KR20240139212A - Substrate treating apparatus - Google Patents

Abstract

The substrate processing apparatus of the present invention comprises: a spin chuck for supporting a substrate; a nozzle unit for discharging a photoresist onto the substrate; and a control unit for controlling a rotational operation of the spin chuck, wherein the control unit maintains the spin chuck at a first rotation speed during a first process time, and accelerates the spin chuck from the first rotation speed to a second rotation speed during a second process time, and the second process time is 1 second to 8 seconds or less.

Description

{SUBSTRATE TREATING APPARATUS}

The present invention relates to a substrate processing device.

The manufacturing process of semiconductor devices includes processes such as photolithography, etching, ashing, thin film deposition, and cleaning. Among these processes, the photolithography, etching, ashing, and cleaning processes are processes that process the substrate by supplying a treatment solution onto the substrate. The photolithography process includes a coating step, an exposure step, and a developing step.

The coating step is a coating process that coats a photosensitive liquid such as photoresist on a substrate, and some of the used photosensitive liquid is recovered through a bowl. The photosensitive liquid has viscosity, and a photosensitive liquid with a viscosity of 100cp or more can be used to refine the pattern of the substrate.

Meanwhile, when applying a photosensitive solution of 100cp or more to a substrate, problems such as fingering occur and require improvement.

The problem to be solved by the present invention is to provide a substrate processing device capable of reducing stains such as fingering phenomenon on a substrate and reducing poor coverage and photoresist scattering.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

An aspect of a substrate processing device of the present invention for achieving the above object comprises: a spin chuck for supporting a substrate; a nozzle unit for discharging a photoresist onto the substrate; and a control unit for controlling a rotational operation of the spin chuck, wherein the control unit maintains the spin chuck at a first rotation speed during a first process time, and accelerates the spin chuck from the first rotation speed to a second rotation speed during a second process time, and the second process time is 1 second to 8 seconds or less.

Another aspect of the substrate processing apparatus of the present invention for achieving the above task comprises: a spin chuck for supporting a substrate; a first nozzle for discharging a photoresist to the substrate; and a control unit for controlling a rotational operation of the spin chuck, wherein the control unit accelerates the spin chuck from a first rotation speed to a second rotation speed greater than the first rotation speed during a first process time, and reduces the spin chuck from the second rotation speed to a third rotation speed less than the second rotation speed and greater than the first rotation speed during a second process time after the first process time, with a time of less than 1 second, wherein the first process time is longer than the second process time, and the time for the acceleration change of the spin chuck is 1 to 8 seconds.

Specific details of other embodiments are included in the detailed description and drawings.

The substrate processing device according to the present invention can improve substrate quality by enabling the photosensitive solution to be uniformly applied over the entire surface of the substrate and improving coating coverage.

FIG. 1 is a cross-sectional view illustrating a substrate processing device according to some embodiments of the present invention.
Figure 2 is a drawing illustrating a rotational tangential force acting on a photosensitive liquid on a substrate.
FIG. 3 is a graph showing the process time and substrate rotation number of a substrate processing device according to the first embodiment of the present invention.
FIG. 4 is a graph showing the process time and substrate rotation speed of a substrate processing device according to the second embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The advantages and features of the present invention and the methods for achieving them will become apparent with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and these embodiments are provided only to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terminology used herein is for the purpose of describing embodiments only and is not intended to be limiting of the invention. As used herein, the singular includes the plural unless the context clearly dictates otherwise. The terms "comprises" and/or "comprising" as used herein do not exclude the presence or addition of one or more other components, steps, operations, and/or elements.

FIG. 1 is a cross-sectional view illustrating a substrate processing device according to some embodiments of the present invention, and FIG. 2 is a drawing illustrating a state in which a rotational tangential force is applied to a photosensitive liquid on a substrate. In addition, FIG. 3 is a graph illustrating a process time and a substrate rotation number of a substrate processing device according to a first embodiment of the present invention.

Referring to FIGS. 1 to 3, a substrate processing device (100) according to an embodiment of the present invention can perform a processing liquid application process. The substrate processing device (100) can include a housing (110), a fan filter unit (120), a substrate support unit (130), a liquid supply module (140), a bowl member (160), and a control unit (170).

