JP2008296351A - Substrate treatment apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate treatment apparatus for polishing a peripheral portion of a substrate to be treated and a substrate treatment method, which performs accurate polishing, while suppressing the cost. <P>SOLUTION: The substrate treatment apparatus 100 for polishing the peripheral portion of the substrate to be treated W comprises: a substrate holding means 2 for holding the substrate to be treated W; a polishing means 6, 7, 8 for polishing the peripheral portion of the substrate to be treated W held by the substrate holding means 2 by bringing an abrasive cloth into sliding contact with that peripheral portion; a holding tank 9 for holding the substrate to be treated W to be polished by the polishing means 6, 7, 8; and treatment solution supply means 11, 13 for supplying a treatment solution into the holding tank 9. During polishing work by the polishing means 6, 7, 8, the peripheral portion of the substrate to be treated W remains immersed in the treatment solution. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus and a substrate processing method for polishing a peripheral portion (bevel portion) of a substrate to be processed such as a semiconductor wafer.

In the manufacture of semiconductor wafers, the front and back surfaces and the peripheral portion (bevel portion) of each wafer are polished before shipment.
However, in recent years, with the miniaturization of semiconductor elements and the increase in the density of semiconductor devices, dust generation due to surface roughness generated at the peripheral edge of the wafer during the manufacturing process of the semiconductor device has become a problem.

  In order to deal with such problems, Patent Document 1 discloses that the surface roughness generated on the peripheral edge of the wafer and the film that becomes a contamination source attached to the peripheral edge can be removed by polishing, and particles are generated on the substrate surface along with this polishing. A substrate processing method capable of preventing adhesion is disclosed.

FIG. 9 is a perspective view of a polishing apparatus to which the substrate processing method disclosed in Patent Document 1 is applied.
In FIG. 9, the polishing apparatus 200 includes a substrate holding mechanism 201 that holds and rotates a wafer W in a horizontal state, and a horizontally movable polishing head equipped with a polishing tape 202 that is used for polishing the peripheral edge of the wafer W. 203.
Then, the polishing tape 203 is brought into contact with and pressed against the side surface of the wafer W by moving the polishing head 203 to the wafer W side.

  Further, the polishing apparatus 200 includes a nozzle 204 for supplying a polishing liquid onto the wafer W. By dripping the polishing liquid from the nozzle 204 onto the center of the surface of the rotating wafer W, the polishing liquid can be supplied to the contact / pressurization portion between the wafer W and the polishing tape 202 by centrifugal force. .

  Further, a nozzle 205 for supplying a chemical solution containing a surfactant onto the wafer W is provided. By dripping a chemical solution containing a surfactant from the nozzle 205 onto the center of the surface of the wafer W and rotating the wafer W, the surfactant can be supplied to the entire surface of the wafer W by centrifugal force. Yes.

According to the substrate processing method using the polishing apparatus 200 having such a configuration, it is possible to prevent particles from adhering to the wafer surface during polishing by performing surface coating with a surfactant in advance before polishing. Can do.
JP 2005-277050 A

  However, in the substrate processing method (polishing apparatus) disclosed in Patent Document 1, if the polishing liquid is not sufficiently supplied from the nozzle 204 during the polishing process, the contact / pressure unit between the wafer W and the polishing tape 202 is used. In some cases, the polishing liquid may not be sufficiently supplied, and polishing unevenness (appearance defect) may occur. Further, since a new polishing liquid is always supplied onto the wafer W during polishing and the used liquid is discarded (called a flow-through method), there is a problem that the consumption of the polishing liquid increases and the cost increases. It was. Further, such a problem occurs not only in the polishing process for flattening the peripheral edge of the wafer but also in the formation of the notch or orientation flat of the wafer.

  The present invention has been made under the circumstances as described above, and in a substrate processing apparatus for polishing a peripheral portion of a substrate to be processed, a substrate processing apparatus and a substrate capable of performing polishing processing with reduced cost and high accuracy. An object is to provide a processing method.

