JP2003203900A - Wafer-processing device and wafer-processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for removing or cleaning a metal film or a contaminated metal which adheres to an edge of a wafer. <P>SOLUTION: This device comprises a wafer-holding mechanism for rotating and simultaneously holding a wafer 10, a surface nozzle 14 for supplying pure water to a central surface of the wafer, an edge nozzle 18 for supplying an etching agent or a cleaning agent to a peripheral surface of the wafer, and a back nozzle 16 for supplying the etching agent or the cleaning agent to the center of the back of the wafer. The surface nozzle 14 and the edge nozzle 18 exist on a surface side of the wafer and inject different liquid chemicals, respectively. A liquid injected from the back nozzle 16 is prevented from infiltrating into the back. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching removal method and apparatus used in a semiconductor device manufacturing process, and more particularly to a cleaning method and apparatus used in a semiconductor device manufacturing process.

[0002]

2. Description of the Related Art In the case of manufacturing a semiconductor device on a wafer, it is common practice to remove unnecessary or undesired materials by etching and clean contaminants adhering to the wafer or device. .

In such removal and cleaning, it is particularly required to remove undesired materials existing around the front surface, edge surface, back surface periphery, and back surface of the wafer, or to remove contaminants. is there. Here, the end surface refers to the side surface of the outer periphery of the wafer, the front surface periphery refers to a region between the device formation region and the end surface on the wafer surface, and the back surface periphery includes an undesired metal film formed on the back surface of the wafer. Refers to the area.

For example, when Cu having a high conductivity is used as the wiring material instead of Al, the Cu wiring is made of SiO ₂
After forming a groove on the film and forming a Cu film by electroplating,
Often formed by chemical mechanical polishing (CMP).
This is a Cu wiring forming method called a so-called damascene method.

To form such Cu wiring, specifically, a groove is formed in the SiO ₂ film and a barrier metal (for example, Ta, TaN, etc.) for preventing Cu diffusion is formed by sputtering. Subsequently, a seed Cu film is formed by sputtering, and a Cu film is formed by electrolytic plating. Electrolytic plating is performed by providing a ring surrounding a device formation region on the wafer surface and injecting a plating solution inside the ring. However, if the plating solution leaks from the ring, Cu is deposited outside the ring, that is, around the surface of the wafer. Such Cu
Membranes are unwanted materials. Because the plated C
This is because the adhesion between u and SiO ₂ is low, so that the Cu film around the wafer surface is peeled off due to stress of the film in the subsequent film forming process and the like, resulting in line contamination. Therefore, the Cu film formed around the wafer surface must be removed.

Further, after CMP, the wafer is contaminated with Cu, which is polishing dust. Such Cu diffuses in the Si substrate and the SiO ₂ film by the subsequent heat treatment, and when it reaches the device region, it causes a bad influence on the performance of the semiconductor device. Cu adhered to the periphery of the front surface, the end surface, and the back surface of the Si substrate, which is a wafer, is difficult to peel off and therefore must be removed by cleaning.

When the size of the wafer used in the above process is, for example, 8 inches, the distance from the edge of the device forming region to the wafer end surface is, for example, about 5 mm. In order to increase the device formation area, it is desirable to further form the SiO ₂ film closer to the wafer end surface by 1.5 to ₂ mm. In such a case, when the seed Cu is deposited by the entire surface sputtering, the seed Cu is deposited around the front surface of the wafer to the end face and even around the back surface. At the time of electrolytic plating in the next step, the plating liquid leaks from the ring and wraps around from the surface periphery to the end face to form a Cu film on the seed Cu.

Since this Cu film is formed on the seed Cu, there is no fear of peeling. However, if Cu is attached to the end surface of the wafer, this Cu will attach to the carrier of the wafer or the robot arm and the transfer system It causes cross pollution. Therefore, it is required to remove Cu attached to the wafer end surface.

The peripheral distance outside the device formation region is 1.5
Since it is extremely small, such as ~ 2 mm, this removal must be well controlled. This means that after CMP, contamination Cu adhered to the periphery of the wafer, the end surface, and the back surface of the wafer.
The same applies when washing the.

As described above, there are the following conventional techniques for removing or cleaning the undesired Cu film and the contaminated Cu on the front surface, the end surface, and the back surface of the wafer.

FIG. 25 shows an example of the prior art. In this conventional technique, the FPM is formed in the device formation area of the wafer 10.
(HF / H ₂ O ₂ / H ₂ O mixed solution) A protective film having resistance is formed, and the entire wafer is immersed in the etching solution FPM to clean the area other than the protective film forming area. After that, the protective film 12 is removed.

