TWI657318B - Developing method - Google Patents

Abstract

The invention aims to ensure the in-plane uniformity of the developing process and improve the yield of the developing process. The invention provides a development processing method, in which a liquid beach of diluted developer solution diluted with pure water is formed at the center of the wafer (time t ₁ ); and then, the wafer is accelerated to a first rotation speed to make the dilution The liquid beach of the developing solution spreads over the entire surface of the wafer, and a liquid film of the diluted developing solution is formed on the wafer surface (time t ₂ ). Thereafter, in a state where a developer supply nozzle having a wetting surface parallel to the wafer and a predetermined gap is secured between the developer supply nozzle and the wafer, the developer supply nozzle supplies the developer solution to the center of the wafer, and Between the wafer and the wetting surface of the developer supply nozzle, a liquid beach of developer is formed (time t ₃ ). While the developer is continuously supplied from the developer supply nozzle while the wafer is being rotated, the developer supply nozzle is moved from the center portion of the wafer to the outer peripheral portion of the wafer.

Description

Development processing method

The present invention relates to a shadow processing method, a computer recording medium, and a development processing device for performing a development process on a substrate formed with a photoresist film to form a predetermined pattern on the substrate.

In the optical lithography step in the manufacturing process of, for example, a semiconductor device, a photoresist coating process for sequentially coating a photoresist liquid on a semiconductor wafer (hereinafter referred to as a “wafer”) as a substrate to form a photoresist film is sequentially performed. , An exposure process for exposing the photoresist film to a predetermined pattern, a heat treatment (post-exposure bake) that promotes chemical reactions in the photoresist film after exposure, a development process for developing the exposed photoresist film, etc., and A predetermined photoresist pattern is formed on the wafer.

At this point in the writing process, there is a method of developing processing. A method is known in which the nozzle is moved in parallel from one end of the wafer to the other while supplying the developer from a long nozzle having a length approximately the same as the diameter of the wafer (patent Document 1), and a method of supplying and dispersing a developer on a wafer rotating at high speed (Patent Document 2).

[Xizhi technical literature]

[Patent Literature]

[Patent Document 1] Japanese Patent No. 3614769

[Patent Document 2] Japanese Patent No. 4893799

However, when developing processing is performed with a long nozzle as shown in Patent Document 1, there is a difference in the time during which one end of the wafer contacts the developing solution at the other end. In addition, as shown in Patent Document 2, when the developer is supplied to the center of the rotating wafer, there is a difference in the time during which the developer is brought into contact with the center of the wafer and the peripheral portion of the wafer. As a result, the line width of the photoresist pattern after the development process is uneven in the wafer surface; however, with the miniaturization of the photoresist pattern due to the high integration of semiconductor elements in recent years, it is becoming increasingly impossible to tolerate the cause. The line width is different in the development time difference.

In view of this, in order to perform a uniform development process on the wafer surface, the use of a developer supply nozzle having a wetted surface parallel to the substrate, for example, is being explored (hereinafter this developer supply nozzle is sometimes referred to as "PAD nozzle"). Specifically, first, the developer is supplied to a stationary substrate with a predetermined gap between the wetted surface of the developer supply nozzle and the wafer, so as to form between the developer supply nozzle and the wafer. Liquid film of developer. At this time, the developer supply nozzle is positioned at the center of the substrate. Next, the wafer is rotated at a low speed of about 30 rpm while the developing solution is continuously supplied from the developing solution supplying nozzle, in other words, the developing solution film between the developing solution supplying nozzle 300 and the substrate is maintained, as shown in FIG. 25 As shown, the developer supply nozzle 300 is moved to the wafer W Outer periphery. Thereby, the developing solution Q is fully supplied to the wafer W, and a uniform developing process can be realized in the wafer surface.

From this point of view, from the viewpoint of improving the yield of wafer processing, it is better to shorten the development time as much as possible. However, according to the team of the inventors of this case, if the development process using the PAD nozzle shortens the development time, as shown in FIG. 26, it is observed that the line width of the photoresist pattern spirally generated in the wafer surface does not reach the desired value. FIG. 26 measures the line width of the photoresist pattern at a plurality of positions on the wafer surface taken each time, and the degree of unevenness of the line width taken by each shot is represented by the color density. 26 shows a case where the development time is, for example, 30 seconds. However, when the development time was set to 60 seconds, as shown in FIG. 27, the spiral tendency was hardly observed, and it was confirmed that the line width in the wafer surface was substantially uniform.

The present invention has been developed in view of this point, and its object is to improve the yield of the development process while ensuring the in-plane uniformity of the development process.

In order to achieve the foregoing object, the present invention provides a developing processing method for supplying a developing solution to a substrate to develop a photoresist film on a substrate that has been exposed to a predetermined pattern. The method includes the following steps: a liquid beach forming step in the center of the substrate Forming a liquid beach of the diluted developer diluted with pure water; a liquid film forming step, after the liquid beach forming step, accelerating the rotation of the substrate to diffuse the liquid beach of the diluted developer to the entire surface of the substrate, Forming a liquid film of the diluted developer; a developer supplying step; and after the liquid film forming step, in a state of ensuring a predetermined gap between the developer supplying nozzle having a wet surface and the substrate, The developer supply nozzle supplies the developer solution to form a liquid beach of the developer solution between the substrate and the wetted surface of the developer supply nozzle. On the one hand, the developer solution nozzle is moved in a radial direction passing through the center of the substrate to supply development. To the substrate.

The team of the inventors of this case conducted a careful investigation into the cause of the uneven line width that occurred spirally when the development time was shortened. As a result, it was found that the spiral shape as shown in FIG. 26 is due to the dissolution product generated in the initial stage of development. In addition, when the development time is set to about 60 seconds as described above, there is no spiral tendency. It is presumed that by ensuring a long development time, the influence of the dissolved product will be relatively small. Caused by becoming smaller.

