CPC H01L 29/66818 (2013.01) [H01L 21/30604 (2013.01); H01L 21/823431 (2013.01); H01L 29/1054 (2013.01); H01L 29/161 (2013.01); H01L 29/42392 (2013.01); H01L 29/66553 (2013.01); H01L 29/6656 (2013.01); H01L 29/785 (2013.01)] | 20 Claims |
1. A method of manufacturing a semiconductor device, comprising:
forming a fin structure in which first semiconductor layers and second semiconductor layers are alternately stacked;
forming a sacrificial gate structure over the fin structure;
etching a source/drain region of the fin structure, which is not covered by the sacrificial gate structure, thereby forming a source/drain space;
laterally etching the second semiconductor layers through the source/drain space;
forming an inner spacer made of a dielectric material on an end of each of the etched second semiconductor layers; and
forming a source/drain epitaxial layer in the source/drain space to cover the inner spacer,
wherein at least one of the first semiconductor layers has a composition which changes along a stacked direction of the first semiconductor layers and second semiconductor layers.
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