TWI815434B - Coating method and coating device - Google Patents

Abstract

The present invention relates to a coating treatment method and a coating treatment device. The central portion of the lower surface of the substrate is held in a horizontal position by the rotation holding portion. The held substrate rotates around the vertical axis. The coating liquid is supplied to the upper surface of the rotating substrate. With the substrate rotating, the liquid flow period from the first time point when supply of the coating liquid ends to the second time point when the coating liquid on the substrate loses fluidity is earlier than the second time point. During the liquid supply period, the volatile rinse liquid is supplied to at least a part of the annular portion of the lower surface of the rotating substrate surrounding the central portion of the lower surface.

Description

Coating treatment method and coating treatment device

The present invention relates to a coating processing method and a coating processing device for forming a coating film on a substrate.

For semiconductor substrates, liquid crystal display devices, organic EL (Electro Luminescence, electroluminescence) display devices and other FPD (Flat Panel Display) substrates, optical disk substrates, magnetic disk substrates, magneto-optical disk substrates, and photomasks A substrate processing apparatus is used to perform various processes on substrates such as substrates, ceramic substrates, and solar cell substrates.

An example of a substrate processing apparatus is a coating processing apparatus that forms a coating film such as a resist film or an antireflection film on the upper surface of a substrate. In the coating processing apparatus, for example, a rotating chuck is used to hold one substrate in a horizontal position. Furthermore, the substrate held by the rotating chuck rotates. A coating liquid corresponding to the type of coating film to be formed is supplied to the upper surface of the rotating substrate. The coating liquid supplied to the substrate spreads to the entire upper surface of the substrate using centrifugal force. A coating film is formed by drying the coating liquid on the substrate.

Preferably, the thickness of the coating film formed on the substrate in the coating processing device is uniform throughout the entire substrate. If the temperature distribution of the coating liquid spread on the substrate is greatly uneven during the process of forming a coating film on the substrate, it will be difficult to make the film thickness distribution uniform. Therefore, a coating treatment method has been proposed in which a temperature-adjusting liquid (temperature-adjusting liquid) is supplied to the lower surface of the substrate while or after supplying the coating liquid to the upper surface of the substrate to adjust the substrate and the substrate. the temperature of the coating liquid above (for example, refer to Japanese Patent Application Laid-Open No. 2000-114152). Japanese Patent Application Laid-Open No. 2000-114152 describes using a solvent such as a diluent as a temperature adjustment liquid.

In recent years, with the high density and high integration of components, there is a requirement to increase the thickness of the coating film formed on the substrate. In order to form a coating film with a larger thickness, a coating liquid with high viscosity is used. This kind of high-viscosity coating liquid is less likely to spread on the substrate than a low-viscosity coating liquid. Furthermore, when a coating film with a large thickness is formed, the time required for drying becomes longer than when a coating film with a small thickness is formed.

Therefore, in the coating process of using a high-viscosity coating liquid to form a coating film with a large thickness, the temperature of the substrate and the coating liquid on the substrate must be adjusted for a long time. However, if the temperature adjustment liquid is continuously supplied to the lower surface of the substrate for a long time, the cost of the coating process will become high.

An object of the present invention is to provide a coating processing method and a coating processing device that can uniformize the film thickness distribution at low cost regardless of the thickness of the coating film.

(1) The coating treatment method according to one aspect of the present invention includes the following steps: using a rotation holding portion to hold the substrate adsorbed at the center portion of the lower surface of the substrate in a horizontal posture and rotating it around a vertical axis; The holding part supplies the coating liquid to the upper surface of the rotating substrate; and in a state where the substrate held by the rotating holding part is rotated, the coating liquid on the substrate is lost after the first time point when the supply of the coating liquid is completed. In the liquid flow period up to the second time point of fluidity, in the liquid supply period earlier than the second time point, the annular portion on the lower surface of the substrate rotating by the rotation holding portion surrounds the central portion of the lower surface At least a portion of it supplies volatile flushing liquid.

