JP5031953B2 - Copper material filled plug and method for producing copper material filled plug - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a copper material filled plug and a method for manufacturing a copper material filled plug, and more particularly to an improvement in a copper material filled plug used in a wiring layer of a semiconductor device and a method for manufacturing the same.
[0002]
[Prior art]
When copper wiring is used in the manufacture of LSI, a barrier metal is formed between the silicon oxide film and the copper wiring in order to prevent copper from diffusing into an insulating film such as a silicon oxide film as a base film. Yes.
[0003]
PVD tantalum nitride (TaN) is mainly used as the material for the barrier metal. This is because tantalum does not form an alloy with copper, and therefore has higher barrier properties against copper diffusion than PVD titanium nitride (TiN) conventionally used in aluminum wiring. However, TaN has a specific resistance more than twice as high as TiN (≦ 100 μΩ · cm) (≧ 200 μΩ · cm). In particular, when the barrier metal is formed as a barrier metal at the via junction, Becomes excessively high.
[0004]
Further, since the TaN thin film has a large internal stress, when the TaN thin film is deposited in the film forming apparatus, the thin film is finely peeled and dust is easily generated.
[0005]
Further, the TaN thin film has poor adhesion to a Cu thin film (hereinafter referred to as a CVD-Cu thin film) formed by the CVD method, and a CVD-Cu thin film is grown using the TaN thin film as a base film, or on the TaN thin film. When a copper plating film is grown using the formed CVD-Cu thin film as a seed layer, the CVD-Cu thin film easily peels off from the interface with the TaN thin film, and the CVD-Cu thin film is put into practical use as a copper wiring. Was the biggest obstacle.
[0006]
[Problems to be solved by the invention]
The present invention was created to meet the above-described prior art requirements. The purpose of the present invention is to have a small specific resistance, high adhesion to a CVD-Cu thin film, and a high internal capacity when a Cu thin film is used as a wiring. The object is to provide a barrier metal with low stress.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is a copper material filled plug, comprising an insulating film, a hole provided in the insulating film, and at least a surface of the insulating film inside the hole. A vanadium oxynitride thin film disposed; and a copper material filled in the hole in which the vanadium oxynitride thin film is disposed.
A second aspect of the present invention is the copper material-filled plug according to the first aspect, wherein the copper material is formed by a CVD method.
A third aspect of the present invention is the copper material-filled plug according to the first aspect, wherein the copper material is formed on the surface of the vanadium oxynitride thin film by a CVD method and on the surface of the copper thin film. And the filled copper material.
A fourth aspect of the present invention is the copper material-filled plug according to any one of the first to third aspects, wherein the vanadium oxynitride thin film contains a maximum of 25% oxygen as an element ratio in the composition.
The invention according to claim 5 is a method of manufacturing a plug filled with a copper material, the step of forming an insulating film provided with a hole on a substrate, and the formation of a vanadium oxynitride thin film in the hole of the insulating film And a step of growing a copper material by a CVD method on the surface of the vanadium oxynitride thin film.
A sixth aspect of the present invention is the method of manufacturing a copper material-filled plug according to the fifth aspect, wherein the vanadium oxynitride thin film is formed by reactive sputtering or CVD.
Invention of Claim 7 is a manufacturing method of the copper material filling plug of any one of Claim 5 or 6. ,Previous The copper material is filled in the hole.
[0008]
According to the present invention, the insulating film formed on the substrate surface, the hole formed in the insulating film, and the surface of the insulating film inside the hole are disposed. Acid It has a vanadium nitride thin film and a copper material filled in the hole.
[0009]
in this way ,acid A vanadium nitride thin film is disposed inside the hole as a barrier metal. This Acid When a CVD-Cu thin film is formed using a vanadium nitride thin film as a base film ,acid Since the vanadium nitride thin film has high adhesiveness with the CVD-Cu thin film, the CVD-Cu thin film is less likely to be peeled off as compared with the conventional case where the TaN thin film is used as the base film.
[0010]
Also ,acid Since the vanadium nitride thin film has a smaller specific resistance than the TaN thin film, the via resistance does not increase even if it is formed thick inside the via.
[0011]
further ,acid Since the vanadium nitride thin film has low internal stress, even if the thin film is deposited inside the manufacturing apparatus, the thin film does not peel finely. Therefore, it does not cause dust generated when the deposited thin film is finely peeled off.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
A method for manufacturing a copper-filled plug according to an embodiment of the present invention will be described below with reference to the drawings.