In order to solve the above problems, a substrate processing apparatus according to the present invention is a substrate processing apparatus for polishing a peripheral portion of a substrate to be processed, the substrate holding means for holding the substrate to be processed, and the substrate holding means. A polishing means for performing a polishing operation by bringing a polishing cloth into sliding contact with the peripheral edge of the substrate to be processed held by the substrate, a storage tank for storing the substrate to be processed polished by the polishing means, and a treatment in the storage tank And a processing liquid supply means for supplying a liquid, wherein a peripheral edge portion of the substrate to be processed is immersed in the processing liquid in a polishing operation by the polishing means.
According to such a configuration, the peripheral edge is polished in a state where the substrate to be processed is immersed in the processing liquid in the storage tank. For this reason, the treatment liquid does not become insufficiently supplied as in the prior art, and problems such as uneven polishing (defective appearance) can be eliminated. Therefore, accurate polishing can be performed.

Further, it is desirable that the processing liquid supply means has a circulation supply means for circulatingly supplying the processing liquid to the storage tank.
By comprising in this way, the process liquid supplied in a storage tank can be circulated and supplied, the consumption amount can be reduced significantly from the conventional pouring method, and cost can be reduced.

Moreover, it is preferable that the said process liquid supply means has a process liquid switching means which switches an abrasive | polishing agent liquid and a washing | cleaning liquid as said process liquid supplied to the said storage tank.
By switching the processing liquid in this way, the polishing operation and the cleaning operation can be continuously performed while the substrate to be processed is stored in the same storage tank.

Further, in order to solve the above-described problems, a substrate processing method according to the present invention is a substrate processing method for polishing a peripheral portion of a substrate to be processed, in a storage tank to which a processing liquid used for polishing work is supplied. And holding the substrate to be processed, and performing a polishing operation by bringing a polishing cloth into sliding contact with the peripheral portion of the substrate to be processed while the peripheral portion of the substrate to be processed is immersed in the processing liquid. Have
According to such a method, the peripheral portion is polished while the substrate to be processed is immersed in the processing liquid in the storage tank. For this reason, the treatment liquid does not become insufficiently supplied as in the prior art, and problems such as uneven polishing (defective appearance) can be eliminated. Therefore, accurate polishing can be performed.

Further, it is desirable that the processing liquid supplied to the storage tank is circulated and supplied.
By doing in this way, the process liquid supplied in a storage tank can be circulated and supplied, the consumption amount can be reduced significantly compared with the conventional pouring method, and cost can be reduced.

Moreover, it is preferable that an abrasive liquid is supplied in the polishing operation using the polishing cloth and a cleaning liquid is supplied in the cleaning operation as the processing liquid supplied to the storage tank.
By switching the processing liquid in this way, the polishing operation and the cleaning operation can be continuously performed while the substrate to be processed is stored in the same storage tank.

  ADVANTAGE OF THE INVENTION According to this invention, in the substrate processing apparatus which grind | polishes the peripheral part of a to-be-processed substrate, cost reduction can be performed and the substrate processing apparatus and substrate processing method which can perform a grinding | polishing process accurately can be obtained.

  Embodiments of a substrate processing apparatus and a substrate processing method according to the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a bevel polishing apparatus 100 as a first embodiment of a substrate processing apparatus according to the present invention, and FIG. 2 is a plan view thereof.

  The bevel polishing apparatus 100 is an apparatus for polishing a peripheral portion (hereinafter, referred to as a bevel portion) of a semiconductor wafer W that is a substrate to be processed. Specifically, the cross-sectional enlarged view of the bevel portion of the wafer W in FIG. As shown in the figure, when forming a bevel portion having a predetermined curvature, the entire bevel portion is polished by polishing the bevel upper portion W1, the bevel side surface W2, and the bevel lower portion W3.

  As shown in FIG. 1, a bevel polishing apparatus 100 includes a disc-shaped chuck stage 2 (substrate holding means) that sucks and holds a wafer W in a horizontal state, a support shaft 3 that supports the chuck stage 2 from below, and a support shaft. 3 is provided with an elevating drive unit 4 for elevating and lowering 3 and a rotary drive unit 5 for rotating the support shaft 3 around a vertical axis in a predetermined direction. That is, the wafer W on the chuck stage 2 can be moved up and down and rotated as the support shaft 3 is driven.