In this coating treatment method, the coating liquid is supplied to the upper surface of the rotating substrate. The coating liquid supplied to the upper surface of the substrate flows on the upper surface of the substrate using centrifugal force. During the liquid supply period, the rinse liquid is supplied to the annular portion of the lower surface of the substrate. At least part of the rinsing liquid supplied to the substrate during the liquid supply period is vaporized from the passage of the liquid supply period to the passage of the second time point. In this case, the temperature of the annular portion on the lower surface of the substrate is adjusted with high efficiency by the vaporization heat generated along with the vaporization of the rinse liquid.

By appropriately adjusting the temperature of the annular portion on the lower surface of the substrate, local changes in the movement state of the coating liquid flowing along the radial direction of the substrate can be suppressed. Thereby, the thickness of the coating film formed on the substrate can be made uniform. Therefore, it is not necessary to continuously supply the temperature adjustment liquid to the substrate during the liquid flow period in order to make the thickness of the coating film uniform. As a result, the film thickness distribution can be made uniform at low cost regardless of the thickness of the coating film.

(2) The second time point may be a time point when the interference fringes generated on the surface of the coating liquid supplied to the upper surface of the substrate disappear after the first time point has passed. In this case, by confirming the occurrence and disappearance of interference fringes in advance, the liquid supply period can be easily and appropriately set.

(3) The length of the liquid supply period may be 10 seconds or less. Thereby, the consumption of flushing fluid can be further reduced. In addition, the temperature of the substrate can be adjusted more appropriately.

(4) Alternatively, the step of rotating the substrate may include: from after the first time point to a third time point before the second time point, so that the coating liquid supplied to the upper surface of the substrate covers the entire substrate The substrate is rotated by the upper surface; the start time point of the liquid supply period is set within 5 seconds from the third time point. Thereby, the temperature of the substrate can be adjusted more appropriately.

(5) The lower surface annular portion may be located between the annular lower surface peripheral portion including the outer peripheral end portion of the substrate and the lower surface central portion of the lower surface of the substrate rotated by the rotation holding portion. Thereby, the temperature of the portion located around the central portion of the lower surface of the substrate can be adjusted more appropriately.

(6) A coating processing apparatus according to another aspect of the present invention is provided with: a rotation holding portion that holds the substrate in a horizontal position by adsorbing the center portion of the lower surface of the substrate and rotates it around a vertical axis; and a coating liquid The supply part supplies the coating liquid to the upper surface of the substrate rotated by the rotation holding part; the rinse liquid supply part supplies the annular portion of the lower surface of the substrate surrounding the central part of the lower surface of the lower surface of the substrate rotated by the rotation holding part. At least a part of the volatile rinse liquid is supplied; and a control part controls the rotation holding part, the coating liquid supply part and the rinse liquid supply part to supply coating to the upper surface of the substrate while the substrate held by the rotation holding part is rotating. liquid, in the liquid supply period that is earlier than the second time point in the liquid flow period from the first time point when the supply of the coating liquid ends to the second time point when the coating liquid on the substrate loses fluidity, The rinse liquid is supplied to the annular portion of the lower surface of the substrate.

In this coating processing apparatus, the coating liquid is supplied to the upper surface of the rotating substrate. The coating liquid supplied to the upper surface of the substrate flows on the upper surface of the substrate using centrifugal force. Then, the rinse liquid is supplied to the annular portion of the lower surface of the substrate during the liquid supply period. At least part of the rinsing liquid supplied to the substrate during the liquid supply period is vaporized from the passage of the liquid supply period to the passage of the second time point. In this case, the temperature of the annular portion on the lower surface of the substrate is adjusted with high efficiency by the vaporization heat generated along with the vaporization of the rinse liquid.

By appropriately adjusting the temperature of the annular portion on the lower surface of the substrate, local changes in the movement state of the coating liquid flowing along the radial direction of the substrate can be suppressed. Thereby, the thickness of the coating film formed on the substrate can be made uniform. Therefore, it is not necessary to continuously supply the temperature adjustment liquid to the substrate during the liquid flow period in order to make the thickness of the coating film uniform. As a result, the film thickness distribution can be made uniform at low cost regardless of the thickness of the coating film.

(7) The second time point may be a time point when the interference fringes generated on the surface of the coating liquid supplied to the upper surface of the substrate disappear after the first time point has passed. In this case, by confirming the occurrence and disappearance of interference fringes in advance, the liquid supply period can be easily and appropriately set.

