Semiconductor device with a fin-shaped active region and an gate electrode

A semiconductor device comprising:

• a substrate including a first region and a second region;
• a channel region including a fin-shaped active region and a nanosheet stacked structure on the fin-shaped active region, the fin-shaped active region including germanium and protruding from each of the first region and the second region of the substrate;
• a gate electrode covering the channel region in each of the first region and the second region of the substrate;
• one pair of first source/drain regions on the fin-shaped active region in the first region, the one pair of first source/drain regions including a group III-V compound semiconductor material or a group II-VI compound semiconductor material having a lattice constant that is higher than a lattice constant of the group IV semiconductor material of the fin-shaped active region;
• one pair of second source/drain regions on the fin-shaped active region in the second region, the one pair of second source/drain regions including a group IV semiconductor material;
• and
• a buffer layer located between the fin-shaped active region and the one pair of first source/drain regions, the buffer layer including an upper buffer layer on a lower buffer layer,
• wherein the lower buffer layer including a group III-V compound semiconductor material or a group II-VI compound semiconductor material that is amorphous, and
• the upper buffer layer including a compound semiconductor material including first atoms and second atoms from different groups, the second atoms having greater atomic radii than the first atoms, a ratio of the first atoms to the second atoms decreases from bottom to top of the upper buffer layer.

A semiconductor device comprising:

• a channel region including a fin-shaped active region that extends in a first direction and a nanosheet stacked structure on the fin-shaped active region, the fin-shaped active region including silicon or germanium;
• a source region and a drain region spaced apart from each other on the fin-shaped active region, the source region and the drain region each including a source/drain compound semiconductor material including source/drain atoms from different groups;
• a lower buffer layer between the fin-shaped active region and the source region and the drain region, the lower buffer layer including a lower buffer compound semiconductor material that is amorphous and includes lower buffer atoms from different groups;
• and
• a gate structure covering the channel region between the source region and the drain region, the gate structure extending in a second direction that crosses the first direction.