JPH09246218A - Polishing method/device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deviation of a polished object such as a semiconductor and to improve polishing uniformity on the polished face of the polished object. SOLUTION: A polishing disk 3 having a polishing pad 4 on a surface 3a and rotated at the time of polishing, a wafer carrier provided with a pressing face 6b for pressing the back 1c of the semiconductor wafer 1, a guide ring 5 which is provided with an inner peripheral face 5a for guiding the outer peripheral part 1b of the semiconductor wafer 1 and forms a wafer storage space 14 constituted of the pressing face 6b of a wafer carrier 6 and the inner peripheral face 5a by making the ring fit to the wafer carrier 6, a polishing disk rotation means for rotating the polishing disk 3 and a carrier rotation means for rotating the wafer carrier 6 are provided. The depth 14a of the wafer storage space 4 is almost equal or deeper to/than the thickness 1d of the semiconductor wafer 1. At the time of polishing the semiconductor wafer 1, the end face 5e of the guide ring 5 and the polished face 1a of the semiconductor wafer 1 form the almost same face.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for polishing a film to be processed formed on a semiconductor wafer which is an object to be polished in a semiconductor manufacturing technique, and more particularly to a polishing technique for improving the holding ability of the semiconductor wafer during polishing. A method and apparatus.

[0002]

2. Description of the Related Art The technology described below studies the present invention,
The present invention was studied by the present inventors upon completion, and its outline is as follows.

A chemical mechanical polishing device, so-called CMP, is used for flattening a wiring interlayer insulating film of a semiconductor wafer to be polished.
(Chemical Mechanical Polish) equipment is used.

Here, the CMP apparatus is for polishing by pressing a semiconductor wafer against the polishing pad while dropping the polishing agent on the polishing pad provided on the surface of the polishing plate.

Further, the CMP apparatus is provided with a wafer carrier which is a pressure holding member for holding the semiconductor wafer under pressure, and the pressure holding member is a guide ring which is a ring-shaped guide member for guiding the outer peripheral portion of the semiconductor wafer. have.

Further, a back pad, which is a soft cushioning member, is provided inside the guide ring and is in contact with the back surface of the semiconductor wafer opposite to the surface to be polished. When the semiconductor wafer is pressed, the back pad is interposed. It is pressurizing. At this time, the pressure applied to the semiconductor wafer is mechanically applied by the wafer carrier, but the application of pressure (auxiliary pressure) to the semiconductor wafer by the fluid may be used as a correction of the mechanical application.

A method for polishing the surface of a semiconductor wafer to make it flat and a CMP apparatus for polishing the surface are described, for example, in Industrial Research Institute, June 1, 1993.
"Electronic Materials, June 1993", pages 58-62.

[0008]

However, in the polishing apparatus according to the above-mentioned technique, the polishing pad is selectively used according to the difference in hardness.

That is, in a soft polishing pad,
Since the polishing pad follows the shape of the surface to be polished of the semiconductor wafer, the uniformity of the polishing amount within the wafer surface is good, but the step flatness for removing the steps on the surface to be polished is poor.

On the other hand, a hard polishing pad, on the contrary, does not follow the shape of the surface to be polished of the semiconductor wafer so that the polishing amount is not uniform, but the step flatness is good.

Here, a commonly used polishing pad has an intermediate performance obtained by combining the above two types of polishing pads.

In order to obtain good step flatness and good polishing amount uniformity with a hard polishing pad, the polishing amount uniformity is not good only by mechanical pressing by the wafer carrier, so that a fluid is used. To correct the load.

However, when pressure is applied directly to the semiconductor wafer by using the fluid, if the pressure due to the mechanical pressure and the pressure due to the fluid are the same or the fluid is higher, the minute difference between the semiconductor wafer and the back pad is caused. The fluid entering the gap balances the pressure, and as a reaction force, pushes up the wafer carrier.

As a result, when the wafer carrier is pushed up, the guide ring also moves (raises) away from the polishing pad.

Here, the surface to be polished of the semiconductor wafer is held so as to protrude from the end surface of the guide ring by about 100 to 150 μm, but when the guide ring rises, the surface to be polished of the semiconductor wafer further protrudes, and as a result, The problem occurs that the semiconductor wafer comes off the guide ring and pops out.

Further, since the polishing pad is distorted and deformed by the load applied by the semiconductor wafer during polishing, the edge of the semiconductor wafer is locally subjected to high stress, and as a result, the polishing rate of the edge of the semiconductor wafer is increased. There is a problem that it becomes faster and the uniformity of polishing is deteriorated.

An object of the present invention is to provide a polishing method and apparatus for preventing the object to be polished such as a semiconductor wafer from coming off and improving the polishing uniformity on the surface to be polished of the object to be polished.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0019]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

That is, the polishing method of the present invention comprises a pressing surface of a pressure holding member for pressing and holding an object to be polished and an inner peripheral surface of a ring-shaped guide member for guiding the outer peripheral portion of the object to be polished. The object to be polished is accommodated in the object-to-be-polished space having a depth substantially equal to or deeper than the thickness of the object to be polished, and the object to be polished is held by the pressure holding member. Press the object to be polished onto the polishing pad,
The end surface of the ring-shaped guide member facing the polishing pad and the surface to be polished of the object to be polished are substantially flush with each other to polish the object to be polished.

