BACKGROUND

1. Field

The present disclosure relates to an etchant composition, and more particularly, to an etchant composition having a high selection ratio which may selectively remove a nitride film while minimizing an etching rate of an oxide film, a method of etching an insulating film, and a method of manufacturing a semiconductor device. In addition, the present disclosure relates a silane compound which is appropriate for use as an additive of the etchant composition.

2. Description of Related Art

An oxide film such as a silicon oxide (SiO2) film and a nitride film such as a silicon nitride (SiNx) film are representative insulator films, and in a semiconductor manufacturing process, the silicon oxide film or the silicon nitride film is used alone or in the form of a laminate in which one or more films are alternately stacked. In addition, the oxide film or the nitride film is also used as a hard mask for forming a conductive pattern such as a metal wiring.

In a wet etching process for removing the nitride film, a mixture of phosphoric acid and deionized water is generally used. The deionized water is added for preventing a decrease in an etching rate and a change in etching selectivity to an oxide film; however, there is a problem in that defects arise in a nitride film etching removal process even with a minute change in an amount of supplied deionized water. In addition, phosphoric acid is a strong acid and corrosive, thereby having a difficulty in handling.

In order to solve the problem, there is a conventionally known technology for removing a nitride film using an etchant composition including fluoric acid (HF), nitric acid (HNO3), or the like in phosphoric acid (H3PO4), but causing a result of inhibiting an etching selection ratio of the nitride film and the oxide film. In addition, there is also known a technology of using an etchant composition including phosphoric acid and a silicate or silicic acid; however, the silicic acid or silicate has a problem of causing particles which may affect a substrate, thereby being somewhat inappropriate for a semiconductor manufacturing process.

Meanwhile, when phosphoric acid is used in a wet etching process for removing the nitride film, not only the nitride film but also an SOD oxide film is etched due to a reduced etching selection ratio between the nitride film and the oxide film, whereby it is difficult to adjust an effective field oxide height (EFH). Accordingly, a sufficient wet etching time for removing the nitride film may not be secured, or an additional process is needed, which causes a change and has a bad influence on device characteristics.

Therefore, an etchant composition having a high selection ratio, which selectively etches a nitride film to an oxide film and does not have a problem such as particle occurrence in a semiconductor manufacturing process, is currently demanded.

SUMMARY

An aspect of the present disclosure may provide an etchant composition having a high selection ratio, which may selectively remove a nitride film while minimizing an etching rate of an oxide film, and does not have problems such as particle occurrence having a bad influence on device characteristics, and a silane compound used in the etchant composition.

According to an aspect of the present disclosure, an etchant composition may include phosphoric acid and a silane compound represented by the following Chemical Formula 1:



wherein R1to R6are independently hydrogen, halogen, a substituted or unsubstituted C1-C20hydrocarbyl group, a C1-C20alkoxy group, a carboxy group, a carbonyl group, a nitro group, a tri(C1-C20) alkylsilyl group, a phosphoryl group, or a cyano group, L is a direct bond or C1-C3hydrocarbylene, A is an n-valent radical, and n is an integer of 1 to 4.

According to an exemplary embodiment, the substituted or unsubstituted C1-C20hydrocarbyl group is a substituted or unsubstituted C1-C20alkyl group or a substituted or unsubstituted C6-C20aryl group, and the substituted C1-C20hydrocarbyl group may be substituted by halogen.

According to an exemplary embodiment, the etchant composition wherein A is C1-C20alkyl, C2-C20alkenyl, C6-C20aryl, a radical having N as a binding site, a radical having S as a binding site, or a radical having P as a binding site, is provided.

According to an exemplary embodiment, the etchant composition wherein the radical having N as a binding site is *—NR11R12, *—NR13—*, *—NR14CONR15—*, *—NR16CSNR17—*, or


is provided, wherein R11and R12are independently hydrogen, C1-C20alkyl, C1-C20aminoalkyl, or CONH2, R13to R17are independently hydrogen or C1-C20alkyl, and L1is C1-C20alkylene.

According to an exemplary embodiment, the etchant composition wherein the radical having S as a binding site is *—S—*, *—S—S—*,


is provided.

According to an exemplary embodiment, the etchant composition wherein the radical having P as a binding site is


is provided, wherein R18and R19are independently hydrogen, C1-C20alkyl, C6-C20aryl, or (C1-C20)alkyl(C1-C20)alkoxy.

According to an exemplary embodiment, the etchant composition wherein in Chemical Formula 1, n is 1, L is a direct bond or C1-C3alkylene, A is a substituted or unsubstituted C1-C20alkyl, a substituted or unsubstituted C1-C20alkenyl, *—NH2, *—NH—(CH2)1—NH2, *—NH—CO—NH2, or *—(CH2)m—C6H5, and l and m is independently an integer of 0 to 10, is provided.

According to an exemplary embodiment, the etchant composition wherein in Chemical Formula 1, n is 2, L is a direct bond or C1-C3alkylene, A is C1-C20alkylene, *—NR13—*, *—NR14—CO—NR15—*, *—S—*, *—S—S—*,


R13to R15, R18, and R19are independently hydrogen, C1-C20alkyl, C6-C20aryl, or (C1-C20)alkyl(C1-C20)alkoxy, is provided.

According to an exemplary embodiment, the etchant composition wherein in Chemical Formula 1, n is 3, L is a direct bond or C1-C3alkylene and A is


is provided.

According to an exemplary embodiment, the etchant composition wherein in Chemical Formula 1, n is 4, is C1-C3alkylene, A is


wherein L1is C1-C10alkylene, is provided.

According an exemplary embodiment, the etchant composition wherein the silane compound is selected from compounds represented by Structural Formulae (1) to (28), is provided:



According to an exemplary embodiment, the etchant composition wherein the silane compound is included in an amount of 0.001 to 1 wt %, based on the total weight of the etchant composition, is provided.

According to an exemplary embodiment, the etchant composition further including a silane compound represented by the following Chemical Formula 2, is provided.

According to an exemplary embodiment, it is preferable that in Chemical Formula 1, R1to R6are hydrogen, and also R1is a substituted or unsubstituted hydrocarbyl, and R2to R6are hydrogen.



wherein R51to R54are independently of each other hydrogen, hydrocarbyl, or heterohydrocarbyl, in which R51to R54exist respectively or two or more of R51to R54form a ring connected to each other by a heteroelement.

According to an exemplary embodiment, the etchant composition further including an ammonium salt is provided.

According to another aspect of the present disclosure, a method of etching an insulating film using the etchant composition is provided.

According to another aspect of the present disclosure, a method of manufacturing a semiconductor device may include the method of etching an insulating film.

According to another aspect of the present disclosure, a silane compound represented by the following Chemical Formula 1, which is appropriate for addition to the etchant composition, is provided.

According to another aspect of the present disclosure, a silane compound represented by the following Chemical Formula 1 is provided:



wherein R1to R6are independently hydrogen, halogen, a substituted or unsubstituted C1-C20hydrocarbyl group, a C1-C20alkoxy group, a carboxy group, a carbonyl group, a nitro group, a tri(C1-C20)alkylsilyl group, a phosphoryl group, or a cyano group, L is a direct bond or C1-C3alkylene, n is 4, A is


as a tetravalent radical, and L1is C1-C10alkylene.

According to an exemplary embodiment, the silane compound wherein Chemical Formula 1 is represented by the following structure, is provided:



