Soi device having an increasing charge storage capacity of transistor bodies and method for manufacturing the same

An SOI device comprising:

• an SOI substrate having a stacked structure including a buried oxide layer and a first silicon layer sequentially stacked on a silicon substrate and the SOI substrate having grooves defined therein whose depth extends from an upper surface of the first silicon layer to a partial depth of the buried oxide layer, wherein the partial depth of the buried oxide layer is less than that of a thickness of the buried oxide layer, wherein each of the grooves has a bulbous-shaped section by forming the grooves using a vertical shaped groove and a substantially spherical shaped groove that is mated to a lower end of the vertical shaped groove;
• an insulation layer formed only on a lower end of the vertical shaped groove, wherein the insulation layer is only on the lower end of the vertical shaped groove because a spacer on an upper end of the vertical shaped groove prevents the insulation layer from being formed on the upper end of the vertical shaped groove;
• a second silicon layer as a body of the SOI device formed to fill the grooves that have the insulation layer formed therein;
• gates formed on the second silicon layer;
• and
• junction regions formed in the first silicon layer on both sides of the gates to contact the insulation layer and the buried oxide layer, such as the second silicon layer is floated by the presence of the junction regions and the buried oxide layer.