Method for forming a fin-based field-effect transistor using opposite-side source/drain and gate cavities

Abstract

A method is provided for forming a FET device. The method includes: forming a preliminary device structure comprising a fin structure comprising a layer stack comprising channel layers and non-channel layers alternating the channel layers, and a deposited layer along a first side of the fin structure and a dummy structure along a second side of the fin structure; forming a mask line; forming along a first side of the fin structure a source and drain trench in the deposited layer; forming a set of source and drain cavities in the layer stack, by etching the fin structure from the source trench and the drain trench; forming a source body and a drain body comprising a respective common body portion a set of prongs protruding from the respective common body portion into the source and drain cavities; embedding the mask line in a cover material and removing the mask structure; forming a gate trench by etching the dummy structure; forming a set of gate cavities in the layer stack by etching the fin structure from the gate trench; and forming a gate body comprising a common gate body portion in the gate trench and a set of gate prongs protruding from the common gate body portion into the gate cavities.