  Further, the bevel polishing apparatus 100 includes a weighing tank 9 (accommodating tank) that can store a predetermined amount of processing liquid, and is supported in a state where the bevel polishing apparatus 100 is inserted into a through-hole 9e formed at the bottom of the weighing tank 9. A shaft 3 is provided. The support shaft 3 can be raised and lowered by sliding with respect to the through-hole 9e. When the wafer W on the chuck stage 2 is lowered as the support shaft 3 is lowered, the wafer W is placed in the weighing tank 9. When the wafer W rises as the support shaft 3 is raised, the wafer W is brought out of the weighing tank 9 as shown in FIG.

The weighing tank 9 is formed with an inlet 9a for supplying an abrasive liquid or pure water as a processing liquid and an outlet 9b for allowing the processing liquid flowing from the inlet 9a to flow out of the tank. Yes. The polishing liquid in the tank 13 is supplied from the inlet 9a into the weighing tank 9 by driving the pump 11 during polishing, and pure water is supplied from the terminal 18 by driving the pump (not shown) during cleaning. .
Note that the three-way valve 16 (processing liquid switching means) switches between the abrasive liquid and the pure water when the processing liquid is supplied. Further, a processing liquid supply means is constituted by a pump and a tank for supplying the processing liquid.

The processing liquid supplied to the weighing tank 9 flows out from the outlet 9b, and is recovered in the tank 13 when the processing liquid is an abrasive liquid, and is recovered through a terminal 19 in a tank (not shown) when the processing liquid is pure water. The circulation structure is made. Note that the three-way valve 17 (processing liquid switching means) switches between the abrasive liquid and the pure water when the processing liquid is discharged.
Thus, since the processing liquid is circulated and supplied in the weighing tank 9, the processing liquid is agitated in the weighing tank 9.
The circulation supply means is constituted by the pump 11, the tank 13, the weighing tank 9, and piping that circulates and connects them. In addition, a drainage port 9d that can be opened and closed is provided at the bottom of the weighing tank 9, and the treatment liquid after being used for the polishing process can be discharged from the drainage port 9d.

As shown in FIG. 2, a constant temperature water circulation pipe 14 is provided on the inner peripheral side of the weighing tank 9, and this pipe 14 is connected to the constant temperature water circulation device through a pipe port 9 c formed on the side surface of the weighing tank 9. 10 is connected. The treatment liquid in the weighing tank 9 is maintained at a predetermined temperature by the radiant heat of the constant temperature water flowing through the constant temperature water circulation pipe 14.
Further, in the weighing tank 9, as a polishing means, a polishing jig 6 for polishing the upper bevel portion W1 of the wafer W shown in FIG. 3, and a polishing jig 7 for polishing the lower bevel portion W3 are provided. A pair of polishing jigs 8 for polishing the side surface W2 of the bevel portion are provided. A polishing cloth for polishing by sliding contact is provided on the surface of each polishing jig 6, 7, 8 that contacts the wafer W.

The polishing jigs 6, 7, and 8 are provided so as to be horizontally movable by a moving mechanism (not shown) along the direction toward the center of the wafer W. The polishing jigs 6, 7, and 8 are provided on the wafer W. The wafer W is accommodated in the weighing tank 9 while being moved toward the outside of the wafer, and the polishing jigs 6, 7, 8 are horizontally moved toward the inside of the wafer W after being accommodated.
Therefore, at the time of polishing, as shown in FIG. 4, the wafer W is rotated by the support shaft 3 in the weighing tank 9 to which the abrasive liquid L is circulated and supplied by the polishing jigs 6, 7, 8. The bevel portions W1, W2, and W3 are polished.

Next, the polishing process in the bevel polishing apparatus 100 configured as described above will be described along the flow of FIG.
When polishing the bevel portion of the wafer W, first, the wafer W held on the chuck stage 2 is lowered and placed in the weighing tank 9 (step ST1 in FIG. 5).
Next, an abrasive liquid containing an abrasive is supplied into the weighing tank 9, and the wafer W is completely immersed in the abrasive liquid (step ST2 in FIG. 5).

  Next, the polishing jigs 6, 7, 8 are moved forward toward the inside of the wafer W, and the polishing cloths of the polishing jigs 6, 7, 8 are brought into contact with the bevel portion of the wafer W in a pressurized state ( Step ST3 in FIG. 5). Then, the polishing cloth of the polishing jigs 6, 7, 8, which is rotated around the vertical axis for a predetermined time, slides while swinging with respect to the bevel portion of the wafer W (step ST 4 in FIG. 5). By this step, the bevel portion is polished.

