JPH1034522A - Polishing apparatus for CMP and apparatus system for CMP - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a CMP polishing apparatus or a CMP device which compensates for problems in CMP polishing using a felt-like polisher, and has a small edge droop of a workpiece to be polished, a high surface accuracy, and a high yield. To provide equipment systems. SOLUTION: At least a surface plate 22, a polishing polisher 21 provided on the surface plate 22 and polishing the surface of the object 3 to be polished and having a smaller size than the object 3 to be polished, a holding portion 24 of the object 3 to be polished, A polishing apparatus for CMP, comprising: a polishing agent supply mechanism for supplying a polishing agent to the surface of an object to be polished; and a pressure applying mechanism 25 for applying a desired polishing pressure to the polishing polisher 21 on the surface of the object to be polished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CMP polishing apparatus and a CMP apparatus system suitable for use in flattening and polishing a semiconductor device in a process of manufacturing a semiconductor such as a ULSI. .

[0002]

2. Description of the Related Art In semiconductor device manufacturing in recent years,
The number of steps in the manufacturing process increases, and the process becomes complicated (for example, multi-layer wiring). Therefore, the shape of the surface of the semiconductor device is not always flat. For example, as shown in FIGS. 6A and 6C. It may have a convex part (step).

Further, in the manufacture of semiconductor devices, as the line width of fine processing becomes narrower, the light source wavelength of photolithography becomes shorter, and the numerical aperture (so-called NA) becomes larger.
The depth of focus for obtaining high resolution is reduced. for that reason,
The line width of fine processing in the manufacture of semiconductor devices is narrow,
As the complexity increases, the surface state of the semiconductor device is not always flat, and there are steps.

The presence of a step on the surface of a semiconductor device causes disconnection of the wiring and an increase in the local resistance value, thereby causing a disconnection or a reduction in current capacity. Further, the presence of a step in the insulating film also leads to deterioration in breakdown voltage and generation of leakage. The presence of such a step indicates that the depth of focus of the semiconductor exposure apparatus has become substantially shallower. That is, when the yield and reliability are improved and the resolution is increased, the depth of focus margin is reduced.
Semiconductor devices need to be flattened.

More specifically, in a semiconductor manufacturing process, for example, a flattening technique as shown in FIG. 6 is required. Here, FIG. 6A shows an example in which an insulating film (for example, a film of BPSG, TEOS-SiO ₂ or the like) formed on a semiconductor device is flattened to flatten an interlayer film, and FIG. FIG. 6 shows an example in which a metal (W, Al, Cu, etc.) film formed on a semiconductor device is flattened to flatten a connection hole.
(C) shows the metal (W, A) formed on the semiconductor device.
This is an example in which an embedded wiring (damascene) is formed by flattening a film (1, l, Cu, etc.).

[0006] As a method of flattening the semiconductor surface, chemical mechanical polishing (Chemical Mechanical Polishing) is used.
Or Chemical Mechanical Planarization, CM
A flattening method using the technique (abbreviated as P) is expected to be promising. FIG. 8 is an explanatory view of a general semiconductor polishing apparatus using the CMP technique. FIG. 8A is a side view of the apparatus, and FIG.
(B) is a plan view of the device.

In this semiconductor polishing apparatus, a polishing cloth (one or two layers) 1 is adhered to a surface plate 2 to form a polisher, and a semiconductor carrier (wafer holder) 4 is mounted on the upper surface of the polishing cloth 1 by a semiconductor carrier (wafer holder). (Silicon wafer) 3 is conveyed. Then, the surface of the semiconductor substrate (silicon wafer) 3 is pressed against the polishing cloth 1 by the pressure applying mechanism 15, and the wafer carrier (wafer holder) is rotated while the platen 2 is rotated while the abrasive 6 is dropped from the abrasive supply mechanism 17. The semiconductor surface is polished by rotating and swinging 4, that is, by rotating and swinging the semiconductor substrate (silicon wafer) 3.

Here, the actual polishing is performed, for example, according to the process shown in FIG. As the polishing cloth 1, a felt-like sheet having a two-layer structure composed of a nonwoven fabric on the lower side and a foamed polyurethane having a fine pore on the upper side is often used. Also,
In a conventional semiconductor polishing apparatus using the CMP technique, a method of detecting a polishing amount and a polishing end point of the surface of the semiconductor substrate 3 during polishing includes controlling a polishing time, and a wafer changing by changing a material to be polished. Detecting the rotational torque of the carrier by a current value or the like; detecting changes in sound due to friction from the surface being polished; making holes in the surface plate 2 and the polishing cloth 1; A detection method of irradiating the surface and measuring using the reflected light is used.

[0009]

However, in the CMP polishing by the conventional semiconductor polishing apparatus using the felt-like polisher, (1) the edge of the semiconductor surface by polishing is large, and (2) when a load is applied. The polisher is apt to undergo compression deformation. (3) When attaching a polishing cloth to the polishing platen,
Unevenness is likely to occur in the adhesive layer, and it is difficult to obtain high flatness.
(4) There is a problem that dressing (sharpening) is necessary because the polisher is liable to be clogged, and (5) it is difficult to obtain a surface accuracy of the workpiece to be polished below λ.

