Semiconductor device and method of manufacturing the same

A semiconductor device comprising:

• a semiconductor substrate;
• a first insulating film formed over an upper surface of the semiconductor substrate;
• a silicon layer formed over the first insulating film;
• a protective film formed over the silicon layer;
• a groove formed in the protective film, the silicon layer, and the first insulating film starting from a top surface of the protective film and so as to reach the upper surface of the semiconductor substrate;
• a seed layer formed over portions of inner side surfaces of the groove;
• a germanium layer embedded in the groove;
• and
• a second insulating film formed over the germanium layer and the protective film,
• wherein the germanium layer is in contact with the upper surface of the semiconductor substrate exposed at a bottom of the groove and is in contact with the seed layer.

A method of manufacturing a semiconductor device, comprising the steps of:

• (a) preparing a SOI substrate including a semiconductor substrate, a first insulating film formed over an upper surface of the semiconductor substrate, and a silicon layer of a first conductivity type over the first insulating film;
• (b) forming a protective film over the silicon layer;
• (c) processing the protective film, the silicon layer, and the first insulating film in sequence so as to form a groove in the protective film, the silicon layer, and the first insulating film, starting from a top surface of the protective film and without reaching the upper surface of the semiconductor substrate;
• (d) forming a seed layer over the protective film and inner a bottom and side surfaces of the groove;
• (e) removing the seed layer formed over the protective film so as to leave the seed layer formed over the bottom and side surfaces of the groove;
• (f) forming a germanium layer in the groove by epitaxial growth;
• and
• (g) forming a second insulating film over the germanium layer and the protective film.