WO2024122377A1 - Development processing method and development processing apparatus - Google Patents

Abstract

This development processing method is for developing a resist film on a substrate (W), the method comprising: (A) a step for discharging a developing solution (DS) from a first discharge part (41) onto the central portion of the substrate while rotating the substrate, to advance the developing of the resist film and also to expel, out of the substrate, a dissolution product resulting from the developing; (B) a step for discharging the developing solution from a second discharge part (42) to thereby expel a dissolution product obtained in step (A) out of the substrate, reduce the concentration of the dissolution product in the developing solution on the substrate, and form puddles (DP) of the developing solution on the substrate; and (C) a step for further advancing development of the resist film while maintaining the puddles (DP) of the developing solution formed in step (B).

Description

Development processing method and development processing device

This disclosure relates to a development processing method and a development processing device.

In the development processing method disclosed in Patent Document 1, a developer supply nozzle that is formed longer than the diameter of the substrate and has multiple developer supply ports along its longitudinal direction moves from one end of the substrate to the other while discharging developer onto the substrate, supplying the developer to the entire surface of the substrate and forming a liquid film of the developer on the substrate. Then, static development is performed for a predetermined time while the substrate is stationary. Next, the substrate is rotated by a spin chuck, and the developer on the substrate is agitated, making the concentration of the developer uniform within the substrate surface. Thereafter, static development is performed again, and when static development is completed, the development processing is completed.

JP 2012-28571 A

The technology disclosed herein improves the dimensional uniformity of the resist pattern.

One aspect of the present disclosure is a development processing method for developing a resist film on a substrate, comprising the steps of: (A) discharging a developer from a first discharge unit onto a center portion of the substrate while rotating the substrate, thereby advancing development of the resist film and discharging dissolved products resulting from development outside the substrate; (B) discharging the developer from a second discharge unit onto the substrate, thereby discharging the dissolved products resulting from the (A) step outside the substrate, reducing the concentration of the dissolved products in the developer on the substrate, and forming a puddle of the developer on the substrate; and (C) maintaining the puddle of the developer formed in the (B) step, while further advancing development of the resist film.

The present disclosure makes it possible to improve the dimensional uniformity of the resist pattern.

1 is a vertical sectional view showing an outline of a configuration of a development treatment apparatus according to an embodiment of the present invention. 1 is a cross-sectional view showing an outline of a configuration of a development treatment apparatus according to an embodiment of the present invention. FIG. 2 is a perspective view showing an outline of a configuration of a first ejection section. FIG. 4 is a perspective view showing an outline of a configuration of a second discharge section. 1 is a flowchart showing main steps of an example 1 of a development processing sequence. 1A and 1B are diagrams illustrating the peripheral state of a wafer during a development processing sequence; 1 is a partially enlarged cross-sectional view of a wafer during a development processing sequence. 1 is a partially enlarged cross-sectional view of a wafer during a development processing sequence. 11A to 11C are diagrams for explaining main effects of the example 1 of the development processing sequence. 11 is a flowchart showing main steps of an example 2 of a development processing sequence. 1A and 1B are diagrams illustrating the peripheral state of a wafer during a development processing sequence; 13 is a flowchart showing main steps of an example 3 of a development processing sequence. 1A and 1B are diagrams illustrating the peripheral state of a wafer during a development processing sequence; 13A and 13B are diagrams illustrating other examples of the first ejection section and the third ejection section. FIG. 13 is a diagram showing a schematic view of the peripheral state of a wafer during peripheral development.

In photolithography processing in the manufacturing process of semiconductor devices, etc., various processes are performed sequentially on a substrate such as a semiconductor wafer (hereinafter referred to as "wafer") to form a specified resist pattern. For example, a resist coating process is performed in which a resist liquid is supplied onto the substrate to form a resist film, an exposure process is performed in which the resist film is exposed to light, and a development process is performed in which a developer is supplied to the exposed resist film and developed, and so on, to form a specified resist pattern.

The above-mentioned development process is carried out by a development processing device. The development processing device has a substrate holding section that holds the substrate, and a developer discharge section that discharges developer onto the substrate held by the substrate holding section, and the resist film on the substrate is developed with the developer from the developer discharge section.

The above-mentioned exposure process is performed by an exposure device. In the exposure device, the resist film on the substrate is exposed through a slit that forms a long, thin beam, and the entire resist film is covered with multiple exposure shots. Here, an exposure shot is the area that is irradiated with a single exposure through the slit.

By the way, there are various types of developer discharge units. For example, some have a discharge port formed over a length that covers the width of the substrate. While there are long developer discharge units like this, there are also short developer discharge units that discharge developer in strips or lines that are narrower than the width of the substrate.

When a long developer discharge section is used, the development processing device, for example, discharges the developer to form a puddle of developer on the substrate, then stops discharging the developer, and then maintains the puddle of developer to develop the resist film and form a resist pattern. That is, the resist pattern is formed by paddle development. However, in this case, the dimensions of the resist pattern may vary within the above-mentioned exposure shot. Specifically, in areas within the exposure shot where the density of the parts that dissolve due to development (hereinafter referred to as "development dissolution density") is high, the gaps between patterns may be narrower, for example, than in areas where the development dissolution density is low.