For example, the uniformity in the wafer surface after CMP polishing by a conventional semiconductor polishing apparatus using a felt-shaped polisher has a large variation of ± 20% with respect to a thickness of 0.5 μm to be polished. In addition, the quality of the CMP polishing is determined by the polishing agent p depending on the material (for example, dielectric or metal) of the object to be polished.
Since it depends on a number of conditions, such as H dependency, the rotation speed of the platen, and the pressure applied to the object to be polished, it is difficult to control the polishing, resulting in a decrease in yield.

Further, among the above methods for detecting the polishing amount and the polishing end point of the semiconductor substrate surface during polishing, there is a problem that the detection accuracy is not good at present, or the polishing amount detection or the polishing end point detection. In order to optically perform the process, it is necessary to make a hole in the surface plate and the polishing cloth, and the position to be detected is limited to the vicinity of the hole. The present invention has been made in view of such a problem, and compensates for the problem of the CMP polishing using the felt-like polisher, so that the edge of the object to be polished is small, the surface accuracy is good, and the yield is high. Polishing machine or CMP with high cost
The purpose of the present invention is to provide an equipment system.

Further, the present invention provides: 1. The edge of the surface of the object to be polished (for example, a semiconductor) due to polishing can be prevented or suppressed. 2. The polisher hardly undergoes compression deformation even when a load is applied. 4. Poor flatness due to joining of the polisher and the polishing plate hardly occurs. 4. No dressing of the polisher is required. 5. High surface accuracy of the object to be polished (for example, a semiconductor) of λ or less can be obtained; 6. During polishing, the amount of polishing on the surface of the object to be polished (for example, a semiconductor) and the end point of polishing can be detected with high accuracy. It is not necessary to make holes in the polisher when optically detecting the amount of polishing or the end point of polishing, so it is possible to detect the polishing state without changing the polishing conditions, and specify the target position for detection. It is an object of the present invention to provide a CMP polishing apparatus or a CMP apparatus system having a part or all of the features of being not limited to a region (direct observation or measurement of a surface of an object to be polished such as a semiconductor surface by light). .

[0013]

For this purpose, the present invention firstly provides "at least a platen, a polishing polisher provided on the platen for polishing the surface of an object to be polished, and an abrasive supplied to the polishing polisher. A polishing agent supply mechanism, a holding / transporting section of the object to be polished, and a pressure applying mechanism which is held by the holding / transporting section and applies a desired polishing pressure to the surface of the object to be polished on the polishing polisher, In a CMP polishing apparatus provided with a swinging mechanism of the holding / transporting unit, a polishing monitor system for confirming a polishing amount distribution or a film thickness distribution or a maximum value of the polishing amount on the surface of the object to be polished during or after polishing is provided. Provided,
When the polishing monitor system detects that the distribution satisfies the predetermined condition, or that the maximum value of the polishing amount is reaching an allowable limit value, the polishing is terminated, otherwise, the polishing is stopped. A polishing apparatus for CMP (claim 1), further comprising a polishing control system for performing continuous or repolishing.

The present invention also provides a second aspect of the present invention wherein the platen is formed of an opaque material having an opening, and the polishing polisher is formed of a polishing cloth having another opening overlapping with the opening. The polishing monitor system includes a light emitting unit that emits light from one surface side of the surface plate toward each opening of the surface plate and the polishing polisher, and a light emitting unit of each opening of the polishing polisher and the surface plate. A light-receiving unit that detects light reflected from the surface of the object to be polished taken out via the light-receiving unit, and confirms a polishing state of the surface of the object to be polished based on a change in reflected light detected by the light-receiving unit; A polishing monitor (Claim 2) according to claim 1, further comprising a polishing monitor for detecting an end point.

The present invention also provides a third aspect of the present invention in which "the surface plate is formed of an opaque material, and the polishing polisher is formed of a transparent material. The polishing monitor system is provided from the end face side of the polishing polisher to the end face of the polishing polisher. A light-emitting unit that emits light toward the light-receiving unit, a light-receiving unit that detects reflected light from the surface of the object to be polished taken out through the polishing polisher, and a light-receiving unit that detects light reflected by the light-receiving unit. The polishing apparatus according to claim 1, further comprising: a polishing monitor for confirming a polishing state of the surface of the object to be polished and detecting a polishing end point.

Further, the present invention provides a fourth aspect of the present invention wherein "the surface plate and the polishing polisher are formed of a transparent material, and the polishing monitor system is arranged so that one surface of the surface plate faces the surface plate and the polishing polisher. A light-emitting unit that emits light, a light-receiving unit that detects light reflected from the surface of the object to be polished taken out through the polishing polisher and the surface plate, and a change in reflected light detected by the light-receiving unit. 2. A CM according to claim 1, further comprising: a polishing monitor for confirming a polishing state of the surface of the object to be polished based on the condition, and detecting a polishing end point.
P polishing apparatus (Claim 4) ".

Further, the present invention is directed to a fifth aspect of the present invention, namely, "at least a surface plate, a polishing polisher provided on the surface plate, which is smaller in size than the object to be polished, and a holder for the object to be polished. CMP comprising: an abrasive supply mechanism for supplying an abrasive to the surface of a workpiece; and a pressure applying mechanism for applying a desired polishing pressure to a polishing polisher on the surface of the workpiece.
Polishing apparatus (claim 5) ".