The treatment liquid of this embodiment is a photosensitive liquid, and the photosensitive liquid may have a viscosity higher than medium viscosity, for example, a viscosity of 100 cp to 2000 cp. In addition, the identification symbol 11 indicates the flow of the treatment liquid, and the identification symbol 13 indicates the air flow. In addition, the process time for treating the substrate (W) may include a time in which a first process time (0 to T1), a second process time (T1 to T3), a third process time (T3 to T4), and a fourth process time (T4 to T5) are sequentially followed.

The housing (110) may be provided with a space in which a substrate support unit (130) and a bowl member (160) are provided. An opening (not shown) may be formed on one side of the housing (110). The opening is an entrance through which a substrate (W) is taken out and a door (not shown) may be installed. When a substrate processing process is performed, the door may block the opening to seal the space of the housing (110).

A first exhaust port (113), a second exhaust port (115), and an exhaust line (117) may be formed at the bottom of the housing (110). The airflow formed within the housing (110) may be exhausted to the outside through the first exhaust port (113) and the second exhaust port (115).

For example, the airflow inside the bail member (160) can be exhausted through the first exhaust port (113), and the airflow outside the bail member (160) can be exhausted through the second exhaust port (115). In addition, a liquid such as a treatment liquid can be discharged to the outside through the discharge line (117).

Although not shown in the drawing, an elevating unit may be provided within the housing (110). The elevating unit may adjust the relative height between the substrate support unit (130) and the bowl member (160). For example, the elevating unit may be provided to be connected to the bowl member (160) or the substrate support unit (130) to elevate and lower it. The elevating unit may include, but is not limited to, a bracket and a motor.

The fan filter unit (120) may be installed at the top of the housing (110). The fan filter unit (120) may be provided with a fan and a filter, and may form a descending airflow in the internal space of the housing (110). Through the descending airflow formed in the internal space of the housing (110), particles may be discharged to the outside via the first exhaust port (113) and the second exhaust port (115). The fan filter unit (120) may be provided with a line connected to the outside, and may supply outside air to the inside of the housing (110) through the line.

The substrate support unit (130) can support and rotate the substrate (W). The substrate support unit (130) can be provided as a spin chuck and can include a support plate (132) and a driver (136). The support plate (132) can be provided as a circular plate having a diameter smaller than that of the substrate (W). The driver (136) can be provided as a motor and can provide a rotational force to rotate the support plate (132). The rotational speed of the driver (136) can be controlled by the control unit (170).

The liquid supply module (140) may include a nozzle unit (141), and the nozzle unit (141) may discharge a treatment liquid (photoresist and/or pre-wet liquid) to a substrate (W) supported by a spin chuck, and may be positioned at the center of the substrate (W) when discharging the treatment liquid. The nozzle unit (141) may include a nozzle for the photoresist and a nozzle for the pre-wet liquid for discharging the treatment liquid, but is not limited thereto. Although not shown in the drawing, the liquid supply module (140) may further include a separate nozzle physically separated from the nozzle unit (141), and various modifications are possible, such that the separate nozzle may discharge a rinse liquid to the substrate (W). The nozzle unit (141) of the present embodiment may discharge the photoresist during the first process time (0 to T1) to the fourth process time (T4 to T5).

In addition, the nozzle unit (141) may include a nozzle arm (not shown), a guide rail (not shown), and a driver (not shown) for changing the position. The nozzle arm may support the nozzle unit (141). The nozzle arm may be moved by the driver, so that the position of the nozzle unit (141) installed on the nozzle arm may be changed. The change in the position of the nozzle unit (141) may be between a coating position for processing a substrate (W) and a waiting position in a home port (not shown).

The control unit (170) can control the rotational operation of the spin chuck provided as the substrate support unit (130). For example, the control unit (170) can control the rotational RPM of the substrate (W) by controlling the operation of the driver (136), and can control the rotational speed of the spin chuck (performed by the operation of the driver (136)) to a first rotational speed (see 'A' of FIGS. 3 and 4), a second rotational speed (see 'C' of FIGS. 3 and 4), and a third rotational speed (see 'B' of FIGS. 3 and 4).

For example, when the substrate (W) rotates, the photoresist having a viscosity higher than that of the medium flowing on the surface of the substrate (W) is not uniformly applied over the entire surface of the substrate (W), and there is a problem that unevenness (fingering phenomenon) occurs. The location where unevenness occurs can be obtained from the equation for the rotational Reynolds number. The rotational Reynolds number (Re _w ) is as follows:

[Mathematical Formula 1]

Re _w = ρωv ^{2 /2} /μ

Here, r represents the radial position, ω represents the rotation angle, ρ represents the density, and μ represents the viscosity.

