KR100940337B1 - Method of manufacturing a semiconductor device - Google Patents

Abstract

PURPOSE: A method of manufacturing a semiconductor device is provided to minimize the change of a chamber by performing second process before the first process is completely. CONSTITUTION: A wiring(210) is formed by using a copper on a semiconductor substrate(200). The semiconductor substrate having a native oxide is loaded at a reaction chamber. A nitrogen source(NH3) is flowed into a reaction chamber and the native oxide on the above semiconductor substrate is removed. A silicon source is increased in the reaction chamber and the silicon nitride layer(230) is formed on the above semiconductor substrate. The nitrogen source and silicon source is excited by using the plasma. The concentration of the silicon source increases at the top of the silicon nitride film.

Description

Method of manufacturing a semiconductor device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing a semiconductor device in which a etch stop film deposition process is continuously performed in situ from a natural oxide film removal process in a damascene process.

BACKGROUND OF THE INVENTION In recent years, as the semiconductor devices become faster and have higher integration, metal wirings have been miniaturized and multilayered. In addition, in order to reduce the RC signal delay, copper is used as the wiring material, and a material having a low dielectric constant k is used as the insulating layer material. In addition, a damascene process, which does not perform metal etching and an insulating layer gap filling process, has been developed due to difficulty in metal patterning due to a reduction in design rule.

In the damascene process, an etch stop film and an interlayer insulating film are formed on a substrate on which a lower wiring using copper, etc. is formed, and then a predetermined area of the interlayer insulating film and the etch stop film is etched to form holes or trenches, and a metal layer is embedded in the holes or trenches. To form a metal wiring. At this time, before the etch stop layer is formed, a natural dead film is formed on the lower wiring, which serves to increase the resistance of the wire, and thus it must be removed before forming the etch stop layer. In addition, in order to improve the characteristics of the wiring, after removing the native oxide film, a silicide film is formed on the lower wiring and an etch stop film is formed.

By the way, a natural oxide film removal process, a silicide film formation process, and an etch stop film formation process are mainly performed using another process chamber. As a result, the process takes a long time and the equipment utility is also lowered, thereby lowering the productivity. In addition, semiconductor substrates having a predetermined structure may be vulnerable to plasma damage, particles, etc. due to the use of plasma, changes in temperature, pressure, process gas, and the like. In addition, in the case of the etch stop film, the film quality in the initial stage of deposition decreases the adhesion property with the lower film, which may cause a problem that the etch stop film is lifted.

The present invention provides a method of manufacturing a semiconductor device in which a plurality of processes are continuously performed in the same chamber while gradually increasing the source of the next process while the source of the previous process is introduced.

The present invention provides a method for manufacturing a semiconductor device in which the second source is gradually increased while the first source is introduced, and subsequently introduced thereto to continuously perform the etching stop film deposition process in situ from the removal of the natural oxide film in the damascene process. .

In the method of manufacturing a semiconductor device according to an aspect of the present invention, a plurality of processes are continuously performed in the same chamber, and a first source is introduced to gradually increase and introduce a second source to perform the first process. The second process begins before or after the process ends.

According to another aspect of the present invention, a method of manufacturing a semiconductor device includes loading a semiconductor substrate into a reaction chamber; Introducing a first source into the reaction chamber to remove a native oxide film on the semiconductor substrate; And gradually increasing and introducing a second source into the reaction chamber before the natural oxide film is completely removed or when the natural oxide film is completely removed to form a thin film on the semiconductor substrate.

The first and second sources are excited using plasma.

The thin film is formed by increasing the concentration of the second source toward the top.

The second source is gradually increased to flow in or in a constant amount after a set time.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, the method including: loading a semiconductor substrate into a reaction chamber; Introducing a first source into the reaction chamber to remove a native oxide film on the semiconductor substrate; Gradually increasing the purge gas into the reaction chamber after the first source is introduced and before the natural oxide film is completely removed; Stopping the flow of the first source and the purge gas and introducing a second source into the reaction chamber to form a silicide film on the semiconductor substrate; And gradually increasing the first source at the same time as the introduction of the second source to form the thin film at the same time as nitriding the silicide layer.

The removal of the natural oxide film and the formation of a thin film are performed by applying a plasma, and the silicide film is formed without applying a plasma.

