Ldmos and fabricating method of the same

A fabricating method of a laterally diffused metal oxide semiconductor (LDMOS), comprising:

• providing a substrate, wherein a dielectric layer covers the substrate, a dummy gate is disposed on the substrate, and a gate dielectric layer is disposed between the substrate and the dummy gate;
• removing the dummy gate to form a recess in the dielectric layer;
• forming a composite structure to fill the recess and cover the dielectric layer, wherein the composite structure comprises a high dielectric material layer, a first work function layer and a second work function layer stacked sequentially from bottom to top;
• forming a metal gate disposed in the recess, wherein two spacers are respectively disposed at a first side and a second side of the metal gate, and the first side and the second side are opposite to each other;
• forming a cap layer covering the metal gate and the composite structure;
• forming a mask layer to cover the metal gate and part of the composite structure at the second side;
• removing the composite structure not covered by the mask layer;
• and
• completely removing the mask layer.

A fabricating method of a laterally diffused metal oxide semiconductor (LDMOS), comprising:

• providing a substrate, wherein a dielectric layer covers the substrate, a dummy gate is disposed on the substrate, and a gate dielectric layer is disposed between the substrate and the dummy gate;
• forming a mask layer to cover the dummy gate and the dielectric layer disposed at one side of the dummy gate;
• removing part of the dielectric layer not covered by the mask layer and disposed at the other side of the dummy gate to form a first recess in the dielectric layer;
• completely removing the mask layer;
• removing the dummy gate to form a second recess in the dielectric layer;
• forming a composite structure covering the first recess, the second recess and the dielectric layer, wherein the composite structure comprises a high dielectric material layer, a first work function layer and a second work function layer stacked sequentially from bottom to top;
• form a metal material layer to cover the composite structure;
• and
• removing the metal material layer disposed outside of the second recess, and removing the composite structure disposed outside of the first recess and the second recess, wherein the metal material layer which remains serves as a metal gate.