Further, in the polishing method of the present invention, the force applied to the polishing pad by the ring-shaped guide member per unit area and the force applied to the polishing pad by the object to be polished per unit area are substantially equal to each other. In addition, the ring-shaped guide member and the object to be polished are pressed.

Further, the polishing apparatus of the present invention comprises a polishing plate having a polishing pad such as a polishing cloth provided on the surface thereof and rotating at the time of polishing, and a pressure surface for applying pressure to the rear surface opposite to the surface to be polished of the object to be polished. A pressure holding member provided with the pressure holding member, and an inner peripheral surface for guiding the outer peripheral portion of the object to be polished, and being attached to the pressure holding member, the pressure holding surface of the pressure holding member and the inner peripheral surface. The ring-shaped guide member forming a storage space for an object to be polished, a polishing plate rotating unit for rotating the polishing plate, and a pressure holding member rotating unit for rotating the pressure holding member are provided. The depth of the space is formed to be substantially equal to or deeper than the thickness of the object to be polished, and when the object to be polished is housed in the object-to-be-polished space and polished, the ring-shaped guide member is provided. The end surface facing the polishing pad and the polishing target Polished surface of the can as it is capable of polishing to form a substantially flush.

As a result, during polishing, the outer peripheral portion of the object to be polished is almost completely surrounded by the inner peripheral surface of the ring-shaped guide member, so that the reaction force generated from the auxiliary pressure of the fluid acts on the pressure holding member. Even if the pressure holding member floats, it is possible to prevent the object to be polished from coming off and jumping out of the ring-shaped guide member.

Therefore, it is not necessary to stop the polishing apparatus once and re-accommodate the object to be polished in the object-accommodating space, so that the operating time of the polishing apparatus can be increased,
As a result, the operating rate of the polishing apparatus can be improved.

Further, in the polishing apparatus of the present invention, a plurality of slurry supply grooves are formed on the end surface of the ring-shaped guide member so as to extend substantially toward the center of the ring-shaped guide member.

In the polishing apparatus of the present invention, the ring-shaped guide member has a claw portion at its tip end portion for supporting the outer peripheral portion of the object to be polished.

Further, in the polishing apparatus of the present invention, a thin film member such as a film member that is deformed by the supply of a fluid is provided in the ring-shaped guide member, and the deformation of the thin film member applies pressure to the object to be polished. It is done.

[0028]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a structural conceptual view showing an example of an embodiment of the structure of a polishing apparatus according to the present invention, and FIG. 2 is a partial sectional view showing an example of an embodiment of the structure of a pressure holding member in the polishing apparatus of the present invention. FIG. 3 is an enlarged partial cross-sectional view showing an example of an embodiment of the structure of the ring-shaped guide member in the polishing apparatus of the present invention, and FIG. 4 is the implementation of the structure of the end face of the ring-shaped guide member in the polishing apparatus of the present invention. It is a bottom view which shows an example of a form.

The polishing apparatus of this embodiment is also called a CMP apparatus (chemical mechanical polishing apparatus), and is used to remove a film to be processed such as an insulating film or a metal film formed on a semiconductor wafer 1 which is a disk-shaped object to be polished. It is to be polished.

The structure of the polishing apparatus will be described.
A polishing pad 3 made of a polishing cloth, polyurethane or the like is provided on the front surface 3a and is a surface plate that rotates during polishing, and a back surface 1 of the semiconductor wafer 1 opposite to the surface 1a to be polished.
The wafer carrier 6 that is a pressure holding member having a pressure surface 6b that presses c, and the inner peripheral surface 5a that guides the outer peripheral portion 1b of the semiconductor wafer 1 are attached to the wafer carrier 6 so that the wafer carrier 6 A guide ring 5 that is a ring-shaped guide member that forms a wafer housing space 14 (a polishing object housing space) that is composed of the pressing surface 6b and the inner peripheral surface 5a.
A polishing plate rotating means 8 such as a motor for rotating the polishing platen 3; a carrier rotating means 9 (a pressure holding member rotating means) such as a motor for rotating the wafer carrier 6;
Slurry supplying means 11 for supplying the slurry 2 containing the polishing agent onto the polishing pad 4 via 0.

In the polishing apparatus according to this embodiment, the depth 14a of the wafer accommodating space 14 is formed to be substantially equal to or deeper than the thickness 1d of the semiconductor wafer 1, and thus the semiconductor wafer 1 is formed. The wafer storage space 14
End surface 5e of the guide ring 5 facing the polishing pad 4 and the surface to be polished 1a of the semiconductor wafer 1 when polishing the semiconductor wafer 1.
And can form almost the same surface and can be polished.

