Method for producing COB-DRAM bit line with nitrogen-oxygen-nitrogen SAC structure

Abstract

A method for preparing COB-DRAM bit line of N-O-N SAC structure includes inserting an aluminium oxide layer being used to replace silicon nitride hard mask in the same thickness in silicon nitric hard mask, knowing that selectively of silicon oxide to aluminium oxide is greater than selectively of silicon oxide to silicon nitride under the same SAC etching process so that said method can raise process permission of SAC etching process.

Description

technical field [0001] The invention relates to a method for making a bit line of a capacitive random dynamic memory (Capacitance Over BitLine-Dynamic Random Access Memory, COB-DRAM), especially a self-aligned contact (Self Aligned Contact) with a nitrogen-oxygen-nitrogen hard mask A method for making a COB-DRAM bit line of Contact, SAC) structure. Background technique [0002] In the manufacturing process of the current capacitive dynamic random access memory (COB-DRAM) on the bit line (COB-DRAM), the self-aligned contact (SAC) method is used to form the contact hole structure. However, in the current application of the self-aligned contact (SAC) technology, there is a problem that the process tolerance of the application of the self-aligned contact (SAC) technology is too small. As the device size becomes smaller and smaller, the process tolerance of the self-aligned contact (SAC) technology application will become smaller and smaller. [0003] In the manufacturing proce...

AI Technical Summary

Problems solved by technology

However, as device dimensions continue to decrease, both larger bottom critical dimension 113 and higher shoulder silicon nitride (Si 3 N 4 )112 Residues are difficult to balance

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