JPH0878409A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE: To ensure that an Al wiring layer in the periphery of a substrate is not corroded by an alkali developer when a resist after exposure is treated with the alkali developer. CONSTITUTION: A barrier metal film 4 is formed on a substrate 1, the substrate 1 is held on a stage 6 by a clamp ring 5 as if covering the barrier metal film 4 outside an element effective region of the periphery of the substrate 1, an aluminum-containing film 7 is formed on the barrier metal film 4 in the element effective region, the clamp ring 5 is removed from the substrate 1, and a reflection preventing film 8, whose reflectivity is lower than that of the aluminium- containing film 7, is formed as if covering the aluminum-containing film 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a manufacturing technique of a wiring structure in which a first-layer Al wiring is sandwiched between a barrier metal made of TiN and an antireflection film. The present invention relates to a method of manufacturing a semiconductor device, which can prevent the Al wiring layer around the substrate from being corroded by the alkaline developer when the exposed resist is treated with the alkaline developer.

Generally, Al (including pure aluminum and aluminum alloy materials) is mainly used for the first layer wiring of a semiconductor device. Recently, TiN, which is excellent in that it can function as a barrier metal between Si and Al, has recently been used as a barrier metal, and an antireflection film prevents the reflection of Al particularly when patterning an Al wiring. The same TiN as the above-mentioned barrier metal, which is excellent in that it can be used, is used, and as a result, the Al wiring has a structure sandwiched between the barrier metal and the TiN of the antireflection film.

As described above, when the wiring patterning process is carried out with the Al wiring sandwiched between the barrier metal and the TiN of the antireflection film, the Al which is sandwiched between the TiN in the peripheral portion of the substrate and the side portions of which are exposed. The problem of being corroded by the alkaline developer is likely to occur due to the battery effect. Therefore, there is a demand for a method of manufacturing a semiconductor device that can prevent the Al wiring layer in the peripheral portion of the substrate from being corroded by an alkali developing solution when performing the Al wiring patterning step.

[0004]

2. Description of the Related Art FIG. 3 is a diagram showing a conventional method of manufacturing a semiconductor device. In the illustrated example, only the peripheral portion of the substrate 1001 is shown. Conventionally, first, after forming a BPSG insulating film 1002 on a Si substrate 1001 by a CVD method or the like,
A Ti film 1003, a TiN barrier metal film 1004, an Al wiring layer 1005 to be the first wiring, and a TiN antireflection film 10 are formed on the BPSG insulating film 1002 by a sputtering method or the like.
06 are sequentially formed (FIG. 3A).

Here, the Ti film 1003 is provided to bring Si of the substrate 1001 in the element effective region into contact with Al of the Al wiring layer 1005 to reduce the contact resistance. The TiN antireflection film 1006 is provided in order to reduce the reflectance of the Al wiring layer 1005 because the reflectance is high only with the Al wiring layer 1005 and it is difficult to perform alignment and the like during patterning. When the antireflection film 1006 is formed from the insulating film 1002 on the substrate 1001,
Around the substrate 1001, the substrate 1001 is held and fixed on the stage by a clamp ring (not shown).

Next, a resist 1007 is applied on the entire surface of the TiN antireflection film 1006 (FIG. 3B), and the resist is patterned by exposure and development with an alkali developing solution to form a resist mask which serves as an etching mask. Then, using this resist mask, TiN is formed by RIE or the like.
The antireflection film 1006 to the Ti film 1003 are etched so that the Al wiring layer 1005 becomes the TiN antireflection film 100.
6 and a TiN barrier metal film 1004 are sandwiched between them to form a wiring structure.

[0007]

However, in the conventional method of manufacturing a semiconductor device as described above, the resist 1007 is exposed to form an etching mask and then patterned with an alkali developing solution.
As shown in A of FIG. 4A, Ti is formed around the substrate 1001.
The exposed Al wiring layer 1005 sandwiched between the N wiring layer 1005 and the TiN barrier metal film 1004 is corroded by the alkaline developer due to the cell effect, and the Al wiring layer 1005 is easily corroded to the peripheral element region of the substrate 1, There is a problem that the Al wiring layer 1005 in the peripheral element region of the substrate 1 may be lost.