The present invention is also directed to a sixth aspect of the present invention which comprises at least a platen, a polishing polisher provided on the platen, the polishing polisher having a smaller size than the object to be polished, and a holder for the object to be polished. A polishing agent supply mechanism for supplying an abrasive to the surface of the object to be polished, a pressure applying mechanism for applying a desired polishing pressure to a polishing polisher on the surface of the object to be polished, the object to be polished during or after polishing A polishing monitor system for checking the polishing state of the surface, if the polishing monitor system detects that the polishing state satisfies a predetermined condition, the polishing is terminated, otherwise, the polishing is continued or re-polished. Polishing apparatus (Claim 6) comprising a polishing control system for performing polishing.

Further, the present invention provides a seventh aspect of the present invention which provides at least a first CMP polishing apparatus according to claims 1 to 4 and a first CM polishing apparatus.
A cleaning device for cleaning the object to be polished after the polishing step by the polishing apparatus for P; a measuring device for measuring a polished state of the object to be polished after the cleaning process by the cleaning device; 7. The polishing apparatus according to claim 5, wherein the object to be polished satisfies a predetermined condition, wherein the object to be polished satisfies a predetermined condition is stored in a storage container. The object to be polished after the polishing step by the polishing device is washed by the cleaning device, the washed object to be polished is measured by the measuring device, and the operation of each device and the transfer of the object to be polished between the devices. Control device for controlling the
P device system (Claim 7). "

Further, the present invention provides an eighth aspect, wherein "the control device comprises:
8. The apparatus according to claim 7, further comprising, based on a result of measurement by said measuring device, a function of discriminating an object not to be polished by said second CMP polishing apparatus from objects to be polished not to be stored in said storage container. The present invention also provides an apparatus system for CMP according to the present invention.

[0021]

In the CMP polishing apparatus or the CMP apparatus system according to the present invention (claims 1 to 8), the polishing amount distribution or the film thickness distribution on the surface of the object to be polished during or after polishing, or Providing a polishing monitor system for checking the maximum value of the polishing amount, when the polishing monitor system detects that the distribution satisfies a predetermined condition, or that the maximum value of the polishing amount is reaching an allowable limit value. Provided a polishing control system for terminating polishing, and in other cases, continuing polishing or performing repolishing.

Therefore, the polishing apparatus for CMP or the apparatus system for CMP according to the present invention (claims 1 to 8) compensates for the disadvantage even when a felt-shaped polishing polisher is used, and reduces the edge droop of the object to be polished. The size can be reduced, and the surface accuracy and the yield can be improved. Further, the present invention (Claims 1 to 5)
The polishing apparatus or system for CMP according to 8), wherein the polishing polisher is formed of a cured product of an epoxy resin to which nylon powder, carbon powder or carbon fiber is added, and a polishing object (for example, a semiconductor). The hardness (or viscoelasticity) of the polishing polisher required for polishing can be sufficiently ensured, and the hardness (or viscoelasticity) of the polishing polisher can be stably maintained for a long time.

Therefore, if a polishing polisher suitable not only for normal polishing but also for polishing under high-speed and high-pressure conditions is formed from a cured product of an epoxy resin to which nylon powder, carbon powder or carbon fiber is added, polishing is performed. In addition, it is possible to stably obtain a high-precision polished object (for example, a semiconductor) surface with little edge droop over a long period of time.

That is, C according to the present invention (claims 1 to 8)
When the polishing polisher is formed of a cured product of an epoxy resin to which nylon powder, carbon powder, or carbon fiber is added, the MP polishing apparatus or the CMP apparatus system includes: 1. The edge of the surface of the object to be polished (for example, a semiconductor) due to polishing can be prevented or suppressed. This has the effect that the polisher is less likely to undergo compressive deformation even when a load is applied.

The polishing polisher is made of nylon powder,
If it is formed of a cured product of carbon powder or epoxy resin with carbon fiber added,
Since the epoxy resin, which is the main component of the polishing polisher, has adhesiveness, by forming the polishing polisher on the surface plate, the surface plate and the polishing polisher can be directly joined.
Therefore, the problem of poor flatness of the polisher surface due to uneven thickness of the bonding layer when the polishing polisher and the surface plate are bonded via an adhesive does not occur.

Further, the polishing polisher is made of nylon powder,
When formed of a cured product of carbon powder or epoxy resin to which carbon fiber is added, a polishing polisher may be bonded on the surface plate using a bonding material.
As such a bonding material, for example, various adhesives such as a rubber-based adhesive and a cyanoacrylate-based adhesive, and a tape-shaped bonding member such as a double-sided tape can be used.

When the polishing polisher (the cured product of the mixed epoxy resin) is bonded on the surface plate using a bonding material, the polishing polisher after bonding is subjected to precision processing to reduce unevenness in the thickness of the bonding layer. It is possible to improve poor flatness of the polisher surface due to the poor flatness. That is, the CMP polishing apparatus or C according to the present invention (claims 1 to 8)
In the case where the polishing polisher is formed of a cured product of an epoxy resin to which nylon powder, carbon powder, or carbon fiber is added, the MP polisher is used in the MP device system. This has the effect that flatness defects associated with the joining of the polisher and the polishing plate are unlikely to occur.