First, a sputtering apparatus and a CVD apparatus used in the method for producing a copper-filled plug will be described. Reference numerals 1 and 5 in FIGS. 1 and 2 show a sputtering apparatus and a CVD apparatus used in this embodiment, respectively.
[0013]
A sputtering apparatus 1 shown in FIG. 1 has a vacuum chamber 2. A gas introduction system 27 and an evacuation system 28 are connected to the vacuum chamber 2, and when the gas introduction system 27 is activated, an Ar gas that is a sputtering gas and an N gas that is a reaction gas. ₂ Gas and O ₂ The gas can be introduced into the vacuum chamber 2. On the other hand, when the vacuum exhaust system 28 is activated, the inside of the vacuum chamber 2 can be evacuated.
[0014]
A target 3 made of metal is disposed on the inner ceiling side of the vacuum chamber 2. This target 3 is made of vanadium. The target 3 is insulated from the grounded vacuum chamber 2 and is connected to a power source 4 provided outside the vacuum chamber 2. When the power source 4 is activated, a DC voltage is applied to the target 3 to supply power. It is comprised so that.
[0015]
On the other hand, an electrostatic adsorption device 21 is disposed on the inner bottom surface side of the vacuum chamber 2.
The surface of the electrostatic adsorption device 21 is flat so that a substrate can be placed thereon. Further, an electrode is disposed inside the electrostatic adsorption device 21, and an electrostatic chuck power source 22 disposed outside the vacuum chamber is connected to the electrode, and the electrostatic chuck power source 22 with the substrate placed thereon. When the is activated, the substrate can be electrostatically adsorbed.
[0016]
Next, the CVD apparatus used in this embodiment will be described. 2, the CVD apparatus includes a vacuum chamber 6, an electrostatic adsorption device 31 disposed on the inner bottom surface of the vacuum chamber 6, and an electrostatic chuck power supply 32 disposed outside the vacuum chamber 6. And.
[0017]
A mesh plate 9 is disposed on the inner ceiling side of the vacuum chamber 6. The mesh plate 9 is connected to a gas introduction system 7 disposed outside the vacuum chamber 6. When the gas introduction system 7 is activated, gas can be introduced into the vacuum chamber 6 through the mesh plate 9. It is configured. An evacuation system 8 is connected to the vacuum chamber 6, and the interior of the vacuum chamber 6 can be evacuated when the evacuation system 8 is activated.
[0018]
The electrostatic adsorption device 31 has a flat surface so that a substrate can be placed thereon. Further, an electrode is disposed inside the electrostatic adsorption device 31, and an electrostatic chuck power source 32 disposed outside the vacuum chamber is connected to the electrode, and the electrostatic chuck power source 32 is placed with the substrate placed thereon. When the is activated, the substrate can be electrostatically adsorbed. Further, a heater (not shown) is arranged inside the electrostatic adsorption device 31, and is configured so that the temperature of the substrate can be raised when the heater is activated in a state where the substrate is electrostatically adsorbed.
[0019]
A method of manufacturing a copper-filled plug in which holes are formed in an insulating film formed on the surface of a substrate made of silicon or the like and a copper material is filled in the holes using the above-described apparatus will be described.
[0020]
First, as shown in FIG. 3A, an insulating film 52 made of a silicon oxide film is formed on the surface of the substrate 51 in advance, and then patterned to form a hole 53 in the insulating film 52. The surface of the substrate 51 is exposed. Here, a circular hole having a depth of 1.6 μm and an opening diameter of 0.3 μm is formed.
[0021]
Next, the inside of the vacuum chamber 2 of the sputtering apparatus 1 is evacuated, and while maintaining the vacuum state inside the vacuum chamber 2, the substrate 51 shown in FIG. It is placed on the electroadsorption device 21.