(8) The length of the liquid supply period may be 10 seconds or less. Thereby, the consumption of flushing fluid can be further reduced. In addition, the temperature of the substrate can be adjusted more appropriately.

(9) The control unit may control the rotation holding unit so that the coating liquid supplied to the upper surface of the substrate from the first time point to the third time point before the second time point covers the entire substrate. On the surface, the start time point of the liquid supply period is set within 5 seconds from the third time point. Thereby, the temperature of the substrate can be adjusted more appropriately.

(10) The lower surface annular portion may be located between the annular lower surface peripheral portion including the outer peripheral end portion of the substrate and the lower surface central portion of the lower surface of the substrate rotated by the rotation holding portion. Thereby, the temperature of the portion located around the central portion of the lower surface of the substrate can be adjusted more appropriately.

Hereinafter, a coating processing method and a coating processing apparatus according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the so-called substrate refers to FPD (Flat Panel Display) substrates, semiconductor substrates, optical disk substrates, magnetic disk substrates, and magneto-optical disks used in liquid crystal display devices or organic EL (Electro Luminescence) display devices. Use substrates, photomask substrates, ceramic substrates or solar cell substrates, etc. Furthermore, in this embodiment, the upper surface of the substrate is the circuit-formed surface (front surface), and the lower surface of the substrate is the surface opposite to the circuit-formed surface (rear surface). Furthermore, in this embodiment, the substrate has a circular shape in plan view except for the portion where the groove is formed.

[1] Overall structure of coating processing device

FIG. 1 is a schematic cross-sectional view of a coating processing device according to an embodiment of the present invention, and FIG. 2 is a schematic plan view of the coating processing device 1 of FIG. 1 . In FIG. 2 , illustration of some of the plurality of components of the coating processing apparatus 1 of FIG. 1 is omitted. In addition, in FIG. 2 , the substrate W of FIG. 1 is represented by a single-dot chain line.

As shown in FIG. 1 , the coating processing device 1 of this embodiment mainly includes a rotation holding device 10 , a liquid supply device 20 , and a control unit 30 . The rotation holding device 10 is configured to adsorb and hold the center portion of the lower surface of the substrate W and rotate the substrate W.

The liquid supply device 20 includes a resist nozzle 21 and a coating liquid supply system 22 . The coating liquid supply system 22 supplies resist liquid as a coating liquid to the resist nozzle 21 . The resist nozzle 21 is provided movably between a side position of the substrate W held by the rotation holding device 10 and an upper position of the substrate W. The resist nozzle 21 sprays the resist liquid supplied from the coating liquid supply system 22 onto the upper surface of the substrate W while being in a position above the substrate W that is adsorbed and held by the rotation holding device 10 and rotated. The control unit 30 includes a CPU (Central Processing Unit) (central processing unit) and a memory, or a microcomputer, and controls the operations of the rotation holding device 10 and the liquid supply device 20 .

The specific structure of the rotation holding device 10 is demonstrated. The rotation holding device 10 includes an adsorption holding part 11 , a rotation shaft 12 , a rotation driving part 13 , a suction device 14 , a guard 15 , a drainage guide pipe 16 , a plurality of lower surface nozzles 17 and a flushing liquid supply system 18 .

The adsorption holding part 11 has a circular upper surface 11u at the center of the lower surface of the substrate W, and is mounted on the upper end of the rotation shaft 12 extending in the up-down direction. A plurality of suction holes h are formed on the upper surface 11u of the adsorption holding part 11 (Fig. 2). The rotation drive unit 13 rotates the rotation shaft 12 around its axis.

As shown by the thick dotted line in FIG. 1 , an air intake path vp is formed inside the adsorption holding part 11 and the rotation shaft 12 . The air intake path vp is connected to the suction device 14 . The suction device 14 includes a suction mechanism such as a suction device. It sucks the space environment on the upper surface 11u of the adsorption holding part 11 through the air intake path vp and the plurality of suction holes h, and discharges it to the outside of the coating processing device 1 .