That is, when the semiconductor wafer 1 is held by vacuum suction or the like before polishing, the end surface 5 of the guide ring 5 is
e and the polished surface 1a of the semiconductor wafer 1 are substantially flush with each other, or the guide ring 5 is formed such that the end surface 5e of the guide ring 5 projects beyond the polished surface 1a of the semiconductor wafer 1. Further, it is attached to the outer peripheral tip portion 6 a of the wafer carrier 6.

As a result, for example, when polishing the film to be processed on the semiconductor wafer 1 on which the wiring pattern has been formed, the end surface 5e of the guide ring 5 and the surface to be polished 1a of the semiconductor wafer 1 are almost removed. Polishing is performed on the same surface.

Here, the guide ring 5 according to the present embodiment guides the semiconductor wafer 1 so as not to come off from the wafer carrier 6 during polishing.
It is formed of a material (for example, epoxy resin or Delrin) that does not adversely affect the semiconductor wafer 1 due to problems such as contamination.

During polishing, the end surface 5 of the guide ring 5 is
Since e and the surface to be polished 1a of the semiconductor wafer 1 are substantially flush with each other, the end surface 5e of the guide ring 5 also contacts the polishing pad 4 and presses the surface 4a of the polishing pad 4.

Therefore, on the end surface 5e of the guide ring 5 according to the present embodiment, as shown in FIG. 4, a plurality of slurry supply grooves 5b linearly formed toward the center 5d of the guide ring 5 are provided. The slurry 2 is provided in the wafer housing space 14 through the slurry supply groove 5b.
Has been supplied.

However, the slurry supply grooves 5b are preferably formed on the end surface 5e of the guide ring 5 at substantially equal intervals in the circumferential direction 5c.

The slurry 2 of this embodiment is a liquid in which an abrasive is suspended in a solvent such as water, and the slurry supply means 11 passes through the nozzle 10 and the slurry supply port 1
It is jetted from 0a and supplied to the surface 4a of the polishing pad 4.

That is, when the slurry 2 is supplied to the surface 4a of the polishing pad 4, the polishing pad 4 holds the abrasive contained in the slurry 2, and the surface to be polished 1a of the semiconductor wafer 1 and the polishing pad 4 are held. The surface to be polished 1a of the semiconductor wafer 1 is polished by the above-mentioned polishing agent by coming into contact with and rubbing against the surface 4a.

Here, the wafer carrier 6 according to the present embodiment has a gas permeable rigid plate 12 which is a porous member and a back pad 7 which is a cushioning member.
When pressurizing, the breathable rigid plate 12 and the back pad 7
The semiconductor wafer 1 is pressed through and.

The breathable rigid plate 12 is a porous (mesh-shaped) plate having both surfaces flattened by grinding and formed of ceramic or the like having high rigidity, and is attached to the wafer carrier 6. .

The back pad 7 has a low rigidity and a thickness of about 600 μm, and through holes 7a having a diameter of about 1 mm are provided over the entire surface thereof at intervals of about 5 mm pitch.

That is, the pressing surface 6b of the wafer carrier 6 according to the present embodiment is the surface of the back pad 7 which is in contact with the back surface 1c of the semiconductor wafer 1, whereby the wafer accommodating space 14 is guided by the guide ring 5. The inner peripheral surface 5a and the pressing surface 6b of the back pad 7 are formed.

Here, the depth 14a of the wafer accommodating space 14
Is formed to be approximately equal to or deeper than the thickness 1d of the semiconductor wafer 1, so that in the wafer carrier 6 according to the present embodiment, each member is formed and attached in a relationship as shown in FIG. ing.

That is, the joining surface 6c of the wafer carrier 6 to which the guide ring 5 is attached and the exposed surface 12a of the breathable rigid plate 12 are joined together so that the back pad 7 and the breathable rigid plate 12 are joined together. Is arranged so as to come into contact with the exposed surface 12a.

Therefore, the thickness 5f of the guide ring 5 and the thickness 7b of the back pad 7 are each formed in the relationship of the thickness 5f of the guide ring 5 ≧ the thickness 7b of the back pad 7 + the thickness 1d of the semiconductor wafer 1. And is installed.

However, the back pad 7 does not necessarily have to be provided. In this case, the pressure surface 6b of the wafer carrier 6 has the breathable rigid plate 12, and the exposed surface 12 thereof.
a corresponds to the pressing surface 6b.

Note that the thickness 5f of the guide ring 5 and the thickness 7b of the back pad 7 are not limited to this relationship, and as a result, the wafer accommodation formed by the wafer carrier 6 and the guide ring 5 is accommodated. Depth 14a of space 14
Is formed to be approximately equal to or deeper than the thickness 1d of the semiconductor wafer 1, and when the semiconductor wafer 1 is housed in the wafer housing space 14 and polished, the end face 5e of the guide ring 5 and the semiconductor It suffices that the surface to be polished 1a of the wafer 1 is formed to be substantially flush with the surface to be polished.