Referring to mathematical expression 1, when the RPM of the substrate (W) increases, ω increases and the rotational Reynolds number increases. Therefore, if the rotational speed of the spin chuck is instantaneously accelerated to a set value provided by the universal actuator (136) during the substrate processing process (e.g., during the second process time (T1 to T3)) (see the slope of 'E1' in FIG. 3, 'E1' is the slope of the comparative example), a fingering phenomenon may occur on the surface of the substrate (W).

And referring to mathematical expression 2, if a small acceleration time is applied compared to the amount of RPM change, the photosensitive liquid may scatter due to an increase in the rotational tangential force (F _t , see arrow in Fig. 2). In other words, if the acceleration time is instantaneous and short, the rotational tangential force may increase, which may increase the scattering problem.

[Mathematical formula 2]

F _t = ma _t

a _t = r(dw/dt) = r(d ² θ/dt ² )

Here, F represents the rotational tangential force, a represents the acceleration, and r represents the radius.

Accordingly, the control unit (170) of the present embodiment can perform control to reduce the fingering phenomenon and scattering by preventing the RPM of the substrate (W) from being instantly accelerated during the substrate processing process. Briefly, the control unit (170) can accelerate the rotation speed of the spin chuck during the process (e.g., during the second process time (T1 to T3)) without accelerating the rotation of the spin chuck to the second rotation speed from the start time when the photoresist is discharged so that the substrate (W) is processed. Here, the time during which the rotation speed is accelerated can be longer than the time during which the speed is reduced at the time when the processing of the substrate (W) is finished (e.g., during the third process time (T3 to T4)).

Specifically, the control unit (170) can control as follows during the first process time (0 to T1) to the fourth process time (T4 to T5), as shown in FIG. 3 and FIG. 4 (see FIG. 3 for E2 graph, E1 for comparative example graph).

First, during the first process time (0 to T1), the spin chuck can be maintained at a first rotation speed (see identification number 'A'). For example, the first rotation speed can be 0 to 200 RPM.

Then, during the second process time (T1 to T3), the spin chuck can be accelerated in rotational speed, so that the spin chuck can be accelerated from the first rotational speed to a second rotational speed (see identification number 'C') greater than the first rotational speed. For example, the second rotational speed can be 1200 to 1800 RPM.

Here, the second process time (T1 to T3) may include a first sub-process time (T1 to T2) and a second sub-process time (T2 to T3) following the first sub-process time (T1 to T2). During the first sub-process time (T1 to T2), the spin chuck may be accelerated from the first rotation speed to the second rotation speed, and during the second sub-process time (T2 to T3), the spin chuck may be maintained at the second rotation speed.

The first sub-process time (T1 to T2) can be delayed so that the rotation speed of the spin chuck is not instantaneously accelerated for less than 1 second. The first sub-process time (T1 to T2) is longer than the fourth process time (T4 to T5), and can be, for example, 1 to 8 seconds or less. That is, rather than setting the instantaneous acceleration time that can be provided as the initial value of the driver (136), the acceleration time can be controlled to an optimized time that can prevent staining.

In this way, since the RPM acceleration time of the substrate (W) is not instantaneous, such as less than 1 second, but can be long, the photoresist can spread slowly, so that coverage can be secured even with a relatively small flow rate compared to increasing the speed with the instantaneous acceleration provided by the general-purpose driver (136). Accordingly, there is an effect of reducing the flow rate of the photoresist, and since the occurrence of scattering of the photoresist is reduced, defects can also be prevented.

In addition, the second process time (T1 to T3) is set as a total time regardless of the first sub-process time (T1 to T2), and if the first sub-process time (T1 to T2) increases according to an embodiment, the second sub-process time (T2 to T3) may decrease correspondingly. That is, if the total time of the second process time (T1 to T3) is 7 seconds, the first sub-process time (T1 to T2) may be 3 seconds, 5 seconds, etc. depending on a variation of the embodiment, and correspondingly, the second sub-process time (T2 to T3) may be 4 seconds, 2 seconds, etc., which is the remaining time excluding the first sub-process time (T1 to T2).