As shown in FIG. 2 , the shield 15 is provided to surround the adsorption holding portion 11 in a plan view, and is configured to be movable to a plurality of positions in the up and down direction by a lifting mechanism (not shown). As shown in FIG. 1 , the shield 15 includes a bottom portion 15x and an outer peripheral wall portion 15y. The base 15x has a generally circular ring shape. The inner peripheral end of the bottom 15x is bent upward by a predetermined height. The outer peripheral wall portion 15y is formed such that it extends upward from the outer peripheral end portion of the bottom portion 15x, is bent by a predetermined height, and then extends obliquely upward toward the adsorption holding portion 11.

A drain port 15d is formed on the bottom 15x of the shield 15. A drain guide pipe 16 is installed in the portion where the drain port 15d is formed in the bottom 15x. The lower end of the drainage guide tube 16 is connected to a drainage system (not shown).

As shown in FIG. 2 , in plan view, a plurality of lower surface nozzles 17 are provided between the inner peripheral end of the outer peripheral wall 15y of the shield 15 and the outer peripheral end of the adsorption and holding part 11 . In this example, four lower surface nozzles 17 are provided. The plurality of lower surface nozzles 17 are arranged at equal angular intervals based on the center of the suction and holding portion 11 so as to surround the suction and holding portion 11 in plan view. A liquid ejection port 17b directed upward is provided at the upper end of each lower surface nozzle 17.

As shown in FIG. 1 , the liquid ejection port 17 b of each lower surface nozzle 17 is located near the outer peripheral end of the adsorption and holding part 11 and faces the lower surface of the substrate W adsorbed and held by the adsorption and holding part 11 . More specifically, each lower surface nozzle 17 is provided at a position about 5 mm to 80 mm away from the outer peripheral end of the adsorption and holding part 11 in the radial direction of the adsorption and holding part 11 in plan view. Furthermore, the coating processing apparatus 1 has a structure in which the rotation holding device 10 and the liquid supply device 20 are accommodated in a casing (not shown). The lower surface nozzle 17 is fixed to the casing of the coating processing apparatus 1, for example. The lower surface nozzle 17 sprays the rinse liquid supplied from the rinse liquid supply system 18 to the lower surface of the substrate W from the liquid ejection port 17 b. In this embodiment, a volatile solvent (thinner, etc.) capable of dissolving the resist film described below is used as the rinse liquid.

Regarding the coating processing apparatus 1 having the above-mentioned structure, an outline of the operation during coating processing will be described. When the coating process of the substrate W is started, the substrate W is first held in a horizontal posture by the suction holding portion 11 . Furthermore, the substrate W is rotated. At this time, the temperature of the adsorption holding part 11 and the substrate W is room temperature (for example, 23° C.).

Furthermore, the shield 15 is positioned in the up-down direction so that the inner peripheral surface of the outer peripheral wall portion 15y faces the outer peripheral end portion of the substrate W in the horizontal direction. In this state, the resist nozzle 21 is moved above the substrate W using a nozzle moving device (not shown). Furthermore, a predetermined amount of the resist liquid is sprayed from the resist nozzle 21 onto the upper surface of the substrate W. Thereby, the resist liquid is coated on the surface of the rotating substrate W. At this time, the temperature of the resist liquid supplied from the resist nozzle 21 to the substrate W is room temperature (for example, 23° C.). In addition, the viscosity of the resist liquid applied to the substrate W is 1 cP or more and 20,000 cP or less at room temperature (for example, 23°C).

The resist liquid scattered outward from the rotating substrate W is caught by the inner peripheral surface of the outer peripheral wall portion 15y of the shield 15 . The caught resist liquid is collected from the bottom 15x of the shield 15, and is guided from the drain port 15d through the drain guide pipe 16 to a drain system (not shown). As mentioned above, in the coating process of the substrate W, the process of applying the resist liquid to the entire upper surface of the substrate W, that is, the process of forming a liquid film of the resist liquid on the entire upper surface of the substrate W, is called a liquid film forming process. .

