Etching composition, and method for producing semiconductor element by utilizing same

Abstract

The present invention relates to an etching composition, and a method for producing a semiconductor element comprising an etching process that utilizes the etching composition, the etching compositioncomprising a first inorganic acid, a first additive, and a solvent. The etching composition can minimize the etching rate of oxide film while selectively removing nitride film, and does not have issues that adversely affect the quality of the element, such particle generation, and is highly selective.

Description

technical field [0001] The present invention relates to an etching composition, and more particularly, to a highly selective etching composition capable of selectively removing a nitride film while minimizing the etching rate of an oxide film, and to a A method of manufacturing a semiconductor device, the method comprising an etching process using the etching composition. Background technique [0002] In semiconductor manufacturing processes, representative insulating films include films such as silicon dioxide (SiO 2 ) and oxide films such as silicon nitride (SiN x ), etc., which are used independently or in one or more alternately laminated layers. In addition, these oxide films and nitride films are also used as hard masks for forming conductive patterns such as metal lines and the like. [0003] In the wet etching process for removing the nitride film, a mixture of phosphoric acid and deionized water is generally used. Deionized water is added in order to prevent a d...

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Problems solved by technology

Deionized water is added in order to prevent a decrease in the etching rate and a change in the etching selectivity to the oxide film; however, there is a problem that even a small change in the amount of deionized water supplied in the process of removing the nitride film by etching will cause defects

In addition, phosphoric acid is a strongly corrosive acid, and the handling of this acid is difficult

[0004] In order to solve these problems, the use of phosphoric acid (H 3 PO 4 ) with hydrofluoric acid (HF) or nitric acid (HNO 3 ) techniques for removing nitride films with etching compositions; however, these techniques conversely lead to a decrease in the etching selectivity between the nitride film and the oxide film

In addition, techniques using compositions for etching containing phosphoric acid and silicate or silicic acid are also known, but these techniques have a problem in that silicic acid or silicate causes particle generation, which adversely affects the substrate, and therefore, They are not suitable for semiconductor manufacturing process

However, in the case of using phosphoric acid in such a wet etching process for removing the nitride film, since the etching selectivity between the nitride film and the oxide film is lowered, the nitride film is etched together with the SOD oxide film, Therefore, it becomes difficult to adjust the effective field oxide height (EFH)

Therefore, a sufficient wet etching time for removing the nitride film cannot be ensured, or an additional process is required, and thus, phosphoric acid causes changes that adversely affect device characteristics

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