JP2007281326A - Developing method and developing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developing method and a developing apparatus which can prevent a developing solution from remaining on the back surface of a wafer. <P>SOLUTION: The developing method develops a photoresist by holding the back surface of a wafer W with a spinner chuck 1 and by dropping a developing solution L onto the front surface of the wafer W, where the wafer W has a photoresist with a predetermined exposed pattern on the front surface and is held by the spinner chuck 1 rotably. A baffle plate 9 surrounding the spinner chuck 1 from the outside is placed on the back surface of the wafer W, a gap is formed between the back surface of the wafer W and the baffle plate 9, and a film F of a rinsing liquid is formed between the back surface of the wafer W and the baffle plate 9 before the developing solution L travels round the periphery around to the back surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a developing method and a developing apparatus, and more particularly to a technique capable of preventing a developer from remaining on the back surface of a wafer.

In the wafer process step, a resist pattern is formed by a photolithography technique. The resist pattern is used as a mask for etching the base layer and a mask for ion implantation. The resist pattern includes, for example, a resist coating process in which a photoresist is applied onto an underlayer on the wafer surface, an exposure process in which a photomask pattern is transferred to the applied photoresist, and a developer is dropped onto the exposed photoresist. And a developing process for revealing the latent pattern.

FIG. 4 is a flowchart showing a photoresist development sequence according to a conventional example.
In step S′1 in FIG. 4, first, the vicinity of the center of the back surface of the wafer is sucked and fixed by the chuck stage, and in this state, the developer is dropped toward the front surface of the wafer. Next, step S
In step '2', the dropping of the developer is stopped and the wafer is rotated and stopped repeatedly to perform a process for promoting development (so-called paddle development). In step S′3, while rinsing the wafer, a rinsing liquid is supplied to the front surface to perform surface rinsing, and at the same time, a rinsing liquid is also supplied to the back surface to perform back rinsing. The developer is removed from the wafer by such surface rinsing and back rinsing. Thereafter, in step S′4, the wafer is rotated at a high speed to perform spin drying, and the photoresist development process is completed.
Japanese Utility Model Publication No. 58-175543

As shown in FIG. 5, in the conventional example, during the discharge of the developer L and the paddle development, the developer L wraps around from the front surface of the wafer W to the back surface side, and the developer L that wraps around is called a jammer plate (also called a knife edge ring). In some cases, it would not stop at 99 and would reach the spinner chuck 91. For such a phenomenon, a nozzle 93 for back rinse is disposed in the vicinity of the spinner chuck 91, and the rinse liquid is discharged from the nozzle 93 to perform back rinse so that the back surface of the wafer W is rotated. The developer L contained can be washed away.

However, in order to prevent the rinsing liquid discharged from the nozzle 93 from entering the spinner chuck 91 side during back rinsing, the nozzle 93 is provided with the spinner chuck 9.
It is arranged at a position away from 1 to some extent outward. For this reason, when the developer L reaches the inside from the position where the nozzle 93 is disposed, there is a problem that it cannot be washed out sufficiently. If the developing process is completed while the developer L remains on the back surface of the wafer W, the developer L remaining on the back surface may contaminate an apparatus used in the subsequent steps.
Accordingly, the present invention has been made in view of such circumstances, and an object of the present invention is to provide a developing method and a developing apparatus capable of preventing the remaining of the developer on the back surface of the wafer.

[Invention 1] In order to achieve the above object, the development method of Invention 1 supports the back surface of a wafer having a photoresist exposed with a predetermined pattern on its surface by a rotation support means, and can be rotated by the rotation support means. A method of developing the photoresist by dropping a developer onto the surface of the wafer supported on a wafer, wherein a ring member surrounding the rotation support means from the outside is disposed on the back side of the wafer, and the wafer A gap is provided between the back surface and the ring member, and before the developer dripped onto the wafer surface travels along the periphery of the wafer and travels to the back surface side, the back surface of the wafer and the ring A rinse liquid film is formed in the gap between the members. Here, as the “rinsing liquid”, for example, pure water is used.

According to the developing method of the first aspect of the present invention, the rinsing liquid film formed between the back surface of the wafer and the ring member can prevent the developer from entering inside the ring member. Therefore, even when there is a region where the back rinse cannot be sufficiently performed on the back surface of the wafer inside the ring member, it is possible to prevent the developer from reaching the region. Thereby, it is possible to prevent the developer from remaining on the back surface of the wafer, and it is possible to prevent contamination of the apparatus used in the subsequent steps by the developer.

[Invention 2] The developing device of Invention 2 supports the back surface of a wafer having a photoresist exposed to a predetermined pattern on the surface thereof by rotation support means, and the wafer surface supported rotatably by the rotation support means. An apparatus for developing the photoresist by dripping a developer onto the wafer, and is disposed on the back side of the wafer so as to surround the rotation support means from outside and to have a gap between the back side of the wafer and the wafer. A rinsing liquid in the gap between the back surface of the wafer and the ring member before the developer dripped onto the surface of the wafer travels along the periphery of the wafer to the back surface side. And a liquid film forming means for forming the film.

