Method for manufacturing gate structure

Abstract

The invention relates to a method for manufacturing a gate structure. The method comprises the following steps of: providing a substrate; forming a gate dielectric layer on the substrate; depositing a sacrificial layer on the gate dielectric layer; etching the sacrificial layer to form a groove which is exposed out of the gate dielectric layer, and then depositing a gate conductive layer on the surface of the formed structure; etching the gate conductive layer from top to bottom through an anisotropic etching process until the sacrificial layer is exposed; and removing the sacrificial layer to obtain the gate structure. The method provided by the invention realizes the manufacturing of the gate structure by adopting a side wall forming process, and is especially suitable for being used for manufacturing gate structures of smaller sizes, particularly double-gate structures of smaller sizes.

Description

technical field [0001] The invention belongs to the technical field of semiconductor integrated circuit manufacturing technology, and in particular relates to a method for manufacturing a gate structure. Background technique [0002] In integrated circuit technology, the size of key graphics such as gate is an important index to measure the performance of semiconductor devices. The formation of the gate structure generally adopts the method of lithography plus etching. However, when the size of the gate is reduced to below 50nm, even if Resolution Enhancement Technology (RET) is adopted, the traditional lithography method cannot meet the process requirements. [0003] At present, lithography at the key level of the technology generation below 45nm will use immersion (Emersion) lithography or double patterning (Double Patterning). These technologies require expensive equipment or special technological processes, which are costly, complicated and difficult. [0004] For exam...

AI Technical Summary

Problems solved by technology

[0005] Double patterning technology is to make up for the lack of ordinary lithography machine capabilities, using high-precision alignment to perform two exposures and processes; the first exposure and process form part of the pattern, and the second exposure and process form the rest of the pattern. Graphics, in this way, can double the precision of lithography. This technology is generally used in technology generations below 32nm; due to the two lithography and processes, the cost increases; at the same time, the process is affected by the alignment accuracy, and the stability is insufficient;

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