JPH09260277A - Spin coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spin coater wherein it does not happen that dissolving agent rebounds and easily attaches to parts except the outer periphery of a wafer when resist on the outer perypery of the wafer is eliminated. SOLUTION: A spin coater is provided with an edge rinse nozzle 30 which sends out resist dissolving agent to the outer periphery of a wafer and washes off resist. A plane 42 having a nozzle hole and a protruding part 40 are formed in the tip part of the nozzle. The side surface of the protruding part 40 of the nozzle hole side is recessed to the rotary shaft of a wafer chuck 12, and a recessed surface wall stretches vertically downward. A wafer 14 is mounted on the wafer chuck 12 and rotated. The nozzle 30 is so arranged that the plane 42 is positioned slightly above the outer periphery of the wafer and the recessed surface wall is positioned slightly outside the outer periphery of the wafer. From the nozzle hole, the dissolving agent is made to flow out, and a liquid reservoir is formed between the recessed surface wall, the plane and the outer periphery of the wafer. The resist on the outer periphery of the wafer is dissolved into the dissolving agent in the reservoir, and scattered by centrifugal force, so that the dissolving agent does not attach to parts except the outer periphery of the wafer and is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spin coater, and more particularly to a spin coater in which a dissolving agent is applied to the outer circumference of a semiconductor wafer to dissolve and remove the resist on the outer circumference of the wafer.

[0002]

2. Description of the Related Art When patterning an exposure technique in the manufacture of a semiconductor wafer, generally, the resist is applied to the wafer and exposed to light for patterning.
At this time, if the resist is still coated on the outer periphery of the wafer, when the wafer is transferred and positioned from the resist coating process to the exposure process, the outer periphery of the wafer hits a positioning device or the like, and the resist is chipped to form particles. The particles thus generated adhere to other wafers, resulting in deterioration of quality. For this reason, usually, a nozzle for spraying a dissolving agent on the wafer is arranged at a predetermined position, and when the resist is coated on the wafer by the spin coater or after the coating, the nozzle is attached to the outer periphery of the rotating wafer from the nozzle under a certain condition. A dissolving agent that dissolves the resist is sprayed onto the outer periphery of the wafer to dissolve and remove the resist on the outer periphery of the wafer. FIG. 4 is a side view showing an example of conventional resist removal on the outer periphery of a wafer. The wafer chuck 12, the 5-inch wafer 14 mounted on the wafer chuck 12, and the wafer chuck 12 are arranged on the wafer 14. Spraying nozzle 2 with a dissolving agent transport pipe 18 connected to the upper end
0 and a spin cup 22 surrounding the wafer 14
It is composed of

The bottom surface of the spin cup 22 is a disk, the side surface is cylindrical, the outside of the upper portion of the side surface is formed in a taper shape which is slightly inward, and the uppermost portion is a donut parallel to the bottom surface toward the inside. A disc-shaped edge 24 is formed. Also,
The spray nozzle 20 has the wafer 1 in the direction of the flow path in the nozzle.
The nozzle 4 is disposed so as to face obliquely outward from the inside and the nozzle tip end faces the outer periphery of the wafer.

When removing the resist on the outer periphery of the wafer 14, first, the wafer 14 is rotated about the W by the wafer chuck 12 as shown in FIG. 4, and then the dissolving agent sent from the dissolving agent transport pipe. Is blown from the tip of the spray nozzle 20 and is sprayed onto the outer periphery of the wafer 14.

As a result, the resist on the outer periphery of the wafer dissolves in the dissolving agent, scatters in the spin cup, and is removed.

[0006]

However, in the conventional spin coater for removing the resist on the outer periphery of the wafer, parameters such as the height and angle of the nozzle, the pressure of the dissolving agent in the nozzle, the flow rate of the dissolving agent, the spraying time and time, etc. Is difficult to control, and if any of the parameters deviates from the set values, the resolving agent bounces at the wafer orientation flat, etc., and the resolving agent adheres to parts other than the outer periphery of the wafer, resulting in problems in subsequent processes. There was a problem to come.

In view of the above circumstances, it is an object of the present invention to provide a spin coater in which the dissolving agent does not bounce when the resist on the outer periphery of the wafer is removed and adheres to a portion other than the outer periphery of the wafer.

