2d semiconductor device and fabrication method therefor

A 2D semiconductor device, comprising a substrate, a two-dimensional (2D) semiconductor material layer disposed on the substrate, and a gate structure disposed on the 2D semiconductor material layer, the gate structure comprising a gate dielectric layer and a gate electrode layer above the gate dielectric layer, wherein the gate dielectric layer comprises a portion covered by a bottom of the gate electrode layer and portions not covered by the bottom of the gate electrode layer, and the portions not covered by the bottom of the gate electrode layer extend outward along a surface of the 2D semiconductor material layer, respectively;

• the portions of the gate dielectric layer not covered by the bottom of the gate electrode layer and both sides of the gate electrode layer are covered with spacers;
• support layers made of a low dielectric constant material are disposed on surfaces of the spacers;
• and tops of the support layers, the spacers, and the gate electrode layer are coplanar, and source and drain metal contact layers vertically penetrate through the support layers, the spacers located on a surface of the gate dielectric layer, the 2D semiconductor material layer, and the substrate.