The main polishing pressure during polishing is the breathable rigid plate 12 and the back pad 7 of the wafer carrier 6.
Although it is mechanically applied to the semiconductor wafer 1 via, the auxiliary pressure for pressure correction is due to the fluid 18 such as nitrogen gas, and the fluid supply pipe 1 provided in the wafer carrier 6
3, the fluid 18 is supplied to the semiconductor wafer 1, etc.
Apply auxiliary pressure to.

That is, the fluid 18 supplied through the fluid supply pipe 13 is permeable to the breathable rigid plate 12 and the back pad 7.
It reaches the back surface 1c of the semiconductor wafer 1 through the through hole 7a, and a pressure is applied to the back surface 1c of the semiconductor wafer 1 as the auxiliary pressure.

Further, the polishing apparatus according to the present embodiment includes
The case 1 which is a cover for covering the dresser 15 and the dresser 15 for scraping and flattening the surface 4a of the polishing pad 4 after polishing.
7 are installed.

This dresser 15 can be used after polishing, etc.
The surface 4a of the polishing pad 4 is rotated by a dresser rotating means 21 such as a motor so as to become accustomed to the surface 4a, and is a member that can rotate and swing.

The polishing pad 4 may be polished by the dresser 15 simultaneously with the polishing of the semiconductor wafer 1.
Alternatively, the polishing may be performed after the polishing of the semiconductor wafer 1 is completed.

Here, the polishing plate 3 can be rotated by the polishing plate rotating means 8 while being covered by the casing 17.

Further, the wafer carrier 6 is also rotated by the carrier rotating means 9, but it can be swung like the dresser 15.

As a result, when polishing the semiconductor wafer 1, the polishing platen 3 is rotated, the wafer carrier 6 and the dresser 15 are rotated, and if necessary, the wafer carrier 6 and the dresser 15 are removed. Swing each.

The fluid supply pipe 13 is covered with a bellows-like dustproof cover 22 to prevent dust and the like generated by the ascent and descent of the wafer carrier 6 from coming out to the outside 5g.

Next, the polishing method according to this embodiment will be described.

First, the pressing surface 6b of the wafer carrier 6 and the inner peripheral surface 5a of the guide ring 5 that guides the outer peripheral portion 1b of the semiconductor wafer 1 are formed.
The semiconductor wafer 1 is accommodated in the wafer accommodating space 14 formed to have a thickness approximately equal to or deeper than the thickness 1d of the semiconductor wafer 1.

That is, the wafer carrier 6 is moved onto the semiconductor wafer 1 placed at a predetermined position, and the semiconductor wafer 1 is sucked and held in the wafer storage space 14 of the wafer carrier 6 by vacuum suction or the like.

For vacuum suction of the semiconductor wafer 1 at this time, evacuation is performed using the fluid supply pipe 13, for example.

Subsequently, the wafer carrier 6 holding the semiconductor wafer 1 by suction is moved to a predetermined position on the polishing platen 3.

Here, the polishing platen 3 is rotated at a rotation speed of about 20 rpm, and the slurry 2 is supplied from the nozzle 10 by the slurry supply means 11 to the surface 4 of the polishing pad 4.
The slurry 2 is supplied to the entire surface 4 a of the polishing pad 4 by dropping it on the surface a.

Further, the wafer carrier 6 is attached to the polishing pad 4
It is lowered to bring the surface to be polished 1 a of the semiconductor wafer 1 into contact with the surface 4 a of the polishing pad 4.

At this time, the wafer carrier 6 is also rotated at the same rotation speed as the polishing platen 3.

Thereafter, while holding the semiconductor wafer 1 by the wafer carrier 6, the semiconductor wafer 1 is polished on the polishing pad 4
Press down on.

As a result, the end surface 5e of the guide ring 5 and the surface to be polished 1a of the semiconductor wafer 1 can be made substantially flush with each other and the surface to be polished 1a can be polished.

The slurry 2 is continuously supplied during polishing. Here, the slurry 2 is the guide ring 5 shown in FIG.
Since the slurry 2 passes through the slurry supply groove 5b formed on the end surface 5e, the slurry 2 can be constantly supplied into the wafer housing space 14.

During polishing, the wafer carrier 6 is not only rotated but also swung so that the surface to be polished 1a of the semiconductor wafer 1 is uniformly polished.

Further, in the polishing method according to the present embodiment, when the semiconductor wafer 1 is polished, the force per unit area exerted on the polishing pad 4 by the guide ring 5 and the unit exerted on the polishing pad 4 by the semiconductor wafer 1 Guide ring 5 so that the force per area is almost equal
That is, the wafer carrier 6 and the semiconductor wafer 1 are pressed.

That is, by using the auxiliary pressure of the fluid 18 such as nitrogen gas, the main polishing pressure mechanically applied to the semiconductor wafer 1 by the wafer carrier 6 and the auxiliary pressure are controlled to their respective predetermined pressures. Pad 4
It is possible to equalize the force per unit area of the guide ring 5 applied to the surface of the semiconductor wafer and the force per unit area applied to the semiconductor wafer 1.

