JPH11307533A - Semiconductor device and producing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly-reliable semiconductor device capable of preventing the release of a protecting film and the disconnection of wiring or the like caused by inert gas generated from an antireflection film. SOLUTION: For a semiconductor device covering a wiring layer (data line 31DL) having a TiNx layer 31C as the antireflection film on the top layer with a protecting film 32, a nitrogen composition ratio (x) of the TiNx layer 31C is adjusted to be less than 1.1. Since the TiNx layer 31C contains nitrogen, while lowering the reflection factor in the surface and maintaining an antireflection function, the generation of nitrogen gas can be decreased. A plasma CVD film, capable of improving information holding characteristics in a nonvolatile storage device, is used for the protecting film 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device and a method for manufacturing the same. In particular, the present invention relates to a semiconductor device having a structure in which a wiring layer having an antireflection film on at least the uppermost layer is covered with a protective film, and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a semiconductor memory device in which stored information can be freely rewritten on a user side, nonvolatile memory devices such as an ultraviolet erasing nonvolatile memory device (EPROM) and an electrically erasing nonvolatile memory device (EEPROM) are known. Are known.

FIG. 12 is a sectional view showing a nonvolatile memory element in a conventional nonvolatile memory device. The nonvolatile memory device is mainly composed of a semiconductor substrate 1 made of a p-type single crystal silicon substrate, and the nonvolatile memory element M is a semiconductor in a region surrounded by an element isolation insulating film (field insulating film) 2. It is formed on the main surface of the substrate 1.

The nonvolatile memory element M includes a channel forming region, a first gate insulating film 3, a floating gate electrode 4, a second gate insulating film 5, a control gate electrode 6, and a pair of n used as a source region and a drain region. It is configured to include a mold semiconductor region 8. The channel formation region is formed on the surface of the semiconductor substrate 1. At least the floating gate electrode 4 is covered with a dense silicon oxide film 7 in order to improve information retention characteristics.

The nonvolatile memory element M has a word line 6W
It is arranged at the intersection of L and data line 11DL, and is electrically connected to each of word line 6WL and data line 11DL. The word line 6WL is formed integrally with the control gate electrode 6 of the nonvolatile memory element M, and is formed of the same conductive layer as the control gate electrode 6. The data line 11DL is formed on an interlayer insulating film 9 covering the nonvolatile memory element M, and is connected to an n-type semiconductor region 8 used as a drain region through a connection hole 10 formed in the interlayer insulating film 9.

On the data line 11DL, a protective film (passivation film) 12 covering the data line 11DL and the nonvolatile memory element M is formed. In the non-volatile memory device, a plasma CVD silicon oxide film formed by a plasma CVD method having a dense film quality and capable of forming a film at a low temperature is used as the protective film 12. Retention characteristics are enhanced.

FIGS. 13 to 15 are cross-sectional structural views showing the respective manufacturing steps for explaining the method of manufacturing the above-mentioned nonvolatile memory device. First, as shown in FIG. 13, a nonvolatile memory element M is formed on the main surface of the semiconductor substrate 1 by a known method. Next, an interlayer insulating film 9 covering the nonvolatile memory element M
Then, as shown in FIG. 14, a connection hole 10 is formed in the interlayer insulating film 9 on the n-type semiconductor region 8 used as the drain region of the nonvolatile memory element M.

[0008] Next, as shown in FIG.
A data line 11DL electrically connected to the n-type semiconductor region 8 through 0 is formed on the interlayer insulating film 9. Data line 11
The DL has at least a two-layer structure of an aluminum alloy film 11A and a TiN layer 11B laminated on the surface of the aluminum alloy film 11A. Aluminum alloy film 1
1A is deposited by a sputtering method and has a thickness of 800 nm. The TiN layer 11B is used as an anti-reflection film that prevents excessive exposure due to a halation phenomenon caused by reflection of the surface of the aluminum alloy film 11A when an etching mask for patterning the data line 11DL is formed by photolithography. You. TiN layer 11
B is similarly deposited by a sputtering method and is formed with a thickness of 30 nm. Aluminum alloy film 11A, TiN layer 11
After deposition, B is patterned by etching using the RIE method.

Next, as shown in FIG. 12, a protective film 12 covering the data line 11DL is formed. As the protective film 12, a plasma CVD silicon oxide film formed by reacting SiH4 gas, N20 gas and N2 gas in a plasma state at a substrate temperature of 400 ° C. is used.

Then, sintering is performed in order to increase the crystal grains of Al in the aluminum alloy film 11A of the data line 11DL and reduce the wiring resistance. The sintering is performed at a heat treatment temperature of 400 to 450 ° C. in a forming gas atmosphere for about 5 minutes. H2: N2 = 1: 9 is used as the forming gas. When these series of manufacturing steps are completed, the nonvolatile memory device is completed.