The present invention is based on this knowledge. According to the present invention, a liquid beach of diluted developer is first formed at the center of the substrate, and then the substrate is rotated to diffuse the liquid beach of diluted developer to the entire surface of the substrate, and on the substrate surface. The liquid surface of the diluted developer is formed. At this time, although a dissolved product is generated on the substrate by diluting the developing solution, by rotating the substrate, the dissolved product and the diluted developing solution are discharged from the substrate together. Next, a liquid film is formed between the developer supply nozzle having the wet surface and the substrate. While the developer is continuously supplied by the developer supply nozzle, the substrate is rotated while the developer supply nozzle is moved to supply the developer solution to the substrate. on. At this time, since the dissolved product has been removed by diluting the developing solution, the development process can be performed without being affected by the dissolved product. As a result, even when the development time is shortened compared with the conventional technique, the development process can be performed uniformly in the plane. Therefore, with the present invention, it is possible to improve the yield of the development process while ensuring the in-plane uniformity of the development process.

The place where the developer supply nozzle of the developer supply step starts to move is the center portion of the substrate, and the place where the developer supply nozzle ends the movement may be the outer peripheral portion of the substrate.

The place where the developer supply nozzle of the developer supply step starts to move is the outer peripheral portion of the substrate, and the place where the developer supply nozzle ends the movement may be the center portion of the substrate.

The formation of the liquid beach that dilutes the developing solution in the liquid beach forming step is to supply pure water to the center portion of the stationary substrate to form a liquid beach of pure water, and then supply the developing solution to the liquid beach of the pure water. You can do it.

In the step of forming the liquid beach, the formation of the liquid beach that dilutes the developing solution may be performed by supplying a diluted developing solution that has been diluted with pure water in advance to the center portion of the stationary substrate.

In the developer supply step, the developer supply nozzle may be moved while the bottom surface of the developer supply nozzle is rotated in a direction opposite to the rotation direction of the substrate.

The liquid film forming step is to accelerate the substrate to a first rotation speed to diffuse the liquid beach of the diluted developer solution over the entire surface of the substrate; and the developer supply step is to make the substrate side at a slower speed than the first rotation speed. 2 The rotation speed may be rotated while moving the developer supply nozzle from the center portion of the substrate to the outer peripheral portion of the substrate.

The first rotation speed is 1500 rpm to 2000 rpm; the second rotation speed is 15 rpm to 30 rpm.

In this liquid film forming step, the stationary substrate is accelerated to a third rotation speed that is slower than the first rotation speed; thereafter, the substrate rotation speed is reduced to a fourth rotation speed that is slower than the third rotation speed; and then, the substrate It is also possible to accelerate to the first rotation speed.

The third rotation speed may be 200 rpm to 400 rpm.

Another aspect of the present invention is to provide a computer recording medium that stores a program and can be read. The program operates on a computer that controls a control unit of a developing processing device to cause the developing processing device to execute the aforementioned developing processing method.

A still further aspect of the present invention is to provide a developing processing device that supplies a developing solution to a substrate and develops a photoresist film on the substrate that has been exposed to a predetermined pattern, and includes a substrate holding portion, holding the back surface of the substrate, and The fixed substrate rotates around a vertical axis; the developer supply nozzle has a wetting surface, and a supply hole for supplying the developer is formed on the wet surface; a moving mechanism moves the developer supply nozzle; and a pure water supply nozzle, Supplying pure water to the substrate; and another moving mechanism to move the pure water supply nozzle.

Still another aspect of the present invention is to provide a developing processing device that supplies a developing solution to a substrate and develops a photoresist film on the substrate that has been exposed to a predetermined pattern. The fixed substrate rotates around a vertical axis; the developer supply nozzle has a wetting surface, and a supply hole for supplying the developer is formed on the wet surface; a moving mechanism moves the developer supply nozzle; and a diluted developer supply A nozzle to supply the diluted developer to the substrate; and another moving mechanism to move the diluted developer to the nozzle.

With the present invention, it is possible to improve the yield of the development process while ensuring the in-plane uniformity of the development process.

1‧‧‧ substrate processing system

10‧‧‧Cassette Station

11‧‧‧processing station

12‧‧‧ exposure device

13‧‧‧Interface Station

20‧‧‧ Cassette Loading Stage

21‧‧‧ Cassette Loading Board

22‧‧‧ transport road

23‧‧‧ Wafer Transfer Device

30‧‧‧Development processing device

31‧‧‧Lower reflection preventing film forming device

32‧‧‧Photoresist coating device

33‧‧‧ Upper reflection preventing film forming device

40 ~ 43‧‧‧ heat treatment equipment

50, 51, 52, 53, 54, 55, 56, 60, 61, 62 ‧‧‧ handover device

70‧‧‧ Wafer Transfer Device

80‧‧‧ Round-trip transfer device

100‧‧‧ Wafer Transfer Device

110‧‧‧ Wafer Transfer Device

111‧‧‧ handover device

130‧‧‧handling container

140‧‧‧Rotary Chuck

141‧‧‧Chuck drive

142‧‧‧ cup body

143‧‧‧Exhaust pipe

144‧‧‧Exhaust pipe

150‧‧‧ track

151‧‧‧The first arm

152‧‧‧ 2nd Arm

153‧‧‧ 3rd arm body

154‧‧‧Pure water supply nozzle

155‧‧‧Nozzle driving unit

156‧‧‧Standby

157‧‧‧Standby

158‧‧‧ dilution developer supply nozzle

159‧‧‧Nozzle driving unit

160‧‧‧Standby

161‧‧‧Developer supply nozzle

161a‧‧‧ bottom face

161b‧‧‧ supply hole

162‧‧‧Rotary drive mechanism

163‧‧‧Nozzle driving unit

164‧‧‧Standby

200‧‧‧Control Department

250‧‧‧Developer tube

251‧‧‧ diluted developer tube

252‧‧‧Pure water pipe

300‧‧‧Developer supply nozzle

C‧‧‧Cassette

D‧‧‧ Wafer Transfer Area

G1‧‧‧ Block 1

G2‧‧‧Block 2

G3‧‧‧ Block 3

G4‧‧‧ Block 4

L‧‧‧ diameter

M‧‧‧ diluted developer

Steps S1 ~ S6‧‧‧‧

T1 ~ T6‧‧‧‧steps

t ₀ ~ t ₆ ‧‧‧ time

P‧‧‧Pure water

R‧‧‧Photoresistive film

Q‧‧‧Developer

U‧‧‧ Dissolved product

W‧‧‧ Wafer

X, Y, θ‧‧‧ directions

[FIG. 1] A plan view schematically showing a configuration of a substrate processing system according to this embodiment.