The present invention provides a method of manufacturing a semiconductor device in which a plurality of processes are continuously performed in the same chamber while gradually increasing the source of the next process while the source of the previous process is introduced. In other words, while maintaining the atmosphere of the first source, the second source is gradually increased while the first process is performed so that the second process starts before the first process is completed.

According to the present invention, the process can be performed while minimizing the change in the reaction chamber with respect to the change in the process step by performing the second process before the first process is completely terminated. Therefore, it is possible to minimize the damage caused by the process damage and particles caused by the plasma, temperature, pressure, and change of the reaction gas. In addition, it is possible to improve the initial film quality of the deposited film can improve the adhesion properties with the lower film.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention and to those skilled in the art. It is provided for complete information. In the drawings, the thickness of layers, films, panels, regions, etc., may be exaggerated for clarity, and like reference numerals designate like elements. In addition, if a part such as a layer, film, area, etc. is expressed as “upper” or “on” another part, each part is different from each part as well as being “right up” or “directly above” another part. This includes the case where there is another part between parts.

1 is a schematic cross-sectional view of a reaction apparatus used in the method of manufacturing a semiconductor device according to the present invention, which is a schematic cross-sectional view of a reaction apparatus that simultaneously performs etching and deposition using plasma.

Referring to FIG. 1, a reaction apparatus used in the present invention includes a reaction chamber 100 having a reaction space therein, a substrate support 110 provided below the reaction chamber 100 to support the substrate 10, and A showerhead 120 disposed above the inside of the reaction chamber 100 facing the substrate support 110 to inject the reaction source, and a first source supply unit 130 to supply the first source to the showerhead 120. And a second source supply unit 140 for supplying a second source to the showerhead 120, and a plasma generator 150 for exciting the first and second sources injected from the showerhead 120. .

The reaction chamber 100 provides a predetermined reaction zone and keeps it airtight. The reaction chamber 100 includes a reaction part having a predetermined space, including a substantially circular flat part and a side wall part extending upwardly from the planar part, and positioned on the reaction part in a substantially circular shape to keep the reaction chamber 100 airtight. It may include a cover. Of course, the reaction unit and the cover may be manufactured in various shapes other than a circle, for example, may be manufactured in a shape corresponding to the shape of the substrate 10.

The substrate support 110 is provided below the reaction chamber 100 and is installed at a position facing the shower head 120. The substrate support 110 may be provided with, for example, an electrostatic chuck so that the substrate 10 introduced into the reaction chamber 100 may be seated. In addition, the substrate support 110 may be provided in a substantially circular shape, but may be provided in a shape corresponding to the shape of the substrate 10 and may be made larger than the substrate 10. A substrate lift 111 is provided below the substrate support 110 to move the substrate support 110 up and down. When the substrate 10 is seated on the substrate support 110, the substrate lift 111 moves the substrate support 110 to approach the showerhead 120. In addition, a heater (not shown) is mounted in the substrate support 110. The heater generates heat to a predetermined temperature to heat the substrate 10 so that a process using the first and second sources, for example, removal of a natural oxide layer, formation of a silicide film, and deposition of an etch stop film may be easily deposited on the substrate 10. do. Meanwhile, a cooling tube (not shown) may be further provided in the substrate support 110 in addition to the heater. The cooling tube allows the coolant to circulate in the substrate support 110 so that the cooling heat is transferred to the substrate 10 through the substrate support 110 to control the temperature of the substrate 10 to a desired temperature.

The shower head 120 is installed at a position opposite to the substrate support 110 in the upper portion of the reaction chamber 100, and sprays the first and second sources to the lower side of the reaction chamber 100. The shower head 120 has an upper portion connected to the first source supply unit 130 and the second source supply unit 140, and the lower portion of the shower head 120 has a plurality of injection holes 122 for injecting the first and second sources onto the substrate 10. ) Is formed. The showerhead 120 may be manufactured in a substantially circular shape, but may be manufactured in the shape of the substrate 10. In addition, the shower head 120 may be manufactured to the same size as the substrate support (110).