[0011]

In the above-mentioned nonvolatile memory device, no consideration is given to the following points. The pattern of the data line 11DL is miniaturized with the increase in the capacity and the speed of the information reading operation, and the TiN layer 11B as an antireflection film formed on the surface layer of the data line 11DL is essential for the miniaturization. . This TiN layer 11B
When the nitrogen composition ratio becomes high, the reflectance of the surface of the TiN layer 11B decreases, and the performance as an antireflection film increases. Therefore, usually, a large amount of N2 gas is supplied during the sputtering of the TiN layer 11B to increase the nitrogen composition ratio of the TiN layer 11B.

However, if the antireflection function is promoted by increasing the nitrogen composition ratio of the TiN layer 11B, the TiN layer 1B is formed by sintering performed after forming the protective film 12.
There has been a problem that the N2 gas is separated or vaporized from 1B, and the generation of the N2 gas has a high possibility of peeling of the protective film 12 and disconnection of the data line 11DL. FIG.
3 is an enlarged sectional structural view of a defective portion. As shown in FIG. 16, the N2 gas generated from the TiN layer 11B is
The protective film 12 is lifted up at the interface between the 1DL and the protective film 12 to form the cavity 13, whereby the protective film 12 is separated from the data line 12DL. Also, TiN
The data line 11DL is cut off by the rapid pressure of the N2 gas generated from the layer 11B and disconnected. The TiN layer 11
As the gas generated from B, in addition to the N2 gas, Ar which generates a plasma atmosphere during sputtering is used as the TiN layer 11B.
Ar is taken in, and the taken Ar is released as Ar gas.

In particular, in a nonvolatile memory device, a plasma CVD silicon oxide film having a dense film quality is used for the protective film 12 for the purpose of improving information retention characteristics.
Either the inert gas 2 or the Ar gas loses the release path. Therefore, the peeling of the protective film 12 and the disconnection of the data line 11DL appear remarkably in the nonvolatile memory device.

Further, in order to prevent peeling of the protective film 12 and disconnection of the data line 11DL, the inventor of the present application performed a heat treatment at about 400 ° C. after patterning the data line 11DL, and performed a nitrogen composition of the TiN layer 11B. An attempt was made to decrease the ratio. As a result, the protection film 12 is peeled off, and the data line 11D
Although the disconnection of L can be suppressed, the problem that aluminum hillrock occurs in the aluminum alloy film 11A of the data line 11DL newly occurs due to the addition of the heat treatment step. FIG. 17 is an enlarged sectional structural view of a defective portion. FIG.
As shown in FIG. 7, the aluminum hillock 11a grows laterally from the patterned side wall of the aluminum alloy film 11A. When the degree of growth is large, the adjacent data line 11
Short circuit between DL.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a reliability capable of preventing peeling of a protective film and disconnection of wiring due to an inert gas generated from an anti-reflection film. It is to provide a semiconductor device having high reliability.

Still another object of the present invention is to provide a highly reliable non-volatile memory capable of improving information retention characteristics while preventing peeling of a protective film and disconnection of wiring due to an inert gas generated from an anti-reflection film. Sexual storage device.

Still another object of the present invention is to provide a method of manufacturing a semiconductor device which can achieve the above-mentioned object and improve the production yield while preventing a short circuit between wirings due to the occurrence of hilllock. is there.

Still another object of the present invention is to provide a method of manufacturing a nonvolatile memory device capable of achieving the above-mentioned object and improving a manufacturing yield while preventing a short circuit between wirings due to generation of hilllock. That is.

[0019]

According to a first aspect of the present invention, in a semiconductor device, a wiring layer having a TiNx layer as an anti-reflection film on an uppermost layer is formed on a substrate. And TiNx layer are covered with a protective film,
The Nx layer has a nitrogen composition ratio x of 1.1 or less. The TiNx layer preferably has a nitrogen composition ratio x of 0.8 or more and 1.1 or less. More preferably, the nitrogen composition ratio x of the TiNx layer is preferably 1.01 or more and 1.1 or less.

In the semiconductor device configured as described above, the TiNx layer formed on the uppermost layer of the wiring can maintain the antireflection function while maintaining the antireflection function because the nitrogen composition ratio x is appropriately secured and the surface reflectance can be reduced. Since the nitrogen composition ratio x of the TiNx layer has been adjusted to 1.1 or less, the amount of N2 gas released or vaporized from the TiNx layer can be reduced, the protective film peels off due to the generation of the N2 gas, and the wiring layer is disconnected. Can be prevented. As a result, a highly reliable semiconductor device in which peeling of the protective film and disconnection of the wiring layer are prevented can be provided.

According to a second aspect of the present invention, in the semiconductor device, a wiring layer having a TiNx layer as an antireflection film on the uppermost layer is formed on the nonvolatile memory element, and the nonvolatile memory element, the wiring layer, and the TiNx layer are formed of a protective film. Covered with TiN
The nitrogen composition ratio x of the x layer is 1.1 or less, and the protective film is formed by a plasma CVD film formed by a plasma CVD method. Preferably, the wiring layer is formed of an aluminum alloy film and a TiNx layer laminated thereon, and the nitrogen composition ratio x of the TiNx layer is 0.8 or more and 1.1 or less, more specifically 1.01 or more and 1.1 or less,
The protective film is formed of a plasma CVD silicon oxide film formed by a plasma CVD method including a gas having a Si—H bond as a source gas.

