JP2001316899A - Semiconductor production device and semiconductor production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for semiconductor production capable of improving uniformness of electrolytic grinding in the face of a substrate to be processed. SOLUTION: Load is dispatched to a metallic layer of a substrate to be processed on which the metallic layer is formed through a plurality of needle bodies electrically kept in contact with the metallic layer and currents flowing in the electrolyte are collected through the load dispatching. Even when grinding reaches the under face of the metallic layer at a part of region, grinding is carried out by other needle bodies in other regions. Hence, a metal to be removed is not unevenly left in a special region. Further, the pressure at which the needle bodies touch the metallic layer is detected and the needle bodies are moved in the substantially vertical direction to the substrate face to be processed to make the detected pressure constant. The surface of the substrate to be processed is prevented from being damaged due to the needle bodies by controlling the contact pressure of the plural needle bodies with the metallic layer to make it constant. In this way, a high quality electrolytic grinding can be realized without flaws on the substrate surface to be processed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus and a semiconductor manufacturing method for performing electrolytic polishing, and more particularly to a semiconductor manufacturing apparatus and a semiconductor manufacturing method capable of improving the uniformity of polishing on the surface of a substrate to be processed.

[0002]

2. Description of the Related Art Many conventional electropolishing apparatuses use a plating apparatus. One of the reasons is that the electropolishing step and the plating step are opposite processes as a reaction process, and can be easily realized by changing the electric polarity applied to the cathode and the anode.

Usually, in a semiconductor manufacturing process, electrolytic polishing is performed following a plating step. Thus, the metal can be patterned only in the fine grooves and holes formed on the wafer to be processed. That is, fine grooves and holes are filled with metal by the plating process, and the metal is also plated on the other surface of the wafer to be processed. Therefore, the metal on the surface of the wafer to be processed is removed by the electrolytic polishing process while leaving the metal in the fine grooves and holes.

Here, a plating apparatus will be briefly described. As an example, a process of performing copper plating on the surface of a wafer to be processed will be described.

When copper plating is performed on the surface of a wafer to be processed, a conductive seeding layer serving as a cathode for electric field plating and serving as a seed for plating is formed on the surface. This seeding layer is, for example, a few nm to 200 nm.
It is about as thick as the later plating and has a different material and a copper layer of the same material.

The wafer to be processed having the seeding layer formed thereon is immersed in a plating solution bath filled with a plating solution based on, for example, copper sulfate, to make contact with an electric conductor from the outer periphery of the wafer to the seeding layer, thereby performing electroplating. Is supplied. The plating solution tank is provided with an anode electrode of, for example, copper containing phosphorus in contact with the plating solution.

With these configurations, since electricity is supplied between the cathode and the anode, reduction of copper occurs at the cathode, which was initially the seeding layer, and copper is formed on the seeding layer as plating.

In the plating apparatus that performs such a plating step, as described above, electrical contact with the surface of the wafer to be processed for power supply is made at the outer peripheral portion.

[0009]

When this apparatus is applied to an electropolishing apparatus, power is supplied to the surface of a wafer to be processed for electropolishing at the outer peripheral portion, similarly to a plating apparatus. In this case, the effect of the metal removal by the electrolytic polishing increases as the position is closer to the outer periphery of the surface of the wafer to be processed.

This is because the electric resistance of the metal causes a slightly higher voltage nearer to the outer periphery of the surface of the wafer to be processed, resulting in a strong electric field between the electrode and the opposing electrode, so that electropolishing proceeds. For this reason, the metal near the outer periphery of the surface of the wafer to be processed is polished first, and when the polishing of that portion reaches the lower surface of the metal layer, the electrical contact between the power supply contact and the metal surface is lost and the surface of the wafer to be processed further Will not be electropolished.

Therefore, the metal to be removed, which is not electropolished, tends to remain at the center of the surface of the wafer to be processed. It is necessary to separately remove the remaining metal to be removed by another method.

The present invention has been made in view of such circumstances, and has as its object to provide a semiconductor manufacturing apparatus and a semiconductor manufacturing method in which the uniformity of electrolytic polishing in the surface of a substrate to be processed is improved. .

[0013]

In order to solve the above-mentioned problems, a semiconductor manufacturing apparatus according to the present invention comprises a plurality of needle-like bodies which are in electrical contact with the metal layer of the substrate on which the metal layer is formed. And a means for supplying power from the needle-shaped body to the substrate to be processed electrically contacted by the needle-shaped body, and an electrode for collecting a current flowing in the electrolytic solution by the power feeding.

