Semiconductor device and method of manufacturing the semiconductor device

A method of manufacturing a semiconductor device, comprising:

• forming a pair of first source/drain regions on a silicon substrate;
• forming an insulation layer pattern and a first silicon epitaxial layer pattern defining a gate forming region to expose the silicon substrate between the pair of first source/drain regions;
• forming a first gate insulation layer on the silicon substrate in the gate forming region;
• forming a second gate insulation layer on a sidewall of the first silicon epitaxial layer pattern;
• forming a second silicon epitaxial layer pattern in the gate forming region and on the first silicon epitaxial layer pattern;
• implanting impurities into a periphery of the second silicon epitaxial layer in the gate forming region to form a pair of second source/drain regions;
• partially etching the second silicon epitaxial layer in the gate forming region to form a second silicon epitaxial layer pattern;
• forming a third gate insulation layer that exposes a surface of the second silicon epitaxial layer pattern in the gate forming region and that covers lateral sides of the pair of second source/drain regions;
• and
• forming a gate on an exposed surface of the second silicon epitaxial layer pattern.

A semiconductor device, comprising:

• a pair of first source/drain regions disposed on a substrate;
• a first epitaxial layer pattern defining a gate forming region that exposes the substrate between the pair of first source/drain regions;
• a first gate insulation layer disposed on the substrate in the gate forming region;
• a second gate insulation layer disposed on a sidewall of the first epitaxial layer pattern;
• a second epitaxial layer pattern disposed in the gate forming region and on the first epitaxial layer pattern;
• a pair of second source/drain regions disposed on the second epitaxial layer pattern;
• a third gate insulation layer exposing the second epitaxial layer pattern in the gate forming region and covering the pair of second source/drain regions;
• and
• a gate disposed on the second epitaxial layer pattern in the gate forming region.