[0008]

As a result of earnest studies, the present inventor devised a shape of a nozzle tip spraying a dissolving agent so that a distance between the nozzle tip and an outer periphery of a wafer is close and the nozzle is melted between them. By forming a puddle of the agent, it was found that the bounce of the agent does not easily occur without strictly controlling various parameters when the agent is sprayed,
The present invention has been completed.

In order to solve the above problems, a spin coater according to the present invention is provided around a wafer chuck, which holds a wafer on a horizontal holding surface and rotates the wafer around a vertical rotation axis. A spin coater provided with a spin cup and an edge rinse nozzle for sending and rinsing a dissolving agent for dissolving a resist to the outer peripheral portion of a wafer, wherein the edge rinse nozzle is a downward horizontal nozzle tip surface with a nozzle opening. And a nozzle tip having a protrusion extending further downward from a part of the nozzle tip surface,
At least a part of the side surface of the protrusion on the nozzle port side is formed by a concave wall that is concave with respect to the rotation axis of the wafer chuck and extends vertically downward, and the nozzle tip surface is a wafer held on the wafer chuck. Located slightly above the upper surface of
The concave wall of the protrusion is located slightly outside the outer circumference of the wafer held on the wafer chuck.

As long as the liquid pool described below is formed, the nozzle tip surface does not need to be completely horizontal, and the concave wall does not have to be completely vertical downward. The concave shape of the concave wall may be any shape such as an arc shape or a rectangular shape as long as a liquid pool is formed, but it is desirable that it is the same shape as the arc shape of the outer periphery of the wafer or is concave rather than the arc shape.

When removing the resist on the outer periphery of the wafer,
The edge rinse nozzle is arranged so that the nozzle tip surface is located slightly above the outer circumference of the rotating wafer and the concave wall of the protrusion is located slightly outside the outer circumference of the wafer.
The distance between the flat and concave walls and the outer circumference of the wafer is 1 ±
It is preferably 0.5 mm.

Next, when a dissolving agent for dissolving the resist is discharged from the nozzle hole between the flat surface and the wafer, centrifugal force and rotational force act on the dissolving agent in contact with the outer periphery of the wafer, but the dissolving agent is supported by the concave wall of the protrusion. Receive a drag. Therefore, the dissolving agent does not flow inside the wafer, but flows out in the wafer rotating direction along the concave wall, and is then blown outside the wafer. Since the dissolving agent is continuously discharged from the nozzle hole, as a result, a liquid pool is formed in the space formed by the outer periphery, flat surface and concave wall of the wafer. While the dissolving agent forms a liquid pool and is in contact with the outer periphery of the wafer, the resist is dissolved in the dissolving agent, and as a result, the resist on the outer periphery of the wafer is removed.

When the liquid pool is not formed due to the space due to the orientation flat of the rotating wafer, the dissolving agent flows under the wafer, and the distance between the nozzle hole and the outer periphery of the wafer is far longer than the conventional one. short. For this reason,
Even if the conditions at the time of applying the dissolving agent are slightly changed, the dissolving agent does not bounce at the edge of the orientation flat of the wafer and adhere to the portion other than the outer periphery of the wafer. Further, since the liquid pool is formed to remove the resist on the outer periphery of the wafer, the amount of the dissolving agent used can be made much smaller than in the conventional case.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples, with reference to the drawings, the present invention will be described in more detail with reference to Examples. FIG. 1 is a side view showing that the resist on the outer periphery of the wafer is removed using the spin coater of this embodiment. In FIG. 1, the configuration is the same as that of FIG. 4 except that an edge rinse nozzle 30 and a link device 31 are used instead of the spray nozzle 20. Therefore, in FIG.
The same parts and components as those in FIG. 4 are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 2 shows the edge rinse nozzle 30 and the link device 3 as seen from below the edge rinse nozzle 30 of FIG.
It is a perspective view which shows only 1. Edge rinse nozzle 30
Is composed of a nozzle body 32 and a positioning portion 34 provided at the base end of the nozzle body 32.