This may be due to the following reasons:
That is, according to the inventors' repeated intensive tests, the higher the concentration of the dissolution product generated by development in the developer, the more difficult the development progresses. Also, in puddle development, the developer is less likely to move on the substrate during development, so the dissolution product generated by development is also less likely to move on the substrate. Therefore, in the region with high development dissolution density in the exposure shot, the concentration of the dissolution product gradually increases during development compared to the region with low development dissolution density, and as a result, it is considered that development is less likely to progress and the gap between patterns becomes narrower.

On the other hand, when using the short developer discharge unit described above, the development processing device, for example, discharges developer onto the center of the substrate while rotating the substrate, thereby spreading the developer over the entire substrate, thereby developing the resist film to form a resist pattern. Hereinafter, this type of development is referred to as center discharge development. In the case of center discharge development, developer containing dissolved products is discharged outside the substrate during development, so that dimensional variations in the resist pattern within the exposure shot can be suppressed. However, in this case, fresh developer not containing dissolved products is continuously supplied to the substrate center, which may result in overdevelopment in the substrate center. In other words, the dimensions of the resist pattern may vary within the substrate surface.

The technology disclosed herein improves the uniformity of the dimensions of the resist pattern. Specifically, it improves the uniformity of the dimensions of the resist pattern within an exposure shot and within the substrate surface.

The developing method and developing device according to this embodiment will be described below with reference to the drawings. Note that in this specification, elements having substantially the same functional configuration will be given the same reference numerals to avoid redundant description.

<Developing Treatment Device>
1 and 2 are longitudinal and transverse sectional views showing the outline of the configuration of a developing treatment device according to the present embodiment. Fig. 3 is a perspective view showing the outline of the configuration of a first discharge unit described below. Fig. 4 is a perspective view showing the outline of the configuration of a second discharge unit described below.

The developing treatment device 1 has a treatment container 10 whose interior can be sealed as shown in FIG. 1. An opening (not shown) for loading and unloading a wafer W as a substrate is formed on the side of the treatment container 10.

Inside the processing vessel 10, a spin chuck 20 is provided as a substrate holding part for holding the wafer W. The spin chuck 20 has a horizontal upper surface, and the upper surface is provided with, for example, a suction port (not shown) for sucking the wafer W. The wafer W can be adsorbed and held on the spin chuck 20 by suction from this suction port.

The spin chuck 20 is connected to a chuck drive mechanism 21 as a rotation mechanism, and can be rotated at a desired speed by the chuck drive mechanism 21. The chuck drive mechanism 21 has a rotation drive source (not shown) such as a motor that generates a drive force for rotating the spin chuck 20. The spin chuck 20 is rotated by the chuck drive mechanism 21, which causes the wafer W to rotate.

Furthermore, the chuck drive mechanism 21 has a lifting drive source (not shown) such as a cylinder, and the spin chuck 20 can be lifted and lowered by the chuck drive mechanism 21. When the spin chuck 20 is lifted and lowered by the chuck drive mechanism 21, the wafer W is lifted and lowered.
The chuck driving mechanism 21 is controlled by a control unit U which will be described later.

A cup 22 is provided to surround the wafer W held by the spin chuck 20. The cup 22 receives and collects liquid that splashes or falls from the wafer W.

As shown in FIG. 2, rails 30A, 30B are formed on the negative X-direction side of cup 22 (the lower side of FIG. 2) and extend along the Y-direction (the left-right direction of FIG. 2). Rails 30A, 30B are formed, for example, from the outside of cup 22's negative Y-direction side (the left side of FIG. 2) to the outside of cup 22's positive Y-direction side (the right side of FIG. 2). Two arms 31, 33 are attached to rail 30A, and one arm 32 is attached to rail 30B.

A first discharge unit 41 is supported on the first arm 31. The first discharge unit 41 is formed separately from the second discharge unit 42 and the third discharge unit 43, and has, for example, a nozzle 41a. The nozzle 41a is capable of discharging the developer to a partial area of the wafer W, including the center of the wafer W held by the spin chuck 20. As shown in FIG. 3, the nozzle 41a has a slit-shaped discharge port 41b at its lower end.
Nozzle 41a is formed so as to be able to discharge the developing solution from discharge port 41b in a band shape narrower than the width, i.e., diameter, of wafer W, and more specifically, is formed so as to be able to discharge the developing solution in the above-mentioned band shape obliquely downward (e.g., at an angle of 45° with respect to the surface of wafer W) toward wafer W held by spin chuck 20. Discharge port 41b is formed, for example, in the shape of a slit that is shorter than the width, i.e., diameter, of wafer W in plan view.

The first arm 31 can be moved on the rail 30A by a nozzle driving mechanism 34 as a moving mechanism shown in FIG. 2. The nozzle driving mechanism 34 has a moving drive source (not shown) such as a motor that generates a driving force for moving the first arm 31. When the first arm 31 moves on the rail 30A by the nozzle driving mechanism 34, the first discharge part 41 can move from the waiting part 35 installed outside the Y direction positive side (right side in FIG. 2) of the cup 22 to above the center or above the peripheral part of the wafer W in the cup 22. The nozzle driving mechanism 34 has a lifting drive source such as a cylinder, and the first arm 31 can be lifted and lowered by the nozzle driving mechanism 34. When the first arm 31 moves up and down by the nozzle driving mechanism 34, the first discharge part 41 moves up and down.
The nozzle driving mechanism 34 is controlled by a control unit U which will be described later.

