JP2002158206A - Resist residues removing method and method of manufacturing semiconductor device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist residues removing method without deterioration of a semiconductor device as recesses on the layer insulation films, spread connection holes or roughed wirings, etc. SOLUTION: A process sequence involving a peeling liquid process using a fluoric peeling liquid for a process time so shortened as not deteriorating a semiconductor device is repeated at least twice.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for cleaning a substrate, and more particularly to a method for removing a resist residue after removing a resist.

[0002]

2. Description of the Related Art With the miniaturization of semiconductor devices, there is an increasing demand for higher performance in the removal of resist residues in the manufacture of semiconductor devices. That is, it is necessary to completely remove only the resist residue without affecting the components of the semiconductor device such as the wiring and the interlayer insulating film. At present, as a method for removing such a resist residue, a method using a fluorine-based stripping solution such as ammonium fluoride is widely known.

[0003]

However, in the above-mentioned prior art, it is necessary to lengthen the processing time using a fluorine-based stripping solution in order to completely remove the resist residue. Since the film has the property of eroding and roughening the surface of the electrode, the longer the processing time, the better the removability.However, the thickness of the interlayer insulating film, which is a component of the semiconductor device, decreases. There is a problem that the characteristics of the semiconductor device are deteriorated, for example, the connection hole is expanded or the connection hole is expanded. For example, NS as an interlayer insulating film
When a G film is used, when a resist residue generated when a connection hole is formed in the G film is subjected to a treatment for 10 minutes with the above-mentioned fluorine-based stripping solution, the connection hole becomes large by about 30 nm, and the integration degree is reduced or reliability is reduced. The property is deteriorated. In addition, the interlayer insulating film is often formed by laminating different kinds of oxide films, and when connecting holes are formed in this interlayer insulating film, the difference in the amount of erosion of each oxide film by the fluorine-based stripping solution causes the inside of the connecting holes to be formed. There is also a problem that a step is formed and a wiring material or the like cannot be formed well, voids are generated, and electrical characteristics and reliability of the wiring are deteriorated.

In the future, as elements are further miniaturized, it becomes increasingly difficult to process wirings and connection holes as designed. For this reason, dry etching requires etching conditions with a strong deposition property, and the resist residue formed under such conditions becomes stronger than before, and as a result, the processing time with a fluorine-based stripping solution is reduced. Becomes longer, and the above-mentioned problems become more apparent.

The present invention has been made in order to solve the above-mentioned problems. Even when a fluorine-based stripping solution is used, erosion of an oxide film such as an interlayer insulating film, surface roughening of an electrode, and the like are prevented. An object of the present invention is to provide a method for removing a resist residue, which can improve the removability of the resist residue while suppressing it as much as possible.

Another object of the present invention is to provide a method for manufacturing a semiconductor device using the above-described method for removing a resist residue.

[0007]

According to the present invention, a processing sequence including a step of stripping a substrate with a fluorine-based stripping solution is continuously repeated at least twice or more.

[0008] Further, a processing sequence including a step of stripping the substrate with a fluorine-based stripping liquid, a step of washing the semiconductor substrate with water after the stripping liquid processing, and a drying step of drying the substrate after the washing with water, is continuously performed. This is repeated at least twice.

Further, a rinsing process is provided between the peeling process and the washing process.

Further, the fluorine-based stripping solution is ammonium fluoride.

Further, the total time of the stripping process in each processing sequence is 10 minutes.

A step of forming an interlayer insulating film on the semiconductor substrate; a step of forming a first conductive film on the interlayer insulating film; and a second step of forming a second conductive film on the first conductive film via a dielectric film. Forming a conductive film, forming a resist film on the second conductive film, using the resist film as a mask,
A step of forming a capacitor electrode by sequentially etching the dielectric film and the first conductive film; and a step of removing the resist film, wherein a resist residue remaining after removing the resist is removed by the above-described method for removing a resist residue. Is what you do.

Further, the first and second conductive films are made of any one material selected from the group consisting of polysilicon, titanium nitride, tungsten, tungsten nitride, tantalum nitride, ruthenium, platinum, and an alloy of platinum and iridium. , And the dielectric film is made of any one material selected from the group consisting of silicon dioxide, silicon oxynitride, silicon nitride, tantalum oxide, BST, and PZT.

A step of forming an interlayer insulating film having a connection hole reaching the semiconductor substrate on the semiconductor substrate; a step of forming a metal plug in the connection hole; and a step of forming a conductive film on the interlayer insulating film and the metal plug. Forming, forming a resist film on the conductive film so as to cover at least part of the surface of the metal plug, etching the conductive film using the resist film as a mask, forming a wiring, Removing the resist residue remaining after the resist is removed by using the above-described method for removing the resist residue.

Further, the metal plug is made of tungsten or polysilicon, and the wiring is made of an aluminum alloy or tungsten.

A step of forming a wiring on the semiconductor substrate, a step of forming an interlayer insulating film on the semiconductor substrate and the wiring, and a step of forming an opening on at least a part of the wiring surface on the interlayer insulating film. Forming a resist film on the substrate, forming a connection hole reaching the surface of the wiring using the resist film as a mask, and removing the resist film. It is to be removed using a method.

