Integrated circuit device

An integrated circuit device comprising:

• a fin-type active region on a substrate and extending in a first horizontal direction;
• a recess formed in the fin-type active region;
• a pair of nanosheet stacks on a fin top of the fin-type active region, the pair of nanosheet stacks being separated from each other in the first horizontal direction with a recess formed therebetween;
• a pair of gate lines on the fin-type active region, each gate line surrounding a corresponding one of the pair of nanosheet stacks, and extending in a second horizontal direction that is different from the first horizontal direction;
• and
• a source/drain region in the recess and in contact with each one of the pair of nanosheet stacks,
• wherein the source/drain region includes a lower main body layer and an upper main body layer, the lower and upper main body layers being sequentially stacked in the recess in the vertical direction,
• wherein a top surface of the lower main body layer includes a pair of lower facets each declining toward the substrate as it extends in a direction from one of the pair of nanosheet stacks to a center of the source/drain region,
• wherein the upper main body layer includes a bottom surface contacting the pair of lower facets and a top surface having an upper facet,
• wherein with respect to a vertical cross section, each lower facet extends along a corresponding first line, the upper facet extends along a second line, and
• wherein each first line and the second line intersect each other.

An integrated circuit device comprising:

• a fin-type active region on a substrate and extending in a first horizontal direction;
• a recess formed in the fin-type active region;
• a pair of nanosheet stacks on a fin top of the fin-type active region, the pair of nanosheet stacks being separated from each other in the first horizontal direction, with the recess therebetween;
• and
• a source/drain region in the recess and in contact with each one of the pair of nanosheet stacks,
• wherein the source/drain region includes a lower main body layer and an upper main body layer, the lower and upper main body layers being sequentially stacked in the recess in the vertical direction and each including an Si1-xGex layer, where 0.15≤x<0.7,
• wherein the lower main body layer has a first Ge concentration, and a top surface of the lower main body layer includes a pair of lower facets each declining toward the substrate as it extends in a direction from a corresponding one of the pair of nanosheet stacks to a center of the source/drain region,
• wherein the upper main body layer has a Ge concentration higher than the first Ge concentration and includes a bottom surface contacting the pair of lower facets and a top surface having an upper facet,
• wherein with respect to a vertical cross section, each lower facet extends along a corresponding first line, the upper facet extends along a second line, and
• wherein each first line and the second line intersect each other.