After the polishing, the semiconductor wafer 1 is again vacuum-sucked by the wafer carrier 6, and in this state,
The wafer carrier 6 is lifted to separate the semiconductor wafer 1 from the polishing pad 4.

Thereafter, the dresser 15 is lowered to bring it into contact with the polishing pad 4.

Then, the dresser 15 is rotated and swung to acclimate the surface 4a of the polishing pad 4 (the surface 4a after polishing is ground and flattened).

The polishing pad 4 may be polished by the dresser 15 simultaneously with the polishing of the semiconductor wafer 1.

According to the polishing method and apparatus of this embodiment, the following operational effects can be obtained.

That is, the pressing surface 6b of the wafer carrier 6
The depth 14a of the wafer accommodating space 14 formed by the inner peripheral surface 5a of the guide ring 5 and the thickness 1d of the semiconductor wafer 1 is formed to be substantially equal to or deeper than the thickness 1d. When housed in the housing space 14 and polished, the end surface 5e of the guide ring 5 and the surface to be polished 1a of the semiconductor wafer 1 can be made substantially flush with each other.

As a result, during polishing, the outer peripheral portion 1b of the semiconductor wafer 1 is almost completely surrounded by the inner peripheral surface 5a of the guide ring 5, so that the reaction force generated from the auxiliary pressure of the fluid 18 acts on the wafer carrier 6. Wafer carrier 6
It is possible to prevent the semiconductor wafer 1 from coming off and jumping out to the outside 5g of the guide ring 5 even if the surface is lifted.

As a result, the polishing apparatus according to the present embodiment does not have to be stopped once and the work of re-accommodating the semiconductor wafer 1 in the wafer accommodating space 14 need not be performed, so that the operating time of the polishing apparatus can be increased. Thereby, the operating rate of the polishing apparatus can be improved.

Furthermore, since the semiconductor wafer 1 can be prevented from coming off and jumping out to the outside 5g of the guide ring 5, damage to the semiconductor wafer 1 can be reduced, and as a result, the yield of the semiconductor wafer 1 can be improved. .

Further, the guide ring 5 and the semiconductor wafer 1 are applied so that the force applied to the polishing pad 4 by the guide ring 5 per unit area and the force applied to the polishing pad 4 by the semiconductor wafer 1 per unit area are substantially equal to each other. By pressing, the strained portion 4b on the surface 4a of the polishing pad 4 formed by the load of the semiconductor wafer 1
(See FIG. 3) can be prevented.

As a result, the polishing rate of the end portion 1e of the semiconductor wafer 1 can be made substantially equal to the polishing rate of the other portions of the semiconductor wafer 1, so that the polishing amount on the polished surface 1a of the semiconductor wafer 1 is uniform. It is possible to improve the sex.

As a result, highly accurate polishing can be realized.

Since the end face 5e of the guide ring 5 is provided with the plurality of slurry supply grooves 5b formed toward the substantially center 5d of the guide ring 5, the entire surface 1a to be polished of the semiconductor wafer 1 is provided. Can be supplied with the slurry 2.

Here, the plurality of slurry supply grooves 5b.
Are formed at substantially equal intervals with respect to the circumferential direction 5c of the end surface 5e of the guide ring 5, so that the slurry 2 is evenly distributed over the entire surface 1a to be polished of the semiconductor wafer 1.
As a result, it is possible to improve the uniformity of the polishing amount within the surface to be polished 1a of the semiconductor wafer 1.

Although the invention made by the inventor has been specifically described based on the embodiments of the present invention, the present invention is not limited to the embodiments of the invention, and does not depart from the gist of the invention. It is needless to say that various changes can be made.

For example, the slurry supply groove 5b formed on the end surface 5e of the guide ring 5 in the above embodiment is
Although a plurality of guide rings are formed linearly toward the center 5d of the guide ring 5 and at substantially equal intervals in the circumferential direction 5c, the guide rings of the other embodiment shown in FIG. 5, the slurry supply groove 5b may be formed radially and curved toward the outer circumference 16 of the guide ring 5.

That is, since the wafer carrier 6 shown in FIG. 1 is rotating, the slurry 2 can be smoothly supplied by forming the slurry supply groove 5b radially and in a curved line.

Also in this case, the slurry supply groove 5b is also used.
Are formed at substantially equal intervals in the circumferential direction 5c of the guide ring 5.

As a result, the slurry 2 can be smoothly and uniformly supplied to the polished surface 1a of the semiconductor wafer 1 even when the wafer carrier 6 is rotating.

Further, although the guide ring 5 according to the above-mentioned embodiment is a fixed type which cannot be moved, like the guide ring 5 according to another embodiment shown in FIG. 6, the guide ring 5 ( The ring-shaped guide member) can be divided into a plurality in the circumferential direction 5c, and the guide ring 5
At least one of them may be a member that is movable (movable) to the outer circumference 16 of the guide ring 5.

That is, the guide ring 5 is divided and movable.