The second arm 32 supports the second discharge part 42. The second discharge part 42 is formed separately from the third discharge part 43, and has, for example, a nozzle 42a. The nozzle 42a can simultaneously discharge the developing solution to the entire width direction of the wafer W held by the spin chuck 20. As shown in FIG. 4, the nozzle 42a has a slit-shaped discharge port 42b at the lower end. The nozzle 42a is formed so that the developing solution can be discharged from the discharge port 42b in a strip shape that is wider than the width, i.e., diameter, of the wafer W. Specifically, the nozzle 42a is formed so that the developing solution can be discharged downward in the strip shape toward the wafer W held by the spin chuck 20. The discharge port 42b is formed over a length that covers the width of the wafer W (specifically, the width of the device formation region). More specifically, the discharge port 42b is formed, for example, in a slit shape that is longer than the width, i.e., diameter, of the wafer W in a plan view. The discharge port 41b may be configured by arranging a large number of holes at intervals in the longitudinal direction of the nozzle 42a in a plan view.

The second arm 32 is movable on the rail 30B by a nozzle driving mechanism 36 as a moving mechanism shown in FIG. 2. The nozzle driving mechanism 36 has a moving drive source (not shown) such as a motor that generates a driving force for moving the second arm 32. When the second arm 32 moves on the rail 30B by the nozzle driving mechanism 36, the second discharge part 42 can move in the Y direction (left and right direction in FIG. 2) above the wafer W in the cup 22 from the waiting part 37 installed outside the Y direction positive side (right side in FIG. 2) of the cup 22. The nozzle driving mechanism 36 has a lifting drive source such as a cylinder, and the second arm 32 can be lifted and lowered by the nozzle driving mechanism 36. When the second arm 32 moves up and down by the nozzle driving mechanism 36, the second discharge part 42 moves up and down.
The nozzle driving mechanism 36 is controlled by a control unit U which will be described later.

The third arm 33 supports the third discharge unit 43. The third discharge unit 43 has, for example, a nozzle 43a. The nozzle 43a is capable of discharging pure water, and more specifically, is capable of discharging the pure water downward toward the wafer W held by the spin chuck 20.

The third arm 33 can be moved on the rail 30A by a nozzle driving mechanism 38 as a moving mechanism. The nozzle driving mechanism 38 has a moving drive source (not shown) such as a motor that generates a driving force for moving the third arm 33. The third arm 33 moves on the rail 30A by the nozzle driving mechanism 38, so that the third discharge part 43 can move from the waiting part 39 installed outside the Y direction negative side (left side in FIG. 2) of the cup 22 to above the center of the wafer W in the cup 22. The nozzle driving mechanism 38 has a lifting drive source such as a cylinder, so that the third arm 33 can be lifted and lowered by the nozzle driving mechanism 38. The third arm 33 is lifted and lowered by the nozzle driving mechanism 38, so that the third discharge part 43 is lifted and lowered.
The nozzle driving mechanism 38 is controlled by a control unit U which will be described later.

A supply mechanism 100 that supplies the developer is connected to the first discharge unit 41 and the second discharge unit 42 (specifically, the nozzle 41a and the nozzle 42a). The supply mechanism 100 has a supply valve (not shown) that switches between supplying and stopping the supply of the developer and a flow rate adjustment valve (not shown) that adjusts the flow rate of the developer for each discharge unit, i.e., for each nozzle.
A supply mechanism 110 that supplies pure water is connected to the third discharge unit 43 (specifically, to the nozzle 43a). The supply mechanism 110 has a supply valve (not shown) that switches between supplying and stopping the supply of pure water, a flow rate control valve (not shown) that adjusts the flow rate of pure water, and the like.
The supply mechanisms 100 and 110 are controlled by a control unit U which will be described later.

The development processing device 1 described above is provided with a control unit U. The control unit U is, for example, a computer equipped with a processor such as a CPU and a memory, and has a program storage unit (not shown). The program storage unit stores a program including instructions for the development processing sequence described below. The program may be recorded on a computer-readable storage medium and installed into the control unit U from the storage medium. The storage medium may be temporary or non-temporary.

<Example 1 of Development Processing Sequence>
Next, an example of a development processing sequence executed by the development processing device 1 will be described. Fig. 5 is a flow chart showing main steps of the development processing sequence example 1. Fig. 6 is a diagram showing a schematic diagram of the peripheral state of the wafer W during the development processing sequence. Figs. 7 and 8 are partially enlarged cross-sectional views of the wafer W during the development processing sequence. Note that each of the following steps is executed under the control of the control unit U based on a program stored in the above-mentioned program storage unit (not shown).

First, the wafer W is carried into the processing chamber 10, and placed on the spin chuck 20 and held thereon by suction.
5 and 6A, specifically, while the wafer W is being rotated, the developer DS is discharged from the first discharge part 41 to the center of the wafer W (step S1). That is, center discharge development is performed using the first discharge part 41.

Specifically, in step S1, the first discharge part 41 is moved above the center of the wafer W held by the spin chuck 20. Then, for a predetermined time T1 (e.g., 5 to 15 seconds), a band of developer DS is discharged obliquely downward from the first discharge part 41 toward the center of the wafer W held by the spin chuck 20, while the wafer W is rotated at a predetermined rotation speed R1 (e.g., 1500 rpm). The total amount of developer discharged is greater in step S2 than in step S1.