Further, as shown in FIG. 4A, the substrate 100
1 In a state where the TiN antireflection film 1006 floats around the periphery,
When etching such as RIE for forming a wiring structure is performed,
There is a problem in that the floating portion of the TiN antireflection film 1006 may fly off and become dust or the like, which may adversely affect the device characteristics. Therefore, as shown in FIG. 4B, the substrate 100 is formed during the etching process for forming wiring after resist development.
1 It is considered that the floating portion of the antireflection film 1006 and the portion where the antireflection film 1006 is corroded in the peripheral portion may be removed by etching at the same time. However, even with this method, after all, at the time of the alkali development described above, It was not possible to prevent the Al wiring layer 1005 from being corroded to the peripheral element region of the substrate 1.

Therefore, according to the present invention, when the resist after exposure is treated with an alkaline developing solution, the Al wiring layer in the peripheral portion of the substrate is prevented from being corroded by the alkaline developing solution so that the Al wiring layer in the element region around the substrate is protected. It is an object of the present invention to provide a method of manufacturing a semiconductor device, which can prevent the generation of dust and the like due to the disappearance and floating of the TiN antireflection film in the peripheral portion of the substrate, and can obtain a stable wiring structure.

[0010]

According to the first aspect of the present invention,
A step of forming a barrier metal film on the substrate, then a step of holding the substrate on the stage by a clamp ring so as to cover the barrier metal film outside the element effective area in the periphery of the substrate, and then the element A step of forming an aluminum-containing film on the barrier metal film in the effective region, and then,
A step of removing the clamp ring from the substrate, a step of forming an antireflection film having a lower reflectance than the aluminum-containing film so as to cover the aluminum-containing film, and a resist on the antireflection film. Coating, exposing and developing the resist to form a resist mask, and then using the resist mask, the antireflection film,
The method is characterized by including the steps of selectively etching the aluminum-containing film and the barrier metal film to form a wiring structure, and then removing the resist mask.

According to a second aspect of the present invention, a step of forming a barrier metal film on the substrate is performed, and then a first clamp ring is used to cover the barrier metal film outside the element effective region in the peripheral portion of the substrate. Holding the substrate on a stage, then forming an aluminum-containing film on the barrier metal film in the element effective region, then removing the first clamp ring from the substrate, and then A step of holding the substrate on the stage by a second clamp ring further outside the peripheral portion of the substrate than the mounting position of the first clamp ring; and then, the aluminum-containing film so as to cover the aluminum-containing film. A step of forming an antireflection film having a lower reflectance than that, and then applying a resist on the antireflection film and exposing and developing the resist to form a resist mask. And a step of forming a wiring structure by selectively etching the antireflection film, the aluminum-containing film and the barrier metal film using the resist mask, and then removing the resist mask It is characterized by including a process.

[0012]

In the present invention, as shown in FIG. 1 of Embodiment 1 which will be described later, the barrier metal film 4 outside the element effective region A is covered with the clamp ring 5 on the barrier metal film 4 in the element effective region A. After the Al wiring layer 7 is formed and the TiN antireflection film 8 is formed so as to cover the entire Al wiring layer 7 up to the peripheral portion of the substrate 1 which is conventionally exposed, the TiN antireflection film 8 is extended to the peripheral portion of the substrate 1 by the Al. With the wiring layer 7 entirely covered, the resist is exposed and processed by alkali development to form an etching mask.

Therefore, the resist after exposure can be treated with an alkaline developing solution in a state where the TiN antireflection film 8 is entirely covered up to the peripheral portion of the substrate 1, so that the Al wiring in the peripheral portion of the substrate 1 can be processed. Layer 7 can be protected from corrosion by alkaline developers. Therefore, disappearance of the Al wiring layer 7 in the peripheral element region A of the substrate 1 and the substrate 1
Since it is possible to prevent dust and the like from being caused by the floating portion of the TiN antireflection film 8 in the peripheral portion, a stable wiring structure can be obtained.

