JP2003151959A - Resist-removing apparatus and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist-removing apparatus and its method for removing resist, even when a resist cured layer is formed through ion implantation. SOLUTION: The resist removing apparatus includes a vacuum chamber 10, a wafer-mounting stage 21 pivotally provided in a reversible state in the vacuum camber 10, and a plasma-generating means 11, mounted at an upper part of the wafer mounting stage 21 for causing the plasma to flow down onto a wafer-mounting face 21a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist removing apparatus and a resist removing method, and in particular, in a semiconductor device manufacturing process, it is used as a mask during ion implantation to remove a resist having a hardened resist layer formed thereon. The present invention relates to a resist removing device and a resist removing method.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, ion implantation and etching are performed using a patterned resist as a mask. Then, after these processes are completed, as a step of removing the resist, for example, an oxygen gas is used as an ashing gas, which is turned into plasma, and an ashing process in a dry process in which oxygen radicals and ozone are downflowed. Is being done. It is known that such a resist ashing process in which oxygen radicals and ozone are downflowed does not damage the underlying layer of the resist.

Here, at the time of ion implantation, an organic material resin such as a novolac resin, a polyvinylphenol (PVP) resin, an acrylate resin is used as a resist. The resist made of these resins is used as a mask. When used as, the ions are also implanted in the resist. For this reason, the substance doped by ion implantation such as arsenic and phosphorus reacts with the resist, and the resist is altered to form a resist hardened layer.

This hardened resist layer has a graphite structure and a diamond structure and is difficult to be ashed. In addition, since the resist hardened layer is formed depending on the concentration distribution of the doped substance in the resist, the resist hardened layer is not formed in the resist near the boundary with the wafer where the doped substance hardly exists. It is known.

When the ashing process is performed on the resist on which the resist hardened layer is formed under the ashing process conditions in which oxygen radicals and ozone are downflowed as described above, the resist near the boundary with the wafer is ashed. Since this is processed, the resist cured layer is peeled from the wafer by removing this portion. However, under the above-described ashing treatment conditions, the resist hardened layer that has been peeled off cannot be removed by ashing, and the resist hardened layer floats in the form of a film or fragments on the wafer surface,
Since it reattaches to the wafer surface and becomes a resist residue,
This has been a cause of pattern defects in the subsequent pattern formation on the wafer surface.

Therefore, in addition to oxygen gas, nitrogen hexagon / hydrogen gas forming gas or sulfur hexafluoride or methane tetrafluoride as a fluorine-based gas is added to increase the reaction probability between the resist hardened layer and radicals. The method was taken. However, even with such a method, it was not possible to reliably remove the cured resist layer, as in the method described above.

Therefore, in addition to the radicals, the resist on the surface of the wafer is irradiated with ions such as oxygen, hydrogen, and fluorine having an energy of several eV or more to ash the resist hardened layer.

Further, before the ashing process, a step of re-applying the resist on the resist having a resist hardened layer and performing hard ashing (ion assist etc.) on about half of these resists, and the remaining resist is damaged to the underlying layer. There has been reported a method for removing a hardened resist layer which is provided with a step of performing an ashing treatment with oxygen radicals (Japanese Patent Laid-Open No. 6-120135).

[0009]

However, the method of irradiating the resist with not only radicals but also ions as described above makes it possible to ash the resist hardened layer. However, ashing is performed under such ashing conditions. There is a problem that the treatment also damages the underlying layer of the resist. Further, according to the method described in JP-A-6-120135, the resist hardened layer cannot be sufficiently removed by ashing, and the resist hardened layer tends to redeposit on the wafer surface to form a resist residue. From such a background, there has been a demand for a resist removing apparatus and a resist removing method capable of removing the hardened resist layer without damaging the underlayer.

[0010]

In order to solve the above-mentioned problems, a resist removing apparatus according to a first aspect of the present invention is provided with a vacuum chamber and a vacuum chamber, which is reversibly rotatable. It is characterized in that it is provided with a movable wafer mounting table and a plasma generating means provided above the wafer mounting table and down-flowing plasma on the wafer mounting surface of the wafer mounting table.

