KR100445077B1 - Manufacturing Method For Semiconductor Device - Google Patents

Abstract

The present invention discloses a method for manufacturing a semiconductor device. According to this, a florin silicate glass layer containing florin (F) is laminated on the semiconductor substrate on which the metal wiring is arranged as an interlayer insulating film. Then, in order to prevent the diffusion of the florin, a silicon ion implantation layer in which ions such as silicon ions are ion implanted is formed near the surface of the florin silicate glass layer.

Therefore, the silicon ions of the silicon ion implantation layer may be combined with the florin to prevent the diffusion of the florin, thereby preventing corrosion of the diffusion barrier formed on the florin silicate glass layer as well as corrosion of the upper metal wires on the diffusion barrier.

Description

Manufacturing Method For Semiconductor Device

The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to prevent the diffusion of florin by ion implantation of silicon ions near the surface of the interlayer insulating film containing florin to prevent corrosion of the metal wiring or the florin diffusion barrier on the interlayer insulating film. The present invention relates to a method for manufacturing a semiconductor device which is prevented.

In general, as the integration of semiconductor devices proceeds, the number of metal interconnections increases and the pitch of metal interconnections decreases. As the pitch of the metal wiring is reduced, not only the resistance of the metal wiring is increased but also the intermetal dielectric (IMD) and the metal wiring which form the parasitic capacitor structure to insulate the metal wiring of the semiconductor device adversely affect the characteristics of the semiconductor device. Crazy That is, the RC constant for determining the response speed of the semiconductor device increases and power consumption also increases.

For this reason, an interlayer insulating film having a low dielectric constant suitable for high integration of semiconductor devices has been desperately desired, and in recent years, Florin Silicate Glass (FSG) has been used as an interlayer insulating film having a low dielectric constant. However, the lower the concentration of fluorine, the lower the dielectric constant of the fluorine silicate glass, but the higher the concentration of fluorine, the higher the bond with water. Therefore, it is common to use a Florin silicate glass of about 3.5 having a relatively high permittivity.

In a conventional semiconductor device, as shown in FIG. 1, an interlayer insulating film 12 is stacked on a semiconductor substrate 10, and contact plugs 14 for electrical contact with the semiconductor substrate 10 are interlayered. It is formed in the via hole 13 of the insulating film 12, the metal wires 16 are arranged on the interlayer insulating film 12 to form an electrical connection with the contact plugs 14, the metal A barrier film 18 is laminated on the wirings 16 and the interlayer insulating film 12, and a florine silicate glass layer 20, which is an interlayer insulating film containing florin, is laminated on the barrier film 18, and the florine silicate glass is laminated. A diffusion barrier 22 is deposited on the layer 20. Here, the barrier film 18 serves to protect the metal wires 16 from being damaged by the florin silicate glass layer 20, and the diffusion barrier 22 is formed of the florin silicate glass layer 20. Prevents the diffusion of florin into adjacent membranes. The barrier layer 18 and the diffusion barrier layer 22 are both made of an undoped Silicate Glass USG layer.

However, in the case of a conventional semiconductor device having a structure in which the diffusion barrier 22 is laminated on the florin silicate glass layer 20, the florin of the florin silicate glass layer 20 is out-diffused to the outside. It is easy to react with moisture absorbed in the diffusion barrier film 22. As a result, hydrofluoric acid (HF) is formed in the diffusion barrier 22, which corrodes the diffusion barrier 22 and further forms voids 23, which are empty spaces of needle eye shape, in the diffusion barrier 22. At the interface of the upper metal wires (not shown) to be generated or formed on the diffusion barrier layer 22, causing an interface defect such as corrosion of the upper metal wires, and forming fluoride on the surface of the upper metal wires. The pad portion of the upper metal wiring may cause poor adhesion with a wire made of, for example, gold during wire bonding. This failure is further aggravated by increasing the concentration of florin in order to obtain a high dielectric constant of the florin silicate glass layer 20.

As a result, such a bad phenomenon lowers the insulating properties of the diffusion barrier 22 and adversely affects the reliability and electrical characteristics of the diffusion barrier 22. In addition, the voids 23 formed in the diffusion barrier film 22 serve as sources of defects in subsequent steps, resulting in lower reliability and lower yield of semiconductor devices.

In addition, in order to effectively prevent the diffusion of florin, a separate interlayer insulating film must be additionally laminated and a heat treatment process must be additionally performed, which is a cost burden.

Accordingly, it is an object of the present invention to provide a method for manufacturing a semiconductor device which prevents the diffusion of florin in an interlayer insulating film including florin.

Another object of the present invention is to provide a manufacturing method of a semiconductor device to improve the reliability and yield by preventing a defect caused by the interlayer insulating film containing florin.

1 is a cross-sectional structural view showing a semiconductor device according to the prior art.

2 is a cross-sectional structural view of a semiconductor device according to an embodiment of the present invention.

3 to 6 are cross-sectional process diagrams illustrating a method of manufacturing a semiconductor device according to an embodiment of the present invention.

