Semiconductor device and method for manufacturing the same

A method for manufacturing a semiconductor device, comprising:

• forming a well region in a semiconductor substrate so that a portion of the semiconductor substrate over the well region forms a semiconductor layer;
• forming a plurality of mask layers on the semiconductor layer;
• forming an opening on a top one of the plurality of mask layers;
• forming another mask layer in a form of a spacer on an inner wall of the opening;
• penetrating the opening through the plurality of mask layers and the semiconductor layer to extend to the well region by utilizing the other mask layer as a hard mask;
• forming a back gate dielectric in the inner wall of the opening;
• forming a back gate conductor in the opening;
• forming an insulating cap including the other mask layer in the opening, the insulating cap covering the back gate dielectric and the back gate conductor;
• patterning the semiconductor layer into semiconductor fins by utilizing the insulating cap as a hard mask;
• forming a front gate stack intersecting the semiconductor fin, the front gate stack including a front gate dielectric and a front gate conductor, and the front gate dielectric isolating the front gate conductor from the semiconductor fin;
• and
• forming a source region and a drain region connected to a channel region provided by the semiconductor fin,
• wherein the back gate conductor, the semiconductor fins formed from the semiconductor layer at both sides of the back gate conductor, as well as the respective back gate dielectric separately isolating the back gate conductor from the semiconductor fins forming an interlayer structure,
• the insulating cap isolating the back gate conductor from the front gate conductor,
• and the well region functioning as one portion of a conductive path of the back gate conductor.