Next, in a state where the spraying of the resist liquid from the resist nozzle 21 to the substrate W is stopped, the substrate W is continued to rotate, thereby throwing off the excess resist liquid in the resist liquid applied to the upper surface of the substrate W. open. Furthermore, the liquid film of the resist liquid remaining on the substrate W is dried. Thereby, a resist film is formed on the upper surface of the substrate W. In this embodiment, the thickness of the resist film formed on the substrate W is 20 nm or more and 20,000 nm or less. As described above, in the coating process of the substrate W, the process of drying the liquid film of the resist liquid applied to the upper surface of the substrate W is called a liquid film drying process. In the liquid film drying process, the rinse liquid is sprayed toward the lower surface of the substrate W from the plurality of lower surface nozzles 17 within a specific period. The reason for this will be described below.

After the resist film is formed on the upper surface of the substrate W, in order to remove the resist liquid or resist film attached to the lower surface of the substrate W, a rinse liquid is sprayed from the plurality of lower surface nozzles 17 toward the lower surface of the substrate W. The temperature of the rinse liquid supplied to the substrate W from each lower surface nozzle 17 is equal to or higher than the temperature of the adsorption holding portion 11 (room temperature in this example).

Then, the spraying of the rinse liquid onto the substrate W from each lower surface nozzle 17 is stopped. In this state, by continuing to rotate the substrate W, the rinse liquid applied to the lower surface of the substrate W is dried. Thereby, the resist liquid or the solid matter of the resist adhered to the lower surface of the substrate W is removed. The substrate W on which the resist film is formed by the above-mentioned series of operations of the coating processing device 1 is carried out from the coating processing device 1 and is exposed by an exposure device (not shown).

[2] Uneven film thickness distribution of the resist film caused by the coating process

In the liquid film drying process in the coating process, the drying state of the resist liquid on the substrate W is uneven due to the temperature distribution of the substrate W and the intensity of the air flow generated in the space surrounding the substrate W. As a result, the film thickness distribution of the resist film formed on the substrate W becomes uneven. FIG. 3 is a plan view showing an example of a resist film in which uneven film thickness distribution occurs. In FIG. 3 , a thick dotted line indicates the outer edge of the portion of the substrate W that is adsorbed and held by the adsorption and holding portion 11 (hereinafter, referred to as the contact portion). In the top view of FIG. 3 , the resist film R2 formed on the substrate W is represented by a dot pattern having a concentration corresponding to the thickness of the resist film R2 . The parts with a higher concentration of the dot pattern represent a larger thickness of the resist film R2, and the parts with a lower concentration of the dot pattern represent a smaller thickness of the resist film R2.

FIG. 4 is a cross-sectional view illustrating a mechanism presumed to cause uneven film thickness distribution in FIG. 3 . Figure 4 shows two upper and lower cross-sectional views. In these cross-sectional views, similarly to the example of the resist film R2 in FIG. 3 , the liquid film of the resist liquid R1 and the resist film R2 formed on the substrate W are represented by dot patterns having concentrations corresponding to their thicknesses.

The coating processing device 1 is basically housed in a clean room. A downward airflow (downflow) of clean air maintained at a predetermined temperature (for example, 23° C.) is formed in the space surrounding the coating processing device 1 . Thereby, as shown by the hollow arrow in the upper section of FIG. 4 , air is continuously blown from above to the substrate W being coated.

In the liquid film drying step, a part of the resist liquid R1 applied to the substrate W (the upper part of the liquid film of the resist liquid R1) spreads from the center of the substrate W toward the outer peripheral end, and scatters toward the outside of the substrate W . Here, the resist liquid of this example contains a volatile solvent. Therefore, as shown by the thick solid arrow in the upper part of FIG. 4 , the solvent of the resist liquid RL spread on the substrate W vaporizes. At this time, the downward airflow toward the substrate W from the upper position promotes the vaporization of the solvent of the resist liquid R1, that is, the drying of the liquid film of the resist liquid R1.

The heat capacity of the portion of the substrate W that is not in contact with the adsorption holding portion 11 (hereinafter referred to as the non-contact portion) is smaller than the heat capacity of the contact portion. Therefore, when the vaporization of the solvent of the resist liquid R1 on the substrate W is promoted, the temperature of the non-contact part is lower than that of the contact part due to the influence of vaporization heat.