7 and 8 are cross-sectional process diagrams showing a method for manufacturing a semiconductor device according to another embodiment of the present invention.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, the method comprising: forming metal wires on a semiconductor substrate; and by the fluorine on the metal wires and the semiconductor substrate. Forming a barrier film for preventing damage to metal wires; and forming an interlayer insulating film made of Flororine Silicate Glass on the barrier film; and forming a florin near the surface of the interlayer insulating film. Forming a silicon ion implantation layer by implanting silicon ions to prevent external diffusion. Preferably, forming a diffusion barrier on the silicon ion implantation layer to prevent external diffusion of the florin. Preferably, the silicon ions are heat-treated at a temperature of 400 ° C. or lower. According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, the method including: forming metal wires on a semiconductor substrate; and protecting the metal wires and damage of the metal wires by florin on the semiconductor substrate. Forming an interlayer insulating film made of florin silicate glass on the barrier film; and forming a diffusion barrier layer on the interlayer insulating film to prevent external diffusion of the florin; And forming a silicon ion implantation layer by implanting silicon ions into the vicinity of a surface of the interlayer insulating layer to prevent external diffusion of the florin.

Hereinafter, a method of manufacturing a semiconductor device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The same code | symbol is attached | subjected to the part of the same structure and the same action as the conventional part.

2 is a cross-sectional structural view showing a semiconductor device according to an embodiment of the present invention. As shown in FIG. 2, in the semiconductor device of the present invention, a lower structure (not shown) such as a gate electrode or a bit line of a transistor is formed on the semiconductor substrate 10. Of course, a diffusion region (not shown) such as a source region or a drain region of the transistor is formed in the semiconductor substrate 10. An interlayer insulating layer 12 is stacked on the semiconductor substrate 10, and contact plugs 14 for electrical contact with the underlying structure are formed in a via hole 13 of the interlayer insulating layer 12. do. The electrical connection with the contact plugs 14 is made, and metal wires 16 are arranged on the interlayer insulating layer 12. The barrier film 18 is stacked on the metal wires 16 and the interlayer insulating film 12. On the barrier film 18, a florin silicate glass layer 20, which is an interlayer insulating film containing florin, is laminated. A silicon ion implantation layer 30, such as a silicon ion implantation layer, is ion implanted into the upper layer of the florin silicate glass layer 20. Here, the barrier film 18 serves to protect the metal wires 16 from being damaged by the florin silicate glass layer 20, and the silicon ion implantation layer 30 is a florin silicate glass layer 20. ) Prevents the diffusion of florin into adjacent membranes. That is, the silicon bonding of the silicon ion implanted layer 30 may be prevented from diffusing out of the florin by bonding with the florin and further preventing the reaction with the external moisture. Therefore, it is not necessary to laminate the conventional diffusion barrier film 22 on the florin silicate glass layer 20.

On the other hand, as shown in the figure, the diffusion barrier layer 40 may be further laminated on the silicon ion implantation layer 30 to more securely prevent the external diffusion of florin. The barrier layer 18 and the diffusion barrier layer 40 may both comprise a USG layer.

Hereinafter, a method of manufacturing a semiconductor device according to an embodiment of the present invention will be described in detail with reference to FIGS. 3 to 6. The same code | symbol is attached | subjected to the part of the same structure and the same effect | action as the part of FIG.

Referring to FIG. 3, first, a diffusion region (not shown) such as a source region or a drain region of a transistor is formed in the semiconductor substrate 10 using a conventional process, and the gate of the transistor is formed on the semiconductor substrate 10. It forms substructures (not shown) such as electrodes or bit lines. Then, an interlayer insulating film 12, such as a USG layer, is stacked on the semiconductor substrate 10 using a photolithography process, and via holes 13 are formed in the interlayer insulating film for electrical connection with the diffusion region or the underlying structure. It forms in (12). Subsequently, contact plugs 14 such as a tungsten silicide layer completely filled only in the via holes 13 are formed. Thereafter, metal wires 16 are formed to be electrically connected to the contact plugs 14, respectively.

After the formation of the metal wires 16 is completed, the barrier film 18 is laminated to protect it from damage by the florin silicate glass layer 20, which is an interlayer insulating film containing florin to be formed in a subsequent process. In more detail, the barrier film 18 is formed on the metallization lines 16 and the interlayer insulating film 12 in a gas atmosphere of silane (SiH ₄ ) and oxygen (O ₂ ) using a high density plasma chemical vapor deposition process. Can be laminated. At this time, it is preferable to determine the thickness of the barrier film 18 to be in a relatively thick range of 500 to 1000 GPa, which is in contact with the florin silicate glass layer 20 and the metal wires 16 of FIG. This is to prevent and protect the metal wires 16.

Referring to FIG. 4, after the formation of the barrier film 18 is completed, an interlayer insulating film including florin, for example, a florine silicate glass layer 20, is stacked on the barrier film 18.

In more detail, a high density plasma chemical vapor deposition process is used to thicken the layer of florin silicate glass 20 on the barrier layer 18 in the gas atmosphere of silane (SiH ₄ ), oxygen (O ₂ ) and SiF ₄ . It can be laminated. Here, it is preferable that the florin silicate glass layer 20 has a florin concentration of 5 to 15% to ensure a low dielectric constant of 3.5 or less. At this time, it is preferable to stack the florin silicate glass layer 20 to a thickness much thicker than the metal wires 16 for the planarization of the surface.