[Fig. 2] A side view schematically showing a configuration of a substrate processing system according to this embodiment.

[FIG. 3] A side view schematically showing a configuration of a substrate processing system according to this embodiment.

4 is a longitudinal sectional view schematically showing a configuration of a developing processing device.

5 is a cross-sectional view schematically showing a configuration of a developing processing device.

6 is a perspective view schematically showing a structure of a developer supply nozzle.

[FIG. 7] A flowchart explaining the main steps of wafer processing.

[Fig. 8] A timing chart showing the wafer rotation speed and the operation of each machine in the development processing step.

[Fig. 9] A longitudinal sectional explanatory view showing a state where a liquid beach of pure water is formed on a wafer.

[Fig. 10] Fig. 10 is a longitudinal sectional explanatory view showing a state where a developing solution for dilution is supplied to a liquid beach of pure water.

11 is a longitudinal cross-sectional explanatory view showing a state where the wafer is rotated and the diluted developer is diffused in the outer circumferential direction of the wafer W.

[Fig. 12] Fig. 12 is a longitudinal sectional explanatory view showing a state in which a developer supply nozzle is moved above a wafer center portion.

13 is a longitudinal sectional explanatory view showing a state in which a liquid film of a developer is formed between a lower end surface of the developer supply nozzle and a wafer.

14 is a longitudinal cross-sectional explanatory view showing a state in which the developer supply nozzle is moved toward the outer peripheral direction of the wafer while the developer solution is being supplied.

[FIG. 15] A plan explanatory view showing a state where the developer supply nozzle is moved toward the outer peripheral direction of the wafer while the developer solution is being supplied.

[FIG. 16] An explanatory diagram showing a line width unevenness of a photoresist pattern subjected to a development process using the development process method of this embodiment.

17 is a longitudinal sectional explanatory view showing a state in which a diluted developer is directly supplied to the photoresist film.

18 is a longitudinal sectional explanatory view showing a state where a developing solution supply nozzle is used to supply a developing solution for dilution.

19 is a cross-sectional explanatory view showing a state in which a developer liquid supply nozzle is used to form a liquid beach of a diluted developer solution.

[FIG. 20] An explanatory view schematically showing a configuration of a developer supply nozzle according to another embodiment.

[FIG. 21] An explanatory view schematically showing a configuration of a developer supply nozzle according to another embodiment.

[FIG. 22] An explanatory view schematically showing a configuration of a developer supply nozzle according to another embodiment.

[Fig. 23] An explanatory view schematically showing a configuration of a developer supply nozzle according to another embodiment.

24 is a longitudinal sectional explanatory view showing a state in which a developer supply nozzle is moved toward a center portion of a wafer while a developer solution is being supplied.

[Fig. 25] A plan explanatory view showing an example of a development processing method using a PAD nozzle.

[Fig. 26] An explanatory diagram showing a line width unevenness of a photoresist pattern.

[Fig. 27] An explanatory diagram showing a line width unevenness of a photoresist pattern.

Hereinafter, embodiments of the present invention will be described. FIG. 1 is an explanatory diagram schematically showing the configuration of a substrate processing system 1 including a development processing apparatus that implements the development processing method of the present embodiment. 2 and 3 are a front view and a rear view, respectively, schematically showing the internal structure of the substrate processing system 1.

As shown in FIG. 1, the substrate processing system 1 has a structure in which the cassette station 10, the processing station 11, and the interface station 13 are integrally connected; the cassette station 10 is used for loading and unloading a cassette C containing a plurality of wafers W; The processing station 11 is provided with a plurality of various processing devices that perform predetermined processing on the wafer W. The interface station 13 transfers the wafer W between the exposure devices 12 adjacent to the processing station 11.

A cassette mounting table 20 is provided at the cassette station 10. A plurality of cassette mounting plates 21 are provided on the cassette mounting table 20, and the cassettes C are mounted when the cassette C is carried in and out of the substrate processing system 1.

The cassette station 10 is provided with a wafer transfer device 23 that can move freely on a transfer path 22 extending in the X direction as shown in FIG. 1. The wafer transfer device 23 can be moved freely in the vertical direction and the direction around the vertical axis (θ direction). The cassette C on each cassette mounting plate 21 and the third block G3 of the processing station 11 described later can be moved. The wafer W is transferred between the transfer devices.

The processing station 11 is provided with, for example, four plural blocks G1, G2, G3, and G4 including various devices. For example, a first block G1 is provided on the front side of the processing station 11 (the negative direction side in the X direction in FIG. 1), and a second area is provided on the back side of the processing station 11 (the positive direction side in the X direction in FIG. 1). Block G2. In addition, a third block G3 is provided on the cassette station 10 side of the processing station 11 (the negative direction side in the Y direction in FIG. 1), and on the interface station 13 side of the processing station 11 (the positive direction side in the Y direction in FIG. 1). , With the fourth block G4.

For example, in the first block G1, as shown in FIG. 2, a plurality of liquid processing devices are sequentially arranged from the bottom, such as a developing processing device 30 for developing the wafer W, and a lower layer of a photoresist film on the wafer W Forming an anti-reflection film (hereinafter referred to as "lower anti-reflection film"), a lower anti-reflection film forming device 31, a photoresist coating device 32 for coating a wafer W with a photoresist liquid to form a photoresist film, and The upper layer of the W resist film forms an anti-reflection film (hereinafter referred to as an "upper anti-reflection film") and an upper anti-reflection film forming device 33.

For example, the development processing device 30, the lower anti-reflection film forming device 31, the photoresist coating device 32, and the upper anti-reflection film forming device 33 are each arranged in a horizontal direction in an arrangement of three. In addition, the number and arrangement of the development processing device 30, the lower reflection preventing film forming device 31, the photoresist coating device 32, and the upper reflection preventing film forming device 33 can be arbitrarily selected.