In the semiconductor device configured as described above, the TiNx layer formed on the uppermost layer of the wiring layer can maintain an antireflection function while maintaining a proper nitrogen composition ratio x and reducing the surface reflectance. , The nitrogen composition ratio x of the TiNx layer is adjusted to 1.1 or less, so that the amount of N2 gas released or vaporized from the TiNx layer can be reduced, the protective film is peeled off due to the generation of the N2 gas, and the wiring layer is disconnected. Etc. can be prevented. In particular, when a plasma CVD film having a dense film quality and capable of reducing the leakage of electric charges serving as information is used as a protective film for improving the information retention characteristics of the nonvolatile memory element, TiNx
The release path of the N2 gas released or vaporized from the layer is blocked by the protective film. The N2 gas whose emission path has been lost at the interface between the TiNx layer and the protective film pushes up the protective film,
Peeling occurs on the protective film. Further, the N2 gas breaks the wiring layer due to generation of a sudden pressure. These phenomena appear remarkably when the protective film is formed by the plasma CVD film. Therefore, by optimally controlling the nitrogen composition ratio x, peeling of the protective film and disconnection of the wiring layer can be prevented while maintaining the original antireflection function, and a plasma CVD film having a dense film quality as the protective film can be obtained. Since it can be used, the information retention characteristics of the nonvolatile memory element can be improved.

According to a third aspect, in the method of manufacturing a semiconductor device, a wiring layer including an aluminum film or an aluminum alloy film is formed on a substrate, and a TiNx layer as an antireflection film is formed on the wiring layer. A step of sequentially patterning each of the TiNx layer and the wiring layer;
a step of forming a protective film covering the iNx layer; and a step of performing heat treatment on the aluminum film or the aluminum alloy film of the wiring layer.
The method includes a step of adjusting the nitrogen composition ratio of the Nx layer to be equal to or less than x1.1. Adjustment of the nitrogen composition ratio x of the TiNx layer is performed by adjusting the N2 ratio of the source gas at the time of forming the TiNx layer. Further, in the method of manufacturing a semiconductor device, after forming the TiNx layer and before patterning the aluminum film or the aluminum alloy film, a heat treatment is performed.
a step of adjusting the nitrogen composition ratio x of the iNx layer to 1.1 or less. More preferably, the method for manufacturing a semiconductor device is a method for manufacturing a nonvolatile memory device, wherein the wiring layer and the TiNx layer are formed on the nonvolatile memory element formed on the main surface of the semiconductor substrate. The protective film covers the nonvolatile memory element, the wiring layer, and the TiNx layer, and is formed by a plasma CVD method including a source gas including a gas having a Si—H bond.

In such a method of manufacturing a semiconductor device, a step of performing heat treatment to adjust the nitrogen composition ratio x of the TiNx layer is performed before patterning the wiring layer. Therefore, it is possible to prevent the occurrence of lateral hilllock that grows laterally from the patterned side wall of the wiring layer after the wiring layer is patterned, and it is possible to prevent a short circuit between adjacent wirings, thereby improving the manufacturing yield of the semiconductor device. it can.

Further, in the method of manufacturing a semiconductor device, after the TiNx layer is formed, the aluminum film or the aluminum alloy film is patterned, and then heat treatment is performed.
a step of adjusting the nitrogen composition ratio x of the iNx layer to 1.1 or less.

[0026]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional structural view showing a nonvolatile memory element in the nonvolatile memory device according to Embodiment 1 of the present invention.
FIG. 3 is a plan view of the nonvolatile memory element. Note that the nonvolatile memory element illustrated in FIG. 1 is a cross-sectional view taken along a section line F1-F1 illustrated in FIG.

The nonvolatile memory device is mainly composed of a semiconductor substrate 21 made of a p-type single crystal silicon substrate. The semiconductor substrate 21 includes a p-type single crystal silicon substrate and a semiconductor substrate having a p-type well region with a slightly higher impurity concentration formed on the main surface thereof;
Alternatively, any semiconductor substrate in which a p-type well region is formed on the main surface of an n-type single crystal silicon substrate can be used. The nonvolatile memory element M is formed on the main surface of the semiconductor substrate 21 in a region surrounded by the element isolation insulating film 22.

The nonvolatile memory element M includes a channel forming region, a first gate insulating film 23, a floating gate electrode (floating gate electrode) 24, a second gate insulating film 25, a control gate electrode (control gate electrode) 26, and a source region. And an integrated n-type semiconductor region 28 used as a drain region. The channel forming region is formed by introducing a threshold voltage adjusting impurity into a surface portion of the semiconductor substrate 1.

The floating gate electrode 24 is formed as an information storage unit for holding electric charges serving as information. Floating gate electrode 2
Numeral 4 is formed of, for example, a polycrystalline silicon film, and this polycrystalline silicon film is doped with an impurity for securing conductivity, preferably P (phosphorus). Further, at least the floating gate electrode 24 is covered with a dense silicon oxide film 27 in order to prevent leakage of electric charges serving as information and improve information retention characteristics.