The polishing polisher is made of nylon powder,
If it is formed of a cured product of carbon powder or epoxy resin with carbon fiber added,
4. No dressing is required for the polisher.
This has the effect. In addition, epoxy resin has low curing shrinkage, excellent transferability with the mold for curing molding, and excellent cutability of the cured product, so the polishing surface of the polishing polisher made of the cured product is formed with high precision can do.

Since the polishing surface accuracy of the polishing polisher is directly related to the polishing accuracy of a sample to be polished (for example, a semiconductor substrate), it is preferable to be as high as possible. Therefore, the polishing apparatus for CMP of the present invention (claims 1 to 8) using a polishing polisher (a cured product of an epoxy resin to which nylon powder, carbon powder or carbon fiber is added) having a polishing surface formed with high precision. Alternatively, the CMP device system includes: There is an effect that a high surface accuracy of the object to be polished of not more than λ can be obtained.

Further, since the cured product constituting the polishing polisher is transparent, the polishing polisher or the CMP system according to the present invention (claims 1 to 8) has a polishing polisher made of nylon powder, carbon powder or 6. In the case of being formed of a cured product of epoxy resin to which carbon fiber is added, When optically detecting the amount of polishing or the end point of polishing, it is not necessary to make a hole in the polisher, it is possible to detect the polishing state without changing the polishing conditions, and the detection target position is specified area. The effect is not limited to this.

Further, according to the present invention (claims 1 to 8),
The polishing system for MP or the system for CMP is formed from a cured epoxy resin to which the polishing polisher is added with nylon powder, carbon powder or carbon fiber (has excellent properties in heat resistance, thermal shock resistance, lubricity, etc.) If so, 8. 8. the heat distortion temperature of the polishing polisher is increased; The generation of frictional heat during polishing of an object to be polished (eg, a semiconductor) can be suppressed.
Also has the effect.

The epoxy resin has mechanical strength characteristics,
Since it has excellent characteristics in resistance to chemicals, a polishing polisher formed using this epoxy resin also has the same excellent characteristics. The polishing polisher according to the CMP polishing apparatus or the CMP apparatus system of the present invention is preferably formed of not only nylon powder, carbon powder or carbon fiber but also a cured product of an epoxy resin further added with glycerin.

When glycerin (having excellent properties as a desiccant and a lubricant) is further added to the epoxy resin, the curing shrinkage of the epoxy resin is further reduced, so that the transferability of the epoxy resin to a mold for curing molding is improved, and the curing of the epoxy resin is improved. 8. The property that the hardness (or viscoelasticity) of the product can be stably maintained for a long time and the cutability of the cured product are further improved; This produces an effect that generation of frictional heat during polishing of a workpiece (for example, a semiconductor) can be suppressed.

In the present invention, the platen is formed of an opaque material (for example, cast iron or zeolite) having an opening, and a polishing polisher is formed of a polishing cloth having another opening overlapping with the opening. The polishing monitor system includes a light emitting unit that emits light (for example, laser light) from one surface side of the surface plate toward each opening of the surface plate and the polishing polisher; A light-receiving unit that detects reflected light from the surface of the object to be polished taken out through each opening of the surface plate; and the object to be polished based on a change in the reflected light detected by the light-receiving unit. It is preferable to provide a polishing monitor for checking the polishing state (for example, film thickness) of the surface and detecting the polishing end point (claim 2).

In this configuration, the point to be monitored (measurement point) 7 is moved from the center point of the initial state by utilizing the fact that the object to be polished (for example, the wafer 3) is rotating and oscillating. By setting it out of position (see Figure 2)
Even if one polishing monitor system is provided for each object to be polished (for example, the wafer 3), monitoring (for example, film thickness measurement) at a plurality of locations on the object to be polished (for example, the wafer 3) can be performed.

Incidentally, regarding the uniformity of the surface of the object to be polished,
It can be known from the distribution of these monitor (for example, film thickness measurement) data. Therefore, the present invention (claim 2)
6. During the polishing, the polishing amount and the polishing end point on the surface of the object to be polished (for example, a semiconductor) can be detected with high accuracy. In the present invention, when the surface plate 2 is formed of an opaque material (eg, cast iron, zeolite, etc.) and the polishing polisher 8 is formed of a transparent material (eg, the epoxy resin mixture), the polishing monitor system is used. The light-emitting portion 9 emits light from the end face side of the polishing polisher 8 toward the end face of the polishing polisher 8 and detects reflected light from the surface of the workpiece 3 extracted through the polishing polisher 8. And a polishing monitor unit 16 for confirming a polishing state of the surface of the workpiece 3 based on a change in reflected light detected by the light receiving unit 10 and detecting a polishing end point. (Claim 3, FIG. 3)
reference).

