Structure of a semiconductor integrated circuit and method of manufacturing the same

A method of manufacturing a semiconductor integrated circuit in which a CMOS transistor is formed on a semiconductor film of a first conductivity type formed on a support substrate of a first conductivity type via a buried insulating film, comprising:

• forming at least one contact hole in a source-body-tie region adjacent to a body region under a source region and a gate electrode of a transistor so that the contact hole reaches a part of the support substrate through the semiconductor film and the buried insulating film on the support substrate, together with alignment marks;
• forming a thermal oxide film on an inner side of the contact hole on the semiconductor film;
• forming impurity regions of a second conductivity type in regions where transistors of a first conductivity type and a second conductivity type are to be formed, which reach an inner portion of the support substrate under the buried insulating film;
• performing thermal diffusion on the impurity regions of a second conductivity type;
• forming an impurity region of a first conductivity type in a region where a transistor of a second conductivity type is to be formed, which reaches the buried insulating film on the semiconductor film;
• forming an impurity region of a first conductivity type in a portion on the support substrate and opposing the impurity region of a first conductivity type with respect to the buried insulating film;
• forming an impurity region of a second conductivity type in a region where a transistor of a first conductivity type is to be formed, which reaches the buried insulating film on the semiconductor film;
• forming a gate oxide film, a gate electrode, a source region, and a drain region after separating elements, and forming an interlayer insulating film;
• forming contacts of the source region and the drain region, and simultaneously, etching the interlayer insulating film so as to be concentric with the contact hole and to have a size surrounding the contact hole;
• and
• forming a wiring on the interlayer insulating film.