The swinging operation of the polishing jigs 6, 7, 8 is determined in advance by a control program executed by a control unit (not shown).
Here, in the polishing operation, since the wafer W is immersed in the abrasive liquid, there is no insufficient supply of the abrasive liquid as in the past, and problems such as polishing unevenness (defective appearance) may occur. Absent. Moreover, since the abrasive | polishing agent liquid supplied in the weighing tank 9 is circulated and supplied, the consumption is restrained small.

When the polishing operation for a predetermined time is completed, the polishing jigs 6, 7, and 8 move toward the outside of the wafer W (step ST5 in FIG. 5), and the supply of the abrasive liquid is stopped (step ST6 in FIG. 5). ).
Next, pure water is supplied into the weighing tank 9 instead of the abrasive liquid, and the wafer W is rotated at a predetermined speed (step ST7 in FIG. 5). As a result, the polished bevel portion is cleaned. Here, in the cleaning operation, since the wafer W is immersed in pure water, no cleaning residue is generated. Moreover, since the pure water supplied to the weighing tank 9 is circulated and supplied, the consumption amount can be reduced.
When the cleaning process is completed, the chuck stage 2 is raised and the wafer W is moved out of the bath (step ST8 in FIG. 5).

As described above, according to the first embodiment of the substrate processing apparatus of the present invention, the bevel portion is polished while the wafer W is immersed in the processing liquid (abrasive liquid, pure water) in the weighing tank 9. And cleaning is performed. For this reason, there is no shortage of supply of the treatment liquid as in the prior art, and there are no problems such as polishing unevenness (appearance defect) and uncleaned residue. Therefore, it is possible to perform polishing with high precision.
Further, since the processing liquid (abrasive liquid, pure water) supplied into the weighing tank 9 is circulated and supplied, the consumption thereof is greatly reduced compared to the conventional pouring method, and the cost can be reduced.

  Next, a second embodiment of the substrate processing apparatus according to the present invention will be described with reference to FIGS. FIG. 6 is a side view of a notch polishing apparatus 101 as a second embodiment of the substrate processing apparatus according to the present invention, and FIG. 7 is a plan view thereof.

The notch polishing apparatus 101 is an apparatus for polishing the notch portion W4 of the semiconductor wafer W.
As shown in FIG. 6, the notch polishing apparatus 101 includes a disc-shaped chuck stage 20 (substrate holding means) that sucks and holds the wafer W in a horizontal state, a support member 21 that supports the chuck stage 2 from the side, a chuck And a drive unit 31 that rotates (inclines) the support member 21 about the notch W1 of the wafer W held by the stage 20 as an axis.
The drive unit 31 is configured not only to rotate the support member 21 but also to move in the horizontal direction.

The notch polishing apparatus 101 includes a weighing tank 22 (accommodating tank) that can store a predetermined amount of processing liquid. The weighing tank 22 is supported by a support shaft 23, and the support shaft 23 is configured to be movable up and down by driving an elevating drive unit 24.
When the weighing tank 22 is lifted by the lifting and lowering drive of the support shaft 23, the wafer W is accommodated in the weighing tank 22, and when the weighing tank 22 is lowered, the wafer W is turned into the weighing tank as shown in FIG. 22 is taken out.

Further, the weighing tank 22 is formed with an inlet 22a for supplying a polishing agent liquid or pure water as a processing liquid, and an outlet 22b for allowing the processing liquid flowing from the inlet 22a to flow out of the tank. Has been.
The abrasive liquid in the tank 28 is supplied into the weighing tank 22 from the inlet 22a by driving the pump 26 during polishing, and pure water is supplied from the terminal 34 by driving the pump (not shown) during cleaning. .
Note that the three-way valve 32 (processing liquid switching means) switches between the abrasive liquid and the pure water when the processing liquid is supplied. Further, a processing liquid supply means is constituted by a pump and a tank for supplying the processing liquid.

The processing liquid supplied to the weighing tank 22 flows out from the outlet 22b, and is recovered in the tank 28 when the processing liquid is an abrasive liquid, and is recovered through a terminal 35 to a tank (not shown) when the processing liquid is pure water. The circulation structure is made. Note that the three-way valve 33 (processing liquid switching means) switches between the abrasive liquid and the pure water when the processing liquid is discharged.
Thus, since the processing liquid is circulated and supplied in the weighing tank 22, the processing liquid is stirred in the weighing tank 22.
The circulation supply means is constituted by the pump 26, the tank 28, the weighing tank 22, the piping for circulatingly connecting them, and the like. Further, a drainage port 22d that can be freely opened and closed is provided at the bottom of the weighing tank 22, and the treatment liquid after being used for the polishing process can be discharged from the drainage port 22d.

  As shown in FIG. 7, a constant temperature water circulation pipe 29 is provided on the inner peripheral side of the weighing tank 22, and this pipe 29 is connected to the constant temperature water circulation device via a pipe port 22 c formed on the side surface of the weighing tank 22. 25. The treatment liquid in the weighing tank 22 is configured to be maintained at a predetermined temperature by the radiant heat of the constant temperature water flowing through the constant temperature water circulation pipe 29.

In addition, a disc-shaped polishing pad 15 having a polishing cloth affixed to the peripheral portion is provided above the weighing tank 22 and on the side of the wafer W held on the chuck stage 20 so as to be rotatable about a horizontal axis. The polishing pad 15 is rotated at a predetermined speed in a predetermined direction by driving of the rotation driving unit 30.
More specifically, the peripheral edge portion of the polishing pad 15 supported in an upright state is arranged so as to be substantially orthogonal to the notch portion W4 of the wafer W held in a horizontal state, and the wafer W advances with respect to the polishing pad 15. Thus, the rotating polishing pad 15 is configured to be in sliding contact with the notch W4.

Next, the polishing process in the notch polishing apparatus 101 configured as described above will be described along the flow of FIG.
First, the notch W4 of the wafer W is aligned (step S1 in FIG. 8), and the wafer W is held by the chuck stage 20 (step S2 in FIG. 8).

Next, the chuck stage 20 moves forward toward the polishing pad 15, and the polishing pad 15 comes into sliding contact with the notch W4 of the wafer W (step S3 in FIG. 8).
Further, the abrasive liquid is supplied to the weighing tank 22, and the weighing tank 22 is raised, so that the wafer W is immersed in the abrasive liquid (step S4 in FIG. 8).
Next, the polishing pad 15 is rotated to start a polishing operation, and during the polishing, the contact angle of the polishing pad 15 with the notch W4 is changed and controlled by a program (step S5 in FIG. 8).
Here, in the polishing operation, since the wafer W is immersed in the abrasive liquid, there is no insufficient supply of the abrasive liquid as in the prior art, and no problems such as uneven polishing occur. Moreover, since the abrasive | polishing agent liquid supplied in the weighing tank 22 is circulated and supplied, the consumption is restrained small.

When the polishing operation for a predetermined time is finished, the supply of the abrasive liquid is stopped (step S6 in FIG. 8), and pure water is supplied into the weighing tank 22 instead of the abrasive liquid. Then, the notch W4 is cleaned by rotating the polishing pad 15 at a predetermined rotation speed (step S7 in FIG. 8). Here, in the cleaning operation, since the wafer W is immersed in pure water, no cleaning residue is generated. Moreover, since the pure water supplied to the weighing tank 22 is circulated and supplied, the consumption amount can be reduced.
Then, the chuck stage 20 is retracted from the polishing pad 15, the weighing tank 22 is lowered, and the wafer W is taken out (step S8 in FIG. 8).

As described above, according to the second embodiment of the substrate processing apparatus of the present invention, notch portion polishing and cleaning in a state where the wafer W is immersed in the processing liquid (abrasive liquid, pure water) in the weighing tank 22. Is done. For this reason, there is no shortage of supply of the treatment liquid as in the prior art, and there are no problems such as polishing unevenness (appearance defect) and uncleaned residue. Therefore, it is possible to perform polishing with high precision.
In addition, since the processing liquid (abrasive liquid, pure water) supplied into the weighing tank 22 is circulated and supplied, the consumption thereof is greatly reduced compared to the conventional pouring method, and the cost can be reduced.
In the second embodiment, the example in which the notch portion of the wafer W is polished has been described. However, the same apparatus configuration can also be applied to the polishing of the orientation flat portion of the wafer W.

  Moreover, in the said embodiment, although the semiconductor wafer was demonstrated to the example as a to-be-processed substrate, it is not restricted to this, The substrate processing apparatus and substrate processing method which concern on this invention can be applied to all plate-shaped substrates. it can.

  The present invention relates to a substrate processing apparatus and a substrate processing method for polishing a peripheral portion (bevel portion and edge portion) of a substrate to be processed such as a semiconductor wafer, and is suitably used in the semiconductor manufacturing industry and the like.

FIG. 1 is a side view of a bevel polishing apparatus as a first embodiment of a substrate processing apparatus according to the present invention. FIG. 2 is a plan view of the bevel polishing apparatus of FIG. FIG. 3 is an enlarged cross-sectional view of the bevel portion of the wafer. FIG. 4 is a cross-sectional view showing a state in which a wafer is polished in a weighing tank in the first embodiment of the substrate processing apparatus according to the present invention. FIG. 5 is a flowchart showing the flow of the polishing process in the first embodiment of the substrate processing apparatus according to the present invention. FIG. 6 is a side view of a notch polishing apparatus as a second embodiment of the substrate processing apparatus according to the present invention. FIG. 7 is a plan view of the notch polishing apparatus of FIG. FIG. 8 is a flowchart showing the flow of the polishing process in the second embodiment of the substrate processing apparatus according to the present invention. FIG. 9 is a perspective view showing a schematic configuration of a conventional polishing apparatus.

Explanation of symbols

2 Chuck stage (substrate holding means)
6 Polishing jig (polishing means)
7 Polishing jig (polishing means)
8 Polishing jig (polishing means)
9 Weighing tank (container)
11 Pump (treatment liquid supply means, circulation supply means)
13 Tank (Processing liquid supply means, circulation supply means)
15 Polishing pad (polishing means)
16 Three-way valve (Processing liquid switching means)
17 Three-way valve (Processing liquid switching means)
20 Chuck stage (substrate holding means)
22 Weighing tank (container)
26 Pump (treatment liquid supply means, circulation supply means)
28 tanks (treatment liquid supply means, circulation supply means)
32 Three-way valve (Processing liquid switching means)
33 Three-way valve (Processing liquid switching means)
100 bevel polishing equipment (substrate processing equipment)
101 Notch polishing equipment (substrate processing equipment)
W Semiconductor wafer (substrate to be processed)

Claims (6)

A substrate processing apparatus for polishing a peripheral portion of a substrate to be processed,
A substrate holding means for holding the substrate to be processed, a polishing means for performing a polishing operation by bringing a polishing cloth into sliding contact with a peripheral edge of the substrate to be processed held by the substrate holding means, and the polishing by the polishing means A storage tank for storing the substrate to be processed; and a processing liquid supply means for supplying a processing liquid into the storage tank;
The substrate processing apparatus, wherein a peripheral edge portion of the substrate to be processed is immersed in the processing liquid in a polishing operation by the polishing means.   The substrate processing apparatus according to claim 1, wherein the processing liquid supply unit includes a circulation supply unit that circulates and supplies the processing liquid to the storage tank.   The substrate processing according to claim 1, wherein the processing liquid supply unit includes a processing liquid switching unit that switches between an abrasive liquid and a cleaning liquid as the processing liquid supplied to the storage tank. apparatus. A substrate processing method for polishing a peripheral portion of a substrate to be processed,
Holding the substrate to be processed in a storage tank supplied with a processing liquid used for polishing work,
A substrate processing method comprising performing polishing work by bringing a polishing cloth into sliding contact with the peripheral edge of the substrate to be processed while the peripheral edge of the substrate to be processed is immersed in the processing liquid.   The substrate processing method according to claim 4, wherein the processing liquid supplied to the storage tank is circulated and supplied.   The processing liquid supplied to the storage tank is supplied with an abrasive liquid in a polishing operation using the polishing cloth, and supplied with a cleaning liquid in the cleaning operation. Substrate processing method.

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