FIG. 26 shows another example of the prior art. In this conventional technique, the wafer is rotated with the front surface of the wafer 10 facing downward, and a gas such as nitrogen is supplied to the front surface of the wafer while supplying the etching solution FPM to the rear surface of the wafer.
While protecting the wafer surface with a gas such as nitrogen, the FPM that wraps around the end surface is controlled to clean the wafer back surface and the wafer surface periphery.

[0013]

The conventional technique of FIG. 25 is as follows.
When forming a wafer surface protective film, it is necessary to devise a method that does not form a protective film around the surface. Also, when removing the protective film, do not damage the semiconductor device wiring material, etc. formed on the wafer surface. Is required.
When the resist is used as a protective film, there is a problem that the number of steps is increased, and it is difficult to remove the protective film without damaging the wiring material or the like.

In the prior art of FIG. 26, the FP to the wafer end surface is used.
The wraparound of M is controlled by the number of rotations of the wafer and the flow rate of gas such as nitrogen supplied to the front surface side of the wafer, which is difficult to control. The portion of the wafer surface (bottom surface) where the gas contacts the cleaning liquid undulates along the wafer periphery, and the cleaning liquid reaches the device formation area in some areas and corrodes the device formation surface, and in some areas the wafer surface peripheral area However, undesired metal films may remain because they cannot be cleaned. Therefore, when the peripheral distance outside the device formation region is as small as 1.5 to 2.0 mm, it cannot be used.

An object of the present invention is to provide an etching removal method and apparatus, and a cleaning method and apparatus, which solve the above problems of the prior art.

[0016]

An etching removing apparatus and a cleaning apparatus of the present invention include means for holding and rotating a wafer, one back nozzle for ejecting a liquid to the center of the back surface of the wafer, and liquid for ejecting the liquid to the center of the front surface of the wafer. And one surface nozzle that ejects.

An etching solution or a cleaning solution is supplied from the edge nozzle and the back surface nozzle depending on the purpose of etching removal or cleaning. Further, a liquid for protecting the wafer surface is supplied from the surface nozzle.

The apparatus of the present invention is particularly suitable for removing Cu formed in the peripheral portion of the wafer due to leakage of the Cu plating solution when Cu wiring is formed by the damascene method, and after chemically plating the Cu, the wafer is removed. It is particularly suitable for cleaning the contaminated Cu adhering to the peripheral portion and the back surface.

In particular, since the liquid is ejected in the form of a beam from the edge nozzle, it is possible to control or remove the undesired metal film and the contaminated metal around the surface with good controllability.

Further, since pure water or the like is supplied to the surface of the wafer from the surface nozzle to protect the surface of the wafer, the wiring material is not damaged.

In the case of the etching removal apparatus, when the metal film to be removed exists only around the surface of the wafer,
The back nozzle can also be omitted.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a view showing a nozzle mounting position in an embodiment of an etching removing apparatus and a cleaning apparatus of the present invention. Since the etching removing device and the cleaning device have basically the same structure, the following description will be made without distinguishing between them.

In this embodiment, the surface nozzle 14 and
An example in which the back nozzle 16 and the edge nozzle 18 are provided is shown. FIG. 1A is a plan view seen from the surface of the wafer 10, and FIG. 1B is a side view.

The front surface nozzle 14 ejects liquid to the center of the wafer surface, the back surface nozzle 16 ejects liquid to the center of the wafer back surface, and the edge nozzle ejects liquid to the periphery of the wafer surface.

The mounting position and mounting angle of these nozzles depend on the wafer size, but are 150 mm, 200 mm, 3
A 00 mm wafer was planned and the position and angle were set.

As an example, the height H1 of the surface nozzle 14 from the wafer surface is 10 to 100 mm, and in this embodiment, it is 50 mm. The height H ₂ of the back nozzle 16 from the back surface of the wafer is 10 to 100 mm, and is 50 mm in this embodiment. Further, the height H ₃ of the edge nozzle 18 from the wafer surface is 5 to 50 mm, and in this embodiment, it is 10 mm.

The distance L1 from the tip of the front surface nozzle 14 to the center of the wafer surface is 70 to 200 mm, which is 120 mm in this embodiment. The distance L ₂ from the tip of the back surface nozzle 16 to the center of the back surface of the wafer is 70 to 200 mm, which is 120 mm in this embodiment. Further, from the tip of the edge nozzle 18, the distance L ₃ of the nozzle center line to a point intersecting the wafer surface is 1 to 50 mm, and a 10mm in this embodiment.

