Semiconductor device including a semiconductor extension layer between active regions

A semiconductor device, comprising:

• a first active region and a second active region, which are disposed in a semiconductor substrate and have side surfaces facing each other;
• an isolation pattern disposed between the first and second active regions;
• a semiconductor extension layer disposed between the first and second active regions;
• a first source/drain semiconductor layer disposed on the first active region;
• and
• a second source/drain semiconductor layer disposed on the second active region;
• wherein the first source/drain semiconductor layer is disposed in a first recessed area in the first active region;
• and
• wherein a level of an upper end of the semiconductor extension layer is higher than a level of a bottom of the first recessed area relative to the semiconductor substrate.

A semiconductor device, comprising:

• a first active region and a second active region, which are disposed in a semiconductor substrate and have side surfaces facing each other;
• an isolation pattern disposed between the first and second active regions;
• a semiconductor extension layer disposed between the first and second active regions;
• a first source/drain semiconductor layer disposed on the first active region;
• and
• a second source/drain semiconductor layer disposed on the second active region;
• wherein the first source/drain semiconductor layer is disposed in a first recessed area in the first active region;
• and
• wherein a level of a bottom of the semiconductor extension layer is lower than a level of a bottom of the first recessed area relative to the semiconductor substrate.