The guide ring 5 shown in FIG.
In the case of the division type, it has a function of moving the guide ring 5 to the outer circumference 16 so that the semiconductor wafer 1 can be easily attached and detached.

Here, the split and movable guide ring 5 is used.
Does not necessarily have to cover the entire circumference of the semiconductor wafer 1.

That is, the guide ring 5 is provided at a predetermined position (for example, 4) on the outer peripheral portion 1b (see FIG. 3) of the semiconductor wafer 1.
It may be a movable pin member that holds the position).

By dividing the guide ring 5 so that it is movable, it is possible to easily attach / detach an object to be polished such as the semiconductor wafer 1.

When the guide ring 5 is divided and movable, the guide ring 5 is attached to the tip portion 5h of FIG.
You may have the claw part 5i as shown to (a).

As a result, the claw portion 5i can reliably support the outer peripheral portion 1b of the semiconductor wafer 1, so that the semiconductor wafer 1 can be prevented from coming off and jumping out to the outside 5g of the guide ring 5.

As a result, the operating time of the polishing apparatus according to the above-mentioned embodiment can be increased and the operating rate of the polishing apparatus can be improved.

Further, in the polishing apparatus, the dresser 15 was provided as a member separate from the wafer carrier 6 as shown in FIG. 1, but the dresser 15 of another embodiment shown in FIG. Like the carrier 6, the guide ring 5 may have the same function as the dresser 15.

That is, the guide ring 5 shown in FIG.
Hard particles 5j such as diamond near the end surface 5e
By embedding the end surface 5e into a hard tooth shape, the polishing pad 4 is attached to the guide ring 5 by this.
Can be imitated.

Here, for example, when the polishing pad 4 is formed of a polishing cloth such as a non-woven fabric, the end surface 5e of the guide ring 5 exerts a pressure on the polishing pad 4 during polishing so that the polishing pad 4 is polished. The fabric can be fluffed.

As a result, since the polishing pad 4 can always hold the polishing agent, it is possible to improve the uniformity of the polishing amount within the surface 1a to be polished of the semiconductor wafer 1 (object to be polished) without decreasing the polishing rate. it can.

Further, since the guide ring 5 has the copying function with respect to the polishing pad 4, it is not necessary for another member (for example, the dresser 15 shown in FIG. 1) to have the copying function. The structure of the polishing apparatus according to the above embodiment can be simplified.

Further, the polishing apparatus is similar to the wafer carrier 6 of another embodiment shown in FIG.
A film member 19 which is a thin film member that is deformed by the supply of the fluid 18 is provided inside, and the semiconductor wafer 1 (workpiece) is deformed by the deformation (expansion here) of the film member 19.
The pressure may be applied to.

This is because when the semiconductor wafer 1 is pressed,
The fluid 18 such as nitrogen gas is used to pressurize the film member 19, and the semiconductor wafer 1 is pressed by the deformation (expansion) of the film member 19.

Here, the film member 19 is made of, for example, polyethylene and has a film thickness of about 250 μm.

As a pressing method using the film member 19, first, a wafer accommodating space (abrasion object accommodating space) in which the depth 14a shown in FIG. 3 is formed deeper than the thickness 1d of the semiconductor wafer 1 is shown. The semiconductor wafer 1 is housed in 14.

Subsequently, the pressure space 2 in the wafer carrier 6
The fluid 18 is supplied to 0 to deform (expand) the film member 19.

Further, the semiconductor wafer 1 is moved in the opening direction 14b (see FIG. 3) of the wafer accommodating space 14 by pressing the semiconductor wafer 1 by the deformation (expansion) of the film member 19 during polishing, and the semiconductor wafer 1 is moved. Are pressed against the polishing pad 4.

As a result, the fluid 1 is directly applied to the semiconductor wafer 1.
Since 8 is not supplied, separation (floating) of the semiconductor wafer 1 in the wafer carrier 6 due to the reaction force of the fluid 18 can be prevented.

As a result, it is possible to prevent the semiconductor wafer 1 from coming off and jumping out to the outside 5g of the guide ring 5.

Further, during polishing, the semiconductor wafer 1 does not come off, and the semiconductor wafer 1 and the back pad 7 (buffer member) provided in the wafer carrier 6 are always in contact with each other. A substantially uniform load can be applied to the entire surface 1a.

As a result, the polished surface 1a of the semiconductor wafer 1
The uniformity of the polishing amount can be improved.

In the polishing apparatus according to the above-described embodiment, the case where the ring-shaped guide member is attached to the pressure holding member has been described. However, the ring-shaped guide member is provided independently of the pressure holding member. May be.

As a result, it is possible to press each of them separately by a mechanical load, and further to apply a mechanical load separately from the object to be polished.

As a result, when adjusting the magnitude of the load applied to the ring-shaped guide member, it can be adjusted separately from the load applied to the object to be polished.

Also in this case, the object-to-be-polished space for accommodating the object to be polished is formed by the pressure surface of the pressure holding member and the inner peripheral surface of the ring-shaped guide member.