When viewed from the side of the wafer in FIG. 1B, the angle .theta.1 formed by the surface nozzle 14 with the wafer surface is 15 to 60.degree. The angle theta ₂ which the back surface nozzle 16 forms with the wafer surface, there ° 15-60 and 45 ° in this embodiment. The angle θ ₃ formed by the edge nozzle 18 with the wafer surface is 10 to 50 °, which is 35 ° in this embodiment.

When the wafer surface in FIG. 1A is viewed from above,
At the point where the center line of the nozzle 18 intersects with the periphery of the wafer surface
Angle θ with the tangent line 20 in the wafer rotation direction _Four Is
The angle is 0 to 90 °, and is 45 ° in this embodiment. sand
That is, the liquid ejected from the edge nozzle 18 is exposed on the wafer surface.
Can be ejected from the periphery of the surface so that it does not flow inward
Good.

The front surface nozzle 14 and the rear surface nozzle 1
The liquid ejected from 6 is spread toward the periphery of the wafer by the centrifugal force generated by the rotation of the wafer.
The liquid jetting state of the back nozzle 16 may be either jetting the liquid in the form of a beam or jetting the liquid in a sprayed state, since the liquid may be supplied to the center of the wafer.

On the other hand, since the edge nozzle 18 is required to bring the liquid into contact with the periphery of the wafer with good controllability, it has a structure for ejecting the liquid into a beam having a diameter of 0.5 to 2.0 mm, or It has a structure of ejecting in a fan shape along the outer peripheral portion of the wafer.

In the above example, one edge nozzle has been described, but the number is not limited to one, and two or more may be provided.

FIG. 2 is a diagram showing an example of a wafer holding mechanism in the present embodiment. (A) is a schematic perspective view,
(B) is a side view.

This wafer holding mechanism is a roller chuck type holding mechanism, and has four wafer rollers 22 each connected to a rotary shaft 24. Grooves 26 that support the wafer 10 are formed on the peripheral side surface of the wafer roller. The wafer 10 is supported by these grooves, and the wafer roller 22 rotates to rotate the wafer.

In this example, the number of wafer rollers was four, but the number is not limited to this, and any number may be used as long as it is within the range of 3 to 8.

In this roller chuck type wafer holding mechanism, since the end surface of the same portion of the wafer is not always supported by the wafer roller, it is required to process the end surface of the entire circumference of the wafer. It is suitable for use in etching removal methods and cleaning methods. Since the positions of the wafer roller 22 and the rotation shaft 24 are fixed, the liquid ejected from the back surface nozzle 16 is not blocked by the rotation shaft 24, and the liquid can be brought into good contact with the wafer back surface without waste.

FIG. 3 is a diagram showing another example of the wafer holding mechanism. (A) is a schematic perspective view and (B) is a side view.

This wafer holding mechanism is a pin chuck type holding machine and has four pins 30 which are connected to the rotary table 28 and which are provided with a step for supporting the wafer.

The wafer 10 is supported on the steps of the pins 30, and the turntable 28 rotates.

Although the number of pins is four in this example,
The number is not limited to this, and may be 3 to 8 or any number.

In this pin chuck type wafer holding mechanism, in order to prevent the pins from always supporting the same position on the wafer end surface, the pin chuck holding mechanism is slightly loosened for a moment during the process to reduce the number of rotations of the wafer. By doing so, the wafer holding position shifts due to inertia. This wafer holding mechanism changes the wafer chuck position.

Alternatively, once the rotation of the wafer is stopped,
The chuck position may be changed by lifting the wafer with a handler or the like.

Alternatively, the chuck position can be changed by providing two wafer holding mechanisms having different chuck positions in the stopped state and transferring the wafer to the second wafer holding mechanism after the processing in the first wafer holding mechanism is completed. can do.

FIG. 4 is a view showing still another example of the wafer holding mechanism. (A) is a schematic perspective view and (B) is a side view.

This wafer holding mechanism is a pin chuck type holding machine as in FIG. 3, but the wafer holding means is different from that in FIG.

This wafer holding mechanism has four pins a,
By arranging four pins b alternately, the wafer 10 is supported by the pin a in the first half of the process, and the wafer 10 is supported by the pin b in the latter half of the process, so that the pin contact portion to the wafer end face is formed. Can be changed.

In this example, if the total number of pins is eight, it is possible to use three pins a and three pins.

Although three examples of the wafer holding mechanism have been described above, a combined method of a roller chuck system and a pin chuck system is also possible. In this case, the pin chuck mechanism itself does not require the wafer holding means as described in FIGS. 3 and 4, and when holding the wafer, the pin chuck is released and the wafer is rotated by the wafer roller. It suffices to pinch the position different from the previous one.

The structures of the semiconductor device etching removal apparatus and the cleaning apparatus have been described above.