The nozzle body 32 comprises a mounting portion 36, a cylindrical nozzle columnar portion 38 provided at the tip of the mounting portion 36, and a nozzle tip 39 at the tip of the nozzle columnar portion 38. The shape of the nozzle tip 39 is a horizontal plane 4 facing downward.
2 and the protrusion 40. Nozzle column 38
A cylindrical flow path 44 is formed on the central axis of the, the tip is tapered and thin, the tip is formed in a thin cylindrical shape, and the tip is formed as a nozzle hole 46 in the plane 42. There is. The diameter of the nozzle hole 46 is indicated by l.

The side surface of the protrusion 40 on the nozzle hole 46 side has an arc shape inside the nozzle hole 46, and the diameter of the arc is 5 inches, which is the same as the diameter of the wafer 14, and the nozzle hole 46 and the arc are formed. Distances are indicated by m. Protrusion 4
The side surface on the opposite side of 0 is the same cylindrical side surface that is seamless with the nozzle body 32.

The positioning portion 34 has a cylindrical mounting portion 48.
And a disk-shaped mover 50 attached to the upper end of the mounting portion 48.
The lower end of the mounting portion 48 is attachable to and detachable from the mounting portion 46. A passage 54 is formed through the central axes of the attachment portion 48 and the mover 50. In FIG. 1, the attachment portion 36 is attached to the attachment portion 48, and the passage 54 and the passage 44 are connected without a gap. There is. The dissolving agent transport pipe 18 is connected to the upper end of the flow path 54.

The link device 31 includes a first arm 56 that has a rotating shaft 55 at its rear end and is freely rotatable, and a first arm 5.
Second arm 5 having a rear end rotatably connected to the front end of 6
8 and a drive device 59 for operating the first arm 56 and the second arm 58, and the rotating shaft 55 is the drive device 5
It is fixed to the upper part of 9. The tip of the second arm 58 is attached to the side wall of the mover 50 on the edge 24 side of the spin cup 22.

When removing the resist on the outer periphery of the wafer 14, first, as shown in FIG. 1, the wafer 14 is rotated around W at a predetermined number of rotations per unit time, and then the driving device 59 is used to rotate the wafer. The 1st arm 56 and the 2nd arm 58 are extended horizontally, and the nozzle body 32 is arranged at a predetermined position so that the distance between the flat surface 42 and the concave wall of the protrusion 40 and the outer periphery of the wafer 14 is 1 mm.

Next, a dissolving agent for dissolving the resist is flown into the edge rinse nozzle 30 from the dissolving agent transport pipe 18 at a predetermined flow rate. All the inflowing dissolution agent is in the flow path 44,
It flows through the nozzle 54 and is discharged from the nozzle hole 46.

Since the wafer 14 is rotating as described above, centrifugal force concave and rotational force act on the dissolving agent discharged and brought into contact with the outer periphery of the wafer 14, but the dissolving agent does not protrude.
It is supported by the concave wall of and receives drag. Therefore, the dissolving agent does not flow inside the wafer 14, but flows out in the wafer rotation direction along the concave wall and is blown to the outside of the wafer 14. Since the dissolving agent is continuously discharged from the nozzle hole, as a result, a liquid pool (not shown) is formed in the space 60 formed by the outer periphery of the wafer 14, the flat surface 42 and the concave wall of the protrusion 40. . The length of the width of the liquid pool in the central axis direction of the wafer can be controlled by adjusting the discharge amount of the dissolving agent. While the dissolving agent forms a liquid pool and is in contact with the outer periphery of the wafer 14, the resist dissolves into the dissolving agent, and as a result, the resist on the outer periphery of the wafer 14 is removed.

FIG. 3 shows the edge rinse nozzle 30 of FIG.
FIG. 6 is a plan view showing a state in which is moved to a position at the end of resist removal. The drive device 59 causes the first arm 56 to rotate upward by 90 degrees while keeping the second arm 58 horizontal, and as a result,
The edge rinse nozzle 30 moves from the inside of the edge 24 of the spin cup 22 to the outside and above.