Further, the wiring is made of an aluminum alloy or copper.

A step of forming a gate insulating film on the semiconductor substrate, a step of forming a metal film on the gate insulating film, a step of forming an insulating film on the metal film, and a step of forming a resist film on the insulating film. Forming a metal gate electrode by etching the insulating film and the metal film using the resist film as a mask, removing the resist film, and ion-implanting the semiconductor substrate using the insulating film and the metal film as a mask And a step of forming a conductive layer by removing the resist residue after the removal of the resist or after the ion implantation.

The metal film is a single-layer or multi-layer conductive film made of a metal material selected from the group consisting of tungsten, tungsten nitride, titanium, and titanium nitride.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 shows a processing procedure of a method for removing a resist residue according to the first embodiment of the present invention. In the drawings used below, the parts denoted by the same reference numerals indicate the same or corresponding parts, and the description may be omitted. In FIG. 1, FIG. 1A shows a processing sequence 100 which is a basic unit of residue removal in the present embodiment.
The cleaning apparatus includes a continuous series of a stripping solution treatment 101 using a fluorine-based stripping solution, a water washing process 102 using pure water, and a drying process 103. In the present embodiment, as shown in FIG. 1B, a processing sequence 100a in which the processing time of the stripping solution processing in the processing sequence 100 is shortened,
100b,... Are continuously repeated.

That is, the processing time of the fluorine-based stripping solution processing in one processing sequence is shortened to suppress the influence on the components of the semiconductor device, and the reduction in the removability due to the shortening of the stripping processing time is processed. This is made up by repeating the sequence. The stripping solution processing time and the number of repetitions in each processing sequence are set so that the influence on the constituent parts of the semiconductor device falls within the standard value and the resist residue is sufficiently removed.

Next, a specific example in which the above-described method for removing a resist residue is applied to a step of forming a capacitor of a semiconductor device and an interlayer insulating film having a connection hole reaching the capacitor will be described. 2 to 5 are cross-sectional views showing steps of forming a capacitor of a semiconductor device and an interlayer insulating film having a connection hole reaching the capacitor. First, referring to FIG. 2A, an interlayer insulating film 2 made of a silicon dioxide film (SiO ₂ ) including a semiconductor element (not shown)
A first conductive film 3a made of polysilicon, a dielectric film 5a made of an oxynitride film (SiON), and a second conductive film 7a made of polysilicon are sequentially formed thereon.

Each conductive film is made of titanium nitride (TiN), tungsten (W), tungsten nitride (WN), tantalum nitride (TaN), ruthenium (Ru), platinum (Pt), platinum / iridium, in addition to the above-mentioned polysilicon. (PT / I
r) An alloy or the like may be used. The dielectric film may be made of silicon dioxide, silicon nitride (Si
N), tantalum oxide (Ta ₂ O ₅ ), barium strontium titanate (BST), lead zirconate titanate (PZ)
T) may be used. Next, referring to FIG. 2B, after a resist film 9 having a capacitor pattern is formed on the second conductive film 7a, the second conductive film 7a and the dielectric Body membrane 5a and first
Is etched by anisotropic dry etching using chlorine gas (Cl ₂ ) plasma to form a capacitor 8 having a laminated structure of a capacitor upper electrode 7, a capacitor insulating film 5 and a capacitor lower electrode 3.

Next, referring to FIG. 3A, the unnecessary resist film 9 is removed by ashing using oxygen plasma. At this time, the resist residue 11 is formed on the side and surface of the capacitor 8 or on the surface of the interlayer insulating film 2.
a, 11b and 11c remain. This resist residue is expected to be composed of a compound in which components of the etching gas, the resist film, or the conductive film are mixed at the time of dry etching. Here, the resist residue is removed by using the above-described resist residue removal method.

FIG. 7 shows a processing procedure by a processing apparatus suitable for this removing method. In FIG. 7, 300
Reference numeral denotes a single-wafer spray remover, 310 denotes a rinsing unit, and 400 denotes a single-wafer drying unit. Also,
Reference numerals 301 and 302 denote spray nozzles for ejecting a fluorine-based stripping solution and pure water, respectively, and reference numeral 302 denotes a stage on which the semiconductor substrate 1 is mounted. These single wafer type spray processing apparatuses perform processing by ejecting a processing liquid from a spray nozzle while rotating a stage.

Using these processing apparatuses, first, FIG.
The processing is performed according to the processing sequence 100a of (b). First, a stripping solution treatment 101a is performed. Stripper treatment 10
1a, a semiconductor substrate 1 on which a resist residue remains is removed for a predetermined period of time, for example, three minutes and twenty minutes, while rotating a stage 302 on which the semiconductor substrate 1 is mounted, using the stripper processing apparatus 300 of FIG. The spraying is performed by spraying the stripping liquid from the spray nozzle for a second. An ammonium fluoride solution is used as a stripping solution as a fluorine-based stripping solution.