[0022]
Next, when the electrostatic chuck power source 22 is activated and a voltage is applied to the electrodes, the entire back surface of the substrate 51 is attracted to the surface of the electrostatic attraction device 21. Once adsorbed, Ar gas as the sputtering gas and N as the reaction gas ₂ And O ₂ A gas mixture gas is introduced from the gas introduction system 27. In the gas introduction system 27, Ar gas and N ₂ Gas and O ₂ Adjust the gas flow rate respectively, O ₂ While the gas is set to 7000 ppm with respect to the total pressure inside the vacuum chamber 2, the power source 4 is activated to supply power to the target 3. Then, discharge occurs and the target 3 is sputtered. Vanadium which is a constituent material of the sputtered target 3 is N ₂ Gas or O ₂ A vanadium oxynitride (VNO) thin film grows on the surface of the insulating film 52 exposed to the inside of the hole 53 and the surface of the insulating film 52 outside the hole 53 by reacting with the gas and reaching the substrate surface. Where O ₂ The density of O atoms contained in the VNO thin film can be controlled by adjusting the partial pressure of the gas. By the way O ₂ If the gas partial pressure is 0, a VN thin film is formed.
[0023]
Although the substrate temperature rises due to the discharge, a cooling device (not shown) is arranged inside the electrostatic adsorption device 21 so that the substrate can be cooled, and the substrate temperature does not rise excessively. It is like that.
[0024]
When the vanadium oxynitride thin film grows and the film thickness reaches the target thickness, the power source 4 is stopped to extinguish the plasma, thereby terminating the growth. Here, the growth is terminated when the VNO thin film grows to 70 nm. Through the above steps, a VNO thin film is formed on the insulating film 52 exposed inside the hole 53 and on the surface of the insulating film 52 outside the hole 53. The state is shown in FIG. Reference numeral 55 in the drawing indicates a VNO thin film formed inside the hole 53, and reference numeral 54 indicates a VNO thin film formed on the surface of the insulating film 52 outside the hole 53.
[0025]
Although the case where the film is formed by reactive sputtering has been described above, it is of course possible to form the film using a thermal CVD method or a plasma CVD method.
In this case, the source gas is VCl for inorganic systems. _Four In organic systems, bis (cyclopentadienyl) vanadium (II), bis (cyclopentadienyl) methyl vanadium (III), 2,4-pentanedionate vanadium (III), oxide bis (2,4-pentanedio Nate) vanadium (III), tris (2,4-pentanedionato) vanadium (III) as appropriate, combined, NH _Three A film can be formed by reacting with a gas. O if necessary ₂ Decomposition may be assisted by adding a gas or using plasma or the like.
[0026]
When the VNO thin films 54 and 55 are thus formed, the substrate 51 is taken out from the vacuum chamber 2 while maintaining the vacuum state inside the vacuum chamber 2.
[0027]
Thereafter, the substrate on which the VNO thin films 54 and 55 are formed is processed inside the CVD apparatus 6. The inside of the CVD apparatus 6 is evacuated in advance, and the taken-out substrate 51 is carried into the vacuum chamber 7 of the CVD apparatus and placed on the surface of the electrostatic chuck 31 while maintaining the vacuum state inside. To do.
[0028]
Next, when the electrostatic chuck power source 32 is activated and a voltage is applied to the electrodes, an attracting force is generated between the substrate 51 and the electrodes, and the entire back surface of the substrate 51 is attracted to the surface of the electrostatic attracting device 31.
[0029]
When the substrate 51 is attracted to the surface of the electrostatic adsorption device 31, the heater is activated to raise the temperature of the substrate 51. When the substrate 51 reaches a temperature suitable for film formation, the source gas for CVD-Cu and the carrier H ₂ A gas mixture is introduced into the vacuum chamber 7 as a reaction gas.
[0030]
Here, the source gas for CVD-Cu is a gas containing a known copper-containing precursor, such as bis (hexafluoroacetylacetonato) copper (II), hexafluoroacetylacetonatocopper (I) trimethylvinylsilane, hexafluoroacetyl. Acetonatocopper (I) bistrimethylsilylacetylene, hexafluoroacetylacetonatocopper (I) 1,5-cyclooctadiene, hexafluoroacetylacetonatocopper (I) 2-butyne, hexafluoroacetylacetonatocopper (I) triethyl A gas containing any one precursor among phosphine, Cu (I) t-butoxide, and Cu (I) t-butoxidecarbonyl is preferable.
[0031]
When such a reaction gas is introduced into the vacuum chamber 7, a copper thin film begins to grow on the inside of the hole 53 and the surfaces of the external VNO thin films 54 and 55.
