Method for forming gate trench of deep trench type super junction including trench gate

Abstract

The invention discloses a method for forming a grate trench of a deep trench type super junction with trench grates. The method for forming the grate trench of the deep trench type super junction with the trench grates comprises the steps of (1) forming a hard mask on a semiconductor substrate, (2) defining a deep trench area through the photolithography technology, (3) removing the hard mask on the deep trench area, using the hard mask as a barrier layer to carry out etching so as to form a plurality of deep trenches which are formed in an alternate mode, (4) filling the deep trenches with semiconductor materials, (5) carrying out back etching on the semiconductor materials until the surfaces of the semiconductor materials are lower than the tops of the deep trenches, (6) depositing oxide film on the obverse side of the semiconductor substrate, (7) carrying out back etching on the oxide film until nitride film of the hard mask is exposed, (8) removing the nitride film through the corrosion technology, keeping the oxide film on the deep trench area, and (9) using the oxide film which is arranged in an alternate mode as masks, and carrying out etching on the semiconductor substrate to form the grate trench. The method for forming the grate trench of the deep trench type super junction with the trench grates can simplify the technological process, can improve alignment accuracy of the technology of products, and can improve performance of the products.

Description

technical field [0001] The invention relates to a manufacturing process method of a semiconductor integrated circuit, in particular to a method for forming a gate trench of a deep trench type super junction containing a trench gate. Background technique [0002] The size of the existing deep trench super junction decreases with the increase of the degree of integration. When the size is close to the submicron size, the gate structure of the existing deep trench super junction needs to use a trench gate structure. In the prior art, when preparing a deep trench superjunction containing a trench gate, it is necessary to perform two photolithographic etching of the trench, which are: [0003] The first etching is to form a deep trench, and the position of the deep trench needs to be defined by a photolithography process. Fill the deep trench with epitaxial silicon or polysilicon to form alternately arranged P-type thin layers and N-type thin layers on the silicon substrate. ...

AI Technical Summary

Problems solved by technology

However, as the size of the product becomes smaller and smaller, the alignment between the two grooves becomes more and more difficult, and poor alignment will reduce the performance of the product

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