An embodiment of the etching removing method and the cleaning method of the present invention will be described below for the case of forming a Cu wiring. The etching removing apparatus and the cleaning apparatus used are any of those described in FIGS. Can also be used.

[0051]

Example 1 FIG. 5 shows a process flow of Example 1. 6 to 11 are cross-sectional views of the edge portion of the wafer including a part of the device formation region in each step.

The steps will be described below in order.

(1) Formation of Wiring Groove As shown in FIG. 6, an oxide film (SiO ₂ ) 34 is formed on the device forming region on the Si substrate 32 forming the wafer to form a wiring groove 36. In this example, the distance from the edge of the device formation region to the wafer end surface is about 5 mm in the peripheral portion of the wafer surface.

(2) Via metal and seed Cu film formation As shown in FIG. 7, a barrier metal (for example, Ta, TaN, etc.) 38 for preventing Cu diffusion is formed by sputtering, and then a seed Cu 40 is formed. Sputter film formation. Here, when the barrier metal 38 and the seed Cu 40 are formed by sputtering, the periphery of the wafer surface is covered with a shield ring,
These sputtered films are prevented from being formed.

(3) Plating Cu film formation As shown in FIG.
A plating solution is injected into the ring to form a plated Cu 42 by electrolytic plating. At this time, as described in the related art, the plating liquid leaks to the outside of the O-ring, and the plated Cu 44 grows on the oxide film 34. The plated Cu 44 is easy to peel off and causes line contamination, so it must be removed.

(4) Etching Removal of Undesired Plating Cu In this step, the wafer is held by the wafer holding mechanism of the above-described etching removing apparatus of the present invention.

From the surface nozzle 14, a solution that does not etch Cu, such as pure water or an organic acid aqueous solution (0.001
% To 5% oxalic acid, citric acid, malonic acid, etc.) are jetted and supplied to the central portion of the wafer surface. In this example,
Pure water shall be supplied.

At the same time, Cu is etched from the edge nozzle 18, but the underlying SiO ₂ is difficult to etch C
A solution with a high u / SiO ₂ selectivity is jetted and supplied to the periphery of the wafer surface.

As a solution for etching Cu, H₂ 
O₂ Acid or alkaline solutions containing
PM (HF / H₂ O₂ / H₂ O), SPM (H₂SO_Four 
/ H₂ O₂ / H₂ O), HPM (HCl / H₂ O₂ / H
₂ O), nitric acid hydrogen peroxide solution (HNO₃ / H₂ O₂ / H₂ 
O), APM (NH_Four OH / H₂ O₂ / H ₂ O), concentrated glass
Acid, etc.

In these solutions, the composition having a high Cu / SiO ₂ etching selection ratio is as follows.

HF: H ₂ O ₂ : H ₂ O = 1 to 10: 1
20: 100 H ₂ SO ₄ / H ₂ O ₂ / H ₂ O = 1 to 10: 1 to 20:
100 HCl / H ₂ O ₂ / H ₂ O = 1 to 10: 1 to 20:10
0 HNO ₃ / H ₂ O ₂ / H ₂ O = 1 to 10: 1 to 20: 1
_{00 NH 4 OH / H 2 O} 2 / H 2 O = 1~10: 1~20:
100 Concentrated nitric acid (30% to 80%) FIG. 12 shows the FPM composition ratio dependence of the Cu / SiO ₂ etching selection ratio as an example. According to FIG. 12, Cu /
The SiO ₂ selection ratio is about 250 at a composition ratio of 1: 10: 100.
It turns out that it is the largest.

In this embodiment, FPM is used as the solution supplied from the edge nozzle.

While the wafer is being rotated in the etching removal apparatus, pure water is ejected from the surface nozzle 14 and FPM is ejected from the edge nozzle 18.

The pure water ejected from the surface nozzle 14 and the FPM ejected from the edge nozzle 18 flow toward the outer periphery of the wafer by the centrifugal force due to the rotation of the wafer, so that the FPM does not flow toward the center of the wafer. To be done. Further, since the device forming region on the wafer surface is covered with pure water, the wafer surface on the device forming region can be protected even when the FPM bounces due to the rotation of the wafer. Therefore, it is possible to avoid damage to the plated Cu 42 and the oxide film 34 formed on the wafer surface.

Further, since the FPM is ejected in the form of a beam from the edge nozzle 18, the position where the FPM comes into contact with the wafer can be accurately adjusted.
u44 can be removed by etching with good controllability. FIG. 9 shows a state where the unwanted plating Cu 44 is removed.

(5) Cu annealing Annealing is performed to improve the film quality of the plated Cu42.