[0032]
When the copper thin film grown on the surfaces of the VNO thin films 54 and 55 reaches the target film thickness in advance, the introduction of the reaction gas is stopped and the growth of the copper thin film is terminated. Here, the growth is terminated when the film is grown to a thickness of 50 nm. The state is shown in FIG. In the figure, reference numeral 71 indicates a copper thin film grown on the surface of the VNO thin film 55 inside the hole 53, and reference numeral 70 indicates a copper thin film formed on the surface of the VNO thin film 54 outside the hole 53.
[0033]
Next, the substrate 51 on which the copper thin films 70 and 71 are formed is taken out while maintaining the vacuum state inside the vacuum chamber 6. Next, copper is grown by electrolytic plating using the copper thin films 70 and 71 as seed layers, and the inside of the hole 53 is filled. The state is shown in FIG. Here, 500 nm of copper is grown. In the figure, reference numeral 56 indicates a filling material filled with copper inside the hole 53, and reference numeral 57 indicates a copper film formed on the surface of the VNO thin film 54 outside the hole 53.
[0034]
Thereafter, the surface of the copper film 57 is polished, and the copper film 57 and the VNO thin film 54 that is the underlying film are completely removed, so that the VNO thin film 55 and the copper thin film 71 are sequentially formed on the surface of the insulating film 52 inside the hole. Then, a copper filling plug 80 in which the copper material 56 is formed on the surface and the hole is filled is formed. The state is shown in FIG.
[0035]
Thus, as a result of observing the surface of the copper-filled plug 80 on which the VNO thin film was formed by SEM, the hole 53 having a depth of 1.6 μm and an opening diameter of 0.3 μm was completely embedded, and was formed by plating. It was confirmed that no peeling was observed in the copper thin film 56.
[0036]
The inventors of the present invention tried to form a TaN thin film with a thickness of 70 nm on the surface of the silicon substrate by sputtering instead of the VNO thin film described above, and formed a copper thin film with a thickness of 50 nm on the surface of the TaN thin film by CVD. Then, a 500 nm copper thin film was deposited by electrolytic plating on the copper thin film. However, in the pure water cleaning process, the copper thin film formed by electrolytic plating was almost completely peeled off.
[0037]
As described above, the copper-filled plug 80 of this embodiment has the VNO thin film 54 formed on the surface of the insulating film 52 inside the hole 53.
[0038]
Since the VNO thin film 54 has a small specific resistance as will be described later, even if the VNO thin film 54 is formed thick inside the hole 53, the contact resistance does not increase excessively. Further, when the VNO thin film 54 is used as a barrier metal, it becomes difficult for copper atoms to be mixed into the insulating film 52 from the copper material 56, and the barrier property against copper becomes high. Furthermore, since the VNO thin film 54 has high adhesion to the CVD-Cu thin film, the copper material 56 is difficult to peel off. Therefore, the VNO thin film 54 is more suitable as a barrier metal for copper than the TaN thin film.
[0039]
In order to confirm the high adhesion between the VNO thin film and the CVD-Cu thin film, the inventors of the present invention confirm the adhesion between the VNO thin film and the CVD-Cu thin film and the adhesion between the TaN film and the CVD-Cu thin film. The test which compares with sex was done.
[0040]
In this test, 20 substrates are first prepared, and a 70 nm thick VNO thin film is formed on the surface of 10 of them, and a 70 nm thick TaN film is formed on the remaining 10 surfaces by reactive sputtering. Two types of samples were prepared in which a CVD-Cu thin film having a thickness of 30 to 100 nm was deposited on the surface of each VNO thin film and TaN film.
[0041]
Then, for each sample on which the TaN film and the VNO thin film are respectively formed, a tape test is performed in which 100 mm squares are drawn on the surface of the CVD-Cu thin film with a cutter, and an adhesive tape is attached to each surface and then peeled off. For each sample, the cells remaining without peeling from the surface after the adhesive tape was peeled off were counted.
As a result, when the film thickness of the CVD-Cu thin film was up to 100 nm, 100% of the mesh on the VNO thin film remained, but no grid on the TaN film remained.