The control gate electrode 26 is applied with a potential necessary for an information writing operation, an information reading operation, and in the electrically erasing type nonvolatile memory element M, an erasing operation of information. The control gate electrode 26 is formed integrally with the word line 26WL electrically connected to the nonvolatile memory element M in the gate width direction. The control gate electrode 26 is formed of a polycrystalline silicon film and a composite film (a so-called polycide film) composed of a silicide film laminated on the surface of the polycrystalline silicon film. The polycrystalline silicon film is doped with an impurity for ensuring conductivity, preferably P. For example, WSi is used for the silicide film.
For example, a compound film of silicon and a high melting point metal such as a TiSi2 film, a MoSi2 film, or the like is used.

The n-type semiconductor region 28 is formed by doping n-type impurities of As (arsenic) and P, which have different diffusion rates, and has a double diffusion structure. In addition, the n-type semiconductor region 28 has a lightly doped D (LDD).
(rain) structure.

A data line (bit line) 31DL is electrically connected to the n-type semiconductor region 28 used as a drain region. The data line 31DL is connected to the nonvolatile memory element M
Formed on an interlayer insulating film 29 covering
9 through the connection hole 30 formed in the n-type semiconductor region 28.
Connected to. The data line 31DL is a barrier metal film 31
A, an aluminum alloy film 31B, and a TiNx layer 31C are each formed of a composite film in which layers are sequentially laminated.

The barrier metal film 31A is formed for the purpose of preventing the alloy spike phenomenon, and a composite film with a TiNx layer is preferably used. The aluminum alloy film 31B has the smallest resistance value among conductors used in the nonvolatile memory device and is used as a wiring main film. Aluminum alloy film 3
1B is Si for controlling alloy spikes on aluminum,
An additive such as Cu that suppresses electromigration is added. Note that a pure aluminum film can be used instead of the aluminum alloy film 31B.

The TiNx layer 31C is formed by a fetrinography technique and is used as an anti-reflection film for preventing an excessive exposure due to a halation phenomenon of an etching mask for patterning the data line 31DL. TiNx layer 31
The higher the nitrogen composition ratio x of C, the lower the reflectance of the surface of the TiNx layer 31C, and the higher the antireflection function. However, if the nitrogen composition ratio x of the TiNx layer 31C is too high, an inert gas such as N2 gas or Ar gas is generated from the TiNx layer 31C during the sintering step (heat treatment step) included in the manufacturing process, and the protection is performed. This causes peeling of the film 32 and disconnection of the data line 31DL.

FIG. 3A is a graph showing the relationship between the nitrogen composition ratio x of the TiNx layer and the rate of occurrence of peeling of the protective film. FIG. 3
As shown in (a), the peeling rate of the protective film becomes substantially zero when the nitrogen composition ratio x is 1.1. Therefore, Ti
The nitrogen composition ratio x of the Nx layer 31C is adjusted to 1.1 or less before the sintering step. Conversely, the nitrogen composition ratio x of the TiNx layer 31C is preferably higher in order to reduce the reflectance, and is preferably adjusted to 0.8 or more in order to maintain a sufficient antireflection function. That is, the nitrogen composition ratio x of the TiNx layer 31C according to the present embodiment is 0.8
It is set to at least 1.1.

As a result of further study, the present inventor found that FIG.
As shown in (b), the nitrogen composition ratio X of the TiNx layer 31C is
If the ratio is 0.8 or more and less than 1.0, it is difficult to form a TiNx layer with a stable composition ratio, and the TiNx layer 31C has a high reflectance close to that of the Ti film.
It has been found that when the nitrogen composition ratio X of C is 1.0, a film can be formed with a stable composition ratio, and the reflectance can be rapidly reduced. Further, the nitrogen composition ratio of the TiNx layer 31C
It was found that by setting X higher than 1.0, a constant low reflectance could be obtained. Specifically, if the nitrogen composition ratio X of the TiNx layer 31C is 1.01 or more, a constant low reflectance can be obtained. That is, the most optimal nitrogen composition ratio X of the TiNx layer 31C is 1.01 or more and 1.1 or less.

The n-type semiconductor region 28 used as a source region is formed integrally with the n-type semiconductor region 28 of another adjacent nonvolatile memory element M, and is used as a ground line.

The data 31D is displayed on the data line 31DL.
A protective film 32 covering the L and the nonvolatile memory element M is formed. As the protective film 32, a plasma CVD silicon oxide film formed by a plasma CVD method having a dense film quality and capable of forming a film at a low temperature is used, and retention characteristics of information stored in the nonvolatile memory element M are improved.

Next, a method for manufacturing the above-mentioned nonvolatile memory device will be described. 4 to 8 are cross-sectional structural views showing the respective manufacturing steps for explaining the method of manufacturing the nonvolatile memory device. (1) First, an inter-element isolation insulating film 22 is formed between the nonvolatile memory elements M of the semiconductor substrate 1. As the element isolation insulating film 22, a silicon oxide film formed by oxidizing the main surface of the semiconductor substrate 1 by a selective oxidation method is used, and the silicon oxide film is formed to a thickness of, for example, 400 to 600 nm.

