KR100282418B1 - Polymer Removal Method of Semiconductor Device - Google Patents

Abstract

The present invention relates to a method for removing a polymer of a semiconductor device, and more particularly, to a method for removing a polymer of a semiconductor device suitable for removing a polymer that is frequently generated at a pad portion. Such a method of removing a polymer of a semiconductor device may include sequentially forming a first barrier metal layer, a conductive layer, and a second barrier metal layer on a substrate, and sequentially forming first and second insulating layers on the second barrier metal layer. Defining a pad region to selectively remove the second and first insulating layers of the pad region, and dry etching the polymer that is generated by selectively removing the second and first insulating layers; Removing the polymer by a developing process.

Description

Polymer Removal Method of Semiconductor Device

The present invention relates to a method for removing a polymer of a semiconductor device, and more particularly, to a method for removing a polymer of a semiconductor device suitable for removing a polymer that is frequently generated at a pad portion.

Hereinafter, a method of removing a polymer of a conventional semiconductor device will be described with reference to the accompanying drawings.

1 (a) to 1 (e) are cross-sectional views of a polymer removal process of a conventional semiconductor device.

First, as shown in FIG. 1 (a), the first barrier metal layer 2, the aluminum layer 3, and the second barrier metal layer 4 are sequentially formed on the substrate 1. At this time, the substrate 1 is an intermetal dielectric (IMD) layer as an insulating film.

As shown in FIG. 1 (b), an oxide film 5 and a nitride film 6 are sequentially formed on the second barrier metal layer 4. In this case, the oxide film 5 and the nitride film 6 are passivation.

As shown in FIG. 1 (c), a photosensitive film PR is coated on the nitride film 6. Subsequently, the pad region is defined by an exposure and development process to pattern the photoresist film PR so that the nitride film 6 of the pad region is exposed.

As shown in FIG. 1 (d), the nitride film 6, the oxide film 5, and the second barrier metal layer 4 are selectively removed by an etching process using the patterned photoresist PR as a mask. At this time, when the nitride film 6 and the oxide film 5, which are protective films, are removed, the polymer 7, which is an etch residue, is generated so that the nitride film 6, the oxide film 5, and the second barrier metal layer 4 of the pad region are generated. ) Will remain on the side. At this time, the polymer (7) as described above is carbon crystallized by the high heat of the plasma generated during the dry etching process using the photosensitive film (PR) as a mask is generated by reacting with the nitride film (6), oxide film (5) Organic or inorganic polymer having a ring).

As shown in FIG. 1 (e), the photosensitive film PR and the polymer 7 are removed. Subsequently, although not shown in the drawings, a pad bonding process and a packaging process are performed on the pad area as described above. At this time, the photoresist film PR is removed by ashing treatment. The ashing treatment condition as described above is O ₂ gas at a power of about 800 W and an temperature of 200 ° C. in an ashing equipment (not shown). Remove about 250sccm. Then, the polymer 7 is removed by a developing process using a chemical solution in the track equipment. In this case, when the amount of the polymer 7 generated during the etching process for exposing the pad region is large, as shown in the drawing, the developing process does not completely remove the polymer 7 and a fine amount remains.

In the conventional method of removing a polymer of a semiconductor device, when a large amount of polymer is generated in a pad region, it is difficult or sufficiently time consuming to remove it sufficiently by a developing process using a chemical solution. As a result, when the polymer is not completely removed, a process defect occurs due to the polymer during the pad bonding process and the package process, and the yield is low. When the polymer removal time is long, the productivity is low.

The present invention has been made to solve the problems of the polymer removal method of the semiconductor device as described above to remove the photosensitive film by the ashing process and then to some extent to remove the polymer by a dry etching process, so that the polymer can be completely removed during the development It is an object of the present invention to provide a method for removing a polymer of a semiconductor device.

1 (a) to 1 (e) are cross-sectional views of a polymer removal process in a pad region of a conventional semiconductor device.

2 (a) to 2 (e) are cross-sectional views of the polymer removal process in the pad region of the semiconductor device of the present invention.

* Explanation of symbols for main parts of the drawings

11 substrate 12 first barrier metal layer

13 conductive layer 14 second barrier metal layer

15: first insulating film 16: second insulating film

17: polymer

In the method of removing a polymer of a semiconductor device according to the present invention, the method comprises sequentially forming a first barrier metal layer, a conductive layer, and a second barrier metal layer on a substrate, and sequentially forming first and second insulating films on the second barrier metal layer. Defining a pad region to selectively remove the second and first insulating layers of the pad region, and dry etching the polymer generated while selectively removing the second and first insulating layers, and remaining after the dry etching. Removing the polymer by a developing process.

