A method for fabricating self-aligned double-layer graphics with no load on the bottom

Abstract

The invention provides a manufacturing method of a self-alignment double-layer pattern without loads at the bottom. The manufacturing method comprises the steps that an amorphous carbon film and a hard mask layer are sequentially formed on a medium layer at the bottom; a photoetching process and an etching process are adopted, and the hard mask layer is patterned; the patterned hard mask layer serves as a mask, the amorphous carbon film is etched through the etching process, and the downward etching height is smaller than the thickness of the amorphous carbon film; the hard mask layer is removed in an etching mode; the amorphous carbon film is etched downwards again and stopped on the surface of the medium layer at the bottom; an insulation side wall is formed on the medium layer at the bottom; the amorphous carbon film is removed, and therefore the self-alignment double-layer pattern is formed. The method can effectively prevent damage to the bottom in an existing process, and can be used for manufacturing the self-alignment double-layer pattern without loads at the bottom.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for fabricating self-aligned double-layer graphics with no load on the bottom. Background technique [0002] With the continuous shrinking of process dimensions, especially in 20nm and below technologies, self-aligned double-layer patterning process (SADP) is widely used in the formation of key layer patterns such as active area (AA) and polysilicon (POLY). [0003] Normally, see Figure 1-10 , figure 1 It is a schematic flow chart of an existing self-aligned double-layer pattern manufacturing method, Figure 2-10 It is a schematic diagram of the cross-sectional structure corresponding to the specific steps of the existing self-aligned double-layer graphics manufacturing method, and the specific steps are: [0004] Step L01: See figure 2 , sequentially forming an amorphous carbon film 2' and a hard mask layer 3' on the bottom dielectric layer 1'; [0005] St...

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Problems solved by technology

[0010] Since the hard mask layer is used in the above process, the hard mask layer must be removed in the subsequent process, otherwise the amorphous carbon film cannot be removed or there is residual

However, etching away the hard mask layer before removing the amorphous carbon film will damage the bottom dielectric layer, resulting in a loading effect at the bottom

Figure 10 The dotted frame area in the middle is the position of the bottom load, and it can be seen that the self-aligned double-layer graphic structure formed by the existing manufacturing method has a bottom load

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