JP7017786B2 - Wet processing equipment - Google Patents

Description

The present invention relates to a wet treatment apparatus for performing a predetermined wet treatment on a circular wafer used for a semiconductor element.

Conventionally, as a device for performing wet processing such as cleaning, etching, and resist peeling on a semiconductor wafer having a circular thin plate shape, a device in which a plurality of wafers are housed in a cassette and batch processing is performed is known. There is. For example, in Patent Document 1, a cassette that supports a plurality of wafers in a vertically placed state at intervals is immersed in a processing tank containing a resist stripping solution, and the wafers in the cassette are placed around the center thereof. A device designed to rotate is shown.

Japanese Unexamined Patent Publication No. 2009-141035

By the way, when a circular wafer is rotated around its center as in the apparatus shown in Patent Document 1, the distance traveled by the rotation differs between the portion near the center and the portion near the outer edge of the wafer (near the outer edge). The moving distance of the part near the center is small with respect to the part). That is, even if the wafer is the same, there is a difference in wet treatment in the radial direction.

An object of the present invention is to solve such a problem, and an object of the present invention is to provide a wet treatment apparatus capable of uniformly performing a predetermined wet treatment on a wafer.

The present invention comprises a cassette that supports a plurality of circular wafers at intervals in the thickness direction in a vertically placed state, and a treatment tank that houses a treatment liquid that performs a predetermined wet treatment on the wafers. A wet processing apparatus including a moving means for moving the cassette immersed in the processing tank in a vertical direction, a horizontal direction, or a combination thereof along the surface of the wafer placed vertically. ..
The "wet treatment" in the present specification and the like includes cleaning, etching, resist peeling and the like.

Further, it is preferable that the inner dimensions of the treatment tank in the vertical direction and the horizontal direction of the area containing the treatment liquid are twice or more the diameter of the wafer.

The moving means preferably moves the cassette immersed in the processing tank in an elliptical shape along a linear, elliptical, or a combination of these trajectories.
In addition, in the present specification and the like, "elliptical shape" means a shape included in an ellipse in a broad sense except for a shape whose shape is specifically specified in drawings and detailed explanations, and is of an elliptical shape or a circular shape. In addition, an ellipse shape or an oval shape surrounded by two straight lines and two arcs, and similar shapes are also included.

According to the wet processing apparatus of the present invention, a cassette immersed in a processing tank can be moved in a vertical direction, a horizontal direction, or a combination thereof along the surface of a wafer placed vertically in the cassette. Therefore, the front surface (back surface) of the wafer can be uniformly wet-treated with the treatment liquid contained in the treatment tank.

In addition, by configuring the processing tank so that the internal dimensions of the area containing the processing liquid in the vertical and horizontal directions are at least twice the diameter of the wafer, the wafer is placed in the position before movement in the processing tank. It can be moved to a position where it does not become. That is, since the wafer can be moved evenly in the processing tank, the wet processing can be performed more uniformly.

Then, when the cassette immersed in the processing tank is moved along an orbit of a linear shape, an elliptical shape, or a combination of these while moving in an elliptical shape, the wafer is moved more evenly with respect to the treatment liquid. Since it can be moved, the processing on the front surface (back surface) of the wafer can be performed more uniformly.

It is a side view which showed 1 Embodiment of the wet processing apparatus which follows this invention. (A) is a cross-sectional view taken along the line AA in FIG. 1, and (b) is an arrow view from arrow B in FIG. It is a figure exemplifying the case where a cassette is moved mainly in an orbit along a straight line in a processing tank. It is a figure exemplifying the case where a cassette is moved in an orbit along a circle or an ellipse in a processing tank. It is an example of the case where the cassette is moved in the orbit along the circle in the processing tank and is moved in the orbit along the circle having a diameter larger than this circle. It is an example of the case where the cassette is moved in the orbit along the circle in the processing tank and is moved in the orbit along the circle whose diameter is smaller than this circle. It is a figure which illustrated the case where the cassette is moved in the orbit along the circle while moving in the orbit along the ellipse in the processing tank. It is a figure exemplifying the case where the cassette is moved in the orbit along the circle in the processing tank, and is moved along the orbit of a straight line, a circle, or a shape which combines these.

Hereinafter, an embodiment of a wet processing apparatus according to the present invention will be described with reference to the drawings. For convenience of explanation, the directions are shown by the XYZ Cartesian coordinate system in the drawings. ), The Z direction indicates the vertical direction (upper and lower direction, + side is upper side,-side is lower side).

FIG. 1 is a side view schematically showing the wet processing apparatus of the present embodiment, and FIG. 2 is a cross-sectional view and an arrow view thereof. In the wet processing apparatus of the present embodiment, the lateral moving means 2 is provided on the base 1 provided on the rear side. The lateral moving means 2 is a slide unit composed of, for example, a ball screw, a servomotor, a linear guide, and the like, and is fixed to the base 1 by driving the servomotor based on a predetermined command. It is possible to move the lateral moving portion 2b to a predetermined position in the X direction.