The first source supply unit 130 is connected to an upper portion of the shower head 120 to supply a first source to the shower head 120, a first source supply pipe 132, and a first source storage unit to store the first source. 134. The first source storage unit 134 removes the native oxide layer and stores a source for forming an etch stop layer such as silicon nitride (SiN), for example, a nitrogen source such as NH ₃ . In addition, the first source storage unit 134 may store the H ₂ source to remove the native oxide layer. Accordingly, the first source storage unit 134 may store the NH ₃ source and the H ₂ source separately. The first source stored in the first source storage unit 134 is supplied to the showerhead 120 through the first source supply pipe 132. In addition, a valve (not shown) is installed between the first source storage unit 134 and the first source supply pipe 134 so as to control the supply and supply amount of the first source.

The second source supply unit 140 is connected to an upper portion of the showerhead 120 to supply a second source to the showerhead 120, a second source supply pipe 142, and a second source storage unit to store the second source. 144. The second source storage unit 144 forms an etch stop film such as, for example, a silicon nitride film, and stores a source for forming a silicide film, for example, a silicon source such as SiH ₄ . The second source stored in the second source storage unit 144 is supplied to the showerhead 120 through the second source supply pipe 142. In addition, a valve (not shown) is installed between the second source storage unit 144 and the second source supply pipe 142 to control the supply and supply amount of the second source.

The plasma generator 150 is installed to excite at least one of the first and second sources. The plasma generator 150 may include a plasma generator coil 152 that may be installed in at least one of the upper and side portions of the reaction chamber 100, and a power supply unit 154 that supplies predetermined power to the plasma generator coil 152. ). Here, when the plasma generating coils 152 are installed at the top and side of the reaction chamber 100 at the same time, these plasma generating coils 152 may be connected in parallel. In addition, the plasma generating coil 152 installed on the upper portion of the reaction chamber 100 has an outer diameter larger than that of the shower head 120 to completely ionize the first and second sources injected from the shower head 120. desirable. Therefore, when a predetermined power is applied to the plasma generating coil 152 from the power supply unit 154, a magnetic field is generated from the plasma generating coil 152 to excite the first and second sources.

In addition, although not shown, a vacuum pump (not shown) for adjusting the pressure in the reaction chamber 100, a discharge port (not shown) for discharging the unreacted gas in the reaction chamber 100, and for supplying a purge gas A purge gas supply unit (not shown) may be further provided.

2 to 6 are cross-sectional views of devices sequentially shown to explain a method of manufacturing a semiconductor device according to an embodiment of the present invention.

Referring to FIG. 2, the semiconductor substrate 200 having a predetermined structure is loaded into the reaction chamber 100. For example, individual elements such as transistors and memory cells are formed on the semiconductor substrate 200, and lower wirings 210 are formed using copper or the like. However, after the lower wiring 210 is formed, the native oxide film 220 is grown on the lower wiring 210 by the transfer of the semiconductor substrate 200. The natural oxide film 220 is formed of a copper oxide film CuO when the lower wiring 210 is formed of copper. When the semiconductor substrate 200 on which the lower wiring 210 is formed is loaded into the reaction chamber 100, the semiconductor substrate 200 is seated on the substrate support 110, and the substrate lift 111 is elevated upwards to thereby support the substrate support ( The interval between the shower head 120 and the shower head 120 is maintained at a predetermined interval.

Referring to FIG. 3, the substrate 10 is maintained at a predetermined temperature, for example, 400 ° C. to 550 ° C. by using a heater (not shown) in the substrate support 110, and a vacuum pump (not shown) is used. Pressure in the reaction chamber 100 to maintain a vacuum, for example. Then, the first source supply unit 130 supplies a first source such as NH ₃ to the shower head 120 and generates a high frequency of 13.56 MHz by applying, for example, 850 W of power by the plasma generator 150. And plasma is generated using the same. That is, the first source is introduced from the first source supply unit 130 in an amount of, for example, 300 to 5000 sccm. When the first source is introduced and a plasma is generated, the natural oxide film 220 is removed after, for example, 10 seconds to 20 seconds. The removal time of the natural oxide film 220 may be controlled according to the thickness and the supply amount of the first source. For example, the natural oxide film 220 may be removed earlier or later than 20 seconds.

Referring to FIG. 4, after the first source is introduced and the set time, that is, after the time when the natural oxide film 220 is removed, for example, after the time when the first source is introduced and after about 10 seconds to 20 seconds, the second source starts. The second source is supplied from the source supply unit 130 in an amount that gradually increases with time. At this time, for example, by applying the power of 200W by the plasma generating unit 150 generates a high frequency of 13.56MHz, by applying this to generate a plasma. In addition, the first source maintains an inflow rate of, for example, 300 to 5000 sccm. That is, the second source is supplied such that the inflow gradually increases, for example, about 5 to 10 sccm every 10 seconds. By the supply of the second source, the etch stop layer 230 of the silicon nitride layer SiN begins to be deposited on the semiconductor substrate 200. However, the etch stop layer 230 which is initially deposited is formed of a silicon nitride film having a low concentration of silicon.