In the above embodiment, the case where the object to be polished is the semiconductor wafer 1 has been described, but the object to be polished is not limited to the semiconductor wafer 1 and may be any other member as long as it is a disk-shaped member. It may be.

[0121]

Advantageous effects obtained by typical ones of the inventions disclosed by the present application will be briefly described as follows.
It is as follows.

(1). The depth of the object-to-be-polished space formed by the pressure-applying surface of the pressure-holding member and the inner peripheral surface of the ring-shaped guide member is substantially equal to or deeper than the thickness of the object-to-be-polished. At this time, since the outer peripheral portion of the object to be polished is almost completely surrounded by the inner peripheral surface of the ring-shaped guide member, the object to be polished can be prevented from coming off and jumping out of the ring-shaped guide member. Thereby, the operating time of the polishing apparatus can be increased, and as a result, the operating rate of the polishing apparatus can be improved.

(2). Since the object to be polished can be prevented from coming off and jumping out of the ring-shaped guide member, damage to the object to be polished can be reduced, and as a result, the yield of the object to be polished can be improved.

(3). By pressing the ring-shaped guide member and the object to be polished so that the force applied to the polishing pad by the ring-shaped guide member per unit area and the force applied to the polishing pad by the object to be polished become substantially equal, The polishing rate at the end of the polishing object can be made substantially equal to the polishing rate at other points in the polishing object.
As a result, it is possible to improve the uniformity of the polishing amount within the surface to be polished of the object to be polished, and as a result, it is possible to realize highly accurate polishing.

(4). The end face of the ring-shaped guide member is provided with a plurality of slurry supply grooves formed toward the center of the ring-shaped guide member and at substantially equal intervals in the circumferential direction of the end face. The slurry can be supplied to the entire surface to be polished of the object to be polished, and as a result, the uniformity of the amount of polishing in the surface to be polished of the object to be polished can be improved.

(5). When the ring-shaped guide member can be divided into a plurality of pieces in the circumferential direction, and at least one of the ring-shaped guide members is a member that can move outward in the circumference, when attaching or detaching an object to be polished, Can be easily attached and detached.

(6). Since the ring-shaped guide member has the claw portion that supports the outer peripheral portion of the object to be polished at the tip end thereof, it is possible to prevent the object to be polished from coming off and jumping out of the ring-shaped guide member. Thereby, the operating time of the polishing apparatus can be increased and the operating rate of the polishing apparatus can be improved.

(7). Since a thin film member such as a film member that is deformed by the supply of a fluid is provided in the ring-shaped guide member and the deformation of the thin film member pressurizes the object to be polished, the fluid is not directly supplied to the object to be polished. It is possible to prevent detachment (floating) of the object to be polished due to the reaction force of the fluid. This can prevent the object to be polished from coming off and jumping out of the ring-shaped guide member.

(8). During polishing, the object to be polished does not come off and the object to be polished and the cushioning member provided in the pressure holding member are constantly in contact with each other, so that a substantially uniform load is applied to the entire surface to be polished of the object to be polished. be able to. As a result, it is possible to improve the uniformity of the polishing amount within the surface to be polished of the object to be polished.

(9). By embedding hard fine particles such as diamond in the vicinity of the end face of the ring-shaped guide member, the ring-shaped guide member can have a function of copying the polishing pad. That is, when the polishing pad is made of a polishing cloth such as a nonwoven fabric, the polishing cloth of the polishing pad can be fluffed by the pressure applied to the end surface of the ring-shaped guide member against the polishing pad during polishing. As a result, the polishing pad can always hold the polishing agent, so that it is possible to improve the uniformity of the polishing amount within the surface to be polished of the object to be polished without decreasing the polishing rate.

(10). Since the ring-shaped guide member has the above-mentioned copying function with respect to the polishing pad, it is not necessary for another member to have the above-mentioned copying function, so that the structure of the polishing apparatus can be simplified.

[Brief description of drawings]

FIG. 1 is a structural conceptual diagram showing an example of an embodiment of a structure of a polishing apparatus according to the present invention.

FIG. 2 is a partial cross-sectional view showing an example of an embodiment of the structure of a pressure holding member in the polishing apparatus of the present invention.

FIG. 3 is an enlarged partial sectional view showing an example of an embodiment of a structure of a ring-shaped guide member in the polishing apparatus of the present invention.

FIG. 4 is a bottom view showing an example of an embodiment of the structure of the end face of the ring-shaped guide member in the polishing apparatus of the present invention.

FIG. 5 is a bottom view showing the structure of the end surface of the ring-shaped guide member in the polishing apparatus according to another embodiment of the present invention.

6A and 6B are views showing a structure of a ring-shaped guide member in a polishing apparatus which is another embodiment of the present invention, wherein FIG. 6A is a partial sectional view and FIG. 6B is a bottom view.

FIG. 7 is a partial cross-sectional view showing the structure of a ring-shaped guide member in a polishing apparatus that is another embodiment of the present invention.