Referring to FIG. 5, after the lamination of the florin silicate glass layer 20 is completed, the surface of the florin silicate glass layer 20 near the surface of the florin silicate glass layer 20 is prevented to prevent the diffusion of florin in the florin silicate glass layer 20. Predetermined ions, for example silicon ions, are implanted into the silicon ions to form the silicon ion implanted layer 30.

Then, the ion implanted silicon ions are heat treated by a heat treatment process. Of course, the heat treatment step of the ion implanted silicon ions may be omitted.

Here, since high density silicon bonding exists in the silicon ion implantation layer 30, the diffusion of the florin ions may be prevented by combining the florin ions in the form of Si-F. Therefore, in the case of upper metal wires (not shown) to be formed on the silicon ion implanted layer 30, an interface failure phenomenon such as corrosion at the interface of the upper metal wires by the florin ions may be prevented.

In addition, since the conventional diffusion barrier 22 is not required to be laminated on the florin silicate glass layer 20, the stacking process of the diffusion barrier 22 may be omitted.

Referring to FIG. 6, after formation of the silicon ion implantation layer 30 is completed, the silicon oxide implantation layer 30 may be formed on the silicon ion implantation layer 30 in order to more effectively prevent external diffusion of florine ions of the florine silicate glass layer 20. It is also possible to further laminate a diffusion barrier 40, such as a USG layer. At this time, the generation of corrosive voids of the diffusion barrier 40 by the florin ions can be prevented.

Therefore, the corrosion of the diffusion barrier film on the florin silicate glass layer by the florin of the florine silicate glass layer can be prevented, and the corrosion of the upper metal wiring on the diffusion barrier film can be prevented. This can prevent the source of defects in the subsequent process to improve the reliability and yield of the semiconductor device.

Hereinafter, a method of manufacturing a semiconductor device according to another embodiment of the present invention will be described. The same code | symbol is attached | subjected to the part of the same structure and the same operation | movement as the part of FIGS.

Referring to FIG. 7, first, the processes of FIGS. 3 and 4 are performed in the same manner. That is, the interlayer insulating film 12 is formed on the semiconductor substrate 10, the contact plugs 14 are formed in the via hole 13 of the interlayer insulating film 12, and the contact plugs ( 14 to form metal wires 16 electrically connected to each other. Then, a barrier film 18 and a florin silicate glass layer 20 that is an interlayer insulating film are laminated on the resultant structure.

After the florin silicate glass layer 20 is stacked, a diffusion barrier 40 such as a USG layer is stacked on the florin silicate glass layer 20.

Referring to FIG. 8, after lamination of the diffusion barrier film 40 is completed, ions, for example, silicon ions, may be added to the florin silicate glass layer to prevent outdiffusion of florin of the florin silicate glass layer 20. Ion implantation near the surface of 20) forms the silicon ion implantation layer 30.

Another embodiment of the present invention by this method can also achieve the same effect as in the above-mentioned embodiment. For convenience of description, detailed description thereof will be omitted in order to avoid duplication of description.

As described in detail above, in the method of manufacturing a semiconductor device according to the present invention, a florin silicate glass layer containing florin is laminated as an interlayer insulating film on a semiconductor substrate on which metal wiring is arranged. Then, in order to prevent the diffusion of the florin, a silicon ion implantation layer in which ions such as silicon ions are ion implanted is formed near the surface of the florin silicate glass layer.

Therefore, the silicon ions of the silicon ion implantation layer may be combined with the florin to prevent the diffusion of the florin, thereby preventing corrosion of the diffusion barrier formed on the florin silicate glass layer as well as corrosion of the upper metal wires on the diffusion barrier.

On the other hand, the present invention is not limited to the contents described in the drawings and detailed description, it is obvious to those skilled in the art that various modifications can be made without departing from the spirit of the invention. .

Claims (8)

delete delete delete Forming metal wires on the semiconductor substrate; Forming a barrier film on the metal wires and the semiconductor substrate to prevent damage of the metal wires due to fluorine; Forming an interlayer insulating film made of florin silicate glass on the barrier film; And forming a silicon ion implantation layer by implanting silicon ions into the vicinity of a surface of the interlayer insulating film to prevent external diffusion of the florin. The method of claim 4, further comprising forming a diffusion barrier layer on the silicon ion implantation layer to prevent external diffusion of the florin. delete The method of claim 4, wherein the silicon ions are heat-treated at a temperature of 400 ° C. or less. Forming metal wires on the semiconductor substrate; Forming a barrier layer on the metal wires and the semiconductor substrate to protect the metal wires from damage by florin; Forming an interlayer insulating film made of florin silicate glass on the barrier film; Forming a diffusion barrier layer on the interlayer insulating layer to prevent diffusion of the florin; And And forming a silicon ion implantation layer by implanting silicon ions into the vicinity of a surface of the interlayer insulating film to prevent external diffusion of the florin.