In this step, the development of the resist film proceeds, and the dissolved products produced by the development are discharged outside the wafer W.
Specifically, as the development of the resist film progresses over the entire surface of the wafer W, the developer containing dissolved products produced by the development moves outward due to centrifugal force, and when it reaches the outer periphery of the wafer W, it is shaken off and released outside the wafer W.

In this process, the resist film FR is not developed until the surface of the wafer W is exposed as shown in FIG. 7. The surface of the wafer W is exposed and the resist pattern RP is formed as shown in FIG. 8 after development in step S3, which will be described later.

Next, the developer is ejected from the second ejection section 42 onto the wafer W, forming a puddle of the developer on the wafer W (step S2).

Specifically, for example, the developer from the first discharge unit 41 is stopped, the first discharge unit 41 is retreated from above the wafer W, and the rotation of the wafer W is stopped. Also, as shown in Fig. 6B, while the rotation of the wafer W is stopped, the second discharge unit 42 is moved from one end to the other end of the wafer W in a direction intersecting the direction in which the discharge port 42b extends (specifically, the orthogonal Y direction (left and right direction in Fig. 2)), and during the movement, a strip of developer DS is discharged downward from the discharge port 42b. As a result, a puddle DP of developer is gradually formed on the surface of the wafer W wetted with the developer DS, and finally, as shown in Fig. 6C, a puddle DP of developer is formed covering the entire upper surface of the wafer W.
The second discharge unit 42 used in step S2 may be located above the developer discharge start position, i.e., above the one end, from the time of the central discharge development using the first discharge unit 41 in step S2. This allows the developer to be discharged from the second discharge unit 42 immediately after the first discharge unit 41 is retracted, thereby improving throughput.

In this process, as the puddle DP of developer is formed, the dissolved products generated in step S1 are discharged outside the wafer W, and the concentration of the dissolved products in the developer on the wafer W is reduced. Therefore, the developer in the puddle DP that is finally formed is the one discharged from the second discharge part 42.

Then, while maintaining the puddle DP of developer, the development of the resist film is further progressed (step S3). In other words, puddle development is performed.

Specifically, in step S3, for example, the discharge of the developing solution from the second discharge unit 42 is stopped, and the second discharge unit 42 is retracted from above the wafer W. Then, as shown in Fig. 6C, stationary development in which the wafer W is kept stationary without being rotated is performed for a predetermined time T2. The development time in step S3, i.e., the above-mentioned predetermined time T2, is longer than the development time in step S1, i.e., the above-mentioned predetermined time T1, and is, for example, 60 to 90 seconds.
It should be noted that, as long as the puddle of the developer is maintained, that is, within the range in which the puddle of the developer does not collapse, the wafer W may be rotated during the development in step S3.

Once development in step S3 is completed, the wafer W is rinsed (step S4).

Specifically, the third discharge part 43 is moved above the center of the wafer W held by the spin chuck 20. Then, for a predetermined time T3 (e.g., 15 seconds), pure water as a rinsing liquid is discharged from the third discharge part 43 to the center of the wafer W held by the spin chuck 20, while the wafer W is rotated at a predetermined rotation speed R2 (e.g., 1000 rpm). This washes away the developing solution on the surface of the wafer W.

Then, the wafer W is dried (step S5).

Specifically, the discharge of the pure water from the third discharge part 43 is stopped, and the third discharge part 43 is retracted from above the wafer W. In addition, the wafer W is rotated at a higher rotation speed R3 (e.g., 3000 rpm) for a predetermined time T4 (e.g., 10 seconds). As a result, the pure water on the surface of the wafer W is shaken off by centrifugal force, and the wafer W is dried.
After drying, the wafer W is unloaded from the processing chamber 10 .

This completes the entire development sequence.

<Main Effects of Example 1 of Development Processing Sequence>
FIG. 9 is a diagram for explaining the main effects of Example 1 of the development processing sequence, and shows the relationship between the development time (horizontal axis) and the line width (vertical axis) of the line and space formed by development when, unlike the present embodiment, only central ejection development is performed using the first ejection section 41.

The inventors have conducted extensive testing and, unlike this embodiment, when only center discharge development is performed, as shown in Figure 9, in areas with short development times, the rate of change in line width after development relative to changes in development time is large, but in areas with long development times, the rate of change is small. In other words, when developing a resist film using a developer, the development progresses quickly in the early stages of development, and it is believed that a large amount of dissolved products is produced.

Therefore, in example 1 of the development processing sequence, in the early stages of development when a large amount of dissolved products are produced, as in step S1, central discharge development is performed using the first discharge section 41, which has high discharge performance for the dissolved products, to suppress the occurrence of variations in the degree of development progress within the exposure shot.
In addition, in Example 1 of the development process sequence, as in steps S2 and S3, paddle development using the second discharge unit 42, which has low performance in discharging dissolved products, is performed after central discharge development using the first discharge unit 41. However, at this stage, development has progressed and the amount of dissolved products generated is smaller than in the initial stage of development, so that the effect of paddle development using the second discharge unit 42 on the variation in the degree of development progress within the exposure shot is small.