The main body 2a is provided with the vertical moving means 3. The vertical moving means 3 has the same configuration as the horizontal moving means 2, and moves to a predetermined position in the Z direction with respect to the main body 3a fixed to the horizontal moving portion 2b and the main body 3a. It is composed of a possible vertical moving portion 3b.

As shown in FIG. 2B, such a lateral moving means 2 and a vertical moving means 3 are configured by being combined in a "ten" shape. In the present specification and the like, a combination of the lateral moving means 2 and the vertical moving means 3 may be referred to as a "moving means".

As shown in FIG. 1, in front of the vertical moving means 3, a partition side wall 4 for partitioning the wet treatment apparatus back and forth and a partition top wall 5 for connecting to the partition side wall 4 are provided. The partition side wall 4 and the partition top wall 5 are for preventing the treatment liquid described later from being applied to the horizontal moving means 2, the vertical moving means 3, and other electrical equipment (not shown). Further, the partition top wall 5 is provided with an opening 6 extending laterally long.

Further, a chamber 7 is provided in front of the partition top wall 5. A recovery tank 8 is provided inside the chamber 7, and a processing tank 9 is provided inside the recovery tank 8. Further, an introduction pipe 10 is provided at the lower part of the processing tank 9.

The introduction pipe 10 introduces a treatment liquid for performing a predetermined wet treatment on a wafer, which will be described later, into the treatment tank 9. As described above, the predetermined wet treatment is, for example, cleaning, etching, resist peeling, etc., and a treatment liquid (for example, an alkaline or acidic chemical liquid, an etching liquid, etc.) corresponding to the target treatment is introduced from the introduction pipe 10 to the treatment tank. Introduced in 9. Although not shown, a buffer tank for storing the treatment liquid is connected to the introduction pipe 10, and the buffer tank is provided with a cooling device or a heating device for cooling or heating the treatment liquid in the tank. It is connected. Therefore, for example, in the case of etching, there is a concern that reaction heat is generated during the treatment and the temperature of the treatment liquid gradually rises. However, according to the wet treatment apparatus of the present embodiment, the above-mentioned incidental equipment may be used. Since the temperature of the treatment liquid in the treatment tank 9 can be kept constant, fluctuations in the wet treatment due to the temperature difference can be suppressed.

In the wet treatment apparatus of the present embodiment, the treatment liquid introduced by the introduction pipe 10 can overflow from the upper part of the treatment tank 9. That is, since the treatment liquid in the treatment tank 9 is replaced, the influence on the wet treatment due to the deterioration of the treatment liquid can be suppressed. The overflowed treatment liquid can be returned to the buffer tank by a recovery means (not shown) provided in the recovery tank 8.

Then, as shown in FIG. 2, a cassette 12 for supporting a plurality of thin sheet circular wafers 11 is immersed in the processing liquid introduced into the processing tank 9. Although detailed description will be omitted, a plurality of wafers 11 are set vertically in the cassette 12 at intervals in the thickness direction. Further, the cassette 12 of the present embodiment is introduced into the processing tank 9 so that the front surface (back surface) of the wafer 11 is parallel to the XZ plane.

Here, the cassette 12 is detachably gripped by the grip portion 13 that opens and closes in the X direction shown in FIG. Further, the grip portion 13 is connected to an arm 14 connected to the vertical moving portion 3b. As shown in FIG. 1, after being connected to the vertical moving portion 3b, the arm 14 extends upward for a long time, passes through the opening 6, extends further to the front side, and then extends downward to grip. It is connected to the unit 13. The cassette 12 gripped by the grip portion 13 is driven by the lateral moving means 2 and the vertical moving means 3, so that the cassette 12 is immersed in the processing liquid introduced into the processing tank 9 in the vertical and horizontal directions. It can be moved in a direction or a combination of these directions. That is, according to the wet treatment apparatus of the present embodiment, the wafer 11 immersed in the treatment liquid of the treatment tank 9 is moved linearly or curvedly in an arbitrary direction along the front surface (back surface) thereof. Can be done.

As described above, in the wet processing apparatus of the present embodiment, the wafer is not rotated around the center thereof as in the conventional apparatus, but the entire wafer can be moved in the same manner with respect to the processing liquid, so that the surface thereof can be moved in the same manner. (Back surface) can be uniformly wet-treated.

Further, in the processing tank 9 of the present embodiment, as shown in FIG. 2A, the vertical inner dimension L1 and the horizontal inner dimension L2 of the area accommodating the treatment liquid are twice the diameter D of the wafer 11. That is all. As a result, the wafer 11 can be moved to a position in the processing tank 9 that does not overlap with the position before the movement. As described above, the treatment liquid in the treatment tank 9 is introduced from the lower central portion by the introduction pipe 10 and overflows from the upper edge portion. Therefore, in the treatment tank 9, the treatment liquid is vertically and horizontally. There is a possibility that the properties of the treatment liquid may differ in the direction (front-back direction). Therefore, if the processing tank 9 is narrow and the wafer 11 cannot be moved significantly, there is a possibility that the wet processing may differ in the vertical direction and the horizontal direction of the wafer 11. However, in the present embodiment, the wafer 11 is used in the processing tank 9. Since it can be moved without bias, the wet treatment can be performed more uniformly. Further, by moving the wafer 11 significantly, the treatment liquid in the treatment tank 9 can be sufficiently agitated, so that the difference in the wet treatment can be eliminated in this respect as well.