(2) A first gate insulating film 23 is formed on the main surface of the semiconductor substrate 1 in the formation region of the nonvolatile memory element M. As the first gate insulating film 23, a silicon oxide film formed by thermally oxidizing the main surface of the semiconductor substrate 1 by a thermal oxidation method is used, and the silicon oxide film is formed to a thickness of, for example, 8 to 15 nm.

(3) A floating gate electrode 24 is formed on the surface of the first gate insulating film 23 (see FIG. 4). As the floating gate electrode 24, a polycrystalline silicon film deposited by a CVD method is used.
It is formed with a thickness of nm. POCl3 for the polycrystalline silicon film
P is doped in the atmosphere to ensure conductivity.
After the deposition, the first patterning of the floating gate electrode 24 for determining the gate width is performed in advance.

(4) On the surface of the floating gate electrode 24, a second
As the second gate insulating film 25 forming the gate insulating film 25, a silicon oxide film formed by oxidizing the surface of the floating gate electrode 24 by a thermal oxidation method is used, and the silicon oxide film has a thickness of, for example, 15 to 35 nm. Is formed.

(5) A control gate electrode 26 is formed on the surface of the second gate insulating film 25 (see FIG. 4). As the control gate electrode 26, a composite film having a polycrystalline silicon film deposited by a CVD method and a silicide film deposited by a sputtering method is used. The polycrystalline silicon film is, for example, 100-
It is formed with a thickness of 250 nm, and the silicide film is, for example, 5 nm.
It is formed with a thickness of 0-300 nm. The polycrystalline silicon film is doped with P for ensuring conductivity in a POCl3 atmosphere. After the control gate electrode 25 is deposited, a second patterning for determining the gate length is performed. This second patterning determines the gate length of the control gate electrode 25 and the gate length of the floating gate electrode 24. I do. That is, each of the control gate electrode 26 and the floating gate electrode 24 is cut off by the second patterning, and the gate length of the insulated gate field effect transistor is determined. A word line 26WL is formed simultaneously with the formation of the control gate electrode 26. The second patterning is performed by anisotropic etching using the RIE method.

(6) A pair of n-type semiconductor regions 28 used as a source region and a drain region are formed on the main surface of the semiconductor substrate 1 by self-alignment with the control gate electrode 26 and the floating gate electrode 24 (FIG. 4). 4). The n-type semiconductor region 28 is formed by using the control gate electrode 26 or a mask formed by patterning the control gate electrode 26 and the insulating film 22 for element isolation as a mask, and implanting n-type impurities into the main surface of the semiconductor substrate 1 by ion implantation. Is formed. As and P have different diffusion coefficients for n-type impurities.
Is used, and the n-type semiconductor region 28 is formed with a double diffusion structure. By forming the n-type semiconductor region 28, the nonvolatile memory element M is completed.

(7) As shown in FIG. 4, a silicon oxide film 27 covering the respective surfaces of the control gate electrode 26 and the floating gate electrode 24 is formed. The silicon oxide film 27 is formed by a thermal oxidation method having a dense film quality in order to improve information retention characteristics.

(8) As shown in FIG.
Is formed on the entire surface of the substrate. A BPSG film is used for the interlayer insulating film 29, and the BPSG film is subjected to a glass flow after the deposition to flatten the surface.

(9) As shown in FIG. 6, an n-type semiconductor region 2 used as a drain region of the nonvolatile memory element M
On 8, a connection hole 30 is formed in the interlayer insulating film 29. The connection hole 30 is formed by anisotropic etching using the RIE method.

(10) As shown in FIG. 7, the interlayer insulating film 2
9, a barrier metal film 31A, an aluminum alloy film 31B, and a TiNx layer 3 for forming a wiring layer over the entire surface of the substrate.
Each of 1C is sequentially deposited. Barrier metal film 31A
For example, a composite film of a Ti layer and a TiNx layer is used,
The Ti layer has a thickness of 10-50 nm, and the TiNx layer has a thickness of 50-50 nm.
Each is formed with a thickness of 100 nm. The aluminum alloy film 31B is formed by a sputtering method, and has a thickness of, for example, 700 to 800 nm. TiNx layer 3
1C is formed by a sputtering method, for example, 20-3
It is formed with a thickness of 0 nm.

In the TiNx layer 31C, the nitrogen composition ratio x is simultaneously adjusted at the time of sputtering in order to prevent the protective film 32 formed later from peeling off while maintaining the antireflection function. The TiNx layer 31C is formed by sputtering using a Ti target in an atmosphere of Ar gas and N2 gas. The ratio of N2 gas at the time of this sputtering is set to about 50% or less, and nitrogen of the TiNx layer 31C after film formation is formed. The composition ratio x is adjusted to 1.1 or less. Preferably, as described above, the nitrogen composition ratio x is adjusted to 0.8 or more and 1.1 or less. Since the adjustment of the nitrogen composition ratio x is performed before the patterning of the aluminum alloy film 31B, the aluminum alloy film 31B is adjusted.
Of lateral aluminum hill rocks growing on the patterned sidewalls can be prevented.