Next, following the above-mentioned stripping solution treatment, a water washing treatment 1
02 is performed. Using the water washing treatment apparatus 310 in FIG. 7, the spraying is performed by spraying pure water from the spray nozzle 311 for a predetermined time, for example, 2 minutes and 20 seconds while rotating the stage 302 on which the semiconductor substrate 1 is mounted. Next, the drying process 10
Perform Step 3. The semiconductor substrate 1 is dried in a nitrogen (N ₂ ) atmosphere set at a temperature of 23 ° C. for a certain period of time, for example, 7 minutes and 15 seconds, using the drying processing apparatus 400 of FIG.
Thus, the first processing sequence 100a ends.

Next, following the processing sequence 100a, a second processing sequence is performed according to the processing sequence 100b of FIG. This processing sequence 1
00b is performed under the same conditions as those in the processing of the processing sequence 100a. Finally, following the above-described processing sequence 100b, a third processing sequence 100c is performed under the same conditions as those of each processing of the processing sequence 100a or 100b, whereby the residue removing step is finally completed. As a result, as shown in FIG. 3B, a clean capacitor 8 having no recess in the interlayer insulating film 2 and no surface roughness of the capacitor electrode 8 and having no residue is formed.

Next, referring to FIG. 4A, an interlayer insulating film 13 made of silicon dioxide is formed on interlayer insulating film 2 so as to cover capacitor 8, and a connection hole pattern is formed thereon. After the resist film 15 is formed, a connection hole 17 reaching the capacitor 8 is formed using the resist film 15 as a mask. Next, referring to FIG. 4B, the unnecessary resist film 15 is removed by ashing using oxygen plasma. At this time, resist residues 19a, 19b and 19c remain on the side and bottom surfaces of the connection hole 17 or on the surface of the interlayer insulating film 13, respectively. here,
This resist residue is processed under the same processing conditions as above.
According to the removal processing procedure shown in FIG. 1B, the removal is performed using the processing apparatus shown in FIG. As a result, as shown in FIG. 5, a clean connection hole structure having no recess in the interlayer insulating film 13 and no expansion of the connection holes 17 and no resist residue is formed.

In the above example, the case where the interlayer insulating film 13 is a single layer is shown, but as shown in FIG.
Even in the case of a two-layer film structure of the PTEOS film 13b and the NSG film 13a, the resist residue can be removed without substantially causing a difference in the amount of erosion of the fluorine-based stripping solution due to a difference in film type. In addition, the characteristics of embedding a conductive film or the like in the connection hole 17 are improved. The same effect is not limited to the film type, and is the same even in a multilayer structure having three or more layers.

In the above-described resist residue removal, a single wafer type spray processing apparatus is used as a processing apparatus, but a batch type spray processing apparatus which can process a plurality of semiconductor substrates at a time may be used. Further, in the above example,
Although the water washing process was performed immediately after the stripping solution treatment, it is preferable that the water washing process be performed in a state where the stripping solution does not remain as much as possible. In this case, the stage is rotated at a high speed after the stripping solution treatment shown in FIG. The residue can be more effectively removed by performing a so-called shaking-off process for removing the stripping solution to be removed.

As described above, according to the resist residue removing method of the first embodiment according to the present invention, at least a processing sequence including a stripping process using a fluorine-based stripping solution that does not affect the constituent parts of the semiconductor device is performed at least. Since the resist residue is repeatedly removed two or more times, it is possible to sufficiently remove the resist residue while minimizing the influence on the components of the semiconductor device. Further, by applying the present residue removing method to a capacitor forming step, a semiconductor device having a highly reliable capacitor can be obtained.

Embodiment 2 FIG. Next, a method of removing a resist residue according to the second embodiment of the present invention, in which a capacitor is formed in the same manner as in the first embodiment, will be described. First, FIG. 8 shows a processing procedure of a method for removing a resist residue according to the second embodiment. FIG. 8A shows a processing sequence 150 which is a basic unit for removing a resist residue.
It comprises a continuous series of processing of a rinsing treatment 152 with a mixed solution of IPA and water, a water washing treatment 153 with pure water, and a drying treatment 154.

In this embodiment, as shown in FIG. 8B, a processing sequence 15 in which the processing time of the stripping solution processing in the processing sequence 150 is shortened similarly to the first embodiment.
0a, 150b,... Are continuously repeated. Next, a specific example of removing the resist residue shown in FIG. FIG. 9 shows a processing procedure by a processing apparatus suitable for this removing method.
In the figure, reference numeral 500 denotes a stripping solution processing apparatus using a batch dip method, 510 denotes the same rinsing processing apparatus, 520 denotes the same rinsing processing apparatus, and 450 denotes a drying processing apparatus. Also, 5
01 is a dip tank for storing the processing, 502 is the semiconductor substrate 1
It is a holder for storing.