Furthermore, in Example 1 of the development process sequence, after central discharge development using the first discharge unit 41, paddle development using the second discharge unit 42 is also performed, so the time it takes for fresh developer to be discharged from the first discharge unit 41 to the central portion of the wafer W is shorter than when only central discharge development using the first discharge unit 41 is performed. Therefore, according to Example 1 of the development process sequence, overdevelopment in the central portion of the wafer W can be suppressed.

Therefore, according to development process sequence example 1, the variation in the degree of development progress within an exposure shot and within the substrate surface can be improved. As a result, the uniformity of the dimensions of the resist pattern within an exposure shot and within the substrate surface can be improved. In other words, the variation in the dimensions of the resist pattern within an exposure shot and within the substrate surface can be suppressed. According to tests conducted by the inventors, in this embodiment, the uniformity of the dimensions of the resist pattern within an exposure shot and within the substrate surface can be improved by about 30% compared to a form in which only paddle development is performed using the second discharge unit 42, which is different from this embodiment.

As a development process sequence that improves the dimensional uniformity of the resist pattern within an exposure shot and within the substrate surface, there is a sequence in which only paddle development using the second discharge unit 42 is repeated multiple times. Compared to this sequence, development process sequence example 1 can reduce the total consumption of developer and can also improve throughput.

<Example 2 of Development Processing Sequence>
Fig. 10 is a flow chart showing main steps of the development process sequence example 2. Fig. 11 is a diagram showing a schematic state of the periphery of the wafer W during the development process sequence.
In the example 2 of the developing process sequence, as shown in FIG. 10, before step S1 in the example 1 of the developing process sequence, pre-wetting of the wafer W is performed (step S11).

Specifically, immediately before step S1, the deionized water PW is discharged from the third discharge part 43 onto the wafer W, as shown in FIG.
More specifically, the third discharge part 43 is moved above the central part of the wafer W held by the spin chuck 20. Thereafter, for a predetermined time T11 (e.g., 1 to 5 seconds), the pure water PW as the pre-wet liquid is discharged from the third discharge part 43 to the central part of the wafer W held by the spin chuck 20, and the wafer W is rotated at a predetermined rotation speed R11 (e.g., 1500 rpm).

<Main Effects of Example 2 of Development Processing Sequence>
In the development process sequence example 2, as in the development process sequence example 1, after the central discharge development using the first discharge unit 41, paddle development using the second discharge unit 42 is also performed, thereby improving the uniformity of the dimensions of the resist pattern.
In the example 2 of the development process sequence, since pre-wetting is performed as described above, the developer can be uniformly spread over the surface of the wafer W in step S1 immediately after pre-wetting.

<Example 3 of development processing sequence>
Fig. 12 is a flowchart showing main steps of the development process sequence example 3. Fig. 13 is a diagram showing a schematic state of the periphery of the wafer W during the development process sequence.
12, in Example 3 of the development process sequence, before step S1 in Example 1 of the development process sequence, while the wafer W is being rotated, the developer is discharged from the first discharger 41 only onto the outer periphery of the wafer W (step S21), i.e., before the center discharge development using the first discharger 41, the outer periphery discharge development using the first discharger 41 is performed. Specifically, before the pre-wetting of the wafer W in step S11 in Example 2 of the development process sequence, the outer periphery discharge development using the first discharger 41 is performed. In other words, the wafer W is pre-wetted after the outer periphery discharge development using the first discharger 41.

More specifically, in step S21, as shown in FIG. 13, the first discharge part 41 is moved above the outer periphery of the wafer W held by the spin chuck 20. Then, for a predetermined time T21 (e.g., 3 to 12 seconds), a band of developer is discharged from the first discharge part 41 toward the outer periphery of the wafer W held by the spin chuck 20, while the wafer W is rotated at a predetermined rotation speed R21. The rotation speed of the wafer in step S21, i.e., the above-mentioned predetermined rotation speed R21, is lower than the rotation speed of the wafer W in step S1, i.e., the above-mentioned predetermined rotation speed R1, and is, for example, 15 rpm to 30 rpm.

At this time, the developing solution from the first discharge part 41 is discharged obliquely downward from the first discharge part 41 so as to head toward the peripheral edge of the wafer W after landing on the wafer W.
Furthermore, the position of the first discharge part 41 when discharging the developing solution in step S21 is, for example, a position 125 mm to 145 mm from the center of the wafer W. The position of the first discharge part 41 may be a position where the band-like developing solution discharged obliquely downward from the first discharge part 41 hits the bevel portion of the wafer W held by the spin chuck 20.

<Main Effects of Example 3 of Development Processing Sequence>
In the development process sequence example 3, as in the development process sequence example 1, after the central discharge development using the first discharge unit 41, paddle development using the second discharge unit 42 is also performed, thereby improving the uniformity of the dimensions of the resist pattern.

In addition, in development process sequence examples 1 and 2, during paddle development, the concentration of dissolved products in the developer may be higher at the outer periphery of the wafer W than at the center, and in such cases, further development may be required at the outer periphery of the wafer W. In contrast, in development process sequence example 3, outer periphery discharge development using the first discharge unit 41 is performed before center discharge development using the first discharge unit 41, so that development can proceed further at the outer periphery of the wafer W. This can further improve the uniformity of the dimensions of the resist pattern.

