Horizontal gate-all-around device having wrapped-around source and drain

A method of forming a semiconductor device, the method comprising:

• forming a fin extending from a substrate, the fin having a plurality of first semiconductor layers and a plurality of second semiconductor layers, the first and second semiconductor layers being alternately stacked;
• forming a dummy gate stack over a channel region of the fin;
• removing portions of the first semiconductor layers from S/D regions of the fin such that first portions of the second semiconductor layers in the S/D regions each are suspended in a respective space;
• epitaxially growing a third semiconductor layer in the S/D regions, wherein the third semiconductor layer wraps around each of the first portions of the second semiconductor layers;
• removing the dummy gate stack, thereby exposing the channel region of the fin;
• removing portions of the first semiconductor layers from the channel region of the fin such that second portions of the second semiconductor layers in the channel region each are suspended in a respective space;
• and
• forming a gate stack over the channel region of the fin, wherein the gate stack wraps around each of the second portions of the second semiconductor layers.

A method of forming a semiconductor device, the method comprising:

• forming a fin over a substrate, the fin having a first semiconductor layer and a second semiconductor layer over the first semiconductor layer, the first and second semiconductor layers have different material compositions;
• forming a first gate stack over a channel region of the fin;
• removing a portion of the first semiconductor layer from a source/drain (S/D) region of the fin such that a first portion of the second semiconductor layer in the S/D region of the fin is suspended in a space;
• epitaxially growing a third semiconductor layer in the S/D region of the fin, wherein the third semiconductor layer wraps around the first portion of the second semiconductor layer, and further wherein the third semiconductor layer has a portion disposed between a remaining portion of the first semiconductor layer and the first portion of the second semiconductor layer;
• removing the first gate stack, thereby exposing the channel region of the fin;
• removing another portion of the first semiconductor layer from the channel region of the fin such that a second portion of the second semiconductor layer in the channel region of the fin is suspended in another space;
• and
• forming a second gate stack over the channel region of the fin, wherein the second gate stack wraps around the second portion of the second semiconductor layer.