The lower the temperature, the longer it takes for the resist liquid to dry (harden). Therefore, the resist liquid R1 applied on the non-contact portion is in a state in which it flows relatively easily due to the rotation of the substrate W. However, in fact, even if it is a non-contact part, at the outer peripheral end of the substrate W and its vicinity, a strong air flow is generated in the surrounding space, which promotes the vaporization of the solvent of the resist liquid R1, so that the resist liquid R1 is easily hardening.

Therefore, ultimately, as shown in the lower part of FIG. 4 , the thickness of the resist film R2 formed near the contact portion in the non-contact portion of the substrate W is smaller than the thickness of the liquid film formed in the contact portion. Furthermore, the thickness of the resist film formed near the outer peripheral end of the substrate W in the non-contact portion of the substrate W is equal to or greater than the thickness of the resist film formed in the contact portion of the substrate W.

In order to suppress the occurrence of uneven film thickness distribution as shown in FIGS. 3 and 4 , in this embodiment, the lower surface of the non-contact portion of the substrate W is continuously sprayed from a plurality of lower surface nozzles 17 during a specific period in the liquid film drying process. Supply volatile flushing fluid. The rinse liquid has a temperature higher than the temperature of the adsorption holding portion 11 (room temperature in this example) when it comes into contact with the substrate W. In the following description, this specific period is called a liquid supply period. The liquid supply period is set from a time point after the start of the liquid film drying process to a time point when the resist liquid on the substrate W loses fluidity.

[3] Specific examples of coating processing using the coating processing device 1

FIG. 5 is a diagram illustrating a specific example of the coating process according to one embodiment of the present invention. In FIG. 5 , a graph shows the change in the rotation speed of the substrate W during the coating process using the coating processing apparatus 1 of FIG. 1 . In the graph of FIG. 5 , the vertical axis represents the rotation speed of the substrate W, and the horizontal axis represents time.

Furthermore, the rotation speed of the substrate W is adjusted by the control unit 30 controlling the rotation drive unit 13 in FIG. 1 . In addition, the supply and stop of the resist liquid R1 to the upper surface S1 of the substrate W is performed by the control unit 30 controlling the coating liquid supply system 22 in FIG. 1 . Furthermore, the supply and stop of the rinse liquid to the lower surface of the substrate W is performed by the control unit 30 controlling the rinse liquid supply system 18 in FIG. 1 .

In the initial state of the coating process performed by the coating processing apparatus 1 , the unprocessed substrate W is suction-held in a horizontal position by the suction-holding unit 11 in FIG. 1 . At this time, the rotation speed of the substrate W is maintained at 0. Furthermore, the shield 15 is positioned in the up-down direction so that the inner peripheral surface of the outer peripheral wall portion 15y of the shield 15 faces the outer peripheral end portion of the substrate W.

As shown in FIG. 5 , when the coating process is started, first the rotation speed of the substrate W increases from 0 to s1. In addition, the rotation speed of the substrate W is maintained at s1. The rotation speed s1 is set, for example, in a range from 0 rpm to 2000 rpm. Then, the liquid film forming process is started from time point t1. Furthermore, in the period from the start time point of the coating process to the time point t1, in order to modify the upper surface of the substrate W, a solvent may be supplied to the upper surface of the substrate W. This treatment is so-called prewetting.

In the liquid film forming process, a predetermined amount of resist liquid is supplied to the upper surface of the rotating substrate W during the period p1 from time point t1 to time point t4. At this time, from time point t1 to time point t2 which is earlier than time points t3 and t4, the rotation speed of the substrate W increases to s2 which is higher than s1. The rotation speed s2 is set within the range of 1000 rpm to 4500 rpm, for example. Thereby, a core (block) with fixedly diffused resist liquid R1 is formed in the center of the upper surface of the substrate W. In addition, after a fixed period has elapsed from time point t2, the rotation speed of the substrate W returns to s1, and from time point t3 to time point t4, the rotation speed of the substrate W is maintained at s1. Thereby, the core of the resist liquid R1 is shaped from time point t3 to time point t4.