FIG. 8 is a partial cross-sectional view showing the structure of a pressure holding member in a polishing apparatus that is another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor wafer (object to be polished) 1a Surface to be polished 1b Outer peripheral portion 1c Back surface 1d Thickness 1e End portion 2 Slurry 3 Polishing plate 3a Surface 4 Polishing pad 4a Surface 4b Strained portion 5 Guide ring (ring-shaped guide member) 5a Inner periphery Surface 5b Slurry supply groove 5c Circumferential direction 5d Center 5e End surface 5f Thickness 5g External 5h Tip portion 5i Claw portion 5j Hard fine particle 6 Wafer carrier (pressure holding member) 6a Outer peripheral tip portion 6b Pressure surface 6c Bonding surface 7 Back pad ( Buffer member) 7a Through hole 7b Thickness 8 Polishing plate rotating means 9 Carrier rotating means (pressurizing holding member rotating means) 10 Nozzle 10a Slurry supply port 11 Slurry supply means 12 Breathable rigid plate 12a Exposed surface 13 Fluid supply pipe 14 Wafer Storage space (storage space for objects to be polished) 14a Depth 14b Opening direction 15 Dresser 16 Outer circumference 17 Housing 18 Fluid 19 Film member (thin film member) 20 Pressurized space 21 Dresser rotating means 22 Dustproof cover

Front Page Continuation (72) Inventor Hiroyuki Kojima, 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Ltd. Production Engineering Research Center, Hitachi, Ltd.

Claims (9)

[Claims] 1. A polishing method for polishing a disk-shaped object to be polished, comprising a ring-shaped guide for guiding a pressure surface of a pressure holding member for holding the object to be polished and an outer peripheral portion of the object to be polished. The object to be polished is accommodated in an object-to-be-polished space formed of an inner peripheral surface of a member and having a depth substantially equal to or deeper than the thickness of the object to be polished, and the pressure holding member. While holding the object to be polished, the object to be polished is pressed against the polishing pad, and the end surface of the ring-shaped guide member facing the polishing pad and the surface to be polished of the object to be polished are substantially flush with each other. A polishing method comprising polishing an object to be polished. 2. The polishing method according to claim 1, wherein the force per unit area exerted on the polishing pad by the ring-shaped guide member and the force per unit area exerted on the polishing pad by the object to be polished are A polishing method comprising pressurizing the ring-shaped guide member and the object to be polished so that they are substantially equal to each other. 3. The polishing method according to claim 1, wherein, when the object to be polished is pressed, a thin film member such as a film member is pressed using a fluid, and the thin film member is deformed to deform the object to be polished. A polishing method comprising pressurizing an abrasive. 4. The polishing method according to claim 3, wherein the object to be polished is accommodated in the object-to-be-polished storage space having a depth deeper than the thickness of the object to be polished, and the thin film is used during polishing. A polishing method characterized in that the object to be polished is pressed by the deformation of the member to move the object to be polished in the opening direction of the object storage space to press the object to be polished against the polishing pad. . 5. A polishing device for polishing a disk-shaped object to be polished, comprising a polishing pad, such as a polishing cloth, provided on the surface and rotating during polishing, and a surface to be polished on the object to be polished. A pressure holding member having a pressure surface for pressing the back surface opposite to the pressure holding member; and an inner peripheral surface for guiding the outer peripheral portion of the object to be polished, and the pressure holding member by being attached to the pressure holding member. A ring-shaped guide member that forms an object-to-be-polished space composed of a pressure surface of the member and the inner peripheral surface, a polishing plate rotating unit that rotates the polishing plate, and a pressure holding member that rotates the pressure holding member. A rotating means, wherein the depth of the object-to-be-polished space is substantially equal to or deeper than the thickness of the object-to-be-polished, and the object-to-be-polished is accommodated in the object-to-be-polished space. When polishing, the polishing of the ring-shaped guide member A polishing apparatus, wherein an end surface facing a pad and a surface to be polished of the object to be polished form substantially the same surface for polishing. 6. The polishing apparatus according to claim 5, wherein the end face of the ring-shaped guide member is provided with a plurality of slurry supply grooves formed substantially toward the center of the ring-shaped guide member. A polishing device characterized by the above. 7. The polishing apparatus according to claim 5, wherein the ring-shaped guide member can be divided into a plurality of pieces in the circumferential direction, and at least one of the ring-shaped guide members is the ring-shaped guide member. A polishing apparatus, which is a member that is movable to the outside of the circumference of a guide member. 8. The polishing apparatus according to claim 5, 6 or 7, wherein the ring-shaped guide member has a claw portion for supporting an outer peripheral portion of the object to be polished at a tip end portion thereof. And polishing equipment. 9. The polishing apparatus according to claim 5, 6, 7 or 8, wherein a thin film member such as a film member which is deformed by the supply of a fluid is provided in the ring-shaped guide member,
A polishing apparatus, wherein pressure is applied to the object to be polished by the deformation of the thin film member.