According to such a resist removing apparatus, since the wafer mounting table can be rotated in a freely reversible manner, the wafer mounting table is reversed while the wafer is held on the wafer mounting table, so that the wafer surface is rotated. Is reversed. Here, after the ashing process, when the wafer surface is inverted while the ashing residue is floating on the wafer surface, the positional relationship between the ashing residue and the wafer surface is maintained. In such a case, the ashing residue floats on the front surface side of the wafer which is turned downward by reversal, that is, below the wafer surface. Therefore, in such a state, if the decompression in the vacuum chamber is weakened and the ashing residue is dropped by its own weight, the ashing residue will fall below the wafer surface without falling. Therefore, the ashing residue can be removed without adhering to the wafer surface.

Further, in the resist removing apparatus according to the second aspect of the present invention, the vacuum chamber, the wafer mounting table provided in the vacuum chamber, and the wafer mounting table provided above the wafer mounting table. It is characterized by comprising plasma generating means for down-flowing the plasma on the wafer mounting surface, and air flow forming means for forming an air flow away from the wafer mounting surface on the wafer mounting surface side.

According to such a resist removing apparatus, the wafer holding surface holds the wafer on the wafer mounting table by providing the airflow forming means for forming the airflow away from the wafer mounting surface. In this state, when the ashing residue is floating on the wafer surface after the ashing process, the ashing residue can be moved away from the wafer surface by being placed on the formed air flow. Therefore, the ashing residue can be removed from above the wafer surface without adhering to the wafer surface.

Further, in the resist removing apparatus according to the fourth aspect of the present invention, the vacuum chamber, the wafer mounting table provided in the vacuum chamber, and the wafer mounting table provided above the wafer mounting table are provided. It is characterized in that it is provided with a plasma generating means for down-flowing the plasma on the wafer mounting surface, and a rotating brush arranged facing the surface of the wafer held on the wafer mounting table with a gap.

According to such a resist removing apparatus, since the rotating brush is arranged to face the surface of the wafer held on the wafer mounting table with a gap, the wafer is held on the wafer mounting table. When the ashing residue floats on the wafer surface after the ashing process, the ashing residue is adsorbed by the rotary brush when the rotating brush is placed facing the wafer surface so as to contact the ashing residue and rotated. Therefore, the ashing residue can be removed from above the wafer surface without adhering to the wafer surface.

According to a sixth aspect of the present invention, in the resist removing method, the resist on the wafer held in a horizontal state is subjected to an ashing treatment in a reduced pressure atmosphere, and then the wafer surface is kept at 90 to 180 degrees with respect to the horizontal state. It is characterized in that the ashing residue floating on the wafer surface side is dropped without being subjected to the ashing process by weakening the reduced pressure in the state of being inclined in the range.

According to such a resist removing method, when the ashing-processed wafer is tilted in the range of 90 ° to 180 ° with respect to the horizontal state while the ashing residue is floating on the wafer surface. , The positional relationship between the ashing residue and the wafer surface is maintained. In such a case, the ashing residue floats on the front surface side of the wafer which is directed downward (or lateral direction) by the inclination, that is, below the wafer surface (or lateral direction). After that, the reduced pressure is weakened and the ashing residue is dropped, so that the ashing residue can be removed without adhering to the wafer surface.

Further, the resist removing method according to claim 7 is characterized in that after the ashing process is performed on the resist pattern on the wafer, the resist is recoated on the wafer and the ashing process is performed again.

According to such a resist removing method, even if the resist residue is left on the wafer after the resist pattern is ashed, the resist is recoated on the wafer and the ashing process is performed again. The resist residue can be removed together with the re-applied resist.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a resist removing apparatus and a resist removing method according to the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 is an overall configuration diagram for explaining an embodiment of a resist removing apparatus according to claim 1, and FIG. 2 is a vacuum chamber 10 and plasma generating means in this resist removing apparatus. It is a principal part block diagram of 11. The resist removing apparatus shown in this figure is RF (Radio
Frequency) down-flow type resist removing apparatus, which includes a vacuum chamber 10 and a plasma generating means 11 provided above the vacuum chamber 10. Further, the vacuum chamber 10 transfers a wafer through a gate valve 13a. The chamber 13 is connected.

A gas exhaust pipe 14 is connected to the bottom of the vacuum chamber 10 and is connected to a vacuum pump 15 so that the gas in the vacuum chamber 10 can be exhausted.

