Manufacturing method of dielectric layer

The invention relates to the technical field of back-end processes of semiconductor integrated circuits, in particular to a manufacturing method of a dielectric layer. The manufacturing method of the dielectric layer comprises the following steps: providing a semiconductor bottom layer, wherein the surface appearance of the semiconductor bottom layer fluctuates to form a gap; depositing and forming a first TEOS layer on the surface of the semiconductor bottom layer at a first deposition rate according to the surface appearance of the semiconductor bottom layer; depositing on the first TEOS layer at a second deposition rate to form a second TEOS layer; the first deposition rate is smaller than the second deposition rate, and the gap is filled with the first TEOS layer and the second TEOS layer. According to the manufacturing method of the dielectric layer, the problem that the contour of the contact hole is not uniform due to different etching rates of the film layers in the insulating dielectric layer can be