[0042]
The inventors of the present invention prepare a sample in which a PVD-Cu thin film having a larger internal stress than that of the CVD-Cu thin film is further laminated on the above-described CVD-Cu thin film on which the VNO thin film is formed. When the test was performed, almost 50% peeled when the PVD-Cu thin film was laminated to 100 nm. However, when the same tape test is performed after heat treatment at 400 ° C., the remaining mesh is 100%, and it can be seen that the adhesion is greatly improved by the heat treatment. On the other hand, even when the TaN thin film was heat treated at 400 ° C., no improvement in adhesion was observed.
[0043]
In this way, it can be confirmed that the adhesion between the barrier metal and the copper thin film is enhanced when the VNO thin film formed by the reactive sputtering method is used as the barrier metal and the CVD-Cu thin film is formed on the VNO thin film. It was.
[0044]
In the embodiment described above, O in the vacuum chamber 2 is used. ₂ As a result of forming the VNO thin film in the vacuum chamber 2 so that the gas had a total pressure of 7000 ppm, it was confirmed that the adhesion between the VNO thin film and the CVD-Cu thin film was good. The inventors have added O ₂ Even when the VNO thin film was formed by changing the gas flow rate, it was confirmed whether or not the adhesion between the VNO thin film and the CVD-Cu thin film was good as described above.
[0045]
Therefore, O inside the vacuum chamber 2 ₂ VN and VNO thin films were formed at a total pressure of 0 ppm, 200 ppm, 6000 ppm, 7000 ppm and 20000 ppm, and a CVD-Cu thin film was formed on the surface of each VNO thin film, and then each VNO thin film and CVD-Cu thin film The adhesion with was investigated. As a result, it was found that in any case, the adhesion between the VN and VNO thin films and the CVD-Cu thin film was good, and the CVD-Cu thin film was difficult to peel from the VN and VNO thin films.
[0046]
Thus, O in the vacuum chamber 2 ₂ Among samples in which the gas becomes 0 ppm, 200 ppm, 6000 ppm, 7000 ppm, 20000 ppm of the total pressure, O ₂ The composition ratio of atoms in each VNO thin film was measured by Auger spectroscopy for each sample whose gas had a total pressure of 6000 ppm and 7000 ppm.
[0047]
Of these measurement results, 6000 ppm O in Ar gas. ₂ The measurement result when the gas is added is shown in FIG. In the graph of FIG. 12, the horizontal axis indicates the sputtering time, and the vertical axis indicates the atomic density.
[0048]
In the drawing, curves (E), (F), (G), and (H) indicate the atomic densities of N, V, O, and Si, respectively. From the curve (G), it can be seen that the atomic density of O atoms in the VNO thin film is about 10%.
[0049]
FIG. 13 shows 7000 ppm O ₂ FIG. 13 shows measurement results when gas is added to Ar gas, and curves (J), (K), (L), and (M) in FIG. 13 indicate atomic densities of N, V, O, and Si, respectively. ing. From the curve (L), it can be seen that the atomic density of O atoms in the VNO thin film is about 15% of the whole.
[0050]
Similarly, O in the vacuum chamber ₂ For each sample in which the VNO thin film was formed so that the gas had a total pressure of 200 ppm and 20000 ppm, the atomic density of O atoms was examined. The atomic density of O atoms was 1% and 25%, respectively. .
[0051]
From the above, the VN film and the VNO thin film containing at least 1%, 10%, 15%, and 25% of oxygen atoms at all have good adhesion to the CVD-Cu thin film, and CVD. -It turns out that Cu thin film is hard to peel.
[0052]
In the above-described embodiment, the copper thin films 70 and 71 are used as seed layers and the holes 53 are filled with the filling material 56 made of copper by electrolytic plating. However, in the process shown in FIG. As shown in FIG. 4A, the copper thin films 70 and 71 are grown thickly on the surfaces of the VNO thin films 54 and 55, respectively, and the inside of the hole is filled with the copper thin film 71. As shown in (b), the copper filling plug 83 may be formed by polishing the copper thin film 70.
[0053]
In order to confirm that the VN and VNO thin films are suitable as a barrier metal for copper wiring, the inventors of the present invention further investigated various characteristics as described below.
[0054]
[Example 1]
The inventors of the present invention examined the nitrogen partial pressure dependence of the specific resistance during sputter deposition for each of the VN and VNO thin films and the other metal nitride thin films. FIG. 5 is a graph showing the results. The horizontal axis represents the nitrogen partial pressure when the pressure inside the vacuum chamber is the total pressure, and the vertical axis represents the specific resistance.