In the present embodiment, when the liquid pool is not formed due to the space due to the orientation flat of the rotating wafer 14, the dissolving agent flows downward, and the distance between the nozzle hole 46 and the outer periphery of the wafer 14 is Much shorter than before. Therefore, even if the conditions at the time of applying the dissolving agent are slightly changed, the dissolving agent does not bounce at the end portion of the orientation flat and adhere to the portion other than the outer periphery of the wafer 14. Further, since the liquid pool is formed and the resist on the outer periphery of the wafer 14 is removed, the amount of liquid used can be reduced to 1/5 of the conventional amount. Further, the edge rinse nozzle 30 is
The spin cup 2 is moved up and down by the link device 31.
It can be placed or put back in place without hitting the two edges 24.

[0025]

According to the present invention, the edge rinse nozzle for applying the dissolving agent for dissolving the resist to the outer periphery of the wafer,
A downward horizontal nozzle tip surface with the nozzle opening opened,
A protrusion extending further downward from a part of the nozzle tip surface is formed, and a side surface of the protrusion on the nozzle opening side is formed as a concave wall that is concave with respect to the rotation axis of the wafer chuck and extends vertically downward. Use edge rinse nozzles. According to the spin coater equipped with this edge rinse nozzle, the nozzle tip surface is arranged slightly above the outer peripheral upper surface of the wafer held and rotated on the wafer chuck, and the concave wall is arranged slightly outside the outer peripheral surface of the wafer. By discharging the dissolving agent from the nozzle port, a liquid pool is formed between the tip surface of the nozzle, the concave wall and the outer periphery of the wafer to apply the dissolving agent to the outer periphery of the wafer. Therefore, the resist on the outer periphery of the wafer is dissolved in the dissolving agent in the liquid pool, and the dissolving agent is scattered to the outside of the wafer by the centrifugal force and the rotating force. As a result, the resist on the outer periphery of the wafer is dissolved and removed without the dissolving agent adhering to a portion other than the outer periphery of the wafer even if the conditions at the time of applying the dissolving agent change to some extent.

[Brief description of drawings]

FIG. 1 is a side view showing that the resist on the outer periphery of a wafer is removed using a spin coater of this embodiment.

FIG. 2 is a perspective view of an edge rinse nozzle and a link device.

FIG. 3 is a side view showing a state where an edge rinse nozzle is moved to the outside of a spin cup.

FIG. 4 is a side view showing conventional resist removal on the outer periphery of a wafer.

[Explanation of symbols]

12 ... Wafer chuck, 14 ... Wafer, 18 ... Dissolving agent transport pipe 18, 20 ... Spray nozzle, 22 ...
... spin cup, 24 ... edge, 30 ... edge rinse nozzle, 31 ... link device, 32 ... nozzle body, 34
…… Positioning part, 36 …… Mounting part, 38 …… Nozzle cylinder part, 39 …… Nozzle tip part, 40 …… Projection part, 42 ……
Plane, 44 ... Flow path, 46 ... Nozzle hole, 48 ... Mounting part, 50 ... Mover, 54 ... Flow path, 55 ... Rotation axis,
56 ... 1st arm, 58 ... 2nd arm, 59 ... Drive device, 60 ... Space.

Claims (2)

[Claims] 1. A wafer chuck for holding a wafer on a horizontal holding surface and rotating the wafer about a vertical rotation axis, a spin cup provided around the wafer chuck, and a dissolving agent for dissolving a resist on the outer periphery of the wafer. A spin coater equipped with an edge rinse nozzle for sending and rinsing to a portion, the edge rinse nozzle extending downward from a downward horizontal nozzle tip surface with an opening of the nozzle mouth and a part of the nozzle tip surface. A nozzle tip portion having a protrusion, and at least a part of the side surface of the protrusion on the nozzle opening side is formed by a concave wall that is concave with respect to the rotation axis of the wafer chuck and extends vertically downward. The surface is located slightly above the upper surface of the wafer held on the wafer chuck, and the concave wall of the protrusion is slightly outside the outer circumference of the wafer held on the wafer chuck. A spin coater characterized by being located on the side. 2. A link device connected to the edge rinse nozzle for freely moving the edge rinse nozzle up and down and rotating, wherein the edge rinse nozzle located outside the spin cup is spin-coated when applying the dissolving agent. The cup is placed at a predetermined position beyond the head of the cup.
The spin coater described in.