By providing a plurality of needles in electrical contact with the metal layer of the substrate on which the metal layer is formed,
Power can be supplied to the substrate to be processed for electrolytic polishing from a plurality of points on the surface. Therefore, even if the polishing reaches the lower surface of the metal layer in a part of the area, the supply of power for electrolytic polishing to the surface of the substrate to be processed is performed by another needle-like body in the other area, and the specific area is non-uniform. No metal to be removed remains.

A current path for electrolytic polishing is formed in the electrolytic solution by an electrode for collecting a current flowing in the electrolytic solution by power supply.

Further, means for detecting a pressure at which the needle-shaped body comes into contact with the metal layer, and a means for moving the needle-shaped body in a direction substantially perpendicular to the surface of the substrate to be processed so as to keep the detected pressure constant. Movable means.

By controlling the pressure at which the plurality of needles contact the metal layer at a constant level, it is possible to prevent the needles from scratching the surface of the substrate to be processed. As a result, high quality electrolytic polishing can be realized without generating any scratches on the surface of the substrate to be processed.

Further, in the method of manufacturing a semiconductor according to the present invention, the plurality of needles may be used to make electrical contact with the metal layer of the substrate on which the metal layer is formed. Power is supplied from the needle-shaped body, the supplied power flows from the metal layer into the electrolytic solution, and the power flowing through the electrolytic solution is collected from an electrode provided in the electrolytic solution. I do.

This manufacturing method can be realized by the configuration of the manufacturing apparatus described above. Therefore, the operation and effect are the same as those described in the above manufacturing apparatus.

Further, the electrical contact detects a pressure at which the needle contacts the metal layer, and moves the needle substantially perpendicular to the surface of the substrate to be processed so as to keep the detected pressure constant. It is characterized by being made movable in the direction.

This manufacturing method can be realized by the configuration of the manufacturing apparatus described above. Therefore, the operation and effect are the same as those described in the above manufacturing apparatus.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the contact pressure of a needle-shaped object on a substrate to be processed is detected, for example, by detecting, using a piezoelectric element, a fine movement at the base of the needle-shaped object caused by the needle-shaped object coming into contact with the substrate surface. It can be obtained by converting it into an electric signal. To move the needle in a direction substantially perpendicular to the surface of the substrate to be processed so as to keep the detected pressure constant, for example, a mechanical element is provided by providing a piezoelectric element at the base of the needle and applying an electric signal. Can be realized by converting to At this time, an electric signal is applied while observing the detection result of the contact pressure described above.

The needle-like body and the piezoelectric element provided at the base thereof can be finely formed on a substrate by using microelectronics technology and micromachining technology.

The substrate includes a glass substrate (for example, for a liquid crystal display) in addition to a semiconductor wafer.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view (FIG. 1A) and a front view (FIG. 1A) schematically showing the structure of a plurality of needles used in a semiconductor manufacturing apparatus according to an embodiment of the present invention. b))
It is. As shown in the figure, a plurality of needle-like bodies 12 are provided on a base material 11.

The needle-shaped body 12 is provided so as to stand substantially perpendicularly to the plate-shaped base member 11 and has substantially the same height.
The density is set so that the voltage difference in the surface of the substrate to be processed, which is generated when the electropolishing process is performed using the needle-like body, is sufficiently small.

Here, since the end of the needle-like body 12 opposite to the base material is brought into contact with the plating layer of the substrate (wafer to be processed) to be manufactured, the needle-like body 12 is brought into contact with the plating layer surely. It is preferable that the material has such rigidity and flexibility that does not cause scratches on the plating layer.

Electric power is supplied to the needle-shaped body 12 through the base material 11. Therefore, the base member 11 is provided with a connection point (not shown) for supplying electricity from the outside, and from this connection point, the needle-shaped bodies 12 are electrically connected to each other. Construct to include body.

Next, a configuration for performing an electropolishing process using such a needle-like body 12 will be described with reference to FIG.
FIG. 1 is a diagram schematically illustrating a configuration of an apparatus that performs an electropolishing process using the needle-shaped body 12.

As shown in FIG. 1, this configuration comprises a mounting table 23 on which a wafer 21 to be processed is mounted, an electrolytic polishing solution tank 25, a cathode electrode 26, an electrolytic film 24, an ejection pipe 28, a pump 21
1. A power supply 27 for electropolishing is provided, and circulation pipes 29 and 210 for circulating the electropolishing liquid are provided in the electropolishing liquid tank 25. In this embodiment, the processing target surface 22 of the processing target wafer 21 is directed upward.

The base material 11 is moved down from above so that the end of the needle-shaped body 12 comes into contact with the processing target wafer 21 whose processing surface 22 is directed upward. Base material 1
A contact (not shown) for making electrical contact with the outside of 1 is electrically connected to the positive side of an electrolytic polishing power supply 27.

