Method for producing copper-gas dielectric suspension Damscus structure

Abstract

This invention relates to a method for preparing copper-gas medium suspended Damascus structure, which applies humid etching and super-critical CO2 method to remove the sacrificial layer material and realizes the copper-air medium Damascus suspended structure, which avoids the conglutination of upper and lower structures caused by surface tensile stress of a liquid during humid etch.

Description

【Technical field】 [0001] The invention relates to the technical field of manufacturing semiconductor devices, in particular to a method for preparing a copper-gas medium suspended damascene structure in the semiconductor back-end process. 【Background technique】 [0002] With the continuous shrinking of the size of semiconductor devices, the requirements for integrated circuit manufacturing technology are getting higher and higher. For back-end integration technology, reducing interconnect delay (RC delay) has become a key issue, so people are constantly looking for low dielectric constant media to replace SiO 2 , to reduce interconnect capacitance. The dielectric constant of the gas medium is extremely low. According to theoretical research, in SiO 2 The gas gap between the metal lines formed in the deposition process will reduce the capacitance between the metal lines in the layer up to 40%, and the overall capacitance between the lines will be reduced by 20%. Damascus m...

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Problems solved by technology

[0004] The method of removing the sacrificial layer can be divided into two categories: dry method and wet method. As we all know, dry etching has better anisotropy, but it is easy to cause damage to the substrate material after plasma bombardment. The shrinking of the process, any loss of material will affect its performance

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