(6) Cu-CMP chemical mechanical polishing is performed up to the surface of the oxide film 34 to remove the plating Cu 42, the seed Cu 40 and the barrier metal 38, and form the Cu wiring 46 as shown in FIG. CM
Due to P, Cu, which is polishing dust, adheres to the periphery of the wafer, the end surface, and the back surface of the silicon substrate 32.

(7) Removal of Contaminated Cu In this step, the wafer is held by the wafer holding mechanism of the above-mentioned cleaning device of the present invention.

Pure water is jetted from the surface nozzle 14 and supplied to the central portion of the wafer surface. At the same time, the FPM is ejected from the edge nozzle 18 and the back surface nozzle 16. The pure water jetted from the front surface nozzle 14 and the FPM jetted from the edge nozzle 18 and the back surface nozzle 16 flow toward the wafer end surface as the wafer rotates. At this time, since the plating Cu 42 and the oxide film 34 in the device formation region are protected by pure water, the contamination C adhered to the periphery of the wafer, the end face, and the back face is not damaged.
u is dissolved in FPM and removed from the Si substrate surface. That is, it is washed. FIG. 11 shows a state in which the contaminated Cu is removed by the above cleaning process.

As the cleaning liquid, similar to the etching liquid,
In addition to FPM, an acid or alkaline solution containing H ₂ O ₂ having a good removal property of contaminated Cu is preferable, and for example, SPM (H ₂
SO ₄ / H ₂ O ₂ / H ₂ O), HPM (HCl / H ₂ O
₂ / H ₂ O), nitric acid hydrogen peroxide solution (HNO ₃ / H ₂ O ₂
/ H ₂ O), APM (NH ₄ OH / H ₂ O ₂ / H ₂
O) and concentrated nitric acid.

The protective liquid supplied from the surface nozzle 14 is not only pure water but also an aqueous solution of an organic acid that does not dissolve Cu (0.001% to 5% oxalic acid, citric acid, malonic acid, etc.). Can also be

[0072]

Second Embodiment A second embodiment is a case where Cu wiring is formed in a state where the device formation region is closer to the wafer end face than in the first embodiment in order to increase the effective device formation region. The process flow is the same as the flow shown in FIG. 13 to 18 are cross-sectional views of the edge portion of the wafer including a part of the device formation region in each step.

The steps will be described below in order.

(1) Formation of Wiring Groove As shown in FIG. 13, an oxide film (SiO ₂ ) 34 is formed on the device forming region on the Si substrate 32 forming the wafer to form a wiring groove 36. In this example, the distance from the edge of the device formation region to the wafer end surface is about 2 mm.

(2) Via Metal and Seed Cu Film Formation As shown in FIG. 14, a barrier metal (for example, Ta, TaN, etc.) 38 for preventing Cu diffusion is formed by sputtering, and then a seed Cu 40 is formed. Sputter film formation. In this case, unlike Example 1, sputtering can be performed without a shield ring, or sputtering can be performed on a mounting table having a diameter slightly smaller than the diameter of the wafer to form a film up to the peripheral area of the back surface of the wafer. As described above, since the distance from the end of the device forming region to the wafer end surface is very short, the seed Cu 40 is formed so as to wrap around from the front surface of the wafer to the end surface and even the back surface. Such seed Cu must be removed because it diffuses into the device region in a later heating step and adversely affects it and also causes cross contamination.

(3) Plating Cu film formation As shown in FIG. 15, an O ring (not shown) is provided,
A plating solution is injected into the O-ring to form a plated Cu 42 by electrolytic plating. At this time, the plating liquid leaks and the plating Cu 44 grows on the seed Cu 40. Such plated Cu causes cross contamination and must be removed.

(4) Undesired seed Cu and plating C
Etching removal of u In this step, the wafer is held in the wafer holding mechanism of the above-described etching removing apparatus of the present invention. While rotating the wafer, pure water is jetted from the surface nozzle 14 and supplied to the central portion of the wafer surface. At the same time, from the edge nozzle 18,
The FPM is supplied to the periphery of the front surface of the wafer, the FPM is supplied from the rear surface nozzle 16 to the center of the rear surface of the wafer, and the seed Cu 40 and the plating Cu 44 around the front surface, the end surface, and the rear surface of the wafer are etched away. The removed state is shown in FIG.

(5) Cu annealing Annealing is performed to improve the film quality of the plated Cu42.

(6) Cu-CMP chemical mechanical polishing is performed up to the surface of the oxide film 34 to remove the plating Cu 42, the seed Cu 40, and the barrier metal 38, and form the Cu wiring 46 as shown in FIG. CM
Due to P, Cu 48, which is polishing dust, adheres to the periphery of the wafer, the end surface, and the back surface of the silicon substrate 32.