In these lower anti-reflection film forming devices 31, photoresist coating devices 32, and upper anti-reflection film forming devices 33, for example, spin coating is performed on a wafer W by applying a predetermined coating liquid. In spin coating, for example, a coating nozzle releases a coating liquid onto the wafer W, and the wafer W is rotated to spread the coating liquid on the surface of the wafer W. The structure of the developing device 30 will be described later.

For example, in the second block G2, as shown in FIG. 3, a plurality of heat treatment apparatuses 40 to 43 for performing heat treatment such as heating and cooling of the wafer W are provided.

For example, in the third block G3, a plurality of transfer devices 50, 51, 52, 53, 54, 55, 56 are provided in this order. Furthermore, in the fourth block G4, a plurality of transfer devices 60, 61, and 62 are provided in this order.

As shown in FIG. 1, an area surrounded by the first block G1 to the fourth block G4 forms a wafer transfer area D. In the wafer transfer area D, a plurality of wafer transfer devices 70 are disposed, and the wafer transfer area 70 includes a transfer arm body that can move freely in, for example, the Y direction, the X direction, the θ direction, and the vertical direction. The wafer transfer device 70 can move within the wafer transfer area D and transfer wafers W to predetermined devices in the surrounding first block G1, second block G2, third block G3, and fourth block G4. .

Further, in the wafer transfer area D, a round-trip transfer device 80 for linearly transferring the wafer W between the third block G3 and the fourth block G4 is provided.

The reciprocating conveying device 80 can move linearly in the Y direction in FIG. 3, for example. The round-trip transfer device 80 moves in the Y direction while supporting the wafer W, and can transfer the wafer W between the transfer device 52 in the third block G3 and the transfer device 62 in the fourth block G4.

As shown in FIG. 1, a wafer transfer device 100 is provided on the X-direction positive side adjacent to the third block G3. The wafer transfer apparatus 100 includes a transfer arm which can move freely in, for example, the X direction, the θ direction, and the vertical direction. The wafer transfer device 100 moves up and down while supporting the wafer W, and can transfer the wafer W to each transfer device in the third block G3.

The interface station 13 is provided with a wafer transfer device 110 and a transfer device 111. The wafer transfer device 110 includes a transfer arm body that can move freely in, for example, the Y direction, the θ direction, and the vertical direction. The wafer transfer device 110 supports the wafer W with a transfer arm, for example, and can transfer the wafer W between each transfer device, the transfer device 111 and the exposure device 12 in the fourth block G4.

Next, the structure of the above-mentioned development processing apparatus 30 is demonstrated. As shown in FIG. 4, the development processing device 30 includes a processing container 130 capable of sealing the inside. A carry-in / out port (not shown) for the wafer W is formed on the side of the processing container 130.

In the processing container 130, a rotation chuck 140 serving as a substrate holding portion is provided, which holds and rotates the wafer W. The rotary chuck 140 can be rotated at a predetermined speed by a chuck driving section 141 such as a motor. In addition, the chuck drive unit 141 is provided with a lifting drive mechanism such as a pressure cylinder, and the rotary chuck 140 is capable of lifting and lowering freely.

Around the rotary chuck 140, a cup 142 is provided for receiving and recovering the liquid scattered or dropped from the wafer W. To the bottom surface of the cup body 142, an exhaust pipe 143 for discharging the recovered liquid and an exhaust pipe 144 for exhausting the air in the cup body 142 are connected.

As shown in FIG. 5, a track 150 extending along the Y direction (left-right direction in FIG. 5) is formed on the side of the X-direction negative direction (lower direction in FIG. 5) of the cup 142. The rail 150 is formed, for example, from the outer side of the negative Y-direction (left direction in FIG. 5) side of the cup 142 to the outer side of the positive Y-direction (right direction in FIG. 5) side. On the rail 150, for example, three arm bodies 151, 152, and 153 are mounted.

The first arm body 151 supports a pure water supply nozzle 154 that supplies pure water. The first arm body 151 is free to move on the rail 150 by the nozzle driving unit 155 shown in FIG. 5. Thereby, the pure water supply nozzle 154 can be moved to the Y of the cup 142 from the standby portion 156 provided on the outer side of the positive direction side of the Y direction of the cup 142 through the center portion of the wafer W in the cup 142. The standby portion 157 on the outer side of the negative direction side.

The second arm body 152 supports a dilution developer supply nozzle 158 for supplying a dilution developer in a first liquid beach formation step described later. The second arm 152 is free to move on the rail 150 by the nozzle driving unit 159 shown in FIG. 5. Thereby, the dilution developer supply nozzle 158 can be moved above the center portion of the wafer W in the cup 142 from the standby portion 160 provided on the outside of the positive direction side in the Y direction of the cup 142. The standby section 160 is provided on the Y-direction positive side of the standby section 156. As the developing solution for dilution, for example, TMAH (tetramethylammonium hydroxide) having a concentration of 2.38% can be used.

The third arm body 153 supports the developer supply nozzle 161 for supplying the developer by the rotation driving mechanism 162. The developer supply nozzle 161 is, for example, as shown in FIG. 6, and has a cylindrical shape as a whole, and a lower end surface 161 a thereof is parallel to the wafer W, for example. The lower end surface 161a functions as a wetting surface in contact with the developer. Lower face 161a does not need to be parallel to the wafer W, as long as it is a shape that can form a liquid film of the developing solution between the lower end surface 161a of the developing solution supply nozzle 161 and the wafer W in the step of forming a liquid beach of the developing solution described later, It may also have, for example, a gently spherical shape or an inclined surface that projects downward. A supply hole 161b for supplying a developer is formed in, for example, a central portion of the lower end surface 161a of the developer supply nozzle 161. The diameter L of the developer supply nozzle 161 is smaller than the diameter of the wafer W. The developer supplied from the developer supply nozzle 161 is the same as the developer supplied from the dilution developer supply nozzle 158, and uses TMAH at a concentration of 2.38%. In this embodiment, the diameter of the wafer W is, for example, 300 mm, and the diameter L of the developer supply nozzle 161 is, for example, 50 mm. The developer supply nozzle 161 is made of a material having chemical resistance, such as PTFE.

