Trench gate structure and manufacturing method thereof

Abstract

The invention relates to a trench gate structure and a manufacturing method thereof. The trench gate structure includes a substrate, a trench on the surface of the substrate, an insulating pad on the substrate, a gate oxide layer on the inner surface of the trench, and a polysilicon gate on the gate oxide layer. The liner is adjacent to the groove through its own slope structure, and the polysilicon gate extends from the groove along the slope structure to the insulating liner, and the insulating liner includes The concave polysilicon gate pull-up region, the polysilicon gate protruding from the trench rides on the polysilicon gate pull-up region. The polysilicon gate in the trench of the present invention is relatively independent from the part extending to the insulating substrate, so the depth of the trench and the depth of the contact hole do not constrain each other. The photolithography step of the polysilicon gate is carried out in the same step as the polysilicon photolithography of the device, and no additional photolithography plate (mask) and photolithography layers are required, so the cost in this aspect will not be increased.

Description

technical field [0001] The invention relates to semiconductor manufacturing technology, in particular to a trench gate structure and a manufacturing method of the trench gate structure. Background technique [0002] Due to cost reasons, traditional trench-type vertical double-diffused metal-oxide-semiconductor field effect transistor (VDMOS) products mostly adopt the method of increasing the end size of the lead-out trench and punching contact holes on it to lead out the trench gate structure. ,Such as figure 1 shown. The advantage of this solution is that it can use the existing mask layer of the product process, without increasing the cost of the mask layer. However, its disadvantage is that it is limited by the technology such as trench depth, polysilicon thickness, and contact hole depth, which limits the application of this traditional solution. Contents of the invention [0003] Based on this, it is necessary to provide a relatively more flexible trench gate struc...

AI Technical Summary

Problems solved by technology

However, its disadvantage is that it is limited by the technology of trench depth, polysilicon thickness, contact hole depth, etc., which limits the application of this traditional solution.

Images