprising a respective common body portion and a set of prongs protruding from the respective common body portion into the source and drain cavities, respectively; and while masking the fin structure from the first side: etching a third fin part from the second side such that a set of gate cavities extending through the third fin part is formed in a second set of layers, and subsequently, forming a gate body comprising a common gate body portion and a set of gate prongs protruding from the common gate body portion into the gate cavities.