The rotation driving mechanism 162 supports the top surface of the developer supply nozzle 161, and can rotate the developer supply nozzle 161 about the vertical axis.

The third arm body 153 is movable on the rail 150 by the nozzle driving unit 163 as a moving mechanism shown in FIG. 5. Thereby, the developer supply nozzle 161 can be moved above the center portion of the wafer W in the cup 142 from the standby portion 164 provided on the outer side in the negative direction of the Y direction of the cup 142. The standby portion 164 is provided on the negative side in the Y direction of the standby portion 157. In addition, the third arm body 153 can be raised and lowered freely by the nozzle driving section 163, and the height of the developer supply nozzle 161 can be adjusted.

The structures of the lower anti-reflection film forming device 31, the photoresist coating device 32, and the upper anti-reflection film forming device 33 of other liquid processing devices are the same as those described above except that the shape and number of the nozzles and the liquid supplied from the nozzles are different. The structure of the development processing device 30 is the same, so the description is omitted.

The above-mentioned substrate processing system 1 is provided with a control unit 200 shown in FIG. 1. The control unit 200 is, for example, a computer, and includes a program storage unit (not shown). In the program storage section, a program for controlling the processing of the wafer W in the substrate processing system 1 is stored. Furthermore, a program for controlling the operations of the drive systems of the various processing apparatuses and conveying apparatuses described above is also stored in the program storage section, so as to implement the peeling process described later on the substrate processing system 1. In addition, the aforementioned programs are stored in a computer-readable recording medium such as a computer-readable hard disk (HD), floppy disk (FD), optical disk (CD), magneto-optical disk (MO), and memory card. The recording medium may be mounted on the control unit 200.

Next, wafer processing performed using the substrate processing system 1 configured as described above will be described. FIG. 7 is a flowchart showing an example of main steps of the wafer processing. In addition, FIG. 8 is a timing chart showing the rotation speed of the wafer W and the operation of each machine in the development processing step performed by the development processing device 30.

First, the cassette C containing a plurality of wafers W is transferred into the cassette station 10 of the substrate processing system 1, and each wafer W in the cassette C is sequentially transferred to the processing station by the wafer transfer device 23. 11 的 交给 装置 53。 11 of the handover device 53.

Next, the wafer W is transferred to the heat treatment device 40 of the second block G2 by the wafer transfer device 70 and subjected to temperature adjustment processing. Thereafter, the wafer W is transferred to, for example, the lower reflection preventing film forming device 31 in the first block G1 by the wafer transfer device 70 to form a lower reflection preventing film on the wafer W (step S1 in FIG. 7). Thereafter, the wafer W is transferred to the heat treatment apparatus 41 in the second block G2 and is subjected to heat treatment.

Thereafter, the wafer W is transferred to the heat treatment device 42 of the second block G2 by the wafer transfer device 70 and subjected to temperature adjustment processing. Thereafter, the wafer W is transferred to, for example, the first block G1 by the wafer transfer device 70. The photoresist coating device 32 forms a photoresist film on the wafer W (step S2 in FIG. 7). Thereafter, the wafer W is transferred to the heat treatment apparatus 43 and subjected to a pre-baking process.

Next, the wafer W is transferred to the upper anti-reflection film forming device 33 in the first block G1, and an upper anti-reflection film is formed on the wafer W (step S3 in FIG. 7). After that, the wafer W is transferred to the heat treatment device 43 in the second block G2 and is subjected to a heat treatment. Thereafter, the wafer W is transferred to the transfer device 56 in the third block G3 by the wafer transfer device 70.

Then, the wafer W is transferred to the transfer device 52 by the wafer transfer device 100, and then transferred to the transfer device 62 in the fourth block G4 by the round-trip transfer device 80. Thereafter, the wafer W is transferred to the exposure device 12 by the wafer transfer device 110 of the interface station 13 and is subjected to exposure processing in a predetermined pattern (step S4 in FIG. 7).

The wafer W is then transferred to the heat treatment device 40 by the wafer transfer device 70 and subjected to a post-exposure bake process. Thereby, a deprotection is performed by an acid generated in the exposed portion of the photoresist film. After that, the wafer W is transferred to the development processing device 30 by the wafer transfer device 70 and development processing is performed (step S5 in FIG. 7).

In the development process, as shown in FIG. 9, firstly, a predetermined amount of pure water P is supplied to the center of the wafer W on which the photoresist film R is formed through the pure water supply nozzle 154 (time t ₀ to t in FIG. 8). ₁ ). At this time, pure water P is supplied while the wafer W is stationary. As a result, a liquid beach of pure water P is formed at the center of the wafer W (step T1 in FIG. 7). In addition, the wafer W does not necessarily need to be stationary at step T1. As long as it can rotate at a low speed such that a pure water P liquid beach can be formed at the center of the wafer W, pure water can be supplied while the wafer W is rotated. P.

Next, while stopping the supply of pure water P, as shown in FIG. 10, the developing developer supply nozzle 158 for dilution is moved above the center of the wafer W, and a predetermined amount of dilution is supplied to the liquid beach of pure water P. Developer Q (time t _{1 in} FIG. 8). Thereby, the developing solution Q is diluted with the pure water P on the wafer W, and a liquid beach for diluting the developing solution M is formed on the wafer W (the liquid beach forming step. Step T2 in FIG. 7). At this time, because the photoresist film R is in contact with the diluted developing solution M, the photoresist film R is developed a little, and a dissolved product U is generated. The dissolved product U stays in the outer peripheral direction of the liquid beach with the flow of the diluted developer M. In addition, the ratio between the supply amount of pure water P and the supply amount of the developer Q, in other words, the concentration of the diluted developer M is set to, for example, the concentration of TMAH to be substantially lower than 2.38%.

Next, while the developer is continuously supplied from the developing developer supply nozzle 158 for dilution, the substrate is accelerated to the first rotation speed by rotating the chuck 140 (time t ₁ to t _{2 in} FIG. 8). Thereby, as shown in FIG. 11, the diluted developer M will diffuse from the center of the wafer W toward the outer peripheral direction. As a result, a liquid film of the diluted developer M is formed on the entire surface of the wafer W (the liquid film forming step. Step T3 in FIG. 7). The first rotation speed may be a speed at which the diluted developer M diffuses toward the outer periphery of the wafer W and is discharged to the outside of the wafer W. For example, the speed is preferably 1500 prm to 2000 rpm. In this embodiment, It is 1500rpm. The acceleration when the wafer W is accelerated is, for example, 3000 rpm / sec.