First, the processing sequence 150 shown in FIG.
The processing is performed according to a. First, remover treatment 151a
I do. In the stripping solution processing 151a, a plurality of semiconductor substrates 1 on which the resist residue remains are set in the holder 502 (for example, for each lot), and the semiconductor substrate 1 is filled with the fluorine-based stripping solution of the stripping solution processing apparatus 500 in FIG. Dipped tank 50
1 is immersed for a predetermined time, for example, 3 minutes and 20 seconds. At this time, the immersed semiconductor substrate is swung vertically and horizontally so that the stripping solution is evenly distributed on the surface. Note that an ammonium fluoride solution is used as the fluorine-based stripping solution.

Next, a rinsing process 152 is performed following the above-mentioned stripping solution process 151a. Again, stripper treatment 151a
Similarly, a plurality of semiconductor substrates are rinsed in a dipping bath filled with a rinsing liquid for a predetermined time by using a rinsing device 510,
For example, it is immersed for 2 minutes and 20 seconds, and swings vertically and horizontally. At this time, a mixed solution obtained by mixing IPA and water at a volume ratio of 4: 1 is used as a rinsing liquid. Next, a water washing process 153 is performed following the above-described rinsing process. Similar to the stripping solution treatment and the rinsing solution treatment, a plurality of semiconductor substrates are immersed in a dip tank filled with pure water for a predetermined time, for example, 2 minutes and 20 seconds, and oscillated vertically and horizontally using a water washing treatment device 520. . Finally, a drying process 154 is performed. The plurality of semiconductor substrates that have been subjected to the water-washing process are dried for a predetermined period of time, for example, 7 minutes and 15 seconds in a nitrogen atmosphere set at a temperature of 23 ° C. using the drying processing device 450. As described above, the first processing sequence 1
End 50a.

Next, following the processing sequence 150a, 2
The first processing sequence is the processing sequence 1 in FIG.
Perform according to 50b. This processing sequence 150b
Is performed under the same conditions as those in the processing of the processing sequence 150a. Finally, the third processing sequence 150c is performed under the same conditions as those of the processing sequence 150a or 150b, and the residue removal step is finally completed. As a result, as shown in FIG. 3B, a clean capacitor having no recess in the interlayer insulating film 1 and no residue is formed.
Thereafter, through the same steps as in the first embodiment and the resist residue removing step, a connection hole structure reaching the surface of the capacitor as shown in FIG. 6 is obtained.

As described above, according to the method for removing a resist residue according to the second embodiment of the present invention, a process including a stripping process using a fluorine-based stripping solution for a short time so as not to affect the components of the semiconductor device. Sequence at least 2
Since the resist residue is repeatedly removed two or more times, it is possible to sufficiently remove the resist residue while minimizing the influence on the constituent parts. In addition, the throughput can be reduced because of batch processing. Furthermore, by applying the present residue removing method to the capacitor forming step, a highly reliable capacitor and a semiconductor device having a connection hole structure reaching this capacitor can be obtained.

Embodiment 3 Next, a third embodiment of the present invention will be described. In the present embodiment, the above-described method for removing a resist residue is applied to a manufacturing process of a semiconductor device having a wiring structure via a metal plug. Figure 10
FIG. 12 is a process sectional view showing a wiring portion of the semiconductor device. Hereinafter, description will be made with reference to these drawings. First, FIG.
Referring to (a), an interlayer insulating film 23 made of silicon dioxide is formed on a silicon substrate 21 including a conductive layer, and a resist film 25 having a pattern of connection holes is formed thereon. Insulating film 2 with mask as mask
By dry-etching 3, for example, a connection hole 27 reaching a conductive layer (not shown) formed in the silicon substrate 21 is formed.

Next, referring to FIG. 10B, the unnecessary resist film 25 is removed by ashing using oxygen plasma. At this time, resist residues 29a, 29b, 29c remain on the side and bottom surfaces of the connection hole 27 or on the surface of the interlayer insulating film 23, respectively. here,
As in the case of the first embodiment, this resist residue is used as shown in FIG.
According to the removal processing procedure shown in (b), the removal is performed using the processing apparatus shown in FIG. Accordingly, a clean connection hole structure without a recess in the interlayer insulating film 23 and expansion of the connection holes 27 and no resist residue is formed.

The interlayer insulating film 23 has a multi-layer structure, for example, from above, plasma TEOS / SOG / plasma TE.
Even in the case of a three-layer film structure of the OS, the resist residue can be removed almost without causing a difference in the amount of erosion of the fluorine-based stripping solution due to a difference in film type. The embedding characteristics of a metal plug or the like to be improved are the same as in the first embodiment. Next, referring to FIG. 10C, a barrier layer 31 having a laminated structure of TiN / Ti is formed on the interlayer insulating film 23 including the inside of the connection hole 27.
Is formed, a metal plug 33 made of tungsten is formed in the connection hole 27.