In the present invention, as shown in FIG. 2 of the second embodiment to be described later, the barrier metal film 4 outside the element effective region A is covered with the clamp ring 5 on the barrier metal film 4 in the element effective region A. The Al wiring layer 7 is formed, and the end portion outside the element effective region A is covered with the clamp ring 11 to the peripheral portion of the substrate 1 which is conventionally exposed.
After the TiN antireflection film 8 is formed so as to entirely cover the Al wiring layer 7 with the TiN antireflection film 8 all the way up to the periphery of the substrate 1, the resist is exposed and alkali-developed to form an etching mask. It is configured to be processed by.

For this reason, the exposed resist can be treated with an alkaline developing solution in a state where the TiN antireflection film 8 is entirely covered up to the peripheral portion of the substrate 1, so that the Al wiring in the peripheral portion of the substrate 1 can be processed. Layer 7 can be protected from corrosion by alkaline developers. Therefore, disappearance of the Al wiring layer 7 in the peripheral element region A of the substrate 1 and the substrate 1
Since it is possible to prevent dust and the like from being caused by the floating portion of the TiN antireflection film 8 in the peripheral portion, a stable wiring structure can be obtained.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a diagram showing a method for manufacturing a semiconductor device according to Embodiment 1 of the present invention. In the illustrated example, only the peripheral portion of the Si substrate 1 is shown.

In this embodiment, first, S is formed by the CVD method or the like.
BP with a thickness of about 5000 angstroms on the i substrate 1
After forming the SG insulating film 2, BPS is performed by a sputtering method or the like.
A Ti film 3 having a film thickness of about 200 to 300 angstroms and a TiN barrier metal film 4 having a film thickness of about 1000 to 1500 angstroms are sequentially formed on the G insulating film 2. Next, the substrate 1 is held and fixed on the stage 6 by the clamp ring 5 so as to cover the barrier metal film 4 outside the element effective region A around the substrate 1. At this time, the element effective area A
The barrier metal film 4 is exposed.

Next, in this state, an Al wiring layer 7 having a film thickness of about 4000 angstrom is formed on the barrier metal film 4 in the element effective region A by the sputtering method or the like (FIG. 1).
(A)). The Ti film 3 is formed on the substrate 1 in the element effective area A.
Is provided to bring Si into contact with Al of the Al wiring layer 7 to reduce the contact resistance. Next, after removing the clamp ring 5 from the substrate 1, TiN having a film thickness of about 500 angstroms, which has a lower reflectance than the Al wiring layer 7 and covers the Al wiring layer 7 by a sputtering method or the like.
The antireflection film 8 is formed (FIG. 1B).

Next, a resist is applied on the TiN antireflection film 8 and exposed to light, and then patterned with an alkali developing solution such as TMAH (tetramethylammonium halide) to form a resist mask. Then, using this resist mask, the TiN antireflection film 8, A
l The wiring layer 7, the TiN barrier metal film 4 and the Ti film 3 are selectively etched to form a wiring structure in which the Al wiring layer 7 is sandwiched between the TiN antireflection film 8 and the TiN barrier metal film 4, and then the resist is formed. The mask is removed by O ₂ ashing or the like. The TiN antireflection film 8 is provided in order to reduce the reflectance of the Al wiring layer 7 because the reflectance is high only with the Al wiring layer 7 and it is difficult to perform alignment during patterning.

As described above, in the present embodiment, the barrier metal film 4 outside the element effective area A is covered with the clamp ring 5 and the Al is formed on the barrier metal film 4 in the element effective area A.
After the wiring layer 7 is formed and the TiN antireflection film 8 is formed so as to cover the Al wiring layer 7 up to the peripheral portion of the substrate 1 which is conventionally exposed, the TiN antireflection film 8 extends to the peripheral portion of the substrate 1 by the Al wiring. With the entire layer 7 covered, the resist is exposed and processed by alkali development to form an etching mask.