Once the liquid film of the diluted developer M is formed on the wafer W, the development of the photoresist film R will be performed slightly on the entire surface of the wafer W to generate a dissolved product U; however, by first rotating at a relatively high speed The speed is such that the diluted developing solution M is diffused, and the dissolved product U is discharged from the outer periphery of the wafer W together with the diluted developing solution M. In FIG. 8, the process of accelerating the wafer W to the first rotation speed is, for example, once the rotation speed is reduced to 200 rpm after reaching 400 rpm. By performing such deceleration, in addition to the centrifugal force, The dilution developing solution M acting on the wafer W is caused by an inertial force in the circumferential direction of the wafer W to make the dilution The release developer M can be more uniformly diffused. When the wafer W is accelerated to the first rotation speed, it is not necessary to perform the deceleration shown in FIG. 8.

When the rotation speed of the wafer W reaches the first rotation speed, the rotation is maintained at the first rotation speed, for example, 0.5 seconds, and then the rotation speed of the wafer W is decelerated to stop the wafer W. At this time, the acceleration when decelerating the wafer W is also 3000 rpm / second (time t ₂ to t _{3 in} FIG. 8). In addition, during the period from time t ₂ to time t ₃ , the developer is continuously supplied from the dilution developer supply nozzle 158.

Next, while stopping the wafer W, the supply of the developing solution Q from the developing solution supply nozzle 158 for dilution is stopped, and the developing solution supply nozzle 158 for dilution is retracted from the wafer W, and as shown in FIG. The liquid supply nozzle 161 moves above the center portion of the wafer W. At this time, a predetermined gap is formed between the lower end surface 161a of the developer supply nozzle 161 and the top surface of the wafer W, and the distance of this gap is about 0.5 mm to 2 mm.

Next, the developing solution Q is supplied from the developing solution supplying nozzle 161. As shown in FIG. 13, a liquid beach of the developing solution Q is formed between the lower end surface 161a of the developing solution supplying nozzle 161 and the wafer W (the step of forming the liquid beach of the developing solution (Step T4 of FIG. 7). At the same time, while the developer is supplied to the nozzle 161 by the rotation driving mechanism 162 to rotate the developer, the movement from the center portion of the wafer W to the outer periphery of the wafer W is started as shown in FIG. 14. At this time, the developer supply nozzle 161 moves and passes through the center of the wafer W. The rotation speed of the developer supply nozzle 161 at this time is preferably 50 rpm to 200 rpm, and in this embodiment is 130 rpm. The speed at which the developer supply nozzle 161 moves toward the outer peripheral portion of the wafer W is preferably 10 mm / s to 100 mm / s, and is 15 mm / s in this embodiment. The rotation direction of the developer supply nozzle 161 is set in a direction opposite to the rotation direction of the wafer W. Thereby, the developing solution Q is stirred on the wafer W, and a more uniform developing process can be performed in the plane.

In addition, at the same time that the developer Q is supplied from the developer supply nozzle 161, the wafer W is accelerated to a second rotation speed that is slower than the first rotation speed (times t ₃ to t _{4 in} FIG. 8). The second rotation speed is preferably about 15 prm to 30 rpm, and is 30 rpm in this embodiment. The acceleration when the wafer W is accelerated is, for example, 3000 rpm / sec. Thereby, as shown in FIG. 15, the developing solution Q is gradually supplied from the center portion of the wafer W to the outer peripheral direction.

When the developer supply nozzle 161 approaches the outer periphery of the wafer W, the rotation speed of the wafer W is further reduced from the second rotation speed to 15 rpm (for example, time t _{5 in} FIG. 8). The acceleration at this time is, for example, 100 rpm / second. In this way, by reducing the rotation speed of the wafer W after the developer supply nozzle 161 reaches the vicinity of the outer periphery of the wafer W, the developer Q can be prevented from being spilled to the outside of the wafer W by the centrifugal force. Then, the rotation speed of the wafer W is maintained at 15 rpm, the developer supply nozzle 161 is moved to the outer peripheral end portion of the wafer W, and the developer is supplied to the entire surface of the wafer W (developer supply step. Step T5). At this time, since a liquid film for diluting the developing solution has been formed on the wafer W in step T3, and the dissolved product U is discharged from the wafer W, even if the developing solution Q is supplied to the wafer W, the dissolution is generated. The amount of the substance U produced can also be suppressed to a very small amount. As a result, the development process of the photoresist film R on the wafer W can be performed without being affected by the dissolution product U.

After the developer supply nozzle 161 reaches the outer peripheral end of the wafer W, the supply of the developer solution Q from the developer supply nozzle 161 is stopped, and the rotation of the developer supply nozzle 161 is stopped (time t _{6 in} FIG. 8), and then The developer supply nozzle 161 is retracted from the wafer W. After stopping the supply of the developing solution Q, in order to make the developing solution Q on the wafer W uniform, the rotation of the wafer W may be continued for a period of time.

After that, once the development process is completed, the rotation speed of the wafer W is decelerated to stop the wafer W. Next, for example, pure water is supplied to the wafer W from the pure water supply nozzle 154, and the wafer W is rinsed (step T6 in FIG. 7). Thereby, the dissolved photoresist and the developing solution Q are washed away together to complete a series of developing processes.

After the development processing is completed, the wafer W is transferred to the heat treatment device 42 by the wafer transfer device 70 to perform a post-baking process (step S6 in FIG. 7). Next, the temperature of the wafer W is adjusted by the heat treatment apparatus 43. Thereafter, the wafer W is transferred to the cassette C of the predetermined cassette mounting plate 21 via the wafer transfer device 70 and the wafer transfer device 23 to complete a series of optical lithography steps.