[0055]
Curve (A) shows the measurement result of the ZrN thin film, and curve (B) shows the measurement result of the CrN thin film. Curve (C) shows the measurement result of the TaN thin film, curve (D) shows the measurement result of the VNO thin film, and curve (N) shows the measurement result of the VN thin film. Here, the VNO thin film was formed by always adding 6000 ppm of oxygen to the total pressure at the time of sputtering film formation, and the oxygen (O) content at this time was about 10%, and the nitrogen partial pressure was It was almost constant against changes.
[0056]
From the curves (A), (B), and (C), the specific resistance of the ZrN thin film, CrN thin film, and TaN thin film fluctuates greatly with the change of the nitrogen partial pressure, and increases rapidly when the nitrogen partial pressure exceeds a certain value. 10 easily ^Three -10 ^Four It reaches to μΩ · cm.
[0057]
On the other hand, as shown in curves (D) and (N), the specific resistance of VNO and VN thin films increases or decreases only in the range of 70 to 200 μΩ · cm even if the nitrogen partial pressure is changed from 10% to 80%. In addition, the resistance is lower than other ZrN thin films, CrN thin films, and TaN thin films.
[0058]
In particular, a TaN thin film conventionally used as a barrier metal was formed at a nitrogen partial pressure at which the specific resistance starts to increase rapidly as a film capable of taking a barrier property against copper (in FIG. 5, the nitrogen partial pressure is around 43%). A membrane is used. The specific resistance value of the TaN thin film at this time is relatively high at about 300 μΩ · cm.
[0059]
On the other hand, when a VNO thin film is manufactured under a condition where the nitrogen partial pressure is around 30%, the specific resistance is about 120 μΩ · cm, which is less than half of the specific resistance of the TaN thin film produced under the same nitrogen partial pressure condition. It is low. The VN thin film is about 90 μΩ · cm, which is 1/3 or less.
[0060]
As described above, the VN and VNO thin films have a smaller specific resistance than the TaN thin film conventionally used as a barrier metal, and particularly when used as a barrier metal inside the hole, the contact resistance is reduced even if it is formed thick inside the hole. Is not excessively large and is suitable as a barrier metal.
[0061]
[Example 2]
The inventors of the present invention examined the barrier properties against copper for each of the VNO thin film and other metal nitride thin films.
[0062]
Four silicon substrates treated with dilute hydrofluoric acid were prepared, and a VNO thin film (containing 10% O atoms) was formed as a barrier film on the surface of each silicon substrate by reactive sputtering under a condition of a nitrogen partial pressure of 43%. ), A TaN thin film, a ZrN thin film, and a CrN thin film were each formed to a thickness of 10 nm, and then a 200 nm PVD-Cu thin film was laminated on each barrier film to prepare four types of samples. Each sample was annealed in a hydrogen atmosphere at 500 ° C. for 2 hours and further at 600 ° C. for 2 hours for a total of 4 hours, and then the substrate surface was observed by a scanning electron microscope (SEM).
[0063]
6, FIG. 7, FIG. 8, and FIG. 9 show surface analysis photographs of samples in which a VNO thin film, a TaN thin film, a CrN thin film, and a ZrN thin film are formed as barrier films, respectively.
[0064]
As shown in FIG. 6, in the sample using a TaN thin film as a barrier film, copper atoms diffuse into the silicon substrate through the barrier film from the PVD-Cu thin film and react with silicon, so that tower-shaped copper is obtained. It can be seen that silicide is formed all over the surface. As shown in FIGS. 8 and 9, the same tower-like copper silicide is formed also on the sample using the CrN thin film and the ZrN thin film as a barrier film.
[0065]
On the other hand, as shown in FIG. 7, the sample using the VNO thin film as a barrier film has a rough surface shape, but no tower-like copper silicide is formed. Thus, regarding the barrier property against copper, it was confirmed that the VNO thin film was the best among these four types of metal nitride thin films. Further, when the VN thin film was also examined, almost the same result as the VNO thin film was obtained.
[0066]
[Example 3]
The inventors of the present invention conducted a test to examine internal stress for each of the VNO thin film and the TaN thin film conventionally used as a barrier metal for copper wiring.