Therefore, the resist after exposure can be treated with an alkali developing solution in a state where the TiN antireflection film 8 covers the entire periphery of the substrate 1 and the Al wiring layer 7 is entirely covered.
It is possible to prevent the Al wiring layer 7 around the substrate 1 from being corroded by the alkali developing solution. Therefore, it is possible to prevent the disappearance of the Al wiring layer 7 in the peripheral element region A of the substrate 1 and the generation of dust or the like due to the floating portion of the TiN antireflection film 8 in the peripheral portion of the substrate 1, which is stable. A wiring structure can be obtained. (Embodiment 2) FIG. 2 is a diagram showing a method for manufacturing a semiconductor device according to a second embodiment of the present invention. In the illustrated example, only the peripheral portion of the Si substrate 1 is shown.

In this embodiment, first, S is formed by the CVD method or the like.
BP with a thickness of about 5000 angstroms on the i substrate 1
After forming the SG insulating film 2, BPS is performed by a sputtering method or the like.
A Ti film 3 having a film thickness of about 200 to 300 angstroms and a TiN barrier metal film 4 having a film thickness of about 1000 to 1500 angstroms are sequentially formed on the G insulating film 2. Next, the substrate 1 is held and fixed on the stage 6 by the clamp ring 5 so as to cover the barrier metal film 4 outside the element effective region A around the substrate 1. At this time, the element effective area A
The barrier metal film 4 is exposed.

Next, in this state, an Al wiring layer 7 having a film thickness of about 4000 angstrom is formed on the barrier metal film 4 in the element effective region A by the sputtering method or the like (FIG. 2).
(A)). The Ti film 3 is formed on the substrate 1 in the element effective area A.
Is provided to bring Si into contact with Al of the Al wiring layer 7 to reduce the contact resistance. Next, after the clamp ring 5 is removed from the substrate 1, the clamp ring 11 is provided outside the peripheral portion of the substrate 1 beyond the mounting position of the clamp ring 5 in FIG.
Hold on.

Next, a film having a reflectance lower than that of the Al wiring layer 7 is 50 so as to cover the Al wiring layer 7 by a sputtering method or the like.
A TiN antireflection film 8 having a thickness of about 0 Å is formed (FIG. 2B). Next, a resist is applied on the TiN antireflection film 8, exposed, and then patterned with an alkali developing solution such as TMAH to form a resist mask.

Then, using this resist mask, RI
TiN antireflection film 8, Al wiring layer 7, TiN
After the barrier metal film 4 and the Ti film 3 are selectively etched to form a wiring structure in which the Al wiring layer 7 is sandwiched between the TiN antireflection film 8 and the TiN barrier metal film 4, the resist mask is O ₂ ashed or the like. To remove. Note that Ti
The N antireflection film 8 is provided in order to reduce the reflectance of the Al wiring layer 7 because the reflectance is high only with the Al wiring layer 7 and it is difficult to perform alignment or the like during patterning.

As described above, in the present embodiment, Al is formed on the barrier metal film 4 in the element effective region A with the clamp ring 5 covering the barrier metal film 4 outside the element effective region A.
The wiring layer 7 is formed, and the Al wiring layer 7 is entirely covered up to the peripheral portion of the substrate 1 which is conventionally exposed in a state where the end portion outside the element effective region A is covered with the clamp ring 11.
After forming the N antireflection film 8, TiN is applied to the peripheral portion of the substrate 1.
With the antireflection film 8 entirely covering the Al wiring layer 7, the resist is exposed and processed by alkali development to form an etching mask.

Therefore, the exposed resist can be treated with an alkaline developing solution in a state where the TiN antireflection film 8 is entirely covered up to the peripheral portion of the substrate 1, so that the Al wiring in the peripheral portion of the substrate 1 can be processed. Layer 7 can be protected from corrosion by alkaline developers. Therefore, disappearance of the Al wiring layer 7 in the peripheral element region A of the substrate 1 and the substrate 1
Since it is possible to prevent dust and the like from being caused by the floating portion of the TiN antireflection film 8 in the peripheral portion, a stable wiring structure can be obtained.

