Preparation method of metal nitride hard mask

Abstract

A preparation method of a stress-adjustable metal nitride hard mask adopts an alloy target material to undergo a sputtering process to make the metal nitride hard mask deposited on a wafer reach a preset thickness, and the growth crystal orientation of the crystal of the metal nitride hard mask is the preset direction. Compared with a method using a single metal material target material for sputtering in the prior art, the preparation method of the invention has the following advantages: new metal atoms are introduced into the metal nitride hard mask to replace part of original metal atoms, sothat lattice distortion is caused when the metal nitride hard mask is deposited, crystals of the metal nitride hard mask grow in the preset direction, the film performance is improved, and the preparation method is particularly suitable for the manufacturing process of 14 nn or below.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to a method for preparing a metal nitride hard mask. Background technique [0002] At present, TiN (Titanium Nitride) is widely used as a multifunctional material in the integrated circuit manufacturing process, and is used to prepare barrier layers, adhesive layers, and metal nitride hard masks. Common methods for preparing hard masks using TiN include PVD (Physical Vapor Deposition, physical vapor deposition) and CVD (Chemical Vapor Deposition, chemical vapor deposition). Among them, the traditional PVD method mostly adopts low-temperature DC magnetron sputtering technology to prepare TiN hard mask. This method has the advantages of high deposition rate, good film uniformity, low pollution and high productivity. However, in the process below 28nm, as the critical dimension becomes smaller, the aspect ratio of the trench becomes larger, which puts forward higher requirem...

AI Technical Summary

Problems solved by technology

The TiN hard mask prepared by traditional PVD has a high resistivity and a large compressive stress (stress < 0, compressive), which leads to distortion of the narrow pattern in the film

Compared with the traditional PVD method, the TiN hard mask film prepared by the CVD method has a high film coverage and has a tensile stress (stress>0, tensile), but the film has many impurities and high resistivity. Therefore, the CVD method is limited in 14nm. Applications in the following processes

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