[0067]
In this test, a VNO thin film (containing 10% O atoms) and a TaN film were grown on a silicon substrate, and the growth was continued until the VNO thin film and the TaN thin film spontaneously peeled off. . As a result, SEM photographs of the surface state when peeling occurs for each of the VNO thin film and the TaN thin film are shown in FIGS. 10 and 11, respectively.
[0068]
The TaN thin film shown in FIG. 11 begins to peel like a scale with a thickness of about 600 nm, whereas the VNO thin film shown in FIG. 10 peels greatly like a ribbon with a thickness of about 1600 nm. This shows that the internal stress of the VNO thin film is smaller than that of the TaN thin film.
[0069]
Since the TaN thin film conventionally used as a barrier metal peels finely in a scale shape, when the TaN thin film is deposited in the manufacturing apparatus, the TaN thin film is finely peeled and then scattered to become dust. As described above, the VNO thin film is largely peeled off and does not peel finely, so that it is difficult to become dust.
[0070]
【Effect of the invention】
A barrier metal suitable for forming a copper wiring can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of a sputtering apparatus used in the present invention.
FIG. 2 is a diagram illustrating the configuration of a CVD apparatus used in the present invention.
FIG. 3A is a first cross-sectional view illustrating a manufacturing process of a copper material-filled plug according to an embodiment of the present invention.
(b): Second cross-sectional view illustrating a manufacturing process of a copper material-filled plug according to an embodiment of the present invention
(c): Third cross-sectional view illustrating a manufacturing process of a copper material-filled plug according to an embodiment of the present invention
(d): 4th sectional view explaining the manufacturing process of the copper material filling plug concerning one embodiment of the present invention.
(e): 5th sectional view explaining the manufacturing process of the copper material filling plug concerning one embodiment of the present invention.
FIG. 4A is a first cross-sectional view illustrating a manufacturing process of a copper material-filled plug according to another embodiment of the present invention.
(b): Second cross-sectional view illustrating a manufacturing process of a copper material-filled plug according to another embodiment of the present invention
FIG. 5 is a graph showing the nitrogen partial pressure dependence of the specific resistance of a metal nitride thin film during sputter deposition.
FIG. 6 is a photomicrograph showing the surface state of a VNO thin film after a test for barrier properties against copper.
FIG. 7 is a photomicrograph showing the surface state of a TaN thin film after a test for barrier properties against copper.
FIG. 8 is a micrograph showing the surface state of a CrN thin film after a test for barrier properties against copper.
FIG. 9 is a micrograph showing the surface state of a ZrN thin film after a test for barrier properties against copper.
FIG. 10 is an electron micrograph showing a state where a VNO thin film is peeled off from a silicon substrate.
FIG. 11 is an electron micrograph showing a state in which a TaN thin film is peeled off from a silicon substrate.
FIG. 12 is a first graph showing an analysis result of the composition ratio of a VNO thin film by Auger spectroscopy.
FIG. 13 is a second graph showing the analysis result of the composition ratio of the VNO thin film by Auger spectroscopy.
[Explanation of symbols]
52 ... Insulating film 53 ... Hole 55 ... Vanadium oxynitride thin film 56 ... Copper material 80 ... Plug filled with copper material

Claims (7)

An insulating film;
A hole provided in the insulating film;
At least, said insulating oxynitride vanadium film disposed on the surface of the membrane within said bore,
Copper material fill plug and a copper material filled prior to the hole inside hexane vanadium nitride thin film is placed.   The copper material-filled plug according to claim 1, wherein the copper material is formed by a CVD method. The copper material is
A copper thin film formed by a CVD technique prior hexane vanadium nitride thin film surface,
The copper material filling plug according to claim 1, comprising a filling copper material formed on a surface of the copper thin film.   The copper material-filled plug according to any one of claims 1 to 3, wherein the vanadium oxynitride thin film contains up to 25% of oxygen as an element ratio in the composition. Forming an insulating film provided with holes on the substrate;
Forming a vanadium oxynitride thin film in the holes of the insulating film ;
A method for producing a plug filled with a copper material, comprising a step of growing a copper material by a CVD method on the surface of the vanadium oxynitride thin film. Before hexane vanadium nitride thin film, the reactive sputtering or manufacturing method of the copper material filling plug of claim 5, wherein formed by a CVD method. Before kidou material, manufacturing method of copper material fill plug according to any one of the holes according to claim 5 or 6 internally filled in.

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