Method for forming bit line air space in semiconductor device manufacturing process

Abstract

The invention discloses a method for forming a bit line air gap in a semiconductor device manufacturing process, which belongs to the field of semiconductor manufacturing, and comprises the following steps of: after forming bit lines in the semiconductor device manufacturing process, sequentially depositing SiN / C / SiN on the bit lines to form three layers of films, forming connecting grooves between the bit lines, and forming the air gap between the bit lines; filling the connecting groove to form contact; the outermost SiN layer in the SiN / C / SiN layers deposited on the side wall of the bit line is removed, so that the C layer in the SiN / C / SiN layers is exposed; then plasma ashing treatment is carried out to remove the C layer so as to form an air gap; and continuously depositing a first metal layer and a second metal layer on the upper part of the formed air opening, and then carrying out patterning treatment to form a bit line air interval. The present invention reduces parasitic capacitance without causing pattern damage, and realizes no additional deposition of a capping film and an air-spaced etching process, thereby minimizing pattern damage.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, and more particularly, to a method for forming an air space between bit lines in a semiconductor device manufacturing process. Background technique [0002] In the prior art, in order to improve the performance of DRAM devices, achieve higher-level scaling and faster memory cell operation, and reduce parasitic capacitances, a scheme of arranging air spacers near bit lines has been developed. However, due to the etching selectivity ratio of the film quality and the effect of galvanic corrosion, the bit line may be damaged in this solution. Therefore, a new solution is needed to form an air gap to prevent this phenomenon from happening. SUMMARY OF THE INVENTION [0003] The purpose of the present invention is to overcome the deficiencies of the prior art, and to provide a method for forming an air space between bit lines in a semiconductor device manufacturing process, which can reduce...

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Problems solved by technology

However, due to the etching selectivity of the film quality and the galvanic corrosion effect of this scheme, the bit line will be damaged.

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