In the present invention, the platen 13 is formed of a transparent material (for example, fused quartz), and the polishing polisher 8 is formed of a transparent material (for example, the epoxy resin mixture).
(When a transparent polishing polisher is bonded on a surface plate using a bonding material, the bonding material is also formed of a transparent material). A light emitting unit 11 that emits light from one surface side of the base 13 toward the surface plate 13 and the polishing polisher 8.
A light receiving unit 12 for detecting reflected light from the surface of the workpiece 3 taken out through the polishing polisher 8 and the surface plate 13; and a change in the reflected light detected by the light receiving unit 12. It is preferable that the polishing apparatus further includes a polishing monitor 16 for checking the polishing state of the surface of the workpiece 3 and detecting the polishing end point (see claim 4 and FIG. 4).

Also in this configuration, the point to be monitored (measurement point) 7 is set at the center of the initial state by utilizing the fact that the object to be polished (for example, the wafer 3) is rotating and oscillating. By setting it at a position deviated from the point (see FIG. 2), even if the polishing monitor system is one per object to be polished (eg, wafer 3), monitors (eg, wafers 3) at a plurality of locations on the object (eg, wafer 3) Film thickness measurement).

Incidentally, regarding the uniformity of the surface of the object to be polished,
It can be known from the distribution of these monitor (for example, film thickness measurement) data. Further, by adopting the above configuration,
The present invention (claims 3 and 4) provides: During polishing, there is an effect that the amount of polishing of the surface of the object to be polished (for example, a semiconductor) and the end point of polishing can be detected with higher accuracy. Further, the surface plate and the polishing polisher are formed of a transparent material (when the transparent polishing polisher is bonded on the surface plate using a bonding material, the bonding material is also formed of a transparent material).
In this case (claim 4), direct observation and measurement of the entire surface of the object to be polished (for example, a semiconductor) during polishing can be performed.

That is, according to the present invention (claims 3 and 4),
During polishing, the surface state of the object to be polished (for example, a semiconductor) can be easily observed or measured from the polisher side, and the amount to be polished can be easily optically managed. Further, at least the surface plate 22 and the object 3 to be polished provided on the surface plate 22.
A polishing polisher 21 that is smaller in size than the object 3 to be polished, a holder 24 for the object 3 to be polished, an abrasive supply mechanism for supplying an abrasive to the surface of the object 3, and the surface of the object 3 According to the polishing apparatus for CMP provided with a pressure applying mechanism 25 for applying a desired polishing pressure to the polishing polisher 21 on the upper side (refer to claims 5, 6, and 5), particularly the minute Polishing of the region can be performed with high precision like a small tool.

Therefore, for example, the CM according to any one of claims 1 to 4
Even when there is a defective portion with insufficient polishing on the surface of the object to be polished by using the polishing device for P, the correction polishing of the defective portion is performed using the polishing device for CMP according to claim 5 or 6. Therefore, the yield in the polishing process can be improved. A polishing apparatus for CMP capable of performing such small tool-like polishing with high precision is a polishing monitor system for checking a polishing state of the surface of the object to be polished during or after polishing, and the polishing state satisfies a predetermined condition. It is preferable that the polishing monitor system further includes a polishing control system for terminating the polishing when the polishing monitor system detects the fact, and for continuing the polishing or performing the repolishing otherwise (claim 6).

With this configuration, the surface accuracy and yield of the object to be polished can be further improved. Further, at least a first CMP polishing apparatus according to claims 1 to 4, a cleaning apparatus for cleaning a workpiece to be polished by the first CMP polishing apparatus, and a polishing apparatus for cleaning the polishing step by the cleaning apparatus. The measuring device for measuring a polished state of a polished object, and polishing a polished object whose measured value does not satisfy a predetermined condition.
A polishing apparatus for MP and an object to be polished whose measurement value measured by the measuring apparatus satisfies predetermined conditions are stored in a storage container, and the second C
The object to be polished after the polishing step by the MP polishing apparatus is cleaned by the cleaning device, the cleaned object to be polished is measured by the measuring device, and the operation of each device and the object to be polished between the devices are further performed. According to the CMP device system having the control device for controlling the transfer of the material, for example, by performing the process according to the process shown in FIG. To reduce the edge droop of the object to be polished, and greatly improve the surface accuracy and the yield.

In the CMP system according to claim 7, the polishing polisher is made of a cured product of an epoxy resin to which nylon powder, carbon powder or carbon fiber is added, or an epoxy resin to which glycerin is further added. It goes without saying that, in addition to the above-described effects, there is an effect that the edge run of the object to be polished can be reduced, and the surface accuracy and the yield can be significantly improved.