Further, as shown in FIG. 2, the vacuum chamber 1
Within 0, a wafer mounting table 21 characteristic of the present invention is provided. An arm 22 for supporting the wafer mounting table 21 is provided on the side periphery of the wafer mounting table 21.
Is connected to a rotary shaft 23 extending in the horizontal direction.
The rotary shaft 23 is connected to a drive means (not shown), and the wafer mount table 21 can be rotated about the rotary shaft 23 in a reversible manner by the drive means.

Here, in a certain rotation state, the wafer mounting table 21 is configured to be in a horizontal state (a) with the wafer mounting surface 21a facing upward, and the wafer mounting table 21 is placed in the horizontal state by the driving means. The wafer mounting surface 21a can be tilted by 90 degrees from the horizontal state to the vertical state (b), and further tilted by 180 degrees from the horizontal state to rotate the wafer mounting surface 21a to the inverted state (c). Further, a stopper (not shown) is attached to this driving means,
The wafer mounting table 21 can be fixed in a tilted state.

In the present embodiment, the wafer mounting table 21 is supported by the arm 22 connected to the rotary shaft 23, and the wafer mounting table 21 is reversibly rotated together with the arm 22. The present invention is not limited to this, and the rotating shaft 23 is extended in the horizontal direction so as to pass through the center of the wafer mounting table 21, and the wafer mounting table 21 can be rotated about the rotating shaft 23 in a reversible manner. It may be configured.

Further, the wafer mounting table 21 is supposed to be provided with a plurality of support pins (not shown) for holding the wafer W by pressing the edge of the wafer W to be mounted. Here, it is assumed that the support pins are made of a material that does not react with the ashing gas during the ashing process. Although the wafer mounting table 21 is provided with the support pins here, it may have a mechanism for holding the wafer W by an electrostatic chuck method. In this wafer mounting table 21,
For example, it is assumed that a temperature adjusting means (not shown) such as a heater is provided inside a cylindrical body.

The plasma generating means 11 is the vacuum chamber 1
A plasma generating chamber 12 communicating with 0, and a gas introducing pipe 16 provided at an upper portion thereof for introducing an ashing gas;
It is composed of a coil 17 provided on the side periphery thereof, and is provided above the wafer mounting table 21 in a horizontal state with the wafer mounting surface 21a facing upward. The coil 17 is connected to, for example, an RF power source, and is provided in a state of being wound around the side circumference of the plasma generation chamber 12.
An RF current is passed through the coil 17 so that the plasma generation chamber 1
The plasma P of the ashing gas is generated in the chamber 2, and the radicals R in the plasma P are downflowed to the wafer mounting surface 21a kept in a horizontal state.

The wafer transfer chamber 13 shown in FIG. 1 is connected to the vacuum chamber 10 via a gate valve 13a. A carrier 18 holding a plurality of wafers W is housed and arranged in a predetermined state in the wafer transfer chamber 13. still,
The surface of the wafer W held by the carrier 18 is provided with the resist used as a mask for etching or a mask for ion implantation in the previous step. The transfer arm 19 is connected to the wafer mounting table 21 of the vacuum chamber 10.
And a carrier 18 housed and arranged in the wafer transfer chamber 13.
The wafer W is carried in and out through the gate valve 13a between the vacuum chamber 10 and the carrier 18, and is provided between the vacuum chamber 10 and the arrangement portion of the carrier 18.

Next, a resist removing method for removing the resist provided on the surface of the wafer W using the resist removing apparatus having the above-described structure will be described. Here, a resist used as a mask at the time of ion implantation is provided on the surface of the wafer W, and the resist is formed of an organic resin such as a novolac resin, a PVP resin, an acrylate resin. To do. Further, it is assumed that the resist hardened layer is formed by ion implantation in this resist.

First, the wafer W held by the carrier 18
Is mounted on the wafer mounting surface 21a of the wafer mounting table 21 using the transfer arm 19 and held by the support pins (not shown). Next, the gate valve 13a is closed, and the pressure in the vacuum chamber 10 is set to 130 Pa to 400 P by the vacuum pump 15.
The wafer W held on the wafer mounting table 21 is evacuated to 10a by the temperature adjusting means of the wafer mounting table 21.
Heat to 0-120 ° C. Here, this heating temperature is set to a temperature at which popping due to resist out gas does not occur.

Thereafter, an ashing gas is introduced into the plasma generation chamber 12 from the gas introduction pipe 16 and an RF current having an output of 2000 kW to 3000 kW is supplied to the coil 17, whereby a plasma P of the ashing gas is generated in the plasma generation chamber 12. To generate. Here, the ashing process is performed under the condition that only oxygen is used as the ashing gas, and the oxygen gas flow rate is 2000 cm ³ / min to 10000 cm ³ /
Set to min. The gas flow rate is the volume flow rate in the standard state. Then, the radicals R in the generated plasma P, that is, oxygen radicals and ozone are downflowed to the wafer W held on the wafer mounting table 21, and the resist on the wafer W is ashed by the radicals R. After performing, introducing ashing gas and R
Stop the F current.

In this ashing process, the resist hardened layer formed on the resist has a graphite structure or a diamond structure and is difficult to ash, so the resist hardened layer is peeled from the wafer W, but removed. Without being formed into a film or a fragment, the wafer W
Floats on the surface.

Next, in a state where the vacuum chamber 10 is kept at a reduced pressure, as shown in FIG. 2, the wafer mounting table 21 holding the wafer W together with the arm 22 about the rotation shaft 23 by the driving means as shown in FIG. Is rotated 180 degrees from the horizontal state and inverted to invert the surface of the wafer W. In this state, the inside of the vacuum chamber 10 is kept in a reduced pressure state, so that the resist hardened layer is kept floating below the surface of the wafer W.

Then, by introducing gas from the gas introducing pipe 16, the decompression in the vacuum chamber 10 is weakened so that the resist hardened layer has a pressure capable of dropping by its own weight, specifically, a pressure of 1060 Pa or more. The pressure in the vacuum chamber 10 is adjusted. When a plurality of wafers W are continuously processed, it is preferable that the depressurization is weakened to the minimum in the range where the resist hardened layer falls due to its own weight, taking workability into consideration. As a result, the resist hardened layer floating below the surface of the wafer W drops without reattaching to the surface of the wafer W and is discharged from the gas exhaust pipe 14.

In this embodiment, the depressurization is weakened when the wafer mounting table 21 is inverted from the horizontal state with the wafer mounting surface 21a facing upward, that is, rotated 180 degrees. However, the present invention is not limited to this, and in a state where the wafer mounting table 21 is inclined at an inclination angle in the range of 90 degrees to 180 degrees with respect to a horizontal state in which the wafer mounting surface 21a is directed upward. The reduced pressure may be weakened. If the inclination angle is within this range, it is possible to drop the resist hardened layer floating on the front surface side of the wafer W by its own weight without reattaching it to the front surface of the wafer by weakening the reduced pressure. However, this tilt angle is
It is assumed that the resist hardened layer floating on the surface side is adjusted to an angle such that the resist hardened layer does not adhere to the surface of the wafer W due to interference by the gas flow introduced when weakening the reduced pressure.

According to the resist removing apparatus and the resist removing method using the same as described above, after the resist on the wafer W is subjected to the ashing treatment, the resist hardened layer is floating on the surface of the wafer W. The wafer W can be inverted. Here, even when the wafer W is inverted, the positional relationship between the resist hardened layer and the surface of the wafer W is maintained, so that the hardened resist layer floats below the surface of the wafer W. Therefore, by weakening the reduced pressure in the vacuum chamber 10, the resist hardened layer can be dropped by its own weight without being reattached to the surface of the wafer W. Further, since the radical R generated by introducing oxygen gas is down-flowed to the resist on the wafer W to perform the ashing treatment and the resist hardened layer can be removed, the underlying layer of the resist is damaged. The hardened resist layer can be removed without application.

(Second Embodiment) FIG. 3 is a schematic view of a main part of a resist removing apparatus to which the invention of claim 3 is applied, and this embodiment will be described below with reference to this drawing.

The resist removing apparatus of the present embodiment is different from the resist removing apparatus of the first embodiment in that a plate-like member 41, which is an air flow forming means, is provided in the vacuum chamber 10, but other configurations are provided. Is the same. 1 and 2
The same components as those of the resist removing apparatus according to the first embodiment described by using the same reference numerals are given, and overlapping description will be omitted.

The plate member 41 is projected from the bottom of the vacuum chamber 10 with the wafer mounting table 21 inverted. Then, the plate-like member 41 is turned upside down so as to change the direction of the air flow due to the gas introduced from the gas introduction pipe 16, and the wafer placing surface 21a of the wafer placing table 21 is inverted.
By being arranged below the plasma generation chamber 12 in a state of being inclined to the side, an air flow C that is distant from the wafer mounting surface 21a on the wafer mounting surface 21a side is formed in the vacuum chamber 10.

The air flow C is, for example, when the gas flow introduced from the gas introduction pipe 16 hits the plate-shaped member 41, the wafer is placed on the wafer mounting table 21 in the inverted state along the inclination of the plate-shaped member 41. The floating material on the surface of the wafer W held on the wafer mounting table 21 and guided to the mounting surface 21 a side is formed so as to be guided to the gas discharge port 14.

The plate-shaped member 41 may be constructed so as to form the air flow C by freely adjusting the inclination angle.
The inclination angle of the plate-like member 41 is fixed, and by adjusting the inclination angle of the wafer mounting table 21, an air flow C is formed on the wafer mounting surface 21a side so as to move away from the wafer mounting surface 21a. It may have been done.

Next, a resist removing method using such a resist removing apparatus will be described. In this embodiment, the resist removal on the wafer W, which is the same as in the first embodiment, will be described as an example. The same method is used up to the resist removing method and the ashing process described in the first embodiment.

After performing the ashing process on the wafer W held on the wafer mounting table 21, the introduction of the ashing gas and the RF current are stopped, and the wafer W is driven by the driving means.
The wafer mounting table 21 holding the is reversed.

Next, the plate-like member 41 is moved to a predetermined position, and gas is introduced into the vacuum chamber 10 from the gas introducing pipe 16. The type of this gas is not particularly limited, and an ashing gas may be used, or an inert gas or clean air may be used. Then, the introduced gas flow is applied to the plate-shaped member 41, the direction of the plate-shaped member 41 is further changed by the inclination of the plate-shaped member 41, and the air flow C goes away along the surface of the wafer W held by the wafer mounting table 21. To form. As a result, the resist-cured layer floating below the surface of the wafer W is placed on the air flow C and moved away from the surface of the wafer, and is guided to the gas exhaust pipe 14 and removed.

By using the resist removing apparatus and the resist removing method as described above, the wafer mounting table 21 is
In the state of being reversed, it is possible to form an air flow C in the vacuum chamber 10 on the side of the wafer mounting surface 21a that moves away from the wafer mounting surface 21a. As a result, in the state where the wafer mounting table 21 holding the wafer W is turned over, the resist hardened layer floating below the surface of the wafer W is put on the air flow C and is kept away from the surface of the wafer W without being subjected to the ashing process. The resist hardened layer can be removed more reliably because it can be removed. Further, by introducing gas to form the air flow C and adjusting the exhaust amount, the pressure reduction in the vacuum chamber 10 is also weakened, so that the resist hardened layer can be dropped by its own weight. It is possible to reduce the time required for

In the present embodiment, the direction of the gas flow introduced from the gas introduction pipe 16 is changed by using the plate member 41 as the air flow forming means with the wafer mounting table 21 inverted. The airflow C is formed so as to move away from the wafer mounting surface 21a, but the present invention is not limited to this, and, for example, an airflow C that can move away from the wafer mounting surface 21a can be formed on the wafer mounting surface 21a side. Air flow C by providing a new gas inlet at a certain position
May be formed.

Further, in the present embodiment, the wafer mounting table 21
The resist removing apparatus having the structure including the air flow forming means in the apparatus including the driving means for reversibly rotating the above has been described. However, the present invention is not limited to this, and an air flow forming means for forming an air flow C away from the wafer mounting surface 21a in an apparatus not provided with a drive means for reversibly rotating the wafer mounting table 21. May be configured. In such an apparatus, the wafer mounting surface 21
While the wafer mounting table 21 is moved in the downward or horizontal direction while maintaining the horizontal state in which a is directed upward, an air flow C is formed in the vacuum chamber 10 so as to move away from the wafer mounting surface 21a. The resist cured layer floating on the W surface may be removed by placing it on the air flow C.

(Third Embodiment) As another form for removing the resist hardened layer floating on the surface of the wafer W after the ashing process, for example, a rotating brush 33 as shown in FIG. May be used. Such an apparatus is provided with the rotating brush 33 in the vacuum chamber 10 of the resist removing apparatus described in the first embodiment, and is held by the wafer mounting table 21 in the state where the wafer mounting table 21 is inverted. Rotating brush 3 for the surface of wafer W
3 are opposed to each other with a space. The gas exhaust pipe 14 of the vacuum chamber 10 is provided at a position where it is not blocked by the arrangement of the rotating brush 33.

Further, the motor 32 for driving the rotating brush 33 is, for example, a stage 31 which is vertically expandable and contractible.
The height of the stage 31 is adjusted according to the rotating state of the wafer mounting table 21 so as not to hinder the rotation of the wafer mounting table 21. In such a resist removing apparatus, for example, a measuring means for measuring the distance between the surface of the wafer W held on the inverted wafer mounting table 21 and the tip of the rotating brush 33, and a means for moving the rotating brush 33 up and down. It is assumed to have drive means and control means for controlling the vertical movement of the rotary brush 33 by the drive means.

The rotary brush 33 has a surface of substantially the same shape as the wafer mounting surface at the tip of a rotary shaft provided on the motor 32, and organic resin fibers, for example, are substantially vertically planted on the surface. And form a brush. The rotating brush 33 is supposed to rotate in a substantially horizontal direction. The rotating brush 33 can process an area having the same shape as the wafer W, and the brush is used for floating matters on the surface of the wafer W.
It is preferably formed of a material that is easily adsorbed. By being formed of such a material, suspended matter on the surface of the wafer W can be adsorbed and removed from the surface of the wafer W.

A resist removing method using such a resist removing apparatus will be described. In the present embodiment, the first
The resist removal on the same wafer W as in the embodiment will be described as an example. The same method is used up to the resist removing method and the ashing process described in the first embodiment.

After the ashing process is performed on the wafer W held on the wafer mounting table 21, the introduction of the ashing gas and the RF current are stopped. Then, the wafer mounting table 21 holding the wafer W is inverted by the driving means. Next, in the state in which the wafer mounting table 21 is inverted, the wafer W held on the wafer mounting table 21 after the ashing process is performed.
The rotating brushes 33 are arranged to face the surface at predetermined intervals. At this time, for example, the distance between the tip of the brush in the rotating brush 33 and the surface of the wafer W is measured by the measuring means, and thereafter the stage 31 is raised by the driving means, and the tip of the brush moves below the surface of the wafer W by the control means. Stop at the position where it contacts the floating resist hardening layer.

Then, the rotating brush 33 is rotated to adsorb the resist hardened layer floating under the surface of the wafer W, thereby removing the resist hardened layer from the surface of the wafer W. The rotating brush 33 may be rotated by dropping the resist hardened layer by its own weight while weakening the reduced pressure in the vacuum chamber 10. As a result, the resist hardened layer dropped due to its own weight can be adsorbed to and removed by the rotating brush 33, so that the rotating brush 33 can be rotated away from the surface of the wafer W to some extent.

By using the resist removing apparatus and the resist removing method as described above, the wafer mounting table 21 on which the wafer W is held is reversed, and the front surface side of the wafer W is floated without being subjected to the ashing process. By rotating the rotating brush 33, the resist hardened layer can be adsorbed by the brush and removed from the surface of the wafer W, so that the resist hardened layer can be removed more reliably. .

In the present embodiment, the method of adsorbing and removing the resist hardened layer on the rotating brush 33 has been described, but the present invention is not limited to this, and the surface of the wafer W is rotated by rotating the rotating brush 33. After the resist hardened layer floating on the side is swept out to the outside of the surface of the wafer W, the reduced pressure in the vacuum chamber 10 may be weakened and the resist hardened layer may be dropped by its own weight.

Further, in the present embodiment, the wafer mounting table 21
The resist removing apparatus having the configuration in which the rotating brush 33 is provided in the apparatus including the driving unit for reversibly rotating the resist has been described. However, the present invention is not limited to this, and in an apparatus that does not include a driving unit that rotates the wafer mounting table 21 in a reversible manner, the wafer W held by the wafer mounting table 21 is arranged to face the wafer W with a gap. Rotating brush 33
May be configured. In such a device,
While the wafer mounting surface 21a is maintained in the horizontal state with the wafer mounting surface 21a facing upward, the wafer mounting table 21 is moved downward or in the horizontal direction and floats on the surface of the wafer W held by the wafer mounting table 21. The rotating brushes 33 are arranged so as to face each other at intervals such that they are in contact with the resist hardening layer, and the rotating brushes 33 are rotated to adsorb the resist hardening layer to the rotating brushes 33 and float on the surface of the wafer W. May be removed.

(Fourth Embodiment) In this embodiment, a resist removal method to which the invention described in claim 7 is applied will be described by taking the same resist removal on a wafer W as that of the first embodiment as an example.

First, as shown in FIG. 5A, the wafer W to be processed has a first pattern formed on its surface.
The resist 51 (resist pattern) is provided. The first resist 51 is used as a mask at the time of ion implantation, and the cured resist layer 51a is formed. An ashing process is performed on the first resist. Here, as in the first embodiment, when oxygen gas is used as the ashing gas and the oxygen radicals or ozone are downflowed to perform the ashing treatment, the hardened layer 51a is difficult to be removed by ashing.
As shown in (b), it is redeposited on the wafer W and becomes a resist residue 51b.

Next, as shown in FIG. 5C, a second resist 52 is applied on the wafer W so as to cover the resist residue 51b. Here, this second resist 52
Does not have to be the same as the first resist 51 and is not particularly limited, but it is preferable that it has good adhesion to the resist residue 51b. Specifically, since an organic resin such as a novolac resin, a PVP resin, and an acrylate resin is used for the first resist 51, these organic resins may be used as the second resist 52. . Then, the ashing process is performed again on the wafer W coated with the second resist 52.

According to such a resist removing method, the second resist 52 is applied onto the wafer W on which the resist residue 51b remains, and the resist residue 51b and the second resist 52 are brought into close contact with each other to perform the ashing process. By performing the above, when the second resist 52 reacts with the radical R to be vaporized, the resist residue 51b adhered to the second resist 52 is also peeled off. As a result, it is possible to remove the resist residue 51b together with the second resist 52 from the wafer W. Further, since it is possible to remove the resist residue 51b composed of the resist hardened layer 51a by performing the ashing process with the radical R generated by using only oxygen as the ashing gas, the underlying layer of the resist is damaged. Instead, the resist residue 51b can be removed from the wafer W.

The resist removing method as described above can be performed using a resist removing apparatus which is generally used. Further, the resist removing device described in the first to third embodiments may be used, and by using the resist removing device of the present invention, it is possible to more reliably remove the resist having the hardened resist layer formed thereon. Is.

As described in the first to fourth embodiments, the present invention is particularly effective in removing the resist having the hardened resist layer, but the present invention is not limited to this. It can also be used for removing the resist used as a mask other than the time of ion implantation and on which the resist hardened layer is not formed.

[0063]

As described above, according to the first aspect of the present invention.
According to the above described resist removing apparatus, the wafer mounting table can be reversibly rotated after the ashing process in the state where the wafer is held on the wafer mounting table. As a result, the positional relationship between the ashing residue and the wafer surface is maintained even when the wafer mounting table is inverted with the ashing residue floating on the wafer surface without being subjected to the ashing process. Ashing residues float below the wafer surface. Therefore, by weakening the reduced pressure in the vacuum chamber in such a state, the ashing residue can be dropped without adhering to the wafer surface.

According to the resist removing apparatus of the second aspect of the present invention, the wafer mounting surface is provided with the air flow forming means for forming the air flow away from the wafer mounting surface. When the ashing residue is floating on the surface of the wafer after the ashing process while the wafer is held, the ashing residue can be moved away from the surface of the wafer by being placed on the formed air flow. Therefore, the ashing residue can be removed from above the wafer surface without adhering to the wafer surface.