The cathode electrode 26 is immersed in the electropolishing liquid in the electropolishing liquid tank 25 and is fixed via the ejection pipe 28, and receives a negative power supply from the electropolishing power supply 27.

The ejection pipe 28 ejects the electropolishing liquid from the bottom side toward the upper surface, and extends from substantially the center of the bottom of the electropolishing liquid tank 25 to substantially the center in the depth direction of the electropolishing liquid tank 25. A pump 2 for jetting out the electrolytic polishing liquid
11 is provided.

An electrolytic film 24 is provided between the outer periphery of the end of the ejection pipe 28 and the electrolytic polishing liquid tank.

Circulation pipes 29 and 21 for circulating the electropolishing liquid are positioned eccentrically from the center of the bottom of the electropolishing liquid tank 25.
0 is provided, and an electropolishing liquid is sucked in from one pipe by an unillustrated pump and supplied from the other pipe to circulate the electropolishing liquid.

The operation for performing the electropolishing process will be described.

First, the wafer 21 to be processed is mounted at a predetermined position on the mounting table 23. When the wafer 21 to be processed is mounted, the pump 211 spouts the electropolishing liquid from the spouting tube 28, and the electropolishing power source 27 connects the surface 22 to be processed with the cathode through the base material 11 and the needle 12. Electricity is supplied to between the electrodes 26.

As a result, the metal on the surface to be processed 22 dissolves in the electrolytic solution, and the metal film is polished.

According to such electrolytic polishing, the surface to be treated 2
Electricity for electrolytic polishing is supplied to the surface to be processed 22 by the plurality of needles 12 irrespective of the outer peripheral portion 2. Therefore, even if the polishing reaches the lower surface of the metal layer in some areas, power is supplied to the processing target surface 22 by the other needle-like bodies in other areas, and the specific area is unevenly polished. No metal to be removed remains.

The surface 22 to be processed of the wafer 21 to be processed
May be performed downward. The configuration for performing the electropolishing step using the needle-like body 12 in this case is as shown in FIG. FIG. 3 is a diagram schematically showing a configuration of an apparatus different from the above, which performs an electropolishing process using the needle-shaped body 12, and the components already described are given the same reference numerals.

That is, the processing target surface 22 of the processing target wafer 21 is brought into contact with the needle-like body 12 provided on the base material 11 and immersed in the electropolishing liquid and directed upward.

In this case as well, electricity is supplied to the surface 22 to be processed by the plurality of needles 12 regardless of the outer peripheral portion of the surface 22 to be processed. Therefore, the surface to be processed 2
The power supply for the electropolishing to 2 is performed even if the polishing reaches the lower surface of the metal layer in some areas, but is performed by other needles in other areas, and the metal to be removed unevenly to a specific area is uneven. Will not remain.

Next, a method of making electrical contact with the surface 22 to be processed of the wafer 21 to be processed, which can be used in the present invention instead of the needle-like body 12 described above, will be described with reference to FIG. FIG. 3 is a cross-sectional structural view schematically showing one of the needle-shaped bodies applicable to a semiconductor manufacturing apparatus according to a different embodiment of the present invention.

As shown in the figure, this needle-like body is provided with a cantilever 33 at a portion close to the surface of the side wall of the recess formed on the surface of a predetermined plate-like body 31 in parallel with the surface. A needle-shaped body is provided at the tip of the body in a direction perpendicular to the surface.

The piezoelectric element 3 is located at the base of the cantilever 33.
2 and 35, of which the piezoelectric element 35 converts the mechanical displacement at the base of the cantilever 33 due to the deflection thereof into an electric signal. The piezoelectric element 32 is applied with a voltage to mechanically deflect the root of the cantilever 33 and move the needle-like body at the tip thereof in a direction perpendicular to the surface.

A metal 34 is arranged on the cantilever 33 and its needle-like body, and this metal mediates electrical contact with the surface 22 to be processed of the wafer 21 to be processed.

A predetermined plate-like body 31 having a large number of such cantilevers 33 is used in place of the base member 11 and the needle-like body 12 described above.

The needle-like body and the piezoelectric elements 32 and 35 provided at the base thereof can be finely formed on a substrate by using microelectronics technology and micromachining technology.

Here, control of the needle-like body using the piezoelectric elements 32 and 35 when the electrolytic polishing step is performed using the plate-like body 31 having the plurality of cantilevers 33 formed thereon will be described with reference to FIG. I do. FIG. 3 is a configuration diagram illustrating control of needle-like bodies using the piezoelectric elements 32 and 35 when performing an electrolytic polishing process using the plate-like body 31 on which a plurality of cantilevers 33 are formed. The same reference numerals are given to the components already described in FIG.