Referring to FIG. 5, the inflow of the first source is maintained and the inflow of the second source is continuously increased to form the etch stop layer 230 of the silicon nitride film on the semiconductor substrate 200. For example, the flow rate of the second source is finally applied to be about 50 to 300 sccm. At this time, for example, by applying the power of 200W by the plasma generating unit 150 generates a high frequency of 13.56MHz, by applying this to generate a plasma. However, since the silicon nitride film is introduced while the supply amount of the second source is gradually increased, the silicon nitride film is formed by changing the film quality from the bottom to the top. That is, the etch stop layer 230 is formed to increase the concentration of silicon toward the top. In detail, an etch stop layer 230 having a low concentration of silicon and a high concentration of silicon toward the upper portion of the portion in contact with the semiconductor substrate 200 is formed. In this case, the second source may increase the inflow amount until the etch stop layer 230 is formed to the set thickness, or increase the inflow amount and keep the inflow constant. Therefore, the adhesion with the lower layer of the etch stop layer 200 is improved.

Referring to FIG. 6, an interlayer insulating layer 240 is formed on the etch stop layer 230. The interlayer insulating layer 240 may be formed of a material having a large difference in etch rate from the etch stop layer 230. That is, since the etch stop layer 230 is formed of silicon nitride, the interlayer insulating layer 240 is formed of an oxide-based material. In addition, the interlayer insulating film 240 is preferably formed of a material having a low dielectric constant. The interlayer insulating film 240 may include a porous silicon oxide film, a phosphorous silicate glass (PSG) film, a boron phosphorous silicate glass (BPSG) film, an undoped silicate glass (USG) film, a fluorine doped silicate glass (FSG) film, a SiOC film, and an HDP (HDP). It is preferable to form a low dielectric constant material such as a high density plasma (PED) film, a plasma enhanced-tetra ethyl ortho silicate (PE-TEOS) film, or a spin on glass (SOG) film. Meanwhile, the interlayer insulating layer 240 may be formed using a reaction chamber different from the reaction chamber 100. That is, the semiconductor substrate 200 on which the etch stop layer 230 is formed is unloaded from the reaction chamber 100 and then loaded into another reaction chamber to form the interlayer insulating layer 240.

7 to 11 are cross-sectional views of devices sequentially illustrated to explain a method of manufacturing a semiconductor device according to another embodiment of the present invention. Here, the description overlapping with the description of the embodiment of the present invention will be omitted.

Referring to FIG. 7, the semiconductor substrate 200 on which the lower wiring 210 is formed is loaded into the reaction chamber 100 using copper or the like. The native oxide film 220 is grown on the lower wiring 210. When the semiconductor substrate 200 is loaded into the reaction chamber 100, the semiconductor substrate 200 is seated on the substrate support 110, and the substrate lift 111 is lifted upward to raise the substrate support 110 and the showerhead 120. ) To maintain a predetermined interval.

Referring to FIG. 8, the substrate 10 is maintained at a predetermined temperature using a heater in the substrate support 110, and the pressure in the reaction chamber 100 is maintained, for example, in a vacuum state. Then, the first source supply unit 130 supplies a first source such as NH ₃ to the shower head 120 and generates a high frequency of 13.56 MHz with a power of 850 W, for example, by the plasma generator 150. This is applied so that the plasma is generated. At this time, helium (He) and the like gradually increase the inflow of the purge gas at the same time as the supply of the first source or after the time at which the natural oxide film 220 is removed. That is, the first source is introduced from the first source supply unit 130 in an amount of, for example, 300 to 5000 sccm, and the purge gas is gradually introduced from the supply amount of, for example, 100 sccm. When the first source is introduced and the plasma is generated, the natural oxide film 220 is removed after 10 seconds to 20 seconds. In addition, the first source is purged at the same time as the natural oxide film 220 is removed.