According to the above embodiment, a liquid beach for diluting the developing solution M is first formed in the center of the wafer W, and then the wafer W is accelerated to the first rotation speed to diffuse the liquid beach for the diluting developing solution M to the entire surface of the wafer W. A liquid level of the diluted developer M is formed on the surface of the wafer W (step T3). At this time, although the dissolved product U is generated on the wafer W by diluting the developing solution M, the dissolved product U and the diluted developing solution M are combined together by accelerating the wafer W to the first rotation speed. It is discharged from the wafer W. Then, a developing solution supply nozzle 161 is formed between the developing solution supply nozzle 161 having a lower end surface 161a (wet surface) parallel to the wafer W and the wafer W, and the developing solution supply nozzle 161 is continuously supplied. While supplying the developer, while rotating the wafer W, the developer supply nozzle 161 is moved from the center of the wafer W to the outer periphery of the wafer W, and the developer Q is applied to the entire surface of the wafer W. At this time, since the dissolved product U has been removed by diluting the developing solution M in step T3, the development process of the photoresist film R can be performed without being affected by the dissolved product U. As a result, as shown in FIG. 16, even when the development time is shortened as compared with the conventional technique, the development process can be performed uniformly in the plane. FIG. 16 shows the unevenness of the line width of the photoresist pattern in the wafer W surface in the case of using the developing processing method of this embodiment to perform the developing processing for 30 seconds in accordance with the density of the color. It can be seen from FIG. 16 that the variation in line width has been suppressed to the development time. The aforementioned FIG. 27, which is 60 seconds, is approximately the same. Therefore, according to the present invention, the in-plane uniformity of the development process can be ensured on the one hand, and the yield of the development process can be improved on the other hand.

In addition, since the developer supply nozzle 161 is rotated toward the outer periphery of the wafer W while rotating in a direction opposite to the rotation direction of the wafer W, the developer solution Q can be stirred on the wafer W to be in-plane. A more uniform development process is performed. In addition, the rotation of the developer supply nozzle 161 does not necessarily need to be performed. According to the team of the inventors of the present invention, it has been confirmed that the required development accuracy can be achieved even without the rotation.

Furthermore, the photoresist used for liquid immersion exposure in recent years has a large contact angle with the developing solution, and it is difficult to uniformly coat the developing solution on the photoresist film; however, as in this embodiment, first, by high speed Rotate the liquid beach of the diluted developer M over the entire surface of the wafer W to perform a prewet treatment on the wafer W, thereby reducing the contact angle between the photoresist film R and the developer Q. (Improving the effect of the developer on the wettability of the photoresist film). As a result, the developer can be uniformly supplied into the wafer W, and the uniformity of the development process in the wafer surface can be further improved. In addition, by reducing the contact angle between the photoresist film R and the developing solution Q, the supply amount of the developing solution Q can be reduced. In addition, according to the inventor's team of this case, in order to develop a wafer W of 300 mm, for example, a developing solution Q of about 80 cc is conventionally required; however, it has been confirmed that it can be reduced to about 43 cc by using the developing method of this embodiment.

In addition, when pre-wetting the wafer W, since the diluted developer M diluted with pure water is used, it does not occur only at the position where the diluted developer M drops. In this embodiment, the wafer W The center of W-development. Therefore, based on this, the development process can also be performed uniformly in the wafer W plane.

In the above embodiment, when the liquid beach for diluting the developing solution M is formed in step T2, the developing solution Q for dilution is supplied to the liquid beach of pure water P, but the method for forming the liquid beach for diluting the developing solution M is not limited. The content of this embodiment. For example, the diluted developer supply nozzle 158 may be supplied with the diluted developer solution M which has been diluted with pure water in advance. For example, as shown in FIG. 17, the diluted developer solution M may be directly supplied to the photoresist film R to form the diluted developer solution. M's liquid beach. Since the step T1 of forming a liquid beach of pure water P can be omitted by this, the yield of the development process can be further improved. In this case, the dilution developer supply nozzle 158 may also function as a dilution developer supply nozzle.

Further, in the above embodiment, when the liquid film of the diluted developer M is formed in step T3, the developer Q is supplied from the developer supply nozzle 158 for dilution, but the developer solution may be supplied from the developer supply nozzle 161 to form the diluted developer solution. Developer Q for liquid film of M. In this case, for example, as shown in FIG. 18, the developer supply nozzle 161 is brought into contact with the liquid beach of pure water P, and the developer solution Q for dilution is supplied in this state. Thereby, the pure water P and the developing solution Q are diluted, and the wafer W is rotated at the first rotation speed in step T3 to form a liquid film of the diluted developing solution M on the wafer W.

In addition, when the liquid film of the diluted developer M is formed by the developer supply nozzle 161, it can also be assumed that the diluted developer M can be supplied by the developer supply nozzle 161, as shown in FIG. 19, directly on the wafer W and the developer. A liquid beach for diluting the developing solution M is formed between the liquid supply nozzles 161. In this case, by rotating the wafer W at the first rotation speed in step T3, a liquid film of the diluted developer M can be formed on the wafer W.

When both the developing solution Q and the diluted developing solution M are supplied from the developing solution supplying nozzle 161, as shown in FIG. 20, the developing solution supplying nozzle 161 is connected to the developing solution pipe 250 for supplying the developing solution Q and the diluted developing solution. Tube 251. When the developing solution supply nozzle 161 is not provided with the rotation driving mechanism 162, as shown in FIG. 21, the developing solution pipe 250 and the diluted developing solution pipe 251 may be placed inside the developing solution supply nozzle 161. confluence. In this case, the developer supply nozzle 161 shown in FIGS. 20 and 21 also functions as a dilution developer supply nozzle. In other words, the developer supply nozzle 161 shares the supply hole 161b with the diluted developer supply nozzle.

In the above embodiment, the supply hole 161b is formed only in the center of the developer supply nozzle 161. For example, as shown in FIG. 22, a plurality of supply holes 161b may be formed in the lower end surface 161a of the developer supply nozzle 161. By forming a plurality of supply holes 161b, the developer Q or the diluted developer M can be uniformly supplied to the lower end surface 161a.

