Developing device and developing method

Abstract

To suppress an over-development or a pattern peeling at a center part of a substrate.SOLUTION: A development apparatus for developing a substrate, comprises: a rotational support part that rotates a substrate around a center part circumference of the substrate; a development nozzle that supplies a development liquid to a front surface of the substrate on the rotational support part; a nozzle movement mechanism that moves the development nozzle above the substrate at least in a horizontal direction; and a control part that controls the supply of the development liquid from the development nozzle, the rotational support part, and the nozzle movement mechanism. The control part is configured to execute the following step A and step B. The step A is a step that the development liquid is supplied from the development nozzle at a first position deviated from the center part of the substrate in a state where the substrate is rotated at a first speed to form an annular liquid film of the development liquid on the front surface of the substrate. The step B is a step that the development liquid is supplied at the first position from the development nozzle in a state where the substrate is rotated at a second speed lower than the first speed to cover the center part of the substrate by expand on the substrate of the development liquid when it is supplied to the substrate.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a development apparatus and a development method. [Background technology]

[0002] Patent Document 1 discloses a spin developer that supplies a rinse liquid from a rinse nozzle to an object to be cleaned after a development process to clean the developer, and is characterized in that the spin developer is provided with a first nozzle that causes the rinse liquid to flow toward the center of the object to be cleaned, and a second nozzle that causes the rinse liquid to flow toward the periphery of the object to be cleaned. This document describes that the developer is dripped from above the center of the wafer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-62549 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology according to the present disclosure suppresses overdevelopment and pattern peeling in the center of the substrate. [Means for solving the problem]

[0005] One aspect of the present disclosure is a developing apparatus for developing a substrate, the developing apparatus including: a rotation support part for rotating the substrate around a center of the substrate; a developing nozzle for supplying a developing solution to a surface of the substrate on the rotation support part; a nozzle movement mechanism for moving the developing nozzle at least horizontally above the substrate; and a control part for controlling the supply of the developing solution from the developing nozzle, the rotation support part, and the nozzle movement mechanism, the control part performing the following steps A and B: repetition A developing device configured to perform Step A: A step of supplying the developer from the developing nozzle at a first position off the center of the substrate while rotating the substrate at a first speed, thereby forming an annular liquid film of the developer on the surface of the substrate. Step B: While rotating the substrate at a second speed slower than the first speed, the developing nozzle supplies the developer at the first position, and the developer spreads over the substrate as it is supplied to the substrate, covering the center of the substrate. Effect of the Invention

[0006] According to the present disclosure, overdevelopment and pattern peeling in the center of the substrate can be suppressed. [Brief description of the drawings]

[0007] [Figure 1] 1 is a side cross-sectional view that illustrates a schematic configuration of a developing device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing a schematic outline of the configuration of the developing device shown in FIG. [Diagram 3] 1A to 1C are perspective views showing a process of a developing method according to an embodiment. [Figure 4] 10A to 10C are perspective views showing a process of a developing method according to another embodiment. [Diagram 5] 11 is a flowchart showing two loops of the process of the developing method according to the embodiment. [Figure 6] 1 is a graph showing the relationship between the position on a wafer and the line width of a pattern when the wafer is developed by a conventional developing method. [Figure 7] 10A to 10C are perspective views showing a process of a developing method according to another embodiment. [Figure 8] 9 is a graph showing the relationship between the position on a wafer and the line width of a pattern when the wafer is developed by the developing method of FIG. 8. [Figure 9] FIG. 13 is a side view showing a state in which the developing nozzle is moved toward the outer periphery above the wafer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] For example, in the manufacturing process of semiconductor devices, a development process is carried out as a liquid process in which a resist film is formed on the surface of a substrate such as a semiconductor wafer (hereinafter sometimes referred to as a "wafer"), a pattern is exposed to light, and then development is carried out. When developing, as disclosed in Patent Document 1, a developer is supplied from above the center of the substrate while rotating the substrate, and the developer is diffused by centrifugal force to cover the entire surface of the substrate.

[0009] With this type of development method, new developer is constantly supplied to the center of the substrate, which can result in over-development in the center, resulting in poor in-plane uniformity of the pattern, or the pressure exerted on the substrate surface when developer is supplied from the development nozzle can cause the pattern to peel off.

[0010] In view of this, the technology disclosed herein suppresses overdevelopment and pattern peeling in the center of the substrate when a developing solution is supplied to the substrate while the substrate is being rotated to perform a developing process.

[0011] Hereinafter, the configuration of the developing device according to the present embodiment will be described with reference to the drawings. In this specification, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description will be omitted.

[0012] 1 is a side cross-sectional view showing a schematic outline of the configuration of a developing device 1 according to this embodiment. The developing device 1 has a spin chuck 11 as a substrate holding unit in a housing 10. The spin chuck 11 horizontally holds a wafer W as a substrate. The spin chuck 11 is connected to a rotating unit 12 that can be raised and lowered, and the rotating unit 12 is connected to a rotation drive unit 13 formed of a motor or the like. Therefore, the held wafer W can be rotated by driving the rotation drive unit 13.

[0013] A cup 21 is disposed outside the spin chuck 11 to prevent the developer, rinse liquid, and mists thereof from scattering to the surroundings. A drain pipe 23 and an exhaust pipe 24 are provided at a bottom 22 of the cup 21. The drain pipe 23 is connected to a drainage device 25 such as a drainage pump. The exhaust pipe 24 is connected via a valve 26 to an exhaust device 27 such as an exhaust pump. With this configuration, the atmosphere around the wafer W held on the spin chuck 11 is exhausted from the exhaust pipe 24. The exhaust pipe 24 and the exhaust device 27 form an exhaust section.

[0014] An air blower 14 is provided at the upper portion within the housing 10 of the developing device 1, for supplying air at a required temperature and humidity as a downflow into the cup 21.

[0015] A developing nozzle 31 that supplies a developing solution onto the wafer W is provided on a nozzle support portion 32. A rinsing nozzle 33 is also provided on the nozzle support portion 32. The developing nozzle 31 and the rinsing nozzle 33 are arranged side by side in a straight line in the X direction.

[0016] 2, the nozzle support 32 is attached to an arm 41, which is connected to a moving mechanism 42. The moving mechanism 42 moves in the X direction along a guide rail 43 extending in the horizontal direction, and can raise and lower the arm 41 (movement in the Z direction). The moving mechanism 42 moves in accordance with a control signal from a control device 100, which will be described later, and the movement of the moving mechanism 42 allows the nozzle support 32 to move between a standby position outside the cup 21 and the center of the wafer W, and to stop at a desired position. The moving distance, moving speed, and moving direction of the moving mechanism 42 are also controlled by control signals from the control device 100.

[0017] The developing nozzle 31 communicates with a developing solution supply source 53 via a valve 51 and a pump 52. The rinsing nozzle 33 communicates with a rinsing solution supply source 56 via a valve 54 and a pump 55.

[0018] The developing apparatus 1 is controlled by a control device 100, which is a control unit. The control device 100 is, for example, a computer equipped with a CPU, a memory, etc., and has a program storage unit (not shown). The program storage unit stores various programs for controlling the developing process of the wafer W in the developing apparatus 1. The above programs may be recorded in a computer-readable storage medium and installed from the storage medium to the control device 100. The storage medium H may be a temporary storage medium or a non-temporary storage medium.

[0019] An example of the control is a series of processes from development to cleaning and drying. For example, a series of sequences of development processes including movement and stopping of the nozzle support part 32, supply and stopping of the developer from the development nozzle 31, rotation and stopping of the spin chuck 11, control of the rotation speed, supply and stopping of the rinse liquid from the rinse nozzle 33, etc. are also controlled.

[0020] Next, a developing method using the developing apparatus 1 having the above configuration will be described with reference to Figs. 3(a) to (d). The following example will be described based on a developing process for a negative type resist. First, the wafer W held on the spin chuck 11 is rotated at a first speed, and the nozzle support 32 is moved toward the center P of the wafer W and stopped at a first position, which is a predetermined position (Fig. 3(a)). Here, the first speed is a relatively high speed rotation (indicated by the arrow HI indicating the rotation direction in the figure), for example, 500 rpm. The first speed is preferably 500 rpm or less, and is preferably 300 rpm to 500 rpm. The first speed is faster than a second speed (relatively low speed rotation) described later, and the preferred rotation speed is faster than the second speed.

[0021] In this example, the first position, which is a predetermined position, is a position where the discharge port of the developing nozzle 31 is spaced a distance D1 of 30 mm from the center P of the wafer W in the horizontal direction. Of course, the present invention is not limited to this, and the distance D1 may be set within a range of, for example, 20 mm to 40 mm.

[0022] Next, at the first position, the developing nozzle 31 supplies the developing solution to the wafer W. The supply time is, for example, 2 to 10 seconds. As a result, a circular area not covered with the developing solution is formed on the wafer W as shown in FIG. 3(b) (step A in the present disclosure). In other words, the developing solution discharged onto the surface of the wafer W while the wafer W is rotating is spread by centrifugal force, while the developing solution discharged onto the surface of the wafer W spreads in a circular shape with the landing point as the center on the surface of the wafer W. When the centrifugal force is greater than the circular spread on the wafer W, a circular area not covered with the developing solution is formed as shown in FIG. 3(b), and the developing solution forms a liquid film of the developing solution in a ring shape with the center P of the wafer W as the center.

[0023] 3(c), while the discharge position of the developing nozzle 31 is kept at the first position, the developer is continuously supplied to the surface of the wafer W while rotating the wafer W at a second speed (indicated by the symbol Lo in the figure) slower than the first speed, for example, 40 rpm (step B in the present disclosure). Then, the centrifugal force decreases with the decrease in the rotation speed, and the developer supplied to the surface of the wafer W spreads more when the developer lands on the surface than the centrifugal force, and spreads to the center of the wafer W including the center P of the wafer W, so that the center of the wafer W is covered with the developer. The second speed may be any speed at which the developer spreads more when the developer lands on the surface than the centrifugal force caused by the rotation of the wafer W, for example, 10 rpm to 50 rpm.

[0024] The supply time can be, for example, 10 to 50 seconds (when multiple loops are not set, as described later), but can be appropriately set in relation to the second speed. For example, it can be appropriately determined based on the residence time of the developer at the center of the wafer W as it spreads to the center, that is, the development time. For example, when the development time is 60 seconds, when the developer is supplied for 10 seconds at the first speed, the developer is supplied for 50 seconds at the second speed. Also, since the developer continues to be supplied from the development nozzle 31 in step B, pattern collapse caused by the sudden movement of the developer on the wafer W due to the sudden deceleration of the rotation speed of the wafer W, so-called pullback, does not occur.

[0025] Thereafter, the discharge of the developer is stopped, and as shown in Fig. 3(d), the nozzle support part 32 is moved toward the center P and stopped at a position where the distance R from the center P of the wafer W to the discharge port of the rinse nozzle 33 is, for example, 10 mm. Then, at this position, a rinse liquid, for example, pure water is supplied from the rinse nozzle 33 to the wafer W. At this time, since the discharge position of the rinse liquid is closer to the center P than the above-mentioned distance D1, the rotation speed of the wafer W may be equal to or higher than the first speed. The distance R can be, for example, 5 mm to 10 mm.

[0026] According to the developing method of this embodiment, the developer is supplied to a position away from the center P of the wafer W, and the developer is not continuously supplied to the center position of the wafer W as in the conventional method. Therefore, it is possible to prevent the pattern from peeling off at the center of the wafer W. In other words, by performing a step of not supplying the developer directly from the developing nozzle 31 to the center P of the wafer W during the developing process, it is possible to control the degree and progress of development at the center of the wafer W.

[0027] According to the inventor's findings, it has been found that pattern peeling is correlated with the integrated value of the pressure (liquid pressure) when the developer is supplied. Therefore, by adopting a process and step in which the developer is not directly supplied to the center of the wafer W as in the above-mentioned embodiment, the integrated value of the liquid pressure at the center of the wafer W can be reduced, and the occurrence of pattern peeling during development can be significantly suppressed.

[0028] In addition, since the developer reaches the center of the wafer W after the wafer W is rotated at the second speed in step B of the present disclosure, the time during which the developer remains in the center, i.e., the developing time, is shorter than in the conventional developing method in which the developer is constantly supplied to the center. Therefore, it is possible to suppress overdevelopment in the center of the wafer W, which was previously observed.

[0029] Furthermore, in the above embodiment, the position where the rinse liquid is supplied by the rinse nozzle 33 is also off the center P of the wafer W, so that it is possible to suppress pattern peeling and pattern collapse at the center of the wafer W due to the supply of the rinse liquid.

[0030] In the above embodiment, step A is performed in which the wafer W is rotated at a first speed, followed by step B in which a developer is supplied at a second rotation speed slower than the first rotation speed. However, step B may be performed first, and then step A may be performed.

[0031] 4 shows the process in this case, in which the wafer W held on the spin chuck 11 is rotated at a second speed, the nozzle support 32 is moved toward the center P of the wafer W, and stopped at a first position, which is a predetermined position (FIG. 4(a)), and then, as shown in FIG. 4(b), while the wafer W is rotating at the second speed, a developer is supplied to the wafer W from the developing nozzle 31 at the first position. Then, the supplied developer spreads to cover the central part of the wafer W including the center P.

[0032] Next, as shown in Fig. 4(c), the wafer W is rotated at a first speed faster than the second speed. Then, since the developing solution is supplied onto the wafer W at a position away from the center P of the wafer W, the developing solution at the center also flows toward the outer periphery of the wafer W due to centrifugal force, and a ring-shaped liquid film of the developing solution is formed on the wafer W. Thereafter, the supply of the developing solution is stopped, the nozzle support part 32 is moved toward the center of the wafer W, the discharge port of the rinse nozzle 33 is positioned at a position distance R from the center P of the wafer W, and the rinse solution is supplied to the wafer W from the rinse nozzle 33 to clean the wafer W (Fig. 4(d)).

[0033] In this manner, step B in the present disclosure is performed first to perform development processing of at least the central portion of the wafer W, and then step A in the present disclosure is performed. Therefore, it is possible to appropriately respond to development processing of a resist in which the overall development processing is dominated by the first half of the development, such as a KrF resist or an ArF resist, in other words, development processing in which the sensitivity differs between the first and second halves of the development processing, and to suitably control development of the central portion of the wafer W.

[0034] In the embodiment of FIG. 3 described above, step A (FIG. 3(b)) is followed by step B (FIG. 3(c)), after which a cleaning step (FIG. 3(d)) is performed by supplying a rinsing liquid. However, steps A and B may be repeated.

[0035] The flow chart in Fig. 5 shows the process in such a case. First, LOOP 1 is explained. The wafer W is rotated at a first speed (step S1), the developer is discharged at a first position (step S2), and the wafer W is rotated at a second speed while the developer is still being discharged (step S3). Then, the supply of the developer is stopped (step S4). In the example shown in Fig. 3, the wafer W is then cleaned by supplying a rinse liquid.

[0036] In the example shown in FIG. 5, after the supply of the developing solution is stopped, the developing solution is replaced and fresh developing solution is newly supplied by rotating the wafer W once to shake off the developing solution on the wafer W (step S5). Next, as LOOP2, the wafer W is rotated at a first speed (step S6), the developing solution is discharged at the first position (step S7), the wafer W is rotated at a second speed while still discharging the developing solution (step S8), and then the supply of the developing solution is stopped (step S9). That is, steps A and B in the present disclosure are repeated. After that, a rinsing solution is supplied to clean the surface of the wafer W (step S10), and then the supply of the rinsing solution is stopped, and the wafer W is rotated to so-called shake off and dry the wafer W (step S11).

[0037] In this manner, by repeatedly performing step A and step B in the present disclosure, it is possible to expand the range of control over the degree of development of the central portion of the wafer W. That is, for example, by adjusting the time of step S2 in LOOP1 and the time of step S7 in LOOP2 or making them different from each other, it is possible to control the degree and progress of development of the central portion of the wafer W, and also to efficiently perform the development process by supplying fresh developer in LOOP2.

[0038] Incidentally, in the conventional method of developing by constantly supplying a developer to the center of the wafer W while rotating the wafer W, as described above, the center of the wafer W is prone to overdevelopment. As a result, as shown in FIG. 6, the line width of the pattern tends to be narrower toward the center and wider toward the periphery, leaving room for improvement in the uniformity of the development process within the substrate surface.

[0039] From this viewpoint, for example, the process shown in Fig. 7 can be proposed. That is, in the above-mentioned step B, initially, as shown in Fig. 7(a), the developing nozzle 31 supplies the developing solution to the wafer W at a first position (e.g., distance D1 = 30 mm) while rotating the wafer W at a second speed. Then, as shown in Fig. 7(b), the developing nozzle 31 is moved to a second position (e.g., distance D2 = 60 mm) on the outer periphery while maintaining the second speed.

[0040] After that, for example, after 5 seconds have elapsed, the developing nozzle 31 is moved to a third position (e.g., D3=90 mm) on the outer periphery side while maintaining the second speed, as shown in FIG. 7(c). In this way, development from the center P of the wafer W to the intermediate portion can be suppressed in stages. As a result, the line width profile of the wafer W after development can be made generally flatter, as shown in FIG. 8, and the in-plane uniformity of the development process can be improved. In such a case, the developing nozzle 31 may be moved continuously, instead of in such a stepwise manner.

[0041] Furthermore, such movement of the development nozzle 31 may be performed when repeating steps A and B in the present disclosure, i.e., when executing LOOP1 and LOOP2, as in the flowchart shown in Figure 5, in each of LOOP1 and LOOP2, or in either LOOP.

[0042] Furthermore, in the case where step A and step B in the present disclosure are repeated three times, that is, in the case of a process having LOOP1 to LOOP3, in step B of LOOP1, the developing nozzle 31 may be discharged at the position shown in FIG. 7(a) (a position at a distance D1 from the center P of the wafer W), in step B of LOOP2, the developing nozzle 31 may be discharged at the position shown in FIG. 7(b) (a position at a distance D2 from the center P of the wafer W), and in step B of LOOP3, the developing nozzle 31 may be discharged at the position shown in FIG. 7(c) (a position at a distance D3 from the center P of the wafer W). That is, the discharge position may be shifted for each LOOP. With such a process, the development from the center P of the wafer W to the intermediate portion can be suppressed in stages, and the line width profile of the wafer W after development can be generally made flatter as shown in FIG. 8.

[0043] The movement of the developing nozzle 31 described above is performed in step B, but also in step A, the developing nozzle 31 may be moved stepwise or continuously from the center side to the peripheral side to supply the developing solution to the wafer W.

[0044] Furthermore, while the movement of the developing nozzle 31 described above is stepwise or continuous from the first position toward the peripheral edge as indicated by the arrow M in Fig. 9, it may be moved from the peripheral edge side to the center side of the wafer W as indicated by the dashed arrow N in Fig. 9. In this case, the rotation speed of the wafer W may be set to a relatively low speed (second speed) when the developing nozzle 31 is located on the peripheral edge side, and may be set to a relatively high speed (first speed) when the developing nozzle 31 is located on the central portion side of the wafer W.

[0045] Although the above example is effective for the development process of a negative type resist, it is not limited to this and is also effective for a positive type resist.

[0046] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0047] 1 Developing device 10. Chassis 11 Spin chuck 12 Rotating section 13 Rotation drive unit 14 Blower 21 cups 22 Bottom 23 Drainage tube 24 Exhaust pipe 25 Drainage device 26 Valve 27 Exhaust system 31 Development nozzle 32 Nozzle support 33 Rinse nozzle 100 Control device P center W wafer

Claims

1. A developing apparatus for developing a substrate, comprising: a rotation support that rotates the substrate around a center of the substrate; a developing nozzle for supplying a developing solution to a surface of the substrate on the rotation support; a nozzle moving mechanism that moves the developing nozzle at least horizontally above the substrate; a control unit that controls the supply of developer from the developing nozzle, the rotation support unit, and the nozzle movement mechanism, The control unit is configured to repeatedly execute the following steps A and B. Step A: While rotating the substrate at a first speed, the developer is supplied from the developing nozzle at a first position off the center of the substrate to form an annular liquid film of the developer on the surface of the substrate. Step B: While rotating the substrate at a second speed slower than the first speed, the developing nozzle supplies the developer at the first position, and the developer spreads over the substrate when supplied to the substrate to cover the center of the substrate.

2. 2. The developing apparatus according to claim 1, wherein said step B is performed after said step A.

3. 2. The developing apparatus of claim 1, wherein step A is performed after step B.

4. 4. The developing device according to claim 1, wherein, when the steps A and B are repeatedly performed, the developing nozzle supplies the developer at a second position different from a first position at which the developer is initially supplied.

5. The developing device according to any one of claims 1 to 4, wherein the first speed is 500 rpm or less.

6. 6. The developing device according to claim 1, wherein in step A or step B, the developing nozzle is moved from the first position toward the peripheral edge of the substrate while supplying a developer from the developing nozzle.

7. 7. The development apparatus of claim 6, wherein the movement is stepwise or continuous.

8. a rinse nozzle for supplying a rinse liquid to a surface of the substrate; a rinse nozzle moving mechanism that moves the rinse nozzle at least horizontally above the substrate; a control unit that controls the supply of the rinse liquid from the rinse nozzle and the rinse nozzle moving mechanism, The control unit is The developing device according to any one of claims 1 to 7, further configured to perform a step of supplying a rinsing liquid to the substrate at a position where the rinse nozzle is off the center of the substrate while rotating the substrate at a second speed slower than the first speed after performing the step A or the step B.

9. A developing method for developing a substrate using a developer, comprising the steps of: supplying a developer to a first position off the center of the substrate while rotating the substrate at a first speed, thereby forming an annular developer film on a surface of the substrate; supplying the developer at the first position while rotating the substrate at a second speed slower than the first speed, so that the developer spreads over the substrate when supplied to the substrate to cover a central portion of the substrate; having The developing method comprises repeating each of the steps.

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