Semiconductor device

A semiconductor device, comprising:

• a buried dielectric layer;
• at least two first gate structures, disposed on a front-side of the buried dielectric layer;
• at least two second gate structures, disposed on a backside of the buried dielectric layer, wherein the second gate structures are electrically coupled to each other;
• a gate contact structure, disposed on the backside of the buried dielectric layer and at backsides of the second gate structures, wherein the gate contact structure is electrically coupled to the second gate structures;
• and
• a contact plug penetrating the buried dielectric layer and electrically coupled to the gate contact structure.

A semiconductor device, comprising:

• a buried dielectric layer;
• at least two first gate structures, disposed on a front-side of the buried dielectric layer;
• at least two second gate structures, disposed on a backside of the buried dielectric layer, wherein each of the second gate structures includes a gate electrode, and work functions of the gate electrodes are different from each other;
• at least two gate contact structures, disposed on the backside of the buried dielectric layer and at backsides of the second gate structures, wherein the gate contact structures are electrically coupled to the second gate structures respectively;
• and
• a contact plug, penetrating the buried dielectric layer and electrically coupled to at least one of the gate contact structures.