Semiconductor device, method of manufacturing the same, and method of evaluating semiconductor device

A semiconductor device comprising:

• a silicon substrate;
• a gate insulating film formed on the silicon substrate;
• a gate electrode formed on the gate insulating film;
• a source/drain region formed in the silicon substrate;
• a SiGe layer formed in a hole in the source/drain region;
• a sidewall formed on the side of the gate electrode,
• an insulating film formed over the gate electrode and the SiGe layer;
• and
• a conductive plug formed in the insulating film and electrically connected to the SiGe layer, wherein
• a first side surface of the hole is located under the sidewall,
• the SiGe layer is located under the sidewall and is not located under the gate electrode;
• the first side surface includes two crystal planes,
• a cross-sectional shape of the first side surface is concave,
• each of the two crystal planes of the first side surface is defined by a (111) plane of the silicon substrate, and
• an upper surface of the SiGe layer is located higher than an interface between the silicon substrate and the gate insulating film.