(7) Removal of Contaminated Cu In this step, the wafer is held by the wafer holding mechanism of the above-mentioned cleaning device of the present invention.

Pure water is jetted from the surface nozzle 14 and supplied to the central portion of the wafer surface. Here, it is desirable that the organic acid is allowed to flow temporarily when the pure water is ejected to clean the contaminated Cu adhering to the surface of the device formation region. At the same time, the FPM from the edge nozzle 18 and the back surface nozzle 16
Gush out. Pure water ejected from the front surface nozzle 14 and F ejected from the edge nozzle 18 and the back surface nozzle 16.
The PM flows toward the wafer end surface due to the rotation of the wafer.

Contamination Cu 48 adhering to the periphery of the front surface, the end surface and the back surface of the wafer is dissolved in FPM and removed from the surface of the Si substrate. That is, it is washed. FIG. 18 shows a state where the contaminated Cu is removed by the above cleaning process. The wafer after CMP may be washed by immersing the entire wafer in a cleaning liquid in a separate step, or may be brush-cleaned, as in the conventional case.

[0083]

Third Embodiment A third embodiment is a case in which the barrier metal is formed so as to wrap around from the surface periphery of the wafer to the end face during the sputter deposition of the barrier metal in the second embodiment. The process flow is the same as the flow shown in FIG. FIG. 19
24A to 24C are cross-sectional views of the edge portion of the wafer including a part of the device formation region in each step.

The steps will be described below in order.

(1) Formation of Wiring Groove As shown in FIG. 19, an oxide film (SiO ₂ ) 34 is formed on the device forming region on the Si substrate 32 forming the wafer to form a wiring groove 36.

(2) Via Metal and Seed Cu Film Forming As shown in FIG. 20, Ta is sputtered as a barrier metal 38 for preventing diffusion of Cu, and then seed Cu 40 is sputtered. In this case, both the barrier metal 38 and the seed Cu 40 are formed so as to wrap around from the periphery of the front surface of the wafer to the end face and further to the periphery of the back surface.

(3) Film formation of plated Cu As shown in FIG. 21, an O ring (not shown) is provided,
A plating solution is injected into the O-ring to form a plated Cu 42 by electrolytic plating. At this time, the plating liquid leaks and the plating Cu 44 grows on the seed Cu 40.

(4) Removal of Undesired Seed Cu, Plating Cu and Ta by Etching In this step, the wafer is held by the wafer holding mechanism of the above-described etching removing apparatus of the present invention. While rotating the wafer, pure water is jetted from the surface nozzle 14 and supplied to the central portion of the wafer surface. At the same time, from the edge nozzle 18,
FPM is supplied to the periphery of the front surface of the wafer, FPM is supplied from the rear surface nozzle 16 to the center of the rear surface of the wafer, and Cu around the front surface, end surface, and rear surface of the wafer is removed by etching.

Subsequently, pure water is ejected from the front surface nozzle 14 and HF solution is ejected from the edge nozzle 18 and the back surface nozzle 16 to remove Ta which is the barrier metal 38. FIG. 22 shows a state in which Cu and Ta are removed.

(5) Cu annealing Annealing is performed to improve the film quality of the plated Cu42.

(6) Cu-CMP chemical mechanical polishing is performed up to the surface of the oxide film 34 to remove the plating Cu, the seed Cu and the barrier metal, and the Cu wiring 46 is formed as shown in FIG. Cu48, which is polishing dust, adheres to the periphery of the wafer, the end surface, and the back surface of the silicon substrate 32 by CMP.

(7) Removal of Contaminated Cu In this step, the wafer is held by the wafer holding mechanism of the above-mentioned cleaning device of the present invention.

Pure water is jetted from the surface nozzle 14 and supplied to the central portion of the wafer surface. At the same time, the FPM is ejected from the edge nozzle 18 and the back surface nozzle 16. The pure water ejected from the front surface nozzle 14 and the FPM ejected from the edge nozzle 18 and the back surface nozzle 16 flow toward the wafer end surface as the wafer rotates.

Contamination Cu adhering to the periphery of the front surface, the end surface and the back surface of the wafer is dissolved in FPM and removed from the surface of the Si substrate. That is, it is washed. FIG. 24 shows a state where the contaminated Cu is removed by the above cleaning process.

Although the above description is based on the example in which the Cu wiring is formed on the oxide film, the present invention is not limited to the case where P is formed on the insulating film.
When forming metal wiring or metal electrode such as t, Ir, IrO, or BST (strontium titanate
It can also be applied when forming a ferroelectric film such as barium) or PZT (lead zirconium titanate).