With such a configuration, the rinsing liquid film formed between the wafer back surface and the ring member can prevent the developer from entering the inside of the ring member. Therefore, even when there is a region where the back rinse cannot be sufficiently performed on the back surface of the wafer inside the ring member, it is possible to prevent the developer from reaching the region. Thereby, it is possible to prevent the developer from remaining on the back surface of the wafer, and it is possible to prevent contamination of the apparatus used in the subsequent steps by the developer.

[Invention 3] The developing device of Invention 3 is characterized in that, in the developing device of Invention 2, a concave portion for holding the rinse liquid is provided on a surface of the ring member facing the back surface of the wafer. To do.
With such a configuration, the rinsing liquid is easily held in the gap between the back surface of the wafer and the ring member, and therefore, it is easy to form and maintain the rinsing liquid film.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a conceptual diagram illustrating a configuration example of a developing device 10 according to an embodiment of the present invention.
A developing apparatus 10 shown in FIG. 1 supports the back surface of a wafer W having a photoresist exposed with a predetermined pattern on the surface thereof by a spinner chuck 1 and also supports the surface of the wafer W rotatably supported by the spinner chuck 1. It is an apparatus for developing a photoresist by dropping a developer L.

A surface (hereinafter referred to as “contact surface”) 1 that contacts the back surface of the wafer W of the spinner chuck 1.
There are a number of holes in a, and these holes are connected to a vacuum pump. When air is sucked from these holes while the wafer W is placed on the spinner chuck 1, the back surface of the wafer W is attracted and fixed to the contact surface 1 a of the spinner chuck 1. The spinner chuck 1 is rotatable about a vertical line passing through the center of the contact surface 1a. Further, above the spinner chuck 1, there are a developer droplet lower nozzle (not shown) for dropping the developer L and a surface rinse nozzle (not shown) for dropping the rinse liquid on the surface of the wafer W. Has been placed. In this embodiment, pure water is used as the rinse liquid, for example.

Further, as shown in FIG. 1, a cup 2 for receiving the developer L and the rinsing liquid on the back side of the wafer W, a back rinse nozzle 3 for discharging the rinsing liquid to the back side of the wafer W,
A jammer plate 9 is provided. Here, the jammer plate 9 surrounds the spinner chuck 1 and the back rinse nozzle 3 from the outside, and the developer L that has come from the front surface of the wafer W to the back surface.
Is to prevent intrusion into the spinner chuck 1 side. The back rinse nozzle 3 and the jammer plate 9 are each fixed to the cup 2. In addition, a gap is provided between the jammer plate 9 and the back surface of the wafer W so as not to hinder the rotation of the wafer W.

FIG. 2A is a conceptual diagram showing an example of the jammer plate 9. As shown in FIG. 2 (A), the jammer plate 9 has a ring shape, and a groove portion 20 extending in the circumferential direction is formed on a surface (hereinafter referred to as “opposing surface”) 9a facing the back surface of the wafer W. Has been. The groove portion 20 is for holding the rinse liquid with the back surface of the wafer W. As shown in FIG. 2A, a plurality of such groove portions 20 are provided concentrically on the facing surface 9a.

FIG. 2B is a cross-sectional view showing an example of the shape of the groove 20. As shown in FIG.
The groove portion 20 includes a slope 21 that obliquely intersects the opposing surface 9a and a vertical surface 22 that intersects perpendicularly to the opposing surface 9a, and the inner peripheral surface of the groove portion 20 is the vertical surface 22 and the groove portion. A surface on the outer peripheral side of 20 is a slope 21. With such a shape, the penetration of the developer L into the groove 20 is prevented by the vertical surface 22, while the penetration of the rinse liquid into the groove 20 is a slope 21.
Inspired by. That is, it is possible to make it difficult to put the developer L into the groove 20, while making it easier to put the rinse liquid into the groove 20. Thereby, since the rinse liquid is easily held in the gap between the wafer W and the jammer plate 9, it is easy to form and maintain the rinse liquid film F.

FIG. 3 is a flowchart showing a photoresist development sequence according to the embodiment of the present invention. Here, a case where the developing sequence is executed using the developing device 10 shown in FIG. 1 will be described.
In step S <b> 1 of FIG. 3, first, the vicinity of the center of the back surface of the wafer W is attracted and fixed by the spinner chuck 1. Then, the rinsing liquid is discharged from the back rinse nozzle 3 toward the back surface of the wafer W while rotating the wafer W at a low speed. As a result, the rinsing liquid spreads along the back surface from the center of the wafer W toward the outer periphery thereof by centrifugal force. A film F of the rinsing liquid is formed in the gap between the facing surface 9a of the jammer plate 9 and the back surface of the wafer W.

Next, in step S2, the developer L is dropped from the developer discharge nozzle toward the surface of the wafer W. In step S2, the wafer W may be rotated at a low speed or may be stopped. In the present invention, step S1 and step S2 may be performed in parallel.
Next, in step S3, a process of promoting development (so-called paddle development) is performed by stopping the dripping of the developer L and repeatedly rotating and stopping the wafer W. In step S4, the rinse liquid is not supplied from the back rinse nozzle 3. However, since the rotation of the wafer W is extremely low, the rinse liquid film F formed between the jammer plate 9 and the back surface of the wafer W is Continue to be retained. Further, a part of the developer L supplied to the surface of the wafer W may wrap around from the front surface of the wafer W to the rear surface side, and the developer L that wraps around may reach the jammer plate 9 in some cases. However, in the present invention, since the rinse liquid film F is formed between the jammer plate 9 and the back surface of the wafer W, it is possible to prevent the developer L from entering the inner side of the jammer plate 9.

In step S4, while rotating the wafer W, the rinsing liquid is dropped from the front surface rinsing nozzle onto the surface of the wafer W, and the rinsing liquid is discharged from the back rinse nozzle 3 toward the rear surface of the wafer W. In this state, the wafer W is discharged. Rotate at high speed. As a result, the developer L is washed away from the front and back surfaces of the wafer W. Thereafter, in step S5, the wafer W is rotated at a high speed to perform spin drying, and the photoresist development process is terminated.

In the present embodiment, the diameter of the wafer W, the rotation speed thereof, the size of the jammer plate, the arrangement position thereof, and the like are set as follows, for example.
Wafer W: diameter is 6 inches and the back surface is hydrophilic (in many cases, the back surface of the wafer W is S
An iO ₂ film is formed and is hydrophilic. )
-Arrangement position of the jammer plate 9: Position where the wafer W enters 1 to 2 cm inward from the outer periphery of the wafer W-Width of the jammer plate 9: 1-5 mm
-Wafer W rotation speed (low speed rotation) in step S1 ... 50 to 100 rpm
-Discharge time of the rinse liquid in step S1 ... 2 to 5 seconds-Wafer W rotation speed (very low speed rotation) in step S3 ... 30 rpm
・ Wafer W rotation speed in step S4 (high speed rotation): 500 rpm

Thus, according to the embodiment of the present invention, the rinsing liquid film F formed between the back surface of the wafer W and the jammer plate 9 prevents the developer L from entering the inner side of the jammer plate 9. be able to. Therefore, even when there is a region where the back rinse cannot be sufficiently performed on the back surface of the wafer W inside the jammer plate 9, the developer L can be prevented from reaching the region. Thereby, it is possible to prevent the developer L from remaining on the back surface of the wafer W, and it is possible to prevent contamination by the developer L of the apparatus used in the subsequent steps.

In this embodiment, the spinner chuck 1 corresponds to the “rotation support means” of the present invention, and the jammer plate 9 corresponds to the “ring member” of the present invention. Further, the film forming process in step S1 by the developing device 10 corresponds to the “liquid film forming unit” of the present invention, and the groove portion 20 corresponds to the “concave portion for holding the rinse liquid” of the present invention.
In this embodiment, the case where the film forming process in step S1 is performed before step S2 or in parallel with step S2 has been described. However, the timing for executing step S1 is not limited to this. In the present invention, before the developer L dropped on the front surface of the wafer W travels around the periphery of the wafer W and travels to the back surface side, step S1 is performed to remove the rinse liquid between the jammer plate 9 and the wafer. A film F may be formed. Thereby, it is possible to prevent the developer L from entering the inner side of the jammer plate 9.

1 is a diagram illustrating a configuration example of a developing device 10 according to an embodiment. The figure which shows an example of the jammer board 9 and the groove part 20. FIG. 5 is a flowchart showing a development sequence according to the embodiment. 9 is a flowchart showing a development sequence according to a conventional example. The figure which shows the trouble of a prior art example.

Explanation of symbols

1 Spinner chuck, 1a contact surface, 2 cup, 3 back rinse nozzle, 9
Jama plate, 9a facing surface, 20 groove portion, 21 slope, 22 vertical surface, F rinse film,
L Developer, W Wafer

Claims (3)

The back surface of a wafer having a photoresist exposed to a predetermined pattern on its surface is supported by a rotation support means, and the developer is dropped onto the surface of the wafer that is rotatably supported by the rotation support means. A method of developing
A ring member surrounding the rotation support means from the outside is disposed on the back side of the wafer, and a gap is provided between the wafer back surface and the ring member,
Before the developer dripped onto the wafer surface travels along the periphery of the wafer to the back surface side, a rinse solution film is formed in the gap between the wafer back surface and the ring member. A developing method characterized by the above. The back surface of a wafer having a photoresist exposed to a predetermined pattern on its surface is supported by a rotation support means, and the developer is dropped onto the surface of the wafer that is rotatably supported by the rotation support means. An apparatus for developing
A ring member that surrounds the rotation support means from the outside and is disposed on the back side of the wafer so as to have a gap with the back side of the wafer;
Before the developer dripped onto the wafer surface travels along the periphery of the wafer to the back surface side, a rinse solution film is formed in the gap between the wafer back surface and the ring member. And a liquid film forming means. The developing device according to claim 2, wherein a concave portion for holding the rinse liquid is provided on a surface of the ring member facing the back surface of the wafer.

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