Referring to FIG. 9, the operation of the plasma generator 150 is stopped to prevent plasma from being generated, and a second source such as SiH _{4 is} supplied from the second source supply unit 140 to the shower head 120. Accordingly, the silicide film 250 is formed on the lower wiring 210. Since the lower interconnection 210 is made of copper, the silicide layer 250 is formed of copper silicide (CuSix). At this time, the first source, for example NH _3, is gradually supplied from the first source supply unit 130 at the same time as the supply of the second source or after a predetermined time.

Referring to FIG. 10, while the supply amount of the second source is maintained as it is, while the supply amount of the first source is gradually increased, the operation of the plasma generator 150 is resumed after a predetermined time so that the plasma is generated. For example, the plasma generator 150 generates a high frequency of 13.56 MHz with a power of 200 W, and applies the same to generate a plasma. This changes the silicide film 250 to the copper silicon nitride film (CuSiN) 260 by the second source, for example NH ₃ . At the same time, the etch stop layer 230 of the silicon nitride layer SiN begins to be deposited on the semiconductor substrate 200. However, the etch stop layer 230 which is initially deposited is formed of a silicon nitride film having a low concentration of silicon.

Referring to FIG. 11, the inflow of the first source is maintained and the inflow of the second source is continuously increased to form the etch stop layer 230 of the silicon nitride film on the semiconductor substrate 200. However, since the silicon nitride film is introduced while the supply amount of the second source is gradually increased, the silicon nitride film is formed by changing the film quality from the bottom to the top. That is, the etch stop layer 230 is formed to increase the concentration of silicon toward the top. In detail, an etch stop layer 230 having a low concentration of silicon and a high concentration of silicon toward the upper portion of the portion in contact with the semiconductor substrate 200 is formed. In this case, the second source may increase the inflow amount until the etch stop layer 230 is formed to the set thickness, or increase the inflow amount and keep the inflow constant.

Referring to FIG. 12, an interlayer insulating layer 240 is formed on the etch stop layer 230. The interlayer insulating layer 240 may be formed of a material having a large difference in etching rate from the etch stop layer 230. That is, since the etch stop layer 230 is formed of silicon nitride, the interlayer insulating layer 240 is formed of an oxide-based material. In addition, the interlayer insulating film 240 is preferably formed of a material having a low dielectric constant.

On the other hand, although the technical spirit of the present invention has been described in detail according to the above embodiment, it should be noted that the above embodiment is for the purpose of explanation and not for the limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention. For example, the present invention can be applied to a manufacturing process of a semiconductor device using an etch stop film in addition to the damascene process.

1 is a schematic cross-sectional view of a reaction apparatus used in the present invention.

2 to 6 are cross-sectional views of devices sequentially shown to explain a method of manufacturing a semiconductor device according to an embodiment of the present invention.

7 to 12 are cross-sectional views of devices sequentially shown to explain a method of manufacturing a semiconductor device according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

200: semiconductor substrate 210: lower wiring

220: natural oxide film 230: etch stop film

240: interlayer insulating film 250: copper silicide film

260 copper silicon nitride film

Claims (7)

delete Loading a semiconductor substrate having a native oxide film grown thereon into a reaction chamber; Introducing a nitrogen source into the reaction chamber to etch and remove the native oxide film on the semiconductor substrate; And Maintaining the inflow of the nitrogen source and gradually increasing the silicon source into the reaction chamber from the time point before or completely removing the natural oxide film to form the silicon nitride film on the semiconductor substrate; Method of manufacturing a semiconductor device. The method of claim 2, wherein the nitrogen source and the silicon source are excited using plasma. The method of claim 2, wherein the silicon nitride layer is formed by increasing a concentration of the silicon source toward an upper portion thereof. The method of claim 2, wherein the silicon source is gradually increased to flow in or in a constant amount after a predetermined time. Loading a semiconductor substrate into the reaction chamber; Introducing a first source into the reaction chamber to remove a native oxide film on the semiconductor substrate; Gradually increasing the purge gas into the reaction chamber after the first source is introduced and before the natural oxide film is completely removed; Stopping the flow of the first source and the purge gas and introducing a second source into the reaction chamber to form a silicide film on the semiconductor substrate; And And gradually increasing the first source simultaneously with the introduction of the second source to nitrate the silicide layer to form a thin film. The method of claim 6, wherein the removal of the native oxide film and the formation of the thin film are performed by applying plasma, and the silicide film is formed without applying plasma.

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