Further, the control device according to the CMP device system, based on the measurement result by the measuring device,
Of the objects to be polished not stored in the storage container,
It is preferable to have a function of determining an object to be polished (a defective product) that is not polished by the polishing apparatus for CMP (claim 8). By adopting such a configuration, it is possible to omit useless polishing processing and the like on the discriminated object to be polished and to improve the throughput of the entire processing system of the CMP apparatus system.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0046]

FIG. 1 is a flowchart showing a CMP process of a semiconductor device (on a wafer) performed by using the CMP apparatus system of the present embodiment. The CMP apparatus system according to the present embodiment includes a first CMP polishing apparatus according to any one of claims 1 to 4, a cleaning apparatus for cleaning an object to be polished after the polishing step by the first CMP polishing apparatus, and a cleaning apparatus using the cleaning apparatus. A measuring device for measuring a polishing state of the object to be polished after the cleaning step, and a polishing apparatus for the second CMP according to claim 5 or 6, wherein the measured value by the measuring device polishes the object to be polished which does not satisfy a predetermined condition. The object to be polished whose measurement value by the measuring device satisfies a predetermined condition is stored in a storage container, and the object to be polished which has been subjected to the polishing process by the second CMP polishing apparatus is cleaned by the cleaning device. A control device that controls the operation of each of the devices and the transfer of the object to be polished between the devices, wherein the control device controls the operation of the measuring device. Based on the measurement result of, among workpiece that does not received in the receiving container also has a function of discriminating the object to be polished is not performed polishing by the first 2CMP polishing apparatus.

First, the control device is operated to take out the wafer to be polished from the wafer cassette and transfer the wafer to and from the wafer carrier of the first CMP polishing apparatus according to claims 1 to 4. In the first CMP polishing apparatus, the polishing state of the semiconductor surface on the wafer during or after polishing (for example, the polishing amount or the distribution of the film thickness or the maximum value of the polishing amount)
And a polishing monitor system for confirming that the polishing state satisfies a predetermined condition (for example, that the distribution satisfies a predetermined condition, or that the maximum value of the polishing amount is reaching an allowable limit value). A polishing control system is provided for terminating the polishing when the monitor system detects it, and for continuing or repolishing otherwise.

Therefore, the polishing state of the semiconductor surface on the wafer during or after polishing (for example, the polishing amount or the distribution of the film thickness or the maximum value of the polishing amount) should be confirmed by the polishing monitor system of the first CMP polishing apparatus. The end point of the polishing is detected, and if the end point is detected, the polishing is terminated by the polishing control system. Otherwise, the polishing is continued or re-polished.

Here, the polishing state of the semiconductor surface on the wafer can be confirmed by a conventionally proposed method (for example, a method in which a change in the motor torque for keeping the rotation of the platen constant is detected by a change in the electric current, and a method during polishing. A method of detecting a change in sound generated at the same time may be used, but in the present embodiment, the light detection method was used. That is, in this embodiment, light (laser light) is applied to the semiconductor surface.
And the end point of polishing was detected by measuring the film thickness using the interference effect.

As shown in FIG. 2, the point (measurement point) 7 to be monitored is set at a position deviated from the center point in the initial state by utilizing the fact that the wafer 3 performs the rotational movement and the oscillating movement. (Refer to FIG. 2), even if the polishing monitor system is one for the object to be polished (for example, wafer 3), it is possible to perform monitoring (for example, film thickness measurement) at a plurality of locations on the object to be polished (for example, wafer 3). it can.

The uniformity of the surface of the object to be polished (film thickness distribution)
Can be known from the distribution of these monitor (for example, film thickness measurement) data. In order to detect the end point of polishing by a light detection method, when using a pad (polishing cloth) 1 as a polishing polisher, it is necessary to provide a continuous opening in the pad and the platen to transmit light. The polishing monitor system may have the configuration according to claim 2.

On the other hand, when a transparent material (for example, the epoxy resin mixture) 8 is used as the polishing polisher, it is not necessary to provide a continuous hole in the pad and the platen to transmit light. In addition, the polishing monitor system is described in claim 3
Alternatively, a configuration according to 4 may be adopted (see FIGS. 3 and 4).
For example, the polishing monitor system shown in FIG. 3 includes a light emitting section 9 that emits light from an end face side of the transparent polishing polisher 8 toward the end face of the polishing polisher 8 and a polishing target 3 taken out through the polishing polisher 8. Receiving unit 10 for detecting light reflected from the surface
And a polishing monitor unit 16 for checking the polishing state of the surface of the workpiece 3 based on the change in the reflected light detected by the light receiving unit 10 and detecting the polishing end point.

The polishing monitor system shown in FIG. 4 includes a light emitting section 11 for emitting light from one surface side of the transparent platen 13 toward the platen 13 and the transparent polishing polisher 8, and a polishing polisher 8. A light receiving unit 12 for detecting reflected light from the surface of the object 3 taken out through the surface plate 13; and a surface of the object 3 based on a change in the reflected light detected by the light receiving unit 12. And a polishing monitor section 16 for checking the polishing state of the sample and detecting the polishing end point.

In this manner, a wafer whose polishing state (film thickness value and film thickness distribution) confirmed by the polishing monitor system falls within the standard is polished by the polishing control system, and further polished by the control device. The process proceeds to the next step (cleaning step). The polishing control system also terminates polishing of a wafer whose thickness decrease (polishing amount) is likely to exceed the original (objective) polishing amount allowable value among a plurality of film thickness measurement data. The control device proceeds to the next step (cleaning step by the cleaning device).

For other wafers, polishing is continued by the polishing control system until the polishing state (film thickness value and film thickness distribution) falls within the standard. The wafer that has proceeded to the next step is cleaned by the cleaning device, and the wafer that has completed the cleaning process (there is no abrasive remaining on the wafer) has an uneven interferometer (wafer coating). (An example of an apparatus for measuring a polishing state) (check by interference fringes).

