Manufacturing method for groove grid power device and structure

Abstract

The invention discloses a manufacturing method for a groove grid power device. Formation steps of each cell of a conduction region comprise that a hard mask layer is formed, and a groove is formed through photolithographic etching; a grid medium layer and a polysilicon grid are formed in the groove; an opening of the hard mask layer is enlarged through isotropic etching, and a self-aligning column is formed; a body region is formed; a source region is formed; deposition of an interlayer film is carried out; chemical mechanical grinding planarization for the interlayer film is carried out to the surface of the top portion of the self-aligning column; an opening of a contact hole at the top portion of the source region formed at the self-aligning column is removed; and metal is filled into the contact hole. The invention further discloses a groove grid power device. According to the manufacturing method, self-aligning definition of the contact hole can be realized, registration redundancy is not needed to consider, the contact hole does not require the exposure technology, manufacturing cost is saved, so threshold voltage stability of the device can be improved, unit dimensions of the device are reduced, and conduction resistance is reduced.

Description

technical field [0001] The present invention relates to a method for manufacturing a semiconductor integrated circuit, in particular to a method for manufacturing a trench gate power device. The invention also relates to a trench gate power device. Background technique [0002] In the manufacturing method of the existing trench gate power device, the conduction region of the device is composed of a plurality of original cells, that is, a unit structure (cell) arranged to form a parallel structure, and the source region in the original cell is formed by general injection, that is, full injection. Contact holes need to be etched through the source region to connect the body region at the bottom of the source region. In the actual process, the registration redundancy of the contact hole and the trench should be considered, and the gap between the contact hole and the trench should be large enough to prevent problems such as threshold voltage drift caused by the exposure and of...

AI Technical Summary

Problems solved by technology

This limits the possibility of reducing the on-resistance by reducing the size of the platform between the trenches. The size of the platform between the trenches is also the distance between the trenches, that is, the width of the epitaxial layer between the trenches.

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