Furthermore, in example 3 of the development process sequence, peripheral discharge development using the first discharge unit 41 is performed before central discharge development using the first discharge unit 41, i.e., before puddle development, thereby providing the following effects.
If the contact angle of the surface of the outer periphery of the wafer W is high, that is, if the surface of the outer periphery of the wafer W is highly water repellent, the shape of the puddle of the developer may be damaged during puddle development. In contrast, as in Example 3 of the development process sequence, if outer periphery discharge development using the first discharge unit 41 is performed before puddle development, the contact angle of the surface of the outer periphery of the wafer W is reduced. Therefore, it is possible to prevent the shape of the puddle of the developer from being destroyed during puddle development.

In addition, in Example 3 of the development process sequence, peripheral discharge development using the first discharge unit 41 is performed before pre-wetting of the wafer W. In other words, in Example 3 of the development process sequence, pre-wetting of the wafer W, i.e., supplying pure water to the wafer W, is performed between peripheral discharge development using the first discharge unit 41 and central discharge development using the first discharge unit 41. When pure water is supplied in this manner, the dissolved products generated in peripheral discharge development using the first discharge unit 41 can be discharged outside the wafer W. Therefore, by adjusting the execution time of pre-wetting of the wafer W, it is possible to control the stopping or suppression of development in the peripheral portion of the wafer W.

<Modification 1 of Development Processing Sequence Example 3>
In the example 3 of the development processing sequence, the outer periphery discharge development using the first discharge unit 41 is performed before the center discharge development using the first discharge unit 41. In contrast, in the modified example 1 of the example 3 of the development processing sequence, the outer periphery discharge development using the first discharge unit 41 may be performed before the puddle development.

However, in this modified example 1, when the development of the outer periphery of the wafer W progresses during the outer periphery discharge development using the first discharge part 41, the development also progresses in the central part of the wafer W. In addition, since the rotation speed of the wafer W is low during the outer periphery discharge development using the first discharge part 41, the dissolved product generated by development in the central part of the wafer W is difficult to move. Therefore, in this modified example 1, there is a risk that the degree of development progress varies in the central part of the wafer W.
In contrast, as in Example 3 of the development process sequence, if the peripheral discharge development using the first discharge unit 41 is performed before the central discharge development using the first discharge unit 41, while the development of the peripheral part of the wafer W progresses, the development does not progress in the central part of the wafer W. Therefore, it is possible to avoid the above-mentioned risk of variation in the degree of development progress in the central part of the wafer W.

<Modification 2 of Development Processing Sequence Example 3>
Prior to the peripheral discharge development using the first discharge unit 41 in step S21, the peripheral discharge development may be performed at a higher rotation speed of the wafer W (e.g., 50 to 150 rpm) than in step S21. In this case, the development time is shorter than that in step S21, for example, 1 second or less.

By carrying out this type of peripheral discharge development prior to step S21, it is possible to suppress variations in the degree of development progress in the circumferential direction of the wafer W at the outer periphery of the wafer W.

<Modifications of Development Processing Sequence Examples 1 to 3>
After outer periphery discharge development using the first discharge unit 41 in step S1, and before the discharge of the developer from the second discharge unit 42 in step S2 (i.e., before the developer puddle formation step), a step of discharging pure water from the third discharge unit 43 onto the wafer W may be performed, similarly to step S11. This makes it possible to prevent the amount of developer from being unevenly distributed in the developer puddle.

During the puddle development in step S3, agitation may be performed to rotate the wafer W at a low rotation speed.
In this case, for example, before agitation, static development is carried out for 7 to 10 seconds, and after agitation, static development is carried out for 60 to 100 seconds.
In the agitation, the wafer W is rotated at a low speed of 10 to 40 rpm for 1 to 4 seconds, three to five times for short periods of time.

FIG. 14 is a diagram showing another example of the first ejection unit and the third ejection unit.
1 and the like, the first discharge portion 41 and the third discharge portion 43 are separate from each other. In contrast, in Fig. 14, the first discharge portion 41A and the third discharge portion 43A are integrated together.

In FIG. 14, in the composite discharge section 44 in which the first discharge section 41A and the third discharge section 43A are integrated, the first discharge section 41A has nozzles 44a and 44b, and the third discharge section 43A has nozzle 44c.

The nozzle 44a has a discharge port 45a formed therein for discharging the developer in a strip shape narrower than the width of the wafer W.
The nozzle 44b is formed with a discharge port 45b for discharging the developing solution in a linear shape.
The nozzle 44c is formed with a discharge port 45c for discharging pure water in a linear shape.

When the composite discharge unit 44 is used, for example, in the central discharge development of step S1, the developer is discharged from the discharge port 45b of the nozzle 44b, and in the peripheral discharge development of step S21, the developer is discharged from the discharge port 45a of the nozzle 44a. Also, for example, in the pre-wetting of the wafer W in step S11, pure water is discharged from the discharge port 45c of the nozzle 44c.

In addition, the portion of the wafer W where the developer discharge starts and ends during the peripheral discharge development in step S21 and the portion of the wafer W where the developer discharge starts during the paddle formation in step S2 may be located opposite each other. This ensures that the portion exposed to the developer for a long time during the peripheral discharge development in step S21 is not the same as the portion exposed to the developer for a long time during the paddle formation in step S2, further improving the uniformity of the resist pattern dimensions within the wafer.