The wafers whose film thickness unevenness is within the allowable value are:
The wafer is stored in the wafer cassette by the control device to proceed to the steps after the CMP. Any part (position) of the wafer whose thickness unevenness does not fall within the allowable value may cause unevenness in the polishing step by the first CMP polishing apparatus or the main inspection step (inspection of the film thickness unevenness by film thickness measurement). Since the coordinates are determined based on the orientation flat of the wafer, based on this data, the control device corrects and polishes the portion (local polishing) using the second CMP polishing device (small tool) shown in FIG. Let it.

In the second CMP polishing apparatus shown in FIG. 5, the surface of the wafer 3 is placed upward and the polisher 21 is
As shown in FIG. 5, a polishing cloth does not cover the entire surface of the wafer, and the surface state can be measured by easily irradiating the wafer 3 with light from the upper side. It can be performed by such a method. Needless to say, since there is data on the film thickness and data on the film thickness unevenness, the polishing can be performed by time management based on experience.

The wafer that has been subjected to the fine correction polishing (local polishing) is sent to a cleaning step by the control device to be cleaned, and then sent again to the inspection step (inspection of film thickness unevenness by film thickness measurement) to remove a defect. If not, it is stored in a wafer cassette to proceed to the next step. Here, the defective wafer is sent again to the correction polishing (local polishing) step by the control device. However, if the reduction in film thickness exceeds the allowable value, the coordinate system based on the orientation flat is used. The data is left, and this data is reflected in the final inspection process of the semiconductor device.

Further, wafers that are judged to be useless even if they are further advanced are stored in a separate cassette by the control device so as to be discarded, and are prevented from proceeding to the next step. As described above, according to the CMP process of a semiconductor device (on a wafer) performed by using the CMP apparatus system of the present embodiment, even if a felt-shaped polishing polisher is used, the disadvantage is compensated for and the polishing is performed. Edge dripping of an object can be reduced, and surface accuracy and yield can be greatly improved.

In the CMP process of the semiconductor device (on the wafer) performed by using the CMP apparatus system of this embodiment, the polishing polisher is made of epoxy resin to which nylon powder, carbon powder or carbon fiber is added, or glycerin is further added. In the case of being formed of a cured product of an epoxy resin which has been obtained, in addition to the above-described effects, it is possible to reduce the edge runout of the object to be polished, and to significantly improve surface accuracy and yield. Needless to say.

Further, the control device according to the CMP device system of the present embodiment, based on the measurement result by the measuring device, performs polishing by the second CMP polishing device among the objects not to be stored in the storage container. Since it also has a function of discriminating an object to be polished, unnecessary polishing processing or the like on the discriminated object can be omitted, and the throughput of the entire processing system of the CMP apparatus system can be improved.

[0062]

As described above, according to the present invention,
Even when a felt-like polishing polisher is used, the disadvantage can be compensated for, the edge of the object to be polished can be reduced, and the surface accuracy and the yield can be improved. According to the present invention,
1. 1. The edge of the surface of the object to be polished (for example, a semiconductor) due to polishing can be prevented or suppressed. 2. The polisher hardly undergoes compression deformation even when a load is applied. 4. Poor flatness due to joining of the polisher and the polishing plate hardly occurs. 4. No dressing of the polisher is required. 5. High surface accuracy of the object to be polished (for example, a semiconductor) of λ or less can be obtained; 6. During polishing, the amount of polishing on the surface of the object to be polished (for example, a semiconductor) and the end point of polishing can be detected with high accuracy. It is not necessary to make holes in the polisher when optically detecting the amount of polishing or the end point of polishing, so it is possible to detect the polishing state without changing the polishing conditions, and specify the target position for detection. 7. It is not limited to a region (direct observation or measurement with light of the surface of the object to be polished such as a semiconductor surface is possible).
8. the heat distortion temperature of the polishing polisher is increased; 9. The generation of frictional heat during polishing of the object to be polished (for example, a semiconductor) can be suppressed. 10. Even when there is a minute portion with insufficient polishing on the surface of the object to be polished by the CMP polishing, it is possible to improve the yield in the polishing process by performing correction polishing of the minute portion. Some or all of the effects of improving the throughput of the CMP process can be obtained.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a CMP process of a semiconductor device (on a wafer) performed using the CMP apparatus system of the embodiment.

FIG. 2 is a plan view showing a positional relationship between a measurement (monitor) position and a wafer when an end point is detected.

FIG. 3 is a schematic configuration diagram showing an example of a polishing monitor system according to a third embodiment.

FIG. 4 is a schematic configuration diagram showing an example of a polishing monitor system according to claim 4;

FIG. 5 shows a polishing apparatus for CMP according to claim 5 (one example).
FIG. 2 is a schematic diagram showing a partial configuration of the first embodiment.

FIG. 6 is a diagram showing an example of a cross-sectional structure of a semiconductor device which is one of the objects to be polished by the polishing apparatus for CMP according to the present invention.

FIG. 7 is a flowchart showing a conventional semiconductor CMP process.