Next, referring to FIG. 11A, a conductive film 34 made of an aluminum alloy and an antireflection film 35 made of titanium nitride are sequentially formed on the barrier layer 31 and the metal plug 33, and further thereon. A resist film 37 having a wiring pattern is formed so as to cover the metal plug 33.
Next, referring to FIG. 11B, using the resist film 37 as a mask, the antireflection film 35, the conductive film 34, and the barrier layer 31 are sequentially irradiated with a mixed gas plasma of CHF ₃ / Ar / Cl ₂ / BCl _3. The aluminum wiring 36 composed of the barrier layer 31, the conductive film 34, and the antireflection film 35 is formed by the used dry etching. Next, referring to FIG.
The unnecessary resist film 37 is removed by ashing using oxygen plasma. At this time, the aluminum wiring 3
Residual residues 39a, 39b, 39c remain on the side surfaces and the surface of layer 6 or on the surface of interlayer insulating film 23, respectively.

Here, this resist residue is used in the first embodiment.
In the same manner as in the case (1), the removal is performed using the processing apparatus shown in FIG. 7 according to the removal processing procedure shown in FIG. First, FIG.
According to the processing sequence 100a of (b), the stripping liquid processing, the water washing processing and the drying processing are continuously performed. In this case, each processing time is set to 3 minutes 20 seconds, 2 minutes 20 minutes.
Seconds and 7 minutes and 15 seconds. Next, under the same processing conditions,
After the first processing sequence 100a, the second processing sequence 100b is performed.

Finally, a third processing sequence 100c is performed again under the same processing conditions, following the second processing sequence 100b, and the final removal step is completed. Note that ammonium fluoride, which is a fluorine-based stripping solution, is used as the stripping solution, and pure water is used for washing. The drying process is performed in a nitrogen atmosphere set at a temperature of 23 ° C.
As a result, as shown in FIG.
Thus, a clean aluminum wiring structure without any recesses, no surface roughness of the aluminum wiring 36, and no residue can be obtained.

In the above example, the metal plug 33 is made of tungsten and the conductive film 34 is made of an aluminum alloy. However, the metal plug 33 may be made of polysilicon and the conductive film 34 may be made of tungsten. In the case where the conductive film 34 is made of tungsten, mixed gas plasma of SF ₆ / Cl ₂ is used for dry etching.

As described above, according to the method for removing a resist residue according to the third embodiment of the present invention, a process including a stripping process using a fluorine-based stripping solution for a short time that does not affect the components of a semiconductor device. Sequence at least 2
Since the resist residue is repeatedly removed at least twice, it is possible to sufficiently remove the resist residue while minimizing the recess and the like of the interlayer insulating film, thereby manufacturing a semiconductor device having a highly reliable wiring structure. be able to.

Embodiment 4 Next, a fourth embodiment of the present invention will be described. In this embodiment, the method for removing a resist residue in Embodiment 1 is applied to a step of forming a wiring connection hole structure for forming a connection hole reaching a wiring. Hereinafter, description will be made with reference to process cross-sectional views shown in FIGS. First, referring to FIG. 13 (a), an aluminum wiring composed of a barrier layer 41 made of titanium nitride / titanium, a conductive film 43 made of an aluminum alloy, and an antireflection film 45 made of titanium nitride on interlayer insulating film 2 46 is formed.

Referring to FIG. 13B, the interlayer insulating film 4 is formed on the interlayer insulating film 2 so as to cover the aluminum wiring 46.
7 is formed. After a resist film 49 having a connection hole pattern is formed thereon, the interlayer insulating film 47 reaches the aluminum wiring 46 by dry etching using a mixed gas plasma of C ₄ F ₈ / Ar / O ₂ using this as a mask. A connection hole 51 is formed. Next, referring to FIG. 14A, the unnecessary resist film 49 is removed by ashing using oxygen plasma. At this time, resist residues 52a, 52b, 52c remain on the side and bottom surfaces of the connection hole 51 or on the surface of the interlayer insulating film 47, respectively.

Here, this resist residue is used in the first embodiment.
In the same manner as in the case (1), the removal is performed using the processing apparatus shown in FIG. 7 according to the removal processing procedure shown in FIG. First, FIG.
According to the processing sequence 100a of (b), the stripping liquid processing, the water washing processing and the drying processing are continuously performed. In this case, each processing time is set to 3 minutes 20 seconds, 2 minutes 20 minutes.
Seconds and 7 minutes and 15 seconds. Next, under the same processing conditions,
After the first processing sequence 100a, the second processing sequence 100b is performed. Finally, the third processing sequence 100c is performed again after the second processing sequence 100b under the same processing time condition.
Finally, the removal step is completed.

It should be noted that ammonium fluoride, which is a fluorine-based stripping solution, is used as the stripping solution, and pure water is used for washing. The drying process is performed in a nitrogen gas atmosphere set at a temperature of 23 ° C. Accordingly, as shown in FIG. 14B, there is no recess in the interlayer insulating film 47, no expansion of the connection hole 51, and the like.
Moreover, a connection hole structure of a clean aluminum wiring having no residue can be obtained.

Next, a second modification according to the present embodiment will be described with reference to the process sectional views shown in FIGS. Although the above example relates to the connection structure in the case where the wiring is an aluminum wiring, the present modification relates to the removal of a resist residue when forming a connection hole on a copper (Cu) wiring. First, referring to FIG. 15A, silicon nitride (SiN) is formed on interlayer insulating film 2 made of silicon dioxide.
A copper diffusion protection film 53 is formed, and an interlayer insulating film 55 is formed thereon.
9 is buried. Note that barrier layers 57 made of tantalum nitride are formed on both side surfaces of the copper wiring 59.
Further, a copper diffusion protection film 61 is formed on the interlayer insulating film 55 and the copper wiring 59.

Next, referring to FIG. 15B, an interlayer insulating film 63 made of silicon dioxide is formed on the copper diffusion protection film 61, and a resist film 65 having a connection hole pattern formed thereon is formed. As a mask, a connection hole 67 reaching the copper wiring 59 is formed in the interlayer insulating film 63 and the copper diffusion protection film 61 by dry etching using a mixed gas plasma of C ₄ F ₈ / Ar / O ₂ . Next, referring to FIG. 16A, the unnecessary resist film 65 is removed by ashing using oxygen plasma. At this time, the connection hole 6
The resist residues 69a, 69b, 69c remain on the side and bottom surfaces of the substrate 7 or on the surface of the interlayer insulating film 63, respectively.

Here, the resist residue is removed using the processing apparatus shown in FIG. 7 according to the removal processing procedure shown in FIG. 1B under the same processing conditions as in the above example. As a result, as shown in FIG. 13B, a clean copper wiring connection hole structure having no recess in the interlayer insulating film 63, no expansion of the connection hole 67, and the like and no resist residue can be obtained. In addition, the HDP-USG / FLARE (Lo)
Even in the case of a two-layer film structure (wk film), the resist residue can be removed with almost no difference in the amount of erosion of the fluorine-based stripping solution due to the difference in film type.

As described above, according to the method for removing a resist residue according to the fourth embodiment of the present invention, a process including a stripping process using a fluorine-based stripping solution for a short time that does not affect the components of a semiconductor device. Sequence at least 2
Since the resist residue is repeatedly removed at least twice, it is possible to sufficiently remove the resist residue while minimizing the recess of the interlayer insulating film and the spread of the connection hole, etc.
A semiconductor device having a highly reliable wiring connection hole structure can be manufactured.

Embodiment 5 Next, a third embodiment of the present invention will be described. In this embodiment, the method for removing a resist residue in Embodiment 1 is applied to a step of forming a metal gate electrode transistor of a semiconductor device. Hereinafter, description will be made with reference to process cross-sectional views shown in FIGS. First, referring to FIG. 17A, a gate insulating film 71 made of silicon dioxide is formed on a silicon substrate 21.
A polysilicon film 73, a tungsten nitride film 75, a tungsten film 77, a silicon nitride film 79, and a TEOS oxide film 81 are sequentially formed, and a resist film 83 having a gate electrode pattern is formed on the TEOS oxide film 81.

Next, referring to FIG. 17B, the TEOS oxide film 81 is dry-etched using the resist film 73 as a mask, and the silicon nitride film 79 and the tungsten film 7 are further etched.
7. Tungsten nitride film 75 and polysilicon film 73
Are sequentially etched to form a metal gate electrode 78 including a tungsten film 77, a tungsten nitride film 75, and a polysilicon film 73. Next, referring to FIG. 18A, the unnecessary resist film 83 is removed by performing ashing using oxygen plasma. At this time, resist residues 85a, 85b and 85c remain on the side surfaces and the surface of the metal gate electrode 78 or on the surface of the gate insulating film 71, respectively.

Here, this resist residue is used in the first embodiment.
The removal is performed using the processing apparatus shown in FIG. 7 according to the removal processing procedure shown in FIG. Thus, as shown in FIG. 18B, the gate insulating film 71 is hardly etched, and a clean metal gate electrode 78 having no resist residue is formed. Thereafter, ion implantation is performed using the metal gate electrode as a mask to form a desired source 87a / drain 87b on the surface of the silicon substrate, thereby completing the metal gate transistor 90. In the above example, the resist residue was removed after forming the gate electrode.
Even after performing source / drain formation by ion implantation,
A similar removal effect can be obtained. Further, the material and structure of the metal gate electrode are not limited to the above example, and may be any material and structure.

As described above, according to the method for removing a resist residue according to the fifth embodiment of the present invention, a process including a stripping process using a fluorine-based stripping solution for a short time that does not affect the constituent parts of a semiconductor device. Sequence at least 2
Since the resist residue is repeatedly removed two or more times, the resist residue can be sufficiently removed without etching the gate insulating film, and a semiconductor device having a highly reliable metal gate electrode transistor can be manufactured. .

In the above-described residue removing method, the total stripping solution processing time in each processing sequence is 10 minutes (3 minutes 2
0 seconds × 3 times), and the case where the number of repetitions of the processing sequence is 3 has been described. May be set according to the nature of the residue, the degree of sticking, and the like due to the difference between the two. For example, when the residue is strong, the stripping solution processing time in each processing sequence is 2 minutes, and the number of repetitions is 5 times. Further, the stripping solution processing times of the respective processing sequences need not be all the same, and the respective stripping solution processing times may be different as long as the total time is the same. In addition, although ammonium fluoride was used as an example of the fluorine-based stripping solution, the invention is not limited to this, and any solution containing a fluorine compound may be used.