Then, during the third process time (T3 to T4), the spin chuck can be varied from the second rotation speed to a third rotation speed (see identification number 'B') that is lower than the second rotation speed. For example, the third rotation speed can be 300 to 800 RPM.

Then, during the fourth process time (T4 to T5), the spin chuck can be maintained at the third rotation speed.

Meanwhile, the second process time (T1 to T3) of the present embodiment includes the first sub-process time (T1 to T2) and the second sub-process time (T2 to T3) following the first sub-process time (T1 to T2), and exemplifies that the second rotation speed is maintained during the second sub-process time (T2 to T3), but is not limited thereto. Other examples will be described below with reference to the drawings.

Hereinafter, a modified example of the present embodiment will be described with reference to FIG. 4, and redundant descriptions of the same components performing the same function will be omitted.

Fig. 4 is a graph showing the process time and substrate rotation speed of a substrate processing device according to the second embodiment of the present invention. With reference to Fig. 4, differences from those described using Fig. 3 will be mainly explained.

The substrate processing device (100) according to the second embodiment can perform a processing liquid application process identical to or similar to that of the first embodiment. The substrate processing device (100) can include a housing (110), a fan filter unit (120), a substrate support unit (130), a liquid supply module (140), a bowl member (160), and a control unit (170).

Meanwhile, in the second embodiment, unlike the first embodiment, the spin chuck is not maintained at the second rotation speed, but is accelerated from the first rotation speed to the second rotation speed during the second process time (T1 to T3), and then immediately decelerated from the second rotation speed to the third rotation speed during the third process time (T3 to T4).

That is, the present embodiments prevent problems such as staining and minimize flying problems by delaying the acceleration time, and the time for accelerating the rotation speed of the spin chuck is made longer than the time for decelerating the rotation speed of the spin chuck, so that the rotation speed of the spin chuck can be maintained for a certain period of time (e.g., the second sub-process time (T2 to T3)) or omitted after reaching the maximum speed.

Although the embodiments of the present invention have been described with reference to the above and the attached drawings, those skilled in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing the technical idea or essential characteristics thereof. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

100: Substrate processing device 110: Housing
140: Liquid supply unit 170: Control unit

Claims (9)

Spin chuck supporting the substrate;
A nozzle unit for ejecting a photosensitive liquid onto the substrate; and
Including a control unit that controls the rotational motion of the spin chuck,
The above control unit,
During the first process time, the spin chuck is maintained at the first rotation speed,
During the second process time, the spin chuck is accelerated from the first rotation speed to the second rotation speed,
A substrate processing device, wherein the second process time is 1 second to 8 seconds or less. In the first paragraph,
The above control unit,
During the third process time, the spin chuck is varied from the second rotation speed to the third rotation speed,
A substrate processing device, which maintains the spin chuck at the third rotation speed during the fourth process time. In the second paragraph,
The above second process time includes the first sub-process time and the second sub-process time following the first sub-process time,
A substrate processing device, wherein the control unit accelerates the spin chuck from the first rotation speed to the second rotation speed during the first sub-process time, and maintains the spin chuck at the second rotation speed during the second sub-process time. In the third paragraph,
A substrate processing device, wherein the first sub-process time is longer than the third process time. In the second paragraph,
The above first process time, the above second process time, the above third process time, and the above fourth process time are sequentially performed,
The above first nozzle discharges the photosensitive liquid during the first process time to the fourth process time,
A substrate processing device, wherein the photosensitive liquid has a viscosity in the range of 100 CP to 2000 CP. In the first paragraph,
A substrate processing device, wherein the first rotation speed is 0 to 200 RPM. In Article 6,
The above second rotation speed is a substrate processing device of 1200 to 1800 RPM. In Article 7,
The third rotation speed is a substrate processing device of 300 to 800 RPM. Spin chuck supporting the substrate;
A first nozzle for ejecting a photosensitive liquid onto the substrate; and
Including a control unit that controls the rotational motion of the spin chuck,
The above control unit,
During the first process time, the spin chuck is accelerated from a first rotation speed to a second rotation speed greater than the first rotation speed,
During a second process time after the first process time, the spin chuck is reduced from the second rotation speed to a third rotation speed that is less than the second rotation speed and greater than the first rotation speed, with a time of less than 1 second.
A substrate processing device wherein the first process time is longer than the second process time, and the acceleration change of the spin chuck has a time of 1 second to 8 seconds or less.

Images