According to the resist removing apparatus of the fourth aspect of the present invention, when the ashing residue is floating on the wafer surface after the ashing process while the wafer is held on the wafer mounting table, the ashing residue comes into contact with the ashing residue. As described above, when the rotating brush is arranged so as to face the wafer surface and rotated, the ashing residue is adsorbed to the rotating brush. Therefore,
The ashing residue can be removed from above the wafer surface without adhering to the wafer surface.

Further, according to the resist removing method of the sixth aspect of the present invention, the wafer after the ashing treatment is in a state where the ashing residue is suspended on the wafer surface, and the angle is from 90 degrees to 180 degrees with respect to the horizontal state. When tilted in the range of degrees,
The positional relationship between the ashing residue and the wafer surface is maintained. In such a case, the ashing residue floats on the surface side of the wafer directed downward (or laterally) by the inclination, that is, below the wafer surface (or laterally). After that, the reduced pressure is weakened and the ashing residue is dropped, so that the ashing residue can be removed without adhering to the wafer surface. Further, even under the ashing process condition in which oxygen radicals and ozone are downflowed to the resist on the wafer, the resist hardened layer can be removed, so that the resist underlayer is prevented from being damaged by the ashing process. You can

According to the resist removing method of the seventh aspect of the present invention, after the resist pattern is ashed, the resist is recoated on the wafer even if the resist residue consisting of the resist cured layer remains on the wafer. Then, by performing the ashing process again, it is possible to remove the resist residue together with the recoated resist. With such a removing method, the resist residue can be removed even under the ashing processing condition in which oxygen radicals and ozone are down-flowed to the resist on the wafer. You can prevent damage.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a resist removing apparatus according to a first embodiment.

FIG. 2 is a main part configuration diagram showing an example of a resist removing apparatus according to a first embodiment.

FIG. 3 is a main part configuration diagram showing an example of a resist removing apparatus of a second embodiment.

FIG. 4 is a main part configuration diagram showing an example of a resist removing apparatus of a third embodiment.

FIG. 5 is a sectional process diagram illustrating a resist removing method according to a fourth embodiment.

[Explanation of symbols]

10 ... Vacuum chamber, 11 ... Plasma generating means, 21 ...
Wafer mounting table, 21a ... Wafer mounting surface, 41 ... Plate-shaped member, 33 ... Rotating brush, 51 ... First resist (resist pattern), 52 ... Second resist, W ... Wafer, P
…plasma

Claims (7)

[Claims] 1. A vacuum chamber, a wafer mounting table that is provided in the vacuum chamber and is rotatable in a reversible manner, and a plasma provided on a wafer mounting surface of the wafer mounting table, the wafer mounting table being provided above the wafer mounting table. And a plasma generation unit for downflowing the resist. 2. A vacuum chamber, a wafer mounting table provided in the vacuum chamber, and plasma generating means provided above the wafer mounting table for down-flowing plasma onto a wafer mounting surface of the wafer mounting table. A resist removing apparatus comprising: an air flow forming unit that forms an air flow away from the wafer mounting surface on the wafer mounting surface side. 3. The resist removing apparatus according to claim 2, wherein the wafer mounting table is rotatable so as to be reversible, and the air flow forming means is the wafer mounting surface of the wafer mounting table in a reversed state. On the side, the resist removing apparatus is configured so as to form an air flow away from the wafer mounting surface. 4. A vacuum chamber, a wafer mounting table provided in the vacuum chamber, and plasma generating means provided above the wafer mounting table for down-flowing plasma onto a wafer mounting surface of the wafer mounting table. And a rotating brush disposed to face the surface of the wafer held on the wafer mounting table with a gap therebetween. 5. The resist removing apparatus according to claim 4, wherein the wafer mounting table is rotatable so as to be reversible, and the rotating brush is the surface of the wafer held by the wafer mounting table in an inverted state. A resist removing device, wherein the resist removing device is arranged so as to face each other with a space therebetween. 6. A state in which a resist on a wafer held in a horizontal state is subjected to an ashing treatment under a reduced pressure atmosphere, and then the wafer surface is inclined in a range of 90 to 180 degrees with respect to the horizontal state. By weakening the decompression,
A method of removing a resist, characterized in that ashing residue floating on the front surface side of the wafer is dropped without being ashed. 7. A resist removing method, comprising: performing ashing treatment on a resist pattern on a wafer, then re-coating the resist on the wafer and performing the ashing treatment again.