(11) As shown in FIG. 8, the TiNx layer 3
1C, aluminum alloy film 31, film B, barrier metal film 3
1A is sequentially patterned, and data lines 31
Form a DL. The patterning is performed by anisotropic etching using RIE using an etching mask (photoresist mask) formed by photolithography. When patterning, the data line 31
A TiNx layer 31C as an anti-reflection film is formed on the uppermost layer of the DL.
Is formed, excessive exposure due to the halation phenomenon caused by the reflection of the surface of the aluminum alloy film 31B can be prevented, and fine processing of the data line 31DL can be realized.

(12) As shown in FIG. 1, a protective film 32 covering the data line 31DL is formed. As the protective film 32, a plasma CVD silicon oxide film formed by reacting SiH4 gas, N2O gas and N2 gas in an Ar plasma atmosphere at a substrate temperature of 400 ° C. is used.

(13) Sintering (heat treatment) is performed to recover the damage of the aluminum alloy film 31B of the data line 31DL. Sintering is 450
At a heat treatment temperature of ℃, in a forming gas atmosphere,
It takes about 5 minutes. H2: N2 =
1: 9 is used. In this sintering step, since the nitrogen composition ratio x of the TiNx layer 31C of the data line 31DL is appropriately adjusted, generation of N2 gas or Ar gas from the TiNx layer 31C substantially does not pose a problem. That is, peeling of the protection film 32 and disconnection of the data line 31DL can be prevented.

When these series of manufacturing steps are completed, the nonvolatile memory device according to the present embodiment is completed. Second Embodiment A second embodiment describes a case where the nitrogen composition ratio is adjusted after depositing a TiNx layer and before forming a protective film in a method of manufacturing a nonvolatile memory device. 9 and 10
FIG. 7 is a cross-sectional structure diagram illustrating each manufacturing process for describing a method for manufacturing a nonvolatile memory device according to Embodiment 2 of the present invention.

(1) After forming the connection hole 30 shown in FIG. 6 in the method of manufacturing the nonvolatile memory device according to the first embodiment, as shown in FIG. Barrier metal film 31 for forming wiring layer
A, an aluminum alloy film 31B, and a TiNx layer 31C are sequentially deposited. At this point, TiNx
The nitrogen composition ratio x of the layer 31C is not adjusted.

(2) As shown in FIG. 10, the TiNx
Heat treatment is performed on the layer 31C to adjust the nitrogen composition ratio x of the TiNx layer 31C. The heat treatment is performed in a temperature range of 380-420 ° C., preferably at a temperature of 400 ° C.
The nitrogen composition ratio x of 1C is adjusted to 1.1 or less.

(3) Thereafter, the data line 31DL is formed by the patterning step shown in FIG. 8 described above, and the subsequent steps are performed in the same manner to complete the nonvolatile memory device according to the present embodiment. I do.

In the nonvolatile memory device according to the second embodiment, similar to the nonvolatile memory device according to the first embodiment, the protection film 32 is peeled and the data line 31DL is disconnected while maintaining the anti-reflection function. And the occurrence of lateral aluminum hill rocks can be prevented.

Third Embodiment In a third embodiment, a case will be described in which a nitrogen composition ratio is adjusted after patterning a TiNx layer and before patterning an aluminum alloy film in a method for manufacturing a nonvolatile memory device. FIG. 11 is a sectional structural view in a predetermined manufacturing step for explaining the method for manufacturing the nonvolatile memory device according to Embodiment 3 of the present invention.

(1) In the method of manufacturing the nonvolatile memory device according to the second embodiment, the via metal film 31A, the aluminum alloy film 31B and the TiNx layer 31C for forming a wiring layer over the entire surface of the substrate shown in FIG. After the sequential deposition, as shown in FIG. 11, only the TiNx layer 31C is patterned into the shape of the data line 31DL. At this point, the nitrogen composition ratio x of the TiNx layer 31C has not been adjusted.

(2) Thereafter, the patterned Ti
A heat treatment is performed on the Nx layer 31C to adjust the nitrogen composition ratio x of the TiNx layer 31C. The heat treatment is performed in a temperature range of 380-420 ° C., preferably at a temperature of 400 ° C.
The nitrogen composition ratio x of the layer 31C is adjusted to 1.1 or less.

(3) Thereafter, the aluminum alloy film 31B and the barrier metal film 31A are sequentially patterned to form data lines 31DL. And
By performing the subsequent steps in the same manner, the nonvolatile memory device according to the present embodiment is completed.

In the nonvolatile memory device according to the third embodiment, similar to the nonvolatile memory device according to the second embodiment, the protection film 32 is peeled off and the data line 31DL is disconnected while maintaining the antireflection function. And the occurrence of lateral aluminum hill rocks can be prevented.