The position at which the developer ejection starts may be determined based on the rotational position, i.e., orientation, of the wafer W. Information relating to the rotational position of the wafer W is acquired, for example, as follows. That is, if the chuck driving mechanism 21 includes an encoder for detecting the rotational position of the spin chuck 20, the position of the reference point is identified based on the information obtained by the encoder, and the information relating to the rotational position is acquired based on the identification result. The position of the reference point may be identified without using an encoder. Also, a method may be used in which a sensor for detecting the rotational position of the spin chuck 20 is provided on or around the spin chuck 20, and the information on the rotational position of the spin chuck 20 obtained from this sensor is acquired as information relating to the rotational position.

After the paddle development in step S3, a process of developing the outer periphery of the wafer W from the center, i.e., peripheral development, may be performed. Figure 15 is a diagram showing a schematic diagram of the state of the periphery of the wafer W during the peripheral development.

Immediately after the start of peripheral development, i.e., immediately after the end of paddle development in step S3, a paddle DP of developer is present, as shown in FIG. 15(A). In this state, the wafer W is rotated at a predetermined number of rotations (e.g., 100 rpm) for a predetermined time (e.g., 1.5 seconds) without ejection of developer or pure water. This causes the developer on the center of the wafer W to move to the outer periphery of the wafer W, as shown in FIG. 15(B).

Then, for a predetermined time (e.g., 0.5 to 2 seconds), the pure water is discharged from the third discharge part 43 toward the center of the wafer W held by the spin chuck 20 as shown in FIG. 15(C), while the wafer W is rotated at a predetermined rotation speed (e.g., 30 rpm).

Thereafter, as shown in FIG. 15(D), the discharge of the pure water is stopped, and in this state, the wafer W is rotated at a predetermined rotation speed (e.g., 10 to 20 rpm) for a predetermined time (e.g., 2 to 4 seconds).
After the peripheral development, the wafer W is rinsed in step S4 and dried in step S5.

During peripheral development, as described above, the developer on the center of the wafer W is concentrated on the outer periphery of the wafer W, and then the pure water is sprayed onto the wafer W, allowing the pure water to hit the wafer W directly. As a result, it is possible to prevent development from progressing in the center of the wafer W. Also, by concentrating the developer on the center of the wafer W on the outer periphery of the wafer W, an area with a large amount of developer is formed on the outer periphery of the wafer W, so that it is possible to prevent the pure water from reaching the outer periphery. As a result, it is possible to prevent the development speed on the outer periphery from decreasing due to the influence of the pure water.

The technology disclosed herein can be applied to both thick resist films on the order of tens of microns, and thin resist films on the order of hundreds of nanometers.

The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various ways without departing from the spirit and scope of the appended claims. For example, the components of the above-described embodiments may be combined in any manner. Such combinations will naturally provide the functions and effects of each of the components in the combination, as well as other functions and effects that will be apparent to those skilled in the art from the description in this specification.

Furthermore, the effects described in this specification are merely descriptive or exemplary and are not limiting. In other words, the technology disclosed herein may achieve other effects that are apparent to a person skilled in the art from the description in this specification, in addition to or in place of the above effects.

Note that the following configuration examples also fall within the technical scope of the present disclosure.
(1) A development processing method for developing a resist film on a substrate, comprising the steps of:
(A) discharging a developer from a first discharge unit onto a central portion of the substrate while rotating the substrate, thereby developing the resist film and discharging a dissolved product produced by the development outside the substrate;
(B) discharging the developer from a second discharge unit onto the substrate, thereby discharging the dissolved product generated in the (A) step outside the substrate, reducing the concentration of the dissolved product in the developer on the substrate, and forming a puddle of the developer on the substrate;
(C) further developing the resist film while maintaining the puddle of developer formed in the (B) step.
(2) The second discharge portion is
a discharge port formed over a length covering the width of the substrate;
The developing method described in (1) above, wherein in the step (B), the developer is discharged from the discharge port while moving the second discharge part from one end to the other end of the substrate in a direction intersecting a direction in which the discharge port extends.
(3) The development method according to (1) or (2) above, wherein the development time in the step (C) is longer than the development time in the step (A).
(4) (D) The development method according to any one of (1) to (3), further comprising a step of discharging pure water from a third discharge unit onto the substrate before the step (A).
(5) (E) The development processing method according to any one of (1) to (3), further comprising, before the step (A), a step of discharging the developer from the first discharge part only onto the outer periphery of the substrate while rotating the substrate.
(6) The development method according to (5), wherein the rotation speed of the substrate in the step (E) is lower than the rotation speed of the substrate in the step (A).
(7) (E) The development method according to (4), further comprising, before the step (A), a step of discharging the developer from the first discharge part only onto the outer periphery of the substrate while rotating the substrate.
(8) The development method according to (7), wherein the step (D) is carried out after the step (E).
(9) The development method according to any one of (1) to (8) above, wherein the total discharge amount of the developer in the step (B) is greater than that in the step (A).
(10) The first ejection section is
The third discharge portion is formed separately from the third discharge portion,
a second discharge port for discharging the developer in a strip shape narrower than the width of the substrate;
The developing method according to (7) or (8), wherein in the step (A) and the step (E), the developer is discharged from the other discharge port.
(11) The first ejection section is
The first discharge portion is integrally formed with the first discharge portion.
a first discharge port that discharges the developer in a strip shape narrower than a width of the substrate;
a second discharge port that discharges the developer in a linear shape,
In the step (A), the developer is discharged from the first discharge port;
The developing method according to (7) or (8), wherein in the step (E), the developer is discharged from the second discharge port.
(12) The development method according to any one of (1) to (11), further comprising the step of discharging pure water from the third discharge section onto the substrate after the step (A) and before the step (B).
(13) A developing apparatus for developing a resist film on a substrate, comprising:
a substrate holder that holds the substrate horizontally;
a rotation mechanism that rotates the substrate holder about a vertical axis;
a first discharge unit and a second discharge unit, each of which supplies a developer to the substrate held by the substrate holding unit;
A control unit,
The control unit is
(a) discharging the developer from the first discharge unit onto a central portion of the substrate while rotating the substrate, thereby developing the resist film and discharging a dissolved product produced by the development outside the substrate;
(b) discharging the developer from the second discharge unit onto the substrate, thereby discharging the dissolved product generated in the process (a) outside the substrate, reducing the concentration of the dissolved product in the developer on the substrate, and forming a puddle of the developer on the substrate;
(c) further developing the resist film while maintaining the puddle of developer formed in the (b) step.
(14) The development processing apparatus described in (13), wherein the control unit further executes a step (d) before the step (a), of ejecting the developer from the first ejection unit only onto the outer periphery of the substrate while rotating the substrate.