Furthermore, in the above-mentioned embodiment, the pure water supply nozzle 154, the dilution developer supply nozzle 158, and the developer supply nozzle 161 are supported by different arm bodies 151, 152, and 153, respectively. However, the pure water supply nozzle may be used. 154. The dilution developer supply nozzle 158 and the developer supply nozzle 161 are supported by either arm. In this case, for example, as shown in FIG. 23, a pure water pipe 252 for supplying pure water P to the developer supply nozzle 161 may be provided in communication.

Further, in the above embodiment, at step T4, the developing solution Q is supplied from the developing solution supply nozzle 161 shifted to the center portion of the wafer W, and the developing solution Q is supplied after a liquid beach is formed at the center portion of the wafer W. 1. While moving the developer supply nozzle 161 from the center portion of the wafer W to the outer peripheral end portion, thereby supplying the developer solution Q to the entire surface of the wafer W, the method of supplying the developer solution Q to the entire surface of the wafer W is not It is limited to the content of this embodiment. For example, in step T4, as shown in FIG. 24, a liquid beach of the developer Q is formed on the outer peripheral end of the wafer W by the developer supply nozzle 161, and then the developer is supplied while the developer solution Q is supplied. The supply nozzle 161 moves to the center of the wafer W to supply the developer Q to the entire surface of the wafer W. In this case, it is also possible to discharge the dissolved product U and the diluted developing solution M from the wafer W in step T3, so that the development process of the photoresist film R can be performed without being affected by the dissolved product U Carried out without impact.

In addition, according to the inventor team of the present case, it has been confirmed that at step T4, as shown in FIG. 24, by moving the developer supply nozzle 161 from the outer peripheral end portion of the wafer W toward the center portion, the development processing can be further improved In-plane uniformity. It is inferred that this is based on the following reasons: That is, since the diluted developing solution M is supplied to the center portion of the wafer W in step T3, the central portion of the wafer W and the outer peripheral portion are respectively compared with the time during which the diluted developing solution M is contacted. There will be a slight gap. Then, since the developing solution M is diluted by this, a slight development is still performed, so compared to the center portion of the wafer W, the line width at the outer periphery of the wafer W can be observed to be slightly wider. tendency. On the other hand, as shown in FIG. 24, after the liquid beach of the developing solution Q is formed at the outer peripheral end portion of the wafer W, the developing solution supply nozzle 161 is moved toward the center portion of the wafer W, so that it can be changed in step T3. The difference between the contact time with the diluted developer M produced is relatively mild. It is speculated that the in-plane uniformity of the development process can be further improved.

As mentioned above, although the preferred embodiment of this invention was described referring an accompanying drawing, this invention is not limited to this example. Those with ordinary knowledge in the technical field understand that they can think about various changes or amendments within the scope of the ideas described in the scope of patent application, and these should also be within the technical scope of the present invention. The present invention is not limited to this example, and various aspects can be adopted. The present invention is applicable even when the substrate is another substrate such as an FPD (Flat Panel Display) other than a wafer, and a reduction mask for a photomask.

[Industrial availability]

The invention is applicable to the development processing performed on the photoresist film on the substrate.

Claims (10)

A developing processing method for supplying a developing solution to a substrate to develop a photoresist film on a substrate that has been exposed to a predetermined pattern. The method includes the following steps: forming a liquid beach, forming a dilution diluted with pure water at the center of the substrate Liquid beach of developing solution; a liquid film forming step, after the liquid beach forming step, accelerating the rotation of the substrate to diffuse the liquid beach of the diluted developing solution over the entire surface of the substrate, and forming a liquid film of the diluted developing solution on the substrate surface And discharging the reaction product from the outer periphery of the substrate; and a developer supply step, after the liquid film forming step, in a state where a predetermined gap is secured between the developer supply nozzle having a wet surface and the substrate On the one hand, the developing solution is supplied by the developing solution supplying nozzle to form a liquid beach of the developing solution between the substrate and the wetted surface of the developing solution supplying nozzle; on the other hand, the developing solution supplying nozzle is at a diameter passing through the center of the substrate. Move up to supply the developer onto the substrate. For example, the development processing method of the scope of application for a patent, wherein the place where the developer supply nozzle of the developer supply step starts to move is the center portion of the substrate; the place where the developer supply nozzle ends movement, It is the outer peripheral portion of the substrate. For example, the development processing method of the scope of application for a patent, wherein the place where the developer supply nozzle of the developer supply step starts to move is the outer peripheral portion of the substrate; the place where the developer supply nozzle ends is moved Is the center of the substrate. For example, in the development processing method according to any one of claims 1 to 3, in the liquid beach formation step, the formation of the liquid beach that dilutes the developing solution is performed by supplying pure water to the center portion of the stationary substrate. To form a liquid beach of pure water, and then supply a developing solution to the liquid beach of pure water to perform. For example, in the development processing method according to any one of claims 1 to 3, in the formation of the liquid beach, the formation of the liquid beach that dilutes the developing solution is developed by diluting the diluted liquid with pure water in advance. The liquid is supplied to the center portion of the stationary substrate. For example, in the developing processing method according to any one of claims 1 to 3, in the developing solution supplying step, the movement of the developing solution supplying nozzle is to make the bottom surface of the developing solution supplying nozzle communicate with the substrate. The rotation is performed in the opposite direction of rotation. For example, the development processing method according to any one of claims 1 to 3, wherein the liquid film forming step is to accelerate the substrate to a first rotation speed so that the liquid beach of the diluted developer solution is diffused to the entire surface of the substrate. The developer supply step moves the substrate from the center portion of the substrate to the outer peripheral portion of the substrate while rotating the substrate at a second rotation speed that is slower than the first rotation speed. For example, the development processing method of the seventh item in the patent application range, wherein the first rotation speed is 1500 rpm to 2000 rpm; the second rotation speed is 15 rpm to 30 rpm. For example, in the development processing method of claim 7 in the scope of patent application, in the liquid film forming step, the stationary substrate is accelerated to a third rotation speed that is slower than the first rotation speed; after that, the substrate rotation speed is decelerated to a speed lower than that of the first rotation speed. 3 The fourth rotation speed with a slow rotation speed; thereafter, the substrate is accelerated to the first rotation speed. For example, the development processing method according to item 9 of the patent application scope, wherein the third rotation speed is 200 rpm to 400 rpm.