Although the present invention has been specifically described based on the above-described embodiment, the present invention is not limited to the above-described embodiment. For example, the nonvolatile memory element M according to the above embodiment has a one-transistor structure having a floating gate electrode 24, but the present invention has a two-transistor structure having an information storage transistor and a cell selection transistor. The present invention can be applied to a nonvolatile storage device having a nonvolatile storage element. Further, the present invention can be applied to either a nonvolatile memory device having a nonvolatile memory element having an MNOS structure or a flash memory (nonvolatile memory device).

Further, the present invention is not limited to a nonvolatile memory device, but a DRAM having an antireflection film on the uppermost layer of a wiring layer,
The present invention can be applied to a semiconductor storage device such as an SRAM and a semiconductor integrated circuit device such as a LOGIC.

Further, the present invention can be applied to a wiring board such as a motherboard, a daughter board, and a printed wiring board. In the present invention in which the semiconductor device is mounted on these wiring boards, the wiring main film of the wiring does not necessarily need to be an aluminum film or an aluminum alloy film,
It may be a u film or a Cu alloy film. In this case, the generation of hillocks does not substantially matter, so the adjustment of the nitrogen composition ratio is within the range from the time of depositing the TiNx layer to before the deposition of the protective film, that is, within the range, that is, after patterning the wiring. There may be.

[0066]

According to the present invention, it is possible to provide a highly reliable semiconductor device capable of preventing peeling of a protective film and disconnection of wiring due to an inert gas generated from an antireflection film. further,
According to the present invention, it is possible to provide a highly reliable non-volatile memory device capable of improving information retention characteristics while preventing peeling of a protective film and disconnection of wiring due to an inert gas generated from an anti-reflection film.

Further, the present invention can provide a method for manufacturing a semiconductor device and a method for manufacturing a nonvolatile memory device, which can improve the yield in manufacturing while preventing shortage of wiring due to generation of hilllock.

[Brief description of the drawings]

FIG. 1 is a sectional structural view showing a nonvolatile memory element in a nonvolatile memory device according to Embodiment 1 of the present invention.

FIG. 2 is a plan view of the nonvolatile memory element.

FIG. 3A is a relationship diagram between a nitrogen composition ratio x of a TiNx layer and a peeling rate of a protective film. (B) shows T
FIG. 4 is a relationship diagram between a nitrogen composition ratio X of an iNx layer and a reflectance of a TiNx layer.

FIG. 4 is a sectional structural view in a first manufacturing step for explaining a method of manufacturing the nonvolatile memory device.

FIG. 5 is a sectional structural view in a second manufacturing.

FIG. 6 is a sectional structural view in a third manufacturing step.

FIG. 7 is a sectional structural view in a fourth manufacturing step.

FIG. 8 is a sectional structural view in a fifth manufacturing step.

FIG. 9 is a sectional structural view in a first manufacturing step for describing a method for manufacturing the nonvolatile memory device according to Embodiment 2 of the present invention.

FIG. 10 is a sectional structural view in a second manufacturing step.

FIG. 11 is a sectional structural view in a predetermined manufacturing step for explaining the method for manufacturing the nonvolatile memory device according to Embodiment 3 of the present invention.

FIG. 12 is a sectional structural view showing a nonvolatile memory element in a nonvolatile memory device according to a conventional technique.

FIG. 13 is a sectional structural view in a first manufacturing step for describing a method for manufacturing a nonvolatile memory device according to a conventional technique.

FIG. 14 is a sectional structural view in a second manufacturing step.

FIG. 15 is a sectional structural view in a third manufacturing step.

FIG. 16 is an enlarged sectional structural view of a defective portion.

FIG. 17 is an enlarged sectional structural view of a defective portion.

[Description of Reference Numerals] 21 semiconductor substrate 22 inter-element isolation insulating film 23, 25 gate insulating film 24 floating gate electrode 26 control gate electrode 26WL word line 28 n-type semiconductor region 29 interlayer insulating film 30 connection hole 31DL data line 31A barrier metal Film 31B Aluminum alloy film 31C TiNx layer 32 Protective film M Non-volatile memory element

Claims (16)