Reference Signs List 1 Development treatment device 20 Spin chuck 21 Chuck drive mechanism 41, 41A First discharge unit 42 Second discharge unit 43, 43A Third discharge unit 44 Composite discharge unit U Control unit W Wafer

Claims (14)

A developing method for developing a resist film on a substrate, comprising the steps of:
(A) discharging a developer from a first discharge unit onto a central portion of the substrate while rotating the substrate, thereby developing the resist film and discharging a dissolved product produced by the development outside the substrate;
(B) discharging the developer from a second discharge unit onto the substrate, thereby discharging the dissolved product generated in the (A) step outside the substrate, reducing the concentration of the dissolved product in the developer on the substrate, and forming a puddle of the developer on the substrate;
(C) further developing the resist film while maintaining the puddle of developer formed in the (B) step. The second discharge portion is
a discharge port formed over a length covering the width of the substrate;
2. The developing method according to claim 1, wherein in the step (B), the developer is discharged from the discharge port while moving the second discharge section from one end to the other end of the substrate in a direction intersecting a direction in which the discharge port extends. The development processing method according to claim 2, wherein the development time in step (C) is longer than the development time in step (A). (D) The development processing method according to claim 3, further comprising a step of ejecting pure water onto the substrate from a third ejection section prior to the step (A). (E) The development processing method according to any one of claims 1 to 3, further comprising, before the step (A), a step of discharging the developer from the first discharge unit only onto the outer periphery of the substrate while rotating the substrate. The development processing method according to claim 5, wherein the rotation speed of the substrate in step (E) is lower than the rotation speed of the substrate in step (A). (E) The development processing method according to claim 4, further comprising a step of discharging the developer from the first discharge unit only onto the outer periphery of the substrate while rotating the substrate, prior to the step (A). The development processing method according to claim 7, in which the step (D) is carried out after the step (E). The development processing method according to any one of claims 1 to 4, wherein the total amount of developer discharged is greater in step (B) than in step (A). The first discharge portion is
The third discharge portion is formed separately from the third discharge portion,
a second discharge port for discharging the developer in a strip shape narrower than the width of the substrate;
The developing method according to claim 7 , wherein in the step (A) and the step (E), the developer is discharged from the other discharge port. The first discharge portion is
The first discharge portion is integrally formed with the first discharge portion.
a first discharge port that discharges the developer in a strip shape narrower than a width of the substrate;
a second discharge port that discharges the developer in a linear shape,
In the step (A), the developer is discharged from the second discharge port;
The development method according to claim 7 , wherein in the step (E), the developer is discharged from the first discharge port. The development processing method according to claim 4, further comprising a step of ejecting pure water from the third ejection section onto the substrate after the step (A) and before the step (B). A developing apparatus for developing a resist film on a substrate, comprising:
a substrate holder that holds the substrate horizontally;
a rotation mechanism that rotates the substrate holder about a vertical axis;
a first discharge unit and a second discharge unit, each of which supplies a developer to the substrate held by the substrate holding unit;
A control unit,
The control unit is
(a) discharging the developer from the first discharge unit onto a central portion of the substrate while rotating the substrate, thereby developing the resist film and discharging a dissolved product produced by the development outside the substrate;
(b) discharging the developer from the second discharge unit onto the substrate, thereby discharging the dissolved product generated in the process (a) outside the substrate, reducing the concentration of the dissolved product in the developer on the substrate, and forming a puddle of the developer on the substrate;
(c) further developing the resist film while maintaining the puddle of developer formed in the (b) step. The developing treatment device according to claim 13, wherein the control unit further executes a step (d) before the step (a), of discharging the developer from the first discharge unit only onto the outer periphery of the substrate while rotating the substrate.

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