Manufacturing method of trench type SGT-MOS device with low electric leakage and high stability

Abstract

The invention provides a trench type SGT-MOS device with low electric leakage and high stability. A plurality of trenches (12) with built-in polycrystalline solids (15) are arranged at an epitaxial layer (1) of the device; the polycrystalline solids are of an I-shaped structure; insulating layers attached to the polycrystalline solids are arranged at the bottom and on the inner side walls of the grooves; the top of an insulating layer at the inner side wall of each groove is lower than the epitaxial layer, so that the insulating layers, the epitaxial layer and the side walls of the polycrystalline solids form two medium grooves (18) at the side walls of the I-type polycrystalline solids; and each insulating layer is a combined structure comprising a first insulating structure (13) and a second insulating structure (14). According to the invention, the problems of non-uniform dielectric thickness, difficult thickness control and large electric leakage of a grid electrode and a source electrode when the dielectric grows in dielectric grooves at the two sides in the device are solved.

Description

technical field [0001] The invention relates to the field of electronic components, in particular to a method for manufacturing a trench type SGT-MOS device with low leakage and high stability. Background technique [0002] Separate gate trench type Mosfet SGT usually adopts a small-scale trench structure (trench width and depth) close to the process limit to make full use of the active area and current path. First, trenches are etched on the epitaxial layer, followed by thermal growth of a certain thickness of silicon dioxide on the sidewalls and bottom of the trenches; doped polysilicon is filled and etched back to the silicon surface at the top of the trenches, and the remaining polysilicon stands on the trenches Between the silicon dioxide in the tank, the shape is similar to the English letter "I". A dielectric tank is made on the left and right sides, filled with polycrystalline and etched back, and finally conductive metal deposition and so on. [0003] However, for ...

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Problems solved by technology

[0004] The invention proposes a method for manufacturing a trench type SGT-MOS device with low leakage and high stability, which improves the uneven thickness of the medium when the dielectric grooves on both sides of the device grow medium, the thickness is not easy to control, and the gate and source The problem of large leakage

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