[Claims] A wiring layer having a TiNx layer as an anti-reflection film on the uppermost layer is formed on a substrate.
A semiconductor device, wherein an Nx layer is covered with a protective film, and a nitrogen composition ratio x of the TiNx layer is 1.1 or less. 2. The semiconductor device according to claim 1, wherein said TiNx layer has a nitrogen composition ratio x of 0.8 or more and 1.1 or less. 3. The TiNx layer has a nitrogen composition ratio x of 1.01.
2. The method according to claim 1, wherein the first and second portions are formed in a range of 1.1 or less.
3. The semiconductor device according to claim 1. 4. A wiring layer having a TiNx layer as an anti-reflection film on the uppermost layer is formed on the nonvolatile memory element, and the nonvolatile memory element and the wiring layer are covered with a protective film. A semiconductor device having a composition ratio x of 1.1 or less, and wherein the protective film is formed of a plasma CVD film formed by a plasma CVD method. 5. The wiring layer is formed of an aluminum alloy film and a TiNx layer laminated on the aluminum alloy film.
The layer is formed with a nitrogen composition ratio x of 0.8 or more and 1.1 or less,
5. The semiconductor device according to claim 4, wherein the protective film is a plasma CVD silicon oxide film formed by a plasma CVD method including a gas having a Si-H bond in a source gas. 6. The wiring layer is formed of an aluminum alloy film and a TiNx layer laminated on the aluminum alloy film.
The layer is formed with a nitrogen composition ratio x of 1.01 or more and 1.1 or less, and the protective film is formed by a plasma CVD method using a gas having a Si—H bond as a source gas.
The semiconductor device according to claim 4, wherein the semiconductor device is a silicon oxide film. 7. A step of forming a wiring layer containing aluminum or an aluminum alloy on a substrate, forming a TiNx layer as an antireflection film on the wiring layer, and sequentially patterning each of the TiNx layer and the wiring layer. Forming a protective film covering the wiring layer and the TiNx layer; and performing a heat treatment on the aluminum or aluminum alloy of the wiring, wherein a heat treatment is performed during the formation of the TiNx layer to form a nitrogen gas on the TiNx layer. A method for manufacturing a semiconductor device, comprising a step of setting a composition ratio x to 1.1 or less. 8. The method according to claim 8, wherein a source gas of N2
The ratio was adjusted so that the nitrogen composition ratio x of the TiNx layer was 1.1.
The method for manufacturing a semiconductor device according to claim 7, further comprising: 9. A step of performing a heat treatment during the formation of the TiNx layer to reduce the nitrogen composition ratio x of the TiNx layer to 1.1 or less, wherein the heat treatment is performed during the formation of the TiNx layer.
9. The method of manufacturing a semiconductor device according to claim 7, wherein the step of setting the nitrogen composition ratio x of the Nx layer to 1.01 or more and 1.1 or less. 10. A step of forming a wiring layer containing aluminum or an aluminum alloy on a substrate, forming a TiNx layer as an antireflection film on the wiring layer, and sequentially patterning each of the TiNx layer and the wiring layer. Forming a protective film covering the wiring layer and the TiNx layer; and performing a heat treatment on aluminum or an aluminum alloy of the wiring layer, and before patterning the wiring layer after the formation of the TiNx layer. And heat treating the TiNx
A method for manufacturing a semiconductor device, comprising a step of setting a nitrogen composition ratio x of a layer to 1.1 or less. 11. A step of performing heat treatment to reduce the nitrogen composition ratio x of the TiNx layer to 1.1 or less after patterning the wiring layer after the formation of the TiNx layer, 11. The method of manufacturing a semiconductor device according to claim 10, wherein a heat treatment is performed before patterning the layer so that the nitrogen composition ratio x of the TiNx layer is 0.8 or more and 1.1 or less. 12. A step of performing a heat treatment to reduce the nitrogen composition ratio x of the TiNx layer to 1.1 or less after patterning the wiring layer after the formation of the TiNx layer, 11. The method of manufacturing a semiconductor device according to claim 10, wherein a heat treatment is performed before patterning the layer so that the nitrogen composition ratio x of the TiNx layer is 1.01 or more and 1.1 or less. 13. The wiring layer and the TiNx layer are formed on a nonvolatile memory element formed on a main surface of a semiconductor substrate.
The protection film includes the nonvolatile memory element, wiring, and TiN
The method of manufacturing a semiconductor device according to claim 5, wherein the x-layer is formed by a plasma CVD method that includes a gas having a Si—H bond as a source gas. 14. A step of forming a wiring layer containing aluminum or an aluminum alloy on a substrate, forming a TiNx layer as an antireflection film on the wiring layer, and sequentially patterning each of the TiNx layer and the wiring layer. Forming a protective film covering the wiring layer and the TiNx layer; and performing a heat treatment on aluminum or an aluminum alloy of the wiring layer, after patterning the wiring layer after forming the TiNx layer. , Heat treatment and the TiNx
A method for manufacturing a semiconductor device, comprising a step of setting a nitrogen composition ratio x of a layer to 1.1 or less. 15. The step of performing a heat treatment to reduce the nitrogen composition ratio x of the TiNx layer to 1.1 or less after patterning the wiring layer after the formation of the TiNx layer, 15. The method of manufacturing a semiconductor device according to claim 14, further comprising a step of performing a heat treatment to pattern the TiNx layer so that the nitrogen composition ratio x of the TiNx layer is 0.8 or more and 1.1 or less after patterning. 16. The step of patterning the wiring layer after the formation of the TiNx layer and then performing a heat treatment to reduce the nitrogen composition ratio x of the TiNx layer to 1.1 or less includes the step of forming the wiring layer after the formation of the TiNx layer. 15. The method of manufacturing a semiconductor device according to claim 14, further comprising a step of performing a heat treatment to pattern the TiNx layer so that the nitrogen composition ratio x of the TiNx layer is 1.01 or more and 1.1 or less.