Further, according to the wet processing apparatus of the present embodiment, the cassette 12 can be moved in various directions and orbits in the processing tank 9. For example, as shown in FIG. 3 (a), the cassette 12 can be moved in a trajectory along a straight line in the vertical and horizontal directions, and as shown in FIG. 3 (b), the moving distance can be changed. be. Further, as shown in FIG. 3C, it is also possible to move the vehicle along a straight line in a direction oblique to the vertical and horizontal directions. Further, as shown in FIG. 3D, two substantially rectangular shapes having arcuate corners may be arranged one above the other and moved along an orbit along the "8" shape. Note that FIGS. 3 to 8 schematically show the cassette 12 and its orbit, and do not specify the relationship between the size of the cassette 12 and the size (length) of the orbit.

Further, the cassette 12 may be moved in an orbit along a circle as shown in FIG. 4A, or may be moved in an orbit along an ellipse as shown in FIG. 4B. Further, as shown in FIG. 4 (c), two circles may be arranged one above the other and moved in an orbit along an "8" shape.

Further, as shown in FIGS. 5 to 8, the cassette 12 may be moved along a trajectory along a circle or an ellipse, and may be moved along a linear, elliptical, or a combination of these. .. FIG. 5A shows a case where the cassette 12 is moved along the orbit T2 along the circle whose diameter is larger than the orbit T1 shown by the alternate long and short dash line while moving the cassette 12 along the orbit T1 along the circle shown by the solid line. Shows. As a result, the wafer 11 can be moved in the trajectory as shown in FIG. 5 (b).

Further, FIG. 6A shows a case where the cassette 12 is moved along the orbit T4 along the circle whose diameter is smaller than that of the orbit T3, which is shown by the alternate long and short dash line, while moving the cassette 12 along the orbit T3 along the circle shown by the solid line. Is shown. As a result, the wafer 11 can be moved in the trajectory as shown in FIG. 6 (b).

FIG. 7A shows a case where the cassette 12 is moved along the orbit T6 along the circle shown by the alternate long and short dash line while being moved along the orbit T5 along the ellipse shown by the solid line. As a result, the wafer 11 can be moved in the trajectory as shown in FIG. 7 (b).

Further, for example, as shown in FIG. 8A, the cassette 12 may be moved along the "ju" -shaped orbit T8 shown by the alternate long and short dash line while being moved along the orbit T7 along the circle shown by the solid line. good. In addition, as shown in FIG. 8B, while moving the cassette 12 along the orbit T9 along the circle shown by the solid line, two circles shown by the alternate long and short dash line are arranged one above the other to form an "8" shape. It may be moved along the orbit T10 along the formed shape, or as shown in FIG. 8 (c), while moving along the orbit T11 along the circle shown by the solid line, the corner portion shown by the alternate long and short dash line is a circle. Two arc-shaped substantially rectangular objects may be arranged one above the other and moved along the orbit T11 along the "8" -shaped shape.

Although the present invention has been described above while showing specific embodiments, the wet treatment apparatus according to the present invention is not limited to the above-described embodiments, and various modifications are made within the scope of the claims. included. For example, in FIG. 1, the vertical moving means 3 is provided for the horizontal moving means 2 provided on the base 1, but the vertical moving means 3 is provided on the base 1 and the vertical moving means 3 is provided with the vertical moving means 3. The means 2 may be configured to be provided.

1: Base 2: Lateral moving means (moving means)
3: Vertical moving means (moving means)
4: Section side wall 5: Section top wall 6: Opening 7: Chamber 8: Recovery tank 9: Processing tank 10: Introduction pipe 11: Wafer 12: Cassette 13: Grip portion 14: Arm

Claims (1)

A cassette that supports multiple circular wafers at intervals in the thickness direction in a vertically placed state,
A treatment tank containing a treatment liquid for performing a predetermined wet treatment on the wafer, and a treatment tank.
A moving means for moving the cassette immersed in the processing tank in the vertical direction, the horizontal direction, or a combination thereof along the surface of the vertically placed wafer is provided .
The moving means is composed of a vertical moving means for moving the cassette in the vertical direction and a horizontal moving means for moving the cassette in the horizontal direction, and the cassette immersed in the processing tank is moved in the vertical direction. By driving the means and the lateral moving means, the means is moved in an elliptical shape, and is moved along a linear, elliptical, or a combination of these trajectories.
The treatment tank is a wet treatment apparatus in which the internal dimensions of the area containing the treatment liquid in both the vertical direction and the horizontal direction are at least twice the diameter of the wafer .

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