FIG. 8 is a schematic view showing a partial configuration of a general CMP polishing apparatus (one example), FIG. 1 (a) is a side view, and FIG.
(B) is a plan view.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Polishing cloth (pad) 2 ... Surface plate 3 ... Polished object (for example, wafer) 4, 5 ... Hold | maintenance and conveyance part (for example, wafer carrier and holder) of a polishing object 6 ... Abrasive 7 ... Measurement (monitor) point 8 ... Polishing polisher (transparent material) 9 ... Laser light source (light emitting unit) 10 ... Detector unit (light receiving unit) 11 ... Laser light source (light emitting unit) 12 ... Detector unit (light receiving unit) 13 ... Surface plate (transparent material) 14 ... Partial reflection mirror 15 ... Pressure applying mechanism 16 ... Polishing monitor unit 17 ... Abrasive supply mechanism 21 Polishing polisher 22 Platen 24 Holder for polishing object (eg wafer holder) 25 Pressure applying mechanism

Claims (8)

[Claims] At least a surface plate, a polishing polisher provided on the surface plate for polishing a surface of an object to be polished, an abrasive supply mechanism for supplying an abrasive onto the polishing polisher, and holding and transporting the object to be polished And a pressure applying mechanism that is held by the holding / transporting unit and applies a desired polishing pressure to the surface of the object to be polished on the polishing polisher, and a CMP mechanism that swings the holding / transporting unit. In the polishing apparatus, a polishing monitor system for checking the maximum value of the polishing amount distribution or film thickness distribution or the polishing amount on the surface of the object to be polished during or after polishing is provided, and the distribution satisfies a predetermined condition, or When the polishing monitor system detects that the maximum value of the polishing amount is reaching an allowable limit value, the polishing is terminated, otherwise, a polishing control system that performs continuation or repolishing is performed. Further CMP polishing apparatus characterized by comprising. 2. The platen is formed of an opaque material having an opening, and the polishing polisher is formed of a polishing cloth having another opening overlapping with the opening. A light-emitting portion for emitting light from one surface side of the plate toward each opening of the platen and the polishing polisher; and a cover taken out through each opening of the polishing polisher and the platen. A light receiving unit that detects light reflected from the surface of the polished object, and a polishing monitor unit that checks a polishing state of the surface of the polished object based on a change in the reflected light detected by the light receiving unit, and detects a polishing end point. The polishing apparatus for CMP according to claim 1, further comprising: 3. The polishing plate is made of an opaque material, and the polishing polisher is made of a transparent material. The polishing monitor system emits light from the end face of the polishing polisher toward the end face of the polishing polisher. A light-receiving unit for detecting reflected light from the surface of the object to be polished taken out through the polishing polisher; and polishing the surface of the object to be polished based on a change in the reflected light detected by the light-receiving unit. The polishing apparatus according to claim 1, further comprising a polishing monitor for checking a state and detecting a polishing end point. 4. The platen and the polishing polisher are formed of a transparent material, and the polishing monitor system emits light from one surface side of the platen toward the platen and the polishing polisher. A light-receiving unit for detecting reflected light from the surface of the object to be polished taken out through the polishing polisher and the surface plate; and a light-receiving unit based on a change in the reflected light detected by the light-receiving unit. 2. The polishing apparatus according to claim 1, further comprising a polishing monitor for checking a polishing state of the surface and detecting a polishing end point. 5. A polishing plate having at least a platen, a polishing polisher provided on the platen and polishing the surface of the object to be polished, the polishing polisher being smaller in size than the object to be polished, a holder for the object to be polished, and a surface of the object to be polished. A polishing apparatus for CMP, comprising: a polishing agent supply mechanism for supplying a polishing agent; and a pressure applying mechanism for applying a desired polishing pressure to a polishing polisher on the surface of the object to be polished. 6. A polishing plate at least having a smaller size than the polished object provided on the surface plate and polishing the surface of the polished object, a holding portion for the polished object, and polishing the surface of the polished object. A polishing agent supply mechanism for supplying a polishing agent, a pressure applying mechanism for applying a desired polishing pressure to a polishing polisher on the surface of the workpiece, and a polishing state of the surface of the workpiece during or after polishing is confirmed. A polishing monitor system, a polishing control system for terminating polishing when the polishing monitor system detects that the polishing state satisfies a predetermined condition, and otherwise performing continuation of polishing or repolishing, Polishing machine for CMP. 7. A polishing apparatus for a first CMP according to claim 1, wherein the cleaning apparatus cleans an object to be polished after the polishing step by the first CMP apparatus, and a cleaning step by the cleaning apparatus. A measuring device for measuring a finished state of the object to be polished, a polishing device for polishing the object to be polished whose measured value by the measuring device does not satisfy a predetermined condition, and the measuring device. The object to be polished whose measurement value satisfies a predetermined condition is stored in a storage container, and the object to be polished after the polishing step by the second CMP polishing apparatus is cleaned by the cleaning device. A control device for controlling the operation of each of the devices and the transfer of the object to be polished between the devices by a measuring device.
MP system. 8. A function of the control device for judging, based on a measurement result by the measuring device, an object to be polished not to be polished by the second CMP polisher, among objects to be polished not to be stored in the storage container. The CMP system according to claim 7, further comprising: