JP2023008218A - Development apparatus and development method - Google Patents

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

The present disclosure relates to a developing device and a developing method.

Patent Document 1 discloses a spin developer that cleans a developing solution by supplying a rinse liquid from a rinse nozzle to an object to be cleaned after development processing, in which a first nozzle that causes the rinse solution to flow out to the center of the object to be cleaned; This document discloses a spin developer characterized by comprising a second nozzle for discharging the rinse liquid to the periphery of the object to be cleaned. is stated.

JP-A-2-62549

The technique according to the present disclosure suppresses overdevelopment and pattern peeling at the center of the substrate.

One aspect of the present disclosure is a developing device that develops a substrate, comprising: a rotation support that rotates the substrate around the center of the substrate; and a development that supplies a developer to the surface of the substrate on the rotation support. a nozzle, a nozzle moving mechanism for moving the developing nozzle at least horizontally above the substrate, and a control unit for controlling supply of developer from the developing nozzle, the rotation support, and the nozzle moving mechanism. , the developing device, wherein the control unit is configured to execute steps A and B below.
Step A: While the substrate is rotated at a first speed, the developer is supplied from the developing nozzle at a first position away from the center of the substrate to form an annular shape on the surface of the substrate. Forming a liquid film of developer.
Step B: With the substrate being rotated at a second speed slower than the first speed, the developing nozzle is positioned at the first position to supply the developer, and when the developer is supplied to the substrate covering the center of said substrate with a spread of developer on said substrate.

According to the present disclosure, overdevelopment and pattern peeling at the center of the substrate can be suppressed.

1 is a side cross-sectional view schematically showing the outline of the configuration of a developing device according to an embodiment; FIG. 2 is a plan view schematically showing the outline of the configuration of the developing device of FIG. 1; FIG. FIG. 4 is a perspective view showing a state of the process of the developing method according to the embodiment; FIG. 10 is a perspective view showing a process of a developing method according to another embodiment; 4 is a flow chart when the process of the developing method according to the embodiment is executed in two loops; 5 is a graph showing the relationship between the position of the wafer and the line width of the pattern when the wafer is developed by a conventional developing method; FIG. 10 is a perspective view showing a process of a developing method according to another embodiment; 9 is a graph showing the relationship between the position of the wafer and the line width of the pattern when the wafer is developed by the developing method of FIG. 8; FIG. 5 is a side view showing how the developing nozzle is moved to the outer peripheral side on the wafer;

For example, in the manufacturing process of semiconductor devices, a resist film is formed on the surface of a substrate such as a semiconductor wafer (hereinafter sometimes referred to as a "wafer"), and after pattern exposure, a development process is performed as a liquid process for development. It is In the case of development, as disclosed in Patent Document 1, the developer can be supplied from above the center of the substrate while the substrate is being rotated, and the developer can be spread over the entire surface of the substrate by centrifugal force. It is done.

According to such a developing method, new developer is constantly supplied to the central portion of the substrate, and the central portion is overdeveloped (overdeveloped), resulting in deterioration of in-plane uniformity of the pattern. Pattern peeling may occur due to the pressure that the substrate surface receives when the developing solution is supplied from the developing nozzle.

Therefore, the technology according to the present disclosure suppresses overdevelopment and pattern peeling at the central portion of the substrate when the developing solution is supplied to the substrate while the substrate is being rotated.

The configuration of the developing device according to this embodiment will be described below with reference to the drawings. In this specification, elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description.

FIG. 1 shows a side cross-sectional view schematically showing the 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 holder 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 portion 12 that can move up and down, and the rotating portion 12 is connected to a rotation driving portion 13 configured by a motor or the like. Therefore, the held wafer W can be rotated by the driving of the rotation drive unit 13 .

A cup 21 is arranged on the outside of the spin chuck 11 to prevent scattering of developer, rinse, and their mist from scattering around. A drain pipe 23 and an exhaust pipe 24 are provided at the bottom 22 of the cup 21 . The drainage pipe 23 leads to a drainage device 25 such as a drainage pump. The exhaust pipe 24 communicates through a valve 26 with an exhaust device 27 such as an exhaust pump. With this configuration, the atmosphere around the wafer W held by the spin chuck 11 is exhausted through the exhaust pipe 24 . The exhaust pipe 24 and the exhaust device 27 constitute an exhaust section.

An air blower 14 is provided above the housing 10 of the developing device 1 to supply air of required temperature and humidity into the cup 21 as a downward flow.

A developing nozzle 31 for supplying developer onto the wafer W is provided on a nozzle supporting portion 32 . A rinse nozzle 33 is also provided in the nozzle support portion 32 . These developing nozzles 31 and rinsing nozzles 33 are arranged linearly in the X direction.

As shown in FIG. 2, the nozzle support part 32 is attached to an arm 41, and the arm 41 is connected to a moving mechanism 42. The moving mechanism 42 can move 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 according to a control signal from the control device 100, which will be described later, and the movement of the moving mechanism 42 moves the nozzle support 32 between the standby position outside the cup 21 and the center of the wafer W. and can be stopped at any 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 .

The developer nozzle 31 communicates with a developer supply source 53 via a valve 51 and a pump 52 . The rinse nozzle 33 communicates with a rinse liquid supply source 56 via a valve 54 and a pump 55 .

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

An example of control is a series of processes from development to washing and drying. For example, the movement and stop of the nozzle support portion 32, the supply and stop of the developing solution from the developing nozzle 31, the rotation and stop of the spin chuck 11, the control of the rotation speed, the supply and stop of the rinse solution from the rinse nozzle 33, etc. A series of developing processing sequences are also controlled.

Next, a developing method using the developing device 1 having the above configuration will be described with reference to FIGS. 3(a) to 3(d). The following examples are described based on the development process of a negative type resist. First, the wafer W held on the spin chuck 11 is rotated at a first speed, the nozzle support portion 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 sign HI indicating the direction of rotation in the drawing), for example, 500 rpm. The first speed is, for example, 500 rpm or less, preferably 300 rpm to 500 rpm. Since the first speed is faster than a second speed (relatively low speed rotation), which will be described later, the preferred rotation speed is faster than the second speed.

In this example, the first position, which is the predetermined position, is the position where the discharge port of the developing nozzle 31 is horizontally separated from the center P of the wafer W by a distance D1 of 30 mm. Of course, the distance D1 is not limited to this, and may be set within a range of 20 mm to 40 mm, for example.

Next, the developing solution is supplied to the wafer W from the developing nozzle 31 at the first position. The supply time is, for example, 2 to 10 seconds. As a result, a circular region not covered with the developer is formed on the wafer W (step A in the present disclosure), as shown in FIG. 3(b). In other words, the developer discharged onto the surface of the wafer W while the wafer W is rotating is spread by centrifugal force, while the developer discharged onto the surface of the wafer W lands on the surface of the wafer W. Spread out in a circle around the center. Then, when the centrifugal force is larger than the circular spread on the wafer W, as shown in FIG. A liquid film of the developer is formed in an annular shape with the center P of W as the center.

Next, as shown in FIG. 3C, the ejection position of the developing nozzle 31 remains at the first position, and the rotational speed of the wafer W is set to a second speed (indicated by Lo (indicated by ), and while rotating at, for example, 40 rpm, the developer is continuously supplied to the surface of the wafer W (step B in the present disclosure). As a result, the centrifugal force decreases as the rotation speed decreases, and the developing solution supplied to the surface of the wafer W spreads more when the developing solution lands on the surface than the centrifugal force. It spreads to the center of the wafer W including P, and the center of the wafer W is covered with the developer. The second speed may be a speed at which the spreading of the developing solution when it lands is greater than the centrifugal force due to the rotation of the wafer W, and is preferably 10 rpm to 50 rpm.

The supply time can be, for example, 10 seconds to 50 seconds (when multiple LOOPs are not set, which will be described later), but can be set as appropriate in relation to the second speed. For example, it can be appropriately determined by the retention 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 developing time is 60 seconds, when the first speed is supplied for 10 seconds, the second speed is supplied for 50 seconds. Also in step B, since the developer continues to be supplied from the development nozzle 31, the pattern collapses due to the rapid movement of the developer on the wafer W due to the rapid deceleration of the rotational speed of the wafer W, which is called pullback. never occurs.

After that, the discharge of the developer is stopped, and the nozzle support portion 32 is moved toward the center P as shown in FIG. Stop at a position where R is 10 mm, for example. At this position, a rinse liquid such as pure water is supplied to the wafer W from the rinse nozzle 33 . At this time, since the discharge position of the rinse liquid is closer to the center P than the distance D1, the rotational speed of the wafer W should be equal to or higher than the first speed. As the distance R, for example, 5 mm to 10 mm can be exemplified.

According to the developing method according to this embodiment, the developer is supplied at a position away from the center P of the wafer W, and the developer is continuously supplied to the center position of the wafer W as in the conventional art. not Therefore, the occurrence of pattern peeling at the central portion of the wafer W is suppressed. That is, by performing a step in which the developing solution is not directly supplied from the developing nozzle 31 to the center P of the wafer W during the developing process, the degree and progress of development of the central portion of the wafer W can be controlled. .

According to the knowledge of the inventors, it has been found that the pattern peeling has a correlation with the integrated value of the pressure (liquid pressure) when the developer is supplied. Therefore, by adopting processes and steps in which the developer is not directly supplied to the center of the wafer W as in the above-described embodiment, the integrated value of the liquid pressure at the center of the wafer W can be reduced. , the occurrence of pattern peeling during development can be greatly suppressed.

Further, since the developer spreads to 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 the developer stays in the center, i.e. The developing time is shorter than the conventional developing method in which developer is continuously supplied to the center. Therefore, it is possible to suppress over-development at the central portion of the wafer W, which is conventionally observed.

Furthermore, in the above-described embodiment, the position where the rinse liquid is supplied by the rinse nozzle 33 is also at a position deviated from the center P of the wafer W. Therefore, the supply of the rinse liquid causes pattern peeling and pattern collapse at the center of the wafer W. can also be suppressed.

In the above embodiment, after step A of rotating the wafer W at the first speed, step B of supplying the developer at the second rotation speed lower than the first rotation speed is performed. , step B may be executed, and then step A may be executed.

FIG. 4 shows the state of the process in such a case. The wafer W held on the spin chuck 11 is rotated at the second speed, the nozzle support section 32 is moved toward the center P of the wafer W, and the predetermined position is reached. (FIG. 4(a)), and thereafter, as shown in FIG. 4(b), the wafer W is rotated at the second speed at the first position. A developing solution is supplied to the wafer W from the developing nozzle 31 . Then, the supplied developer spreads over the central portion of the wafer W including the center P due to its spreading.

Next, as shown in FIG. 4(c), the wafer W is rotated at a first speed higher than the second speed. Then, since the developer is supplied onto the wafer W at a position away from the center P of the wafer W, the developer at the center also flows toward the outer periphery of the wafer W due to the centrifugal force, and the wafer W is displaced. An annular liquid film of the developing solution is formed on the . After that, the supply of the developer 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 of the distance R from the center P of the wafer W, and the rinse nozzle 33 Then, the wafer W is cleaned by supplying the rinse liquid to the wafer W (FIG. 4(d)).

In this way, step B in the present disclosure is performed first to develop at least the central portion of the wafer W first, and then step A in the present disclosure is performed. In addition, the central portion of the wafer W is appropriately handled in response to the developing process of the resist in which the overall developing process is dominant in the first half of the developing process, in other words, the developing process with different sensitivities between the first half and the latter half of the developing process. development can be suitably controlled.

Further, in the embodiment of FIG. 3 described above, step B (FIG. 3(c)) is executed after step A (FIG. 3(b)), and then a washing step (FIG. 3(d)) by supplying a rinse liquid. was executed, step A and step B may be executed repeatedly.

The flowchart of FIG. 5 shows the process in such a case. First, LOOP1 will be described. The wafer W is rotated at a first speed (step S1), and the developer is discharged at the first position (step S2). , the wafer W is rotated at the second speed while discharging the developer (step S3). After that, the supply of the developer is stopped (step S4). In the example shown in FIG. 3, after that, the wafer W is cleaned by supplying the rinsing liquid.

In the example shown in FIG. 5, after stopping the supply of the developer, the wafer W is once rotated to shake off the developer on the wafer W in order to replace the developer and supply fresh developer. (Step S5). Next, in LOOP2, the wafer W is rotated at a first speed (step S6), the developer is discharged at the first position (step S7), and the wafer W is rotated at the second speed while discharging the developer. (step S8), and then the supply of the developer is stopped (step S9). That is, step A and step B in the present disclosure are repeated. After that, the rinse liquid is supplied to clean the surface of the wafer W (step S10), and after stopping the supply of the rinse liquid, the wafer W is rotated to dry the wafer W (step S11).

By repeating Step A and Step B in the present disclosure in this way, the range of control of the degree of development of the central portion of the wafer W can be increased. That is, for example, by adjusting the time of step S2 in LOOP1 and the time of step S7 in LOOP2, or setting them to mutually different times, the degree and progress of development of the central portion of wafer W can be controlled, and The supply of fresh developing solution in the step makes it possible to carry out development processing efficiently.

By the way, in the conventional method of developing by continuously supplying the developer to the center of the wafer W while rotating the wafer W, as described above, the center of the wafer W tends to be overdeveloped. 6, the line width of the pattern tends to be thin at the center and thicken toward the outer periphery, leaving room for improvement in the uniformity of the development treatment within the substrate surface.

From this point of view, for example, the process shown in FIG. 7 can be proposed. That is, in the step B described above, initially, as shown in FIG. 7A, the wafer W is rotated at the second speed while being moved from the developing nozzle 31 to the wafer W at the first position (for example, the distance D1=30 mm). supply the developer to the After that, as shown in FIG. 7B, the developing nozzle 31 is moved to a second position (for example, distance D2=60 mm) on the outer peripheral side while maintaining the second speed.

After, for example, five seconds have passed, the second speed is maintained and the developing nozzle 31 is moved to a third position (for example, D3=90 mm) on the outer peripheral side as shown in FIG. 7(c). By doing so, the development from the center P of the wafer W to the intermediate portion can be suppressed step by step. As a result, the line width profile of the wafer W after development can be generally made flatter as shown in FIG. 8, and the in-plane uniformity of the development process can be improved. In such a case, the movement of the developing nozzle 31 may be continuous instead of stepwise movement.

In addition, such movement of the development nozzle 31 is performed when steps A and B in the present disclosure are repeated, that is, when LOOP1 and LOOP2 are executed, as in the flowchart shown in FIG. may be performed in a LOOP of

Furthermore, when steps A and 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 position of the developing nozzle 31 (the center of the wafer W) shown in FIG. P), and in step B of LOOP2, discharge is performed at the position of the developing nozzle 31 shown in FIG. In step B of 1, the liquid may be discharged at the position of the developing nozzle 31 shown in FIG. That is, the ejection position may be shifted for each LOOP. Also by such a process, the development from the center P to the intermediate portion of the wafer W can be suppressed in stages, so that the line width profile of the wafer W after development is as shown in FIG. It can be generally flatter.

The movement of the developing nozzle 31 described above is performed in step B. In step A as well, the developing nozzle 31 is moved stepwise or continuously from the center side to the peripheral side to spread the developer onto the wafer W. may be supplied to

Furthermore, the movement of the developing nozzle 31 described above was to move stepwise or continuously from the first position to the peripheral edge side as indicated by the arrow M in FIG. , the wafer W may be moved from the peripheral edge side to the center side. In this case, the rotational speed of the wafer W is relatively low (second speed) when the developing nozzle 31 is positioned on the peripheral side, and is relatively high when the developing nozzle 31 is positioned on the center side of the wafer W. (first speed).

The example described above is effective for developing a negative type resist, but is not limited to this and is also effective for a positive type resist.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The embodiments described above may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

Reference Signs List 1 developing device 10 housing 11 spin chuck 12 rotating portion 13 rotation driving portion 14 blowing device 21 cup 22 bottom portion 23 drainage pipe 24 exhaust pipe 25 drainage device 26 valve 27 exhaust device 31 development nozzle 32 nozzle support portion 33 rinse nozzle 100 Controller P Center W Wafer

Claims (10)

A developing device for developing a substrate,
a rotation support that rotates the substrate around the center of the substrate;
a developing nozzle that supplies a developing solution to the surface of the substrate on the rotation support;
a nozzle moving mechanism for moving the developing nozzle at least horizontally above the substrate;
a control unit that controls supply of the developer from the development nozzle, the rotation support unit, and the nozzle movement mechanism;
The developing device, wherein the control unit is configured to execute steps A and B below.
Step A: While the substrate is rotated at a first speed, the developer is supplied from the developing nozzle at a first position away from the center of the substrate to form an annular shape on the surface of the substrate. Forming a liquid film of developer.
Step B: With the substrate being rotated at a second speed slower than the first speed, the developing nozzle is positioned at the first position to supply the developer, and when the developer is supplied to the substrate covering the center of said substrate with a spread of developer on said substrate. 2. The developing device according to claim 1, wherein said step B is performed after said step A. 2. The developing device according to claim 1, wherein said step A is performed after said step B. 4. The developing device according to claim 1, wherein said step A and said step B are repeatedly performed. 5. The development according to claim 4, wherein when said step A and said step B are repeatedly performed, said developer nozzle supplies developer at a second position different from the first position where it is initially supplied. Device. The development device according to any one of claims 1 to 5, wherein said first speed is 500 rpm or less. 7. The method according to any one of claims 1 to 6, wherein in step A or step B, the developing nozzle is moved from the first position to the peripheral edge side of the substrate while supplying the developing solution from the developing nozzle. Developing apparatus as described. 8. The development device of claim 7, wherein said movement is stepwise or continuous. a rinse nozzle that supplies a rinse liquid to the 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
After executing the step A or the step B, and while the substrate is being rotated at a second speed lower than the first speed, the rinse nozzle is placed at a position away from the center of the substrate. supplying the rinsing liquid to the substrate at the position, and spreading the rinsing liquid on the substrate when supplied to the substrate at the position to spread the rinsing liquid to the center of the substrate. The development device according to any one of claims 1 to 8, wherein: A developing method for developing a substrate using a developer,
While rotating the substrate at a first speed, a developer is supplied at a first position away from the center of the substrate to form an annular liquid film of the developer on the surface of the substrate. a step;
While the substrate is rotated at a second speed slower than the first speed, the developer is supplied at the first position, and the developer is applied to the substrate when supplied to the substrate. covering a central portion of the substrate with an extension;
A developing method.

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