In the present invention, as shown in FIG. 2 of Embodiment 2 described later, the barrier metal film 4 outside the element effective region A is covered with the clamp ring 5 on the barrier metal film 4 in the element effective region A. The Al wiring layer 7 is formed, and the end portion outside the element effective region A is covered with the clamp ring 11 to the peripheral portion of the substrate 1 which is conventionally exposed.
After the TiN antireflection film 8 is formed so as to entirely cover the Al wiring layer 7 with the TiN antireflection film 8 all the way up to the periphery of the substrate 1, the resist is exposed and alkali-developed to form an etching mask. It is configured to be processed by.

For this reason, the resist after exposure can be treated with an alkaline developing solution in a state where the TiN antireflection film 8 is entirely covered up to the peripheral portion of the substrate 1, so that the Al wiring in the peripheral portion of the substrate 1 can be processed. Layer 7 can be protected from corrosion by alkaline developers. Therefore, disappearance of the Al wiring layer 7 in the peripheral element region A of the substrate 1 and the substrate 1
Since it is possible to prevent dust and the like from being caused by the floating portion of the TiN antireflection film 8 in the peripheral portion, a stable wiring structure can be obtained.

In the above embodiment, the antireflection film 8 formed on the Al wiring layer 7 was made of TiN.
The present invention is not limited to this, and may be formed using a metal that is nobler than Al, TiW, or the like.

[0031]

According to the present invention, when the exposed resist is treated with an alkaline developing solution, the Al wiring layer in the peripheral portion of the substrate is prevented from being corroded by the alkaline developing solution so that the Al wiring in the peripheral element region of the substrate is prevented. It is possible to prevent generation of dust and the like due to disappearance of the layer and floating of the TiN antireflection film in the peripheral portion of the substrate, and it is possible to obtain a stable wiring structure.

[Brief description of drawings]

FIG. 1 is a diagram showing a method for manufacturing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a method for manufacturing a semiconductor device according to a second embodiment of the present invention.

FIG. 3 is a diagram showing a method of manufacturing a semiconductor device of a conventional example.

FIG. 4 is a diagram showing a problem of a conventional example.

[Explanation of symbols]

 1 substrate 2 insulating film 3 Ti film 4 barrier metal film 5, 11 clamp ring 6 stage 7 Al wiring layer 8 antireflection film

Claims (2)

[Claims] 1. A step of forming a barrier metal film (4) on a substrate (1), and then covering the barrier metal film (4) outside the element effective region in the peripheral portion of the substrate (1). Holding the substrate (1) on the stage (6) by a clamp ring (5), and then forming an aluminum-containing film (7) on the barrier metal film (4) in the element effective region, Next, a step of removing the clamp ring (5) from the substrate (1), and then an antireflection film (8) having a lower reflectance than the aluminum-containing film (7) so as to cover the aluminum-containing film (7). ) Is formed, and
Next, a step of applying a resist on the antireflection film (8) and exposing and developing the resist to form a resist mask, and then using the resist mask, the antireflection film (8) and the aluminum A method of manufacturing a semiconductor device, comprising: a step of selectively etching the containing film (7) and the barrier metal film (4) to form a wiring structure; and then a step of removing the resist mask. . 2. A step of forming a barrier metal film (4) on a substrate (1), and then covering the barrier metal film (4) outside the element effective region in the peripheral portion of the substrate (1). A step of holding the substrate (1) on the stage (6) by the first clamp ring (5), and then forming an aluminum-containing film (7) on the barrier metal film (4) in the element effective region. And then removing the first clamp ring (5) from the substrate (1), and then outside the peripheral portion of the substrate (1) further than the mounting position of the first clamp ring (5). The second clamp ring (1
1) holding the substrate (1) on the stage (6), and then an antireflection film having a lower reflectance than the aluminum-containing film (7) so as to cover the aluminum-containing film (7). A step of forming (8), and then applying a resist on the antireflection film (8), exposing the resist,
A step of developing to form a resist mask, and then using the resist mask, the antireflection film (8), the aluminum-containing film (7) and the barrier metal film (4) are selectively etched to form wiring. A method of manufacturing a semiconductor device, comprising: a step of forming a structure; and then a step of removing the resist mask.