[0096]

According to the present invention, on the surface of a rotating wafer, a processing solution is supplied to the periphery of the surface by a nozzle, and at the same time, the central part of the wafer is protected from being affected by the processing solution. Since the liquid such as pure water is supplied by the nozzle, the processing liquid does not flow toward the central portion of the surface of the wafer. Therefore, without damaging the semiconductor device wiring material, etc. around the surface of the wafer,
It is possible to effectively remove the metal contamination and the metal film existing on the end surface and the back surface of the wafer.

Further, since the processing liquid around the surface of the wafer is supplied in the form of a beam by the nozzle, the precision of the contact position of the processing liquid around the wafer can be improved. Therefore, the device is formed as close to the wafer end face as possible. It becomes possible to secure an area.

[Brief description of drawings]

FIG. 1 is a view showing a nozzle mounting position in an embodiment of an etching removing apparatus or a cleaning apparatus of the present invention.

FIG. 2 is a diagram showing an example of a wafer holding mechanism.

FIG. 3 is a diagram showing another example of a wafer holding mechanism.

FIG. 4 is a view showing still another example of the wafer holding mechanism.

FIG. 5 is a process flow chart of an example.

FIG. 6 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the first embodiment.

FIG. 7 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the first embodiment.

FIG. 8 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the first embodiment.

FIG. 9 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the first embodiment.

FIG. 10 is a cross-sectional view of the edge portion of the wafer including a device formation region in each step of the first embodiment.

FIG. 11 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the first embodiment.

FIG. 12 is a diagram showing FPM composition ratio dependence of Cu / SiO ₂ etching selection ratio.

FIG. 13 is a cross-sectional view of the edge portion of the wafer including a device formation region in each step of the second embodiment.

FIG. 14 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the second embodiment.

FIG. 15 is a sectional view of the edge portion of the wafer including a part of the device formation region in each step of the second embodiment.

FIG. 16 is a cross-sectional view of the edge portion of the wafer including a device formation region in each step of the second embodiment.

FIG. 17 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the second embodiment.

FIG. 18 is a cross-sectional view of the edge portion of the wafer including a device formation region in each step of the second embodiment.

FIG. 19 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the third embodiment.

FIG. 20 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the third embodiment.

FIG. 21 is a cross-sectional view of the edge portion of the wafer including a device formation region in each step of the third embodiment.

FIG. 22 is a cross-sectional view of the edge portion of the wafer including a device formation region in each step of the third embodiment.

FIG. 23 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the third embodiment.

FIG. 24 is a cross-sectional view of the edge portion of the wafer including a part of the device formation region in each step of the third embodiment.

FIG. 25 is a diagram showing an example of a conventional technique.

FIG. 26 is a diagram showing another example of the conventional technique.

[Explanation of symbols]

14 Surface nozzle 16 Back nozzle 18 edge nozzle 22> Wafer roller 30 pin 32 Si substrate 34 Oxide film 36 wiring groove 38 Barrier metal 40 seed Cu 42,44 plated Cu 48 Contamination Cu

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) B05D 7/00 H01L 21/304 643A H01L 21/304 643 21/306 JF term (reference) 4D075 AC01 AC64 AE21 BB66Y DA08 DA35 DC22 EA05 EB01 4F042 AA07 BA08 CC04 CC09 DA01 EB08 EB09 EB17 5F043 AA26 BB18 DD02 EE07 EE08 EE35 FF10 GG02 GG04

Claims (18)