An output is supplied from the drive circuit 42 to the piezoelectric element 32. The drive circuit 42 receives the set contact pressure and receives a detection output from the detection circuit 41. Detection circuit 4
1 is supplied with a detection output from the piezoelectric element 35. With these configurations, it is possible to control the contact pressure of the needle-shaped body of the cantilever 33 on the surface to be processed of the wafer to be processed.

In other words, these relationships are grasped in advance by measuring the displacement of the cantilever 33 with respect to the output value of the drive circuit 42. If the needle-shaped body comes into contact with an object on the surface while the drive circuit 42 is supplying a certain output to the cantilever 33, a displacement different from this relationship occurs in the cantilever 33, but this displacement is detected by the piezoelectric element 35. Can be. So, the original cantilever 3
The shift from the position 3 (the position where no object is in contact) is the detected contact pressure. Therefore, the output of the drive circuit 42 may be set so that this deviation becomes a predetermined value.

By using such a needle-like body, the pressure at which the plurality of needle-like bodies come into contact with the metal layer can be controlled to be constant, and the surface of the wafer to be processed is prevented from being scratched by the needle-like body.
Therefore, high-quality electrolytic polishing can be realized. That is,
Optimal electrical contact is possible following the state in which the metal layer becomes thinner by polishing in the electrolytic polishing process.

[0054]

As described in detail above, according to the present invention,
Since a plurality of needles electrically contact the metal layer of the substrate on which the metal layer is formed, the power for electrolytic polishing on the surface of the substrate is supplied to the lower surface of the metal layer in some regions. Even if it reaches, the other area | region is made by another needle-shaped object, and the metal which should be removed in a specific area does not remain non-uniformly.

Further, the pressure at which the needle-shaped body comes into contact with the metal layer is detected, and the needle-shaped body is moved in a direction substantially perpendicular to the surface of the substrate to be processed so as to keep the detected pressure constant. Prevents the surface from being scratched by needles. As a result, high quality electrolytic polishing can be realized without generating any scratches on the surface of the substrate to be processed.

[Brief description of the drawings]

FIG. 1 is a plan view (FIG. 1A) and a front view (FIG. 1B) schematically showing a configuration of a plurality of needles used in a semiconductor manufacturing apparatus according to an embodiment of the present invention. .

FIG. 2 is a diagram schematically showing a configuration of an apparatus for performing an electrolytic polishing process using a needle-like body 12.

FIG. 3 is a sectional structural view schematically showing one of needle-like bodies applicable to a semiconductor manufacturing apparatus according to a different embodiment of the present invention.

FIG. 4 is a diagram showing a plate-like body 31 on which a plurality of cantilevers 33 are formed.
When performing the electropolishing step using the piezoelectric element 32,
The block diagram explaining control of the needle-shaped object using 35.

FIG. 5 is a diagram schematically showing a configuration of an apparatus different from the above, which performs an electropolishing process using the needle-like body 12.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Base material 12 Needle-like object 21 Wafer to be processed 22 Surface to be processed 27 Power supply for electrolytic polishing 31 Plate-like body 32 Piezoelectric element 33 Cantilever 34 Metal 35 Piezoelectric element 41 Detection circuit 42 Drive circuit

Claims (4)

[Claims] A plurality of needles electrically contacting the metal layer of the substrate on which a metal layer is formed; and a plurality of needles electrically contacting the substrate electrically contacted by the needles. A semiconductor manufacturing apparatus comprising: means for supplying power; and an electrode for recovering a current flowing in an electrolytic solution by the power supply. 2. The semiconductor manufacturing apparatus according to claim 1, further comprising: means for detecting a pressure at which the needle-shaped body comes into contact with the metal layer; and a step of setting the needle-shaped body to keep the detected pressure constant. 2. The semiconductor manufacturing apparatus according to claim 1, further comprising: means for moving in a direction substantially perpendicular to the surface of the substrate to be processed. 3. A plurality of needles electrically contact the metal layer of the substrate on which the metal layer is formed, and the needle-like body supplies power to the electrically contacted substrate to be processed. A method of manufacturing a semiconductor, comprising: feeding supplied electricity from the metal layer into an electrolyte; and collecting electricity passed through the electrolyte from an electrode provided in the electrolyte. 4. The semiconductor manufacturing method according to claim 3, wherein the electrical contact detects a pressure at which the needle-shaped body contacts the metal layer, and the needle-shaped to keep the detected pressure constant. 4. The method according to claim 3, wherein the method is performed by moving a body in a direction substantially perpendicular to the surface of the substrate to be processed.