KR19980048839A - Method of forming a contact hole in a semiconductor device - Google Patents

Abstract

The present invention discloses a method for forming a contact hole in a semiconductor device. This is accomplished by using a silicon compound (Si _x N _y ) containing nitrogen (N) and a silicon compound (SiO _x N _Y ) containing nitrogen (N) and oxygen (O) a capping layer; A second step of forming an interlayer insulating layer using an insulating material on the capping layer / conductive layer; A third step of etching the interlayer dielectric layer to expose the capping layer using the etch selectivity of the interlayer dielectric layer and the capping layer; And a fourth step of etching the capping layer. That is, by adding a capping layer serving as an etching stopper layer on top of another stepped portion, it is possible to minimize the damage of the underlying film during the etching process for forming the contact hole.

Description

Method of forming a contact hole in a semiconductor device

The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a method of forming a contact hole in a semiconductor device.

In the flattening process during the manufacturing process of the semiconductor device, a step is generated due to the structure of the lower film quality, and the lower film quality is damaged if the etching process for forming the contact hole on the film quality causing the step is performed.

SUMMARY OF THE INVENTION The present invention provides a method of forming a contact hole in a semiconductor device for minimizing damage of a lower film.

1A to 1C are cross-sectional views illustrating a method of forming a contact hole in a semiconductor device according to the present invention.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, which includes using a silicon compound (Si _x N _Y ) containing nitrogen (N) and a silicon compound (SiO _x N _Y ) containing nitrogen (N) A first step of forming a capping layer on the conductive layer; A second step of forming an interlayer insulating layer using an insulating material on the capping layer / conductive layer; A third step of etching the interlayer dielectric layer to expose the capping layer using the etch selectivity of the interlayer dielectric layer and the capping layer; And a fourth step of etching the capping layer.

In the third step, it is preferable to etch using a mixed gas containing carbon (C) and fluorine (F).

In the fourth step, it is preferable to etch using a mixed gas containing C ₂ F ₆ and Ar.

Accordingly, the method of forming a contact hole of a semiconductor device according to the present invention can minimize the damage of the underlying film during the etching process for forming a contact hole by adding a capping layer serving as an etching stopper layer on the top of the film having different steps have.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings.

1A to 1C are cross-sectional views illustrating a method of forming a contact hole in a semiconductor device according to the present invention.

Reference numeral 1 denotes a first conductive layer, 3 denotes a second conductive layer, 5 denotes a first capping layer, 7. 7a denotes a first interlayer insulating layer, 9 denotes a third conductive layer, 11 denotes a second Reference numeral 13. 13a denotes a second interlayer insulating layer. Reference numeral 15 denotes a photoresist pattern. Reference numerals 16a, 16b, 16c, 16a ', 16b' and 16c 'denote contact holes.

1A, a step of forming a second conductive layer 3 by depositing a conductive material on a first conductive layer 1 and then patterning the conductive layer 3, forming a first conductive layer 1 and a second conductive layer 3 Forming a capping layer 5 surrounding the first capping layer 5, forming a first interlayer insulating layer 7 on the first capping layer 5 using an insulating material, A step of forming a third conductive layer 9 by depositing a conductive material on the insulating layer 7 and then patterning the conductive layer 9, a step of forming a second capping layer 11 on the third conductive layer 9, A step of forming a second interlayer insulating layer 13 on the second capping layer 11 by using a material to form a second interlayer insulating layer 13 on the second interlayer insulating layer 13, The photoresist pattern 15 is then patterned so as to expose a part to be formed with the contact layer in the resultant product formed by the processes, It advances the process to turn.

The first, second and third conductive layers 1, 3, and 9 may be a semiconductor substrate, a gate electrode, or a wiring layer in a semiconductor device. The first, second, and third conductive layers may be formed of polycrystalline silicon doped with impurities, polycrystalline silicon not doped with impurities, And silicide.

The first half interlayer insulating layers 7 and 13 are formed using an insulating material such as SiO ₂ .

The first and second capping layers 5 and 11 are used as an etch stop layer in a subsequent etching process for forming a contact hole, A silicon compound (Si _x N _Y ) containing nitrogen (N) and a silicon compound (SiO _x N _Y ) containing nitrogen (N) and oxygen (O) Is formed using any one of them.

1B, using the photoresist pattern 15 as a mask and using a mixed gas containing carbon (C) and fluorine (F), the first interlayer insulating layer 7 and the second interlayer insulating layer 13 ) Is etched.

This is due to the high etch selectivity between the constituent materials of the first and second ½ insulating layers 7 and 13 and the ½ capping layer 5 and 11, (F / C < / = 3) mixed gas having a ratio of not more than 3, such as C ₂ F ₆ , C ₃ F ₈ , C ₄ F ₈ , CH ₂ F ₂ and CH ₃ F.

As a result, contact holes 16a and 16b having a large step are formed on the first and second conductive layers 1 and 3, and a contact hole 16c having a low step is formed on the third conductive layer 9 do.

That is, the first and second capping layers 5 and 11 serve as an etch stop layer to prevent the first and second / third conductive layers 1, 3 and 9 from being etched.

Referring to FIG. 1C, a mixed gas containing CO, C ₂ F _6, and Ar is used to expose the first / second capping layer 5, 11) is etched.

In this case, CHF ₃ may be added to the mixed gas containing CO, C ₂ F _6, and Ar, and CO ₂ or O ₂ may be used instead of CO.

As a result, the contact holes 16a ', 16b', and 16b 'are formed so as not to cause damage to the first, second, and third conductive layers 1, 3, and 9, 16c '.

Then, the photoresist pattern 15 is removed.

It is obvious that the present invention is not limited thereto and that many modifications are possible within the technical scope of the present invention by those skilled in the art.

As described above, the method of forming a contact hole of a semiconductor device according to the present invention can improve a contact hole forming property by adding a capping layer serving as an etching stopper layer on top of a film having a different step, ) Can be minimized.

Claims (3)

A silicon compound (Si _x N _y ) containing nitrogen (N) and a silicon compound (SiO _x N _Y ) containing nitrogen (N) and oxygen (O) layer; A second step of forming an interlayer insulating layer using an insulating material on the capping layer / conductive layer; A third step of etching the interlayer dielectric layer to expose the capping layer using the etch selectivity of the interlayer dielectric layer and the capping layer; And And a fourth step of etching the capping layer. The method according to claim 1, wherein in the third step Wherein the etching is performed using a mixed gas containing carbon (C) and fluorine (F). The method according to claim 1, wherein in the fourth step C ₂ F _6, and Ar is used as the etching gas.