Further, in the above-described third to fifth embodiments, the case where a single-wafer type spray processing apparatus is used has been described. However, similarly to the case of the second embodiment, a batch type dipping type processing apparatus may be used. Similar effects can be obtained. The processing procedure in this case is as shown in FIG.

[0061]

Since the present invention is configured as described above, it has the following effects. According to the first aspect of the invention, since the processing sequence including the processing using the fluorine-based stripping solution is repeated twice or more, the resist residue can be removed without deteriorating the substrate.

According to the second aspect of the present invention, the processing sequence including the fluorine-based stripping solution treatment and the washing or drying treatment is repeated twice or more, so that the resist residue can be sufficiently removed without deteriorating the substrate. can do.

According to the third aspect of the present invention, the removability of the resist residue can be further improved.

According to the fourth aspect of the present invention, the resist residue can be more efficiently removed.

According to the invention of claim 5, it is possible to remove the resist residue while controlling the deterioration of the constituent parts of the semiconductor device within a desired standard value.

According to the sixth aspect of the present invention, the capacitor is formed by using a method for removing a resist residue, which repeats a processing sequence including a fluorine-based stripping solution treatment and a washing treatment or a drying treatment two or more times. A highly reliable semiconductor device without a resist residue can be manufactured.

According to the seventh aspect of the invention, a semiconductor device with higher reliability can be manufactured.

Further, according to the invention of claim 8, the wiring through the metal plug is formed by using a method for removing a resist residue by repeating a processing sequence including a fluorine-based stripping solution treatment and a washing treatment or a drying treatment two or more times. Because it is formed
A highly reliable semiconductor device without a resist residue can be manufactured.

According to the ninth aspect, a semiconductor device with higher reliability can be manufactured.

According to the tenth aspect of the present invention, a contact structure on a wiring is formed by using a method of removing a resist residue by repeating a processing sequence including a fluorine-based stripping solution treatment and a washing treatment or a drying treatment at least twice. So
A highly reliable semiconductor device can be manufactured.

According to the eleventh aspect, a semiconductor device with higher reliability can be manufactured.

According to the twelfth aspect of the present invention, the metal gate electrode is formed by using a method for removing a resist residue by repeating a treatment sequence including a fluorine-based stripping solution treatment and a washing treatment or a drying treatment two or more times. Thus, a highly reliable semiconductor device can be manufactured.

According to the thirteenth aspect, a more reliable semiconductor device can be manufactured.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a procedure for processing a resist residue according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating the manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 3 is a cross-sectional view illustrating a manufacturing step of the semiconductor device according to the first embodiment of the present invention;

FIG. 4 is a cross-sectional view illustrating the manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 5 is a cross-sectional view showing a manufacturing step of the semiconductor device according to the first embodiment of the present invention;

FIG. 6 is a cross-sectional view illustrating a manufacturing process of the semiconductor device according to the first embodiment of the present invention;

FIG. 7 is a conceptual diagram showing a removal processing procedure by the processing device according to the first embodiment of the present invention.

FIG. 8 is a conceptual diagram showing a procedure for processing a resist residue according to a second embodiment of the present invention.

FIG. 9 is a conceptual diagram showing a removal processing procedure by a processing device according to a second embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a manufacturing step of the semiconductor device according to Embodiment 3 of the present invention.

FIG. 11 is a sectional view showing a manufacturing step of the semiconductor device according to the third embodiment of the present invention;

FIG. 12 is a cross-sectional view illustrating the manufacturing process of the semiconductor device according to the third embodiment of the present invention;

FIG. 13 is a cross-sectional view illustrating the manufacturing process of the semiconductor device according to the fourth embodiment of the present invention;

FIG. 14 is a cross-sectional view showing a manufacturing step of the semiconductor device according to the fourth embodiment of the present invention.

FIG. 15 is a cross-sectional view showing a manufacturing step of the semiconductor device according to the fourth embodiment of the present invention.

FIG. 16 is a cross-sectional view illustrating the manufacturing process of the semiconductor device according to the fourth embodiment of the present invention;

FIG. 17 is a sectional view showing the manufacturing process of the semiconductor device according to the fifth embodiment of the present invention;