[Claims] 1. A wafer processing apparatus for etching and removing an undesired metal film on a wafer, wherein a means for holding and rotating the wafer and a first liquid which does not react with the film formed in a device formation region are used for the wafer. A surface nozzle ejecting to the center of the surface, and one or more edge nozzles ejecting a second liquid to remove the undesired metal film existing around the wafer surface outside the device formation region to the wafer surface periphery. ,
The wafer processing apparatus, wherein the front surface nozzle and the edge nozzle are provided on the front surface side of the wafer. 2. In a wafer processing apparatus for cleaning a contaminant metal adhered on a wafer, a means for holding and rotating the wafer and a first liquid which does not react with a film formed in a device formation area are discharged from a surface nozzle. A surface nozzle that ejects to the center of the wafer surface and a second nozzle for cleaning adhered contaminant metal
1. A wafer processing apparatus comprising: one or more edge nozzles for ejecting the above liquid to the periphery of the wafer surface, wherein the surface nozzle and the edge nozzle are provided on the wafer surface side. 3. The wafer processing according to claim 1, further comprising a back surface nozzle for ejecting a third liquid for etching or cleaning a metal film or a contaminated metal attached to the back surface of the wafer onto the back surface of the wafer. apparatus. 4. A means for holding and rotating a wafer having a device formation area on its surface, a surface nozzle for ejecting a first liquid into the device formation area on the wafer surface, and said first nozzle.
A second liquid of a different type from the above liquid, and one or more edge nozzles for ejecting the liquid around the wafer surface outside the device formation region. The surface nozzle and the edge nozzle are provided on the wafer surface side. A wafer processing apparatus characterized by the above. 5. The wafer processing apparatus according to claim 4, further comprising a back surface nozzle for ejecting a third liquid of the same type as the second liquid onto the back surface of the wafer. 6. The wafer processing according to claim 1, wherein a direction of ejecting the second liquid from the edge nozzle is a rotation direction of the wafer or an outside of a tangent line of the wafer. apparatus. 7. The distance from the tip of the edge nozzle to the point where the central axis of the nozzle intersects with the periphery of the wafer surface is 1-5.
The angle between the central axis of the edge nozzle and the tangent to the wafer rotation direction at the point where the central axis of the edge nozzle intersects with the periphery of the wafer surface when viewed from the top surface of the wafer is 0 to 90 °. The wafer processing apparatus according to any one of claims 1 to 6, wherein: 8. The distance from the tip of the back surface nozzle to the center of the wafer back surface is 70 to 200 mm, and the angle formed by the central axis of the back surface nozzle and the wafer surface is 15 to 60 °. The wafer processing apparatus according to claim 3 or 5. 9. The distance from the tip of the surface nozzle to the wafer surface is 70 to 200 mm, and the angle formed by the central axis of the surface nozzle and the wafer surface is 15 to 60 °. The wafer processing apparatus according to claim 1. 10. The wafer processing apparatus according to claim 1, wherein the edge nozzle ejects the second liquid in a beam shape. 11. The wafer processing apparatus according to claim 1, wherein the means for holding and rotating the wafer is of a roller chuck system having a plurality of rollers. 12. A wafer processing method comprising: a step of forming a metal film on a wafer surface consisting of a wafer surface center and a wafer surface periphery; and a step of etching and removing the metal film around the wafer surface, while rotating the wafer. A first liquid that does not react with the metal film is ejected to the center of the wafer surface from a surface nozzle provided on the wafer surface side, and at the same time, a second liquid that etches the metal film is ejected from an edge nozzle provided on the wafer surface side. A wafer processing method, characterized in that a metal film formed on the periphery of the wafer surface is removed by etching by ejecting the metal film around the wafer surface. 13. A wafer processing method for etching and removing an undesired metal film existing on a wafer, wherein a first liquid which does not react with the metal film is provided at the center of the wafer surface and on the wafer surface side while rotating the wafer. The second liquid that etches the metal film at the same time as being ejected from the surface nozzle
A third liquid that ejects from the edge nozzle provided on the wafer surface side to the periphery of the wafer surface and etches the metal film,
A wafer processing method characterized in that an undesired metal film existing on the periphery, end face, and back surface of a wafer is removed by etching by jetting from a back surface nozzle provided on the back surface side of the wafer to the back surface of the wafer. 14. A wafer processing method for cleaning contaminated metal adhered to the periphery, end face and back surface of a wafer, wherein the contaminated metal reacts from a front nozzle provided on the front surface of the wafer to a center of the front surface of the wafer while rotating the wafer. The first step of cleaning the contaminated metal in the device formation region by ejecting the first liquid, and simultaneously with the first step, the contaminated metal around the wafer surface from the edge nozzle provided on the wafer surface side. A second liquid that reacts is ejected, and a third liquid that reacts with a contaminant metal is ejected from the back surface nozzle provided on the back surface side of the wafer to the center of the back surface of the wafer, around the front surface of the wafer,
A second step of cleaning the contaminated metal adhering to the end surface and the back surface, and a wafer processing method. 15. The first step of cleaning comprises cleaning the wafer with C
15. The wafer processing method according to claim 14, which is performed after MP is performed. 16. The method according to claim 12, wherein the second liquid is jetted from the edge nozzle in the rotating direction of the wafer or outside the tangent line to the wafer for etching or cleaning.
16. The wafer processing method according to any one of 15. 17. The case where the undesired metal film is a Cu film
And the second liquid and the third liquid are H ₂O₂ Acid containing
Or an alkaline solution.
17. The wafer processing method according to any one of to 16. 18. The wafer processing method according to claim 12, wherein the step of holding and rotating the wafer is performed by rotating the wafer by a roller chuck having a plurality of rollers.