Such a polymer removal method of the semiconductor device of the present invention will be described with reference to the accompanying drawings.

2 (a) to 2 (e) are cross-sectional views of the polymer removal process of the semiconductor device of the present invention.

First, as shown in FIG. 2 (a), the first barrier metal layer 12, the conductive layer 13, and the second barrier metal layer 14 are sequentially formed on the substrate 11. In this case, the substrate 11 is an intermetal dielectric (IMD) layer as an insulating film.

As shown in FIG. 2 (b), the first insulating film 15 and the second insulating film 16 are sequentially formed on the second barrier metal layer 14. In this case, the first insulating film 15 and the second insulating film 16 are passivation.

As shown in FIG. 2 (c), a photosensitive film PR is coated on the second insulating film 16. Subsequently, the photoresist film PR is patterned such that the pad region is defined by an exposure and development process so that the second insulating film 16 of the pad region is exposed.

As shown in FIG. 2 (d), the second insulating layer 16, the first insulating layer 15, and the second barrier metal layer 14 are formed by an etching process using the patterned photoresist pattern PR as a mask. Selectively remove it to open the pad area. At this time, when the second insulating film 16 and the first insulating film 15, which is a protective film, are removed, the polymer 17, which is an etch residue, is generated so that the second insulating film 16 and the first insulating film 15 of the pad region are removed. And a polymer 17 having a carbon ring on the side of the second barrier metal layer 14.

As shown in FIG. 2 (e), the photoresist film PR and the polymer 17 are removed. Subsequently, although not shown in the drawings, a pad bonding process and a packaging process are performed on the pad area as described above. At this time, the photoresist film PR pattern is removed by ashing. Ashing conditions as described above are about 700 W of power, about 250 ° C., and about 100 to 15000 sccm of O ₂ gas. I shall shed it. Immediately after the ashing process as described above, the polymer 17 is removed by flowing about 700 to 1000 sccm of CF ₄ gas for about 10 to 20 seconds. At this time, the polymer removal step as described above is carried out under the following conditions while flowing about 700 to 1000 sccm of CF ₄ gas for about 10 to 20 seconds. That is, O ₂ gas is flowed at a temperature of 250 ° C., and power is performed under conditions of about 650 to 850 W. The polymer 17 removing step reduces the bonding force of the polymer 17 having a carbon ring by flowing CF ₄ gas at about 700 to 1000 sccm for about 10 to 20 seconds under the same conditions as the ashing process, and optionally the polymer (17). ) Can be removed. Then, the polymer 17 having weakened binding force even after the dry polymer removal process as described above is removed by a developing process using a chemical solution in the track equipment. In this case, since a developing process for removing the polymer after the dry etching process is added, the polymer 17 may be completely removed.

In the method of removing a polymer of a semiconductor device according to the present invention, the polymer generated when the pad region is selectively opened by a photoresist film is weakened by a dry etching process using CF ₄ gas immediately after the photoresist pattern removal process, thereby weakening the bonding strength of the polymer and a predetermined amount of polymer. Since the polymer can be completely removed during the developing process, defects can be prevented during the pad bonding process and the package process, which are subsequent processes, thereby providing a highly reliable semiconductor device.

Claims (4)

Sequentially forming a first barrier metal layer, a conductive layer, and a second barrier metal layer on the substrate; Sequentially forming first and second insulating layers on the second barrier metal layer; Defining a pad region to selectively remove the second and first insulating films of the pad region; Dry etching the polymer generated by selectively removing the second and first insulating layers; And removing the polymer remaining after the dry etching process by a developing step. The method of claim 1, wherein the removing of the polymer is performed at a power of 650 to 850 W for about 100 to 15000 sccm of O ₂ and about 700 to 1000 sccm of CF ₄ mixed gas at a temperature of about 250 ° C. for about 10 to 20 seconds. Removing the polymer during the flow of the semiconductor device. 2. The method of claim 1, wherein a dry etching process using a photosensitive film pattern as a mask is used to selectively remove the second and first insulating films of the pad region. 4. The polymer removal of the semiconductor device according to claim 1 or 3, wherein the dry etching process is performed in an ashing device for removing the photoresist pattern used when selectively removing the second and first insulating films. Way.