FIG. 18 is a sectional view showing the manufacturing process of the semiconductor device according to the fifth embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 semiconductor substrate, 2 interlayer insulating film, 3a first conductive film, 5a dielectric film, 7a second conductive film, 8
Capacitor, 9 resist film, 11a to 11c
Resist residue, 13 interlayer insulating film, 15 resist film, 17 connection hole, 19a to 19c resist residue, 21 silicon substrate, 23 interlayer insulating film, 2
5 resist film, 27 connection holes, 29a to 29c resist residue, 33 metal plug, 34 conductive film,
36 aluminum wiring, 37 resist film, 39a-3
9c resist residue, 46 aluminum wiring, 47 interlayer insulating film, 49 resist film, 51 connection hole, 5
2a to 52c resist residue, 55 interlayer insulating film,
59 copper wiring, 63 interlayer insulating film, 65 resist film, 67 connection hole, 69a-69c resist residue, 71 gate insulating film, 73 polysilicon film,
75 tungsten nitride film, 77 tungsten film, 78 metal gate electrode, 85a-85c resist residue, 90 metal gate transistor, 10
0 treatment sequence, 101 stripper treatment, 102
Washing process, 103 drying process, 150 processing sequence

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/304 642 H01L 21/304 647Z 643 647A 647 648H 651L 648 21/306 S 651 21/30 572B F term (Reference) 2H096 AA25 HA23 LA03 3B201 AA03 AB34 AB38 AB42 AB44 BB02 BB22 BB33 BB87 BB93 BB95 CC01 CC11 5F043 AA40 BB30 CC20 DD13 EE02 EE07 EE08 GG10 5F046 MA02 MA06

Claims (13)

[Claims] 1. A method for removing a resist residue, wherein a processing sequence including a step of stripping a substrate with a fluorine-based stripping solution is continuously repeated at least twice or more. 2. A processing sequence comprising a step of stripping a substrate with a fluorine-based stripping liquid, a step of washing the substrate with water after the stripping liquid processing, and a drying step of drying the substrate after the water washing processing is continuously performed. And removing the resist residue at least twice. 3. Between the peeling treatment step and the water washing treatment step,
3. The method according to claim 2, further comprising a rinsing step. 4. The method for removing a resist residue according to claim 2, wherein the fluorine-based stripping solution is ammonium fluoride. 5. The method for removing a resist residue according to claim 2, wherein the total time of the stripping process in each processing sequence is 10 minutes. 6. A step of forming an interlayer insulating film on a semiconductor substrate, a step of forming a first conductive film on the interlayer insulating film, and a step of forming a first conductive film on the first conductive film via a dielectric film. Forming a second conductive film, forming a resist film on the second conductive film, and using the resist film as a mask, forming the second conductive film, the dielectric film, and the first conductive film. 3. A method for manufacturing a semiconductor device, comprising: a step of forming a capacitor by sequentially etching; and a step of removing the resist film, wherein a resist residue remaining after the removal of the resist is removed.
A method for manufacturing a semiconductor device, comprising removing the resist residue by using the above-described method for removing a resist residue. 7. The first and second conductive films are any one material selected from the group consisting of polysilicon, titanium nitride, tungsten, tungsten nitride, tantalum nitride, ruthenium, platinum, and an alloy of platinum and iridium. 7. The semiconductor device according to claim 6, wherein the dielectric film is made of any one material selected from the group consisting of silicon dioxide, silicon oxynitride, silicon nitride, tantalum oxide, BST, and PZT. Production method. 8. A step of forming an interlayer insulating film having a connection hole reaching the semiconductor substrate on a semiconductor substrate; a step of forming a metal plug in the connection hole; and forming a metal plug on the interlayer insulating film and the metal plug. Forming a conductive film; forming a resist film on the conductive film so as to cover at least a part of the surface of the metal plug; etching the conductive film using the resist film as a mask to form a wiring A method of manufacturing a semiconductor device, comprising: a step of removing the resist film; and a step of removing a resist residue remaining after removing the resist.
A method for manufacturing a semiconductor device, comprising removing the resist residue by using the above-described method for removing a resist residue. 9. The method according to claim 8, wherein the metal plug is made of tungsten or polysilicon, and the wiring is made of an aluminum alloy or tungsten. 10. A step of forming a wiring on a semiconductor substrate; a step of forming an interlayer insulating film on the semiconductor substrate and the wiring; and an opening on at least a part of the wiring surface on the interlayer insulating film. Forming a connection hole reaching the surface of the wiring using the resist film as a mask; and removing the resist film. And removing the resist residue remaining after removing the resist.
A method for manufacturing a semiconductor device, comprising removing the resist residue by using the above-described method for removing a resist residue. 11. The method according to claim 10, wherein the wiring is made of an aluminum alloy or copper. 12. A step of forming a gate insulating film on a semiconductor substrate; a step of forming a metal film on the gate insulating film; a step of forming an insulating film on the metal film; A step of forming a resist film, a step of forming a metal gate electrode by etching the insulating film and the metal film using the resist film as a mask, a step of removing the resist film, and a step of removing the insulating film and the metal film. Forming a conductive layer on the semiconductor substrate by ion implantation on a mask, wherein the resist residue remaining after the removal of the resist or after the ion implantation is removed. A method for manufacturing a semiconductor device, comprising: removing using a removing method. 13. The method according to claim 12, wherein the metal film is a single-layer or multi-layer conductive film made of a metal material selected from the group consisting of polysilicon, tungsten, tungsten nitride, titanium, and titanium nitride. A method for manufacturing a semiconductor device.