Next, in a state where the supply of the resist liquid R1 to the substrate W is stopped, the rotation speed of the substrate W increases from s1 to s2 from time point t4 to time point t5. Furthermore, after a fixed period has elapsed from the time point t5, the rotation speed of the substrate W decreases to s3 which is higher than s1 and lower than s2 at the time point t6. The rotation speed s3 is set in a range from 400 rpm to 2500 rpm, for example.

From the above time point t4 to the time point t6, the resist liquid R1 spreads from the center of the substrate W toward the outer peripheral end. Thereby, at time point t6, a liquid film of the resist liquid R1 is formed on the entire upper surface of the substrate W, and the liquid film forming process is completed.

Next, the liquid film drying process begins. In the liquid film drying process, from time point t6 to time point t9, the rotation speed of the substrate W is maintained at s3. Here, at time point t9, the entire resist liquid R1 on the substrate W is dried, thereby completing the liquid film drying process.

In the initial stage of the liquid film drying process, a part of the resist liquid R1 supplied to the substrate W (the upper part of the liquid film of the resist liquid R1) spreads from the center of the substrate W toward the outer peripheral end, and spreads toward the outer edge of the substrate W. Scattered outside. Then, after a part of the solvent component of the resist liquid R1 on the substrate W is vaporized so that the fluidity of the resist liquid R1 is lost, the liquid film thickness of the resist liquid R1 on the substrate W is approximately determined to be the thickness of the resist film R2 thickness. Therefore, in order to make the film thickness distribution of the resist film R2 on the substrate W uniform, it is necessary to adjust the resist film to be formed on the substrate W before the time when the resist liquid R1 on the substrate W loses fluidity. Processing of R2 thickness.

Therefore, in the example of FIG. 5 , the time point at which the resist liquid R1 on the substrate W loses fluidity after the time point t6 passes is defined as the time point t8 , and then from the time point t6 to the time before the time point t8 During the period p2 to point t7, the rinse liquid is continuously supplied to the non-contact portion of the lower surface of the substrate W. This period p2 corresponds to the above-mentioned liquid supply period. In the following description, the time point t8 when the resist liquid R1 loses fluidity is appropriately referred to as the film thickness distribution determination time point.

As described above, the rinse liquid has a temperature higher than the temperature of the adsorption holding portion 11 (room temperature in this example). Therefore, during the liquid supply period (period p2), the temperature of the non-contact portion of the substrate W temporarily increases. In the portion where the temperature of the substrate W rises, the temperature of the resist liquid R1 rises, and the fluidity of the resist liquid R1 decreases, so that the resist film R2 tends to become thicker. Thereby, in the non-contact portion of the substrate W, the thickness of the resist film R2 formed near the contact portion can be suppressed from becoming smaller than the thickness of the resist film R2 formed near the contact portion.

In addition, in the liquid film drying process, after the liquid supply period (period p2) has elapsed and before the film thickness distribution determination time point (time point t8), the rinse liquid supplied to the lower surface of the substrate W is vaporized. Thereby, the temporarily raised temperature of the non-contact portion of the substrate W is adjusted by the vaporization heat of the rinse liquid. In this way, the temperature of the non-contact portion of the substrate W is locally adjusted from time point t6 to time point t8. As a result, the film thickness distribution of the resist liquid R1 on the substrate W can be made uniform until the film thickness distribution determination time point (time point t8) passes when the resist liquid R1 on the substrate W stops flowing.

Furthermore, consider the case where a resist film R2 having a thickness of about 4.5 μm is formed on the substrate W using a resist liquid R1 having a viscosity of about 60 cP at room temperature (for example, 23° C.). In this case, the length of the liquid film drying process period from time point t6 to time point t9 is set to 30 seconds or more and 90 seconds or less, for example. Moreover, the length of the liquid supply period (period p2) from time point t6 to time point t7 is set to 1 second or more and 5 seconds or less, for example.

During the period from time point t8 to time point t9 in the liquid film drying process, the vaporization of the solvent component of the resist liquid R1 that does not flow on the substrate W continues to be accelerated. Thereby, the resist liquid R1 on the substrate W dries at the time when the liquid film forming process is completed. That is, the resist film R2 is formed on the substrate W.

Next, from time point t9 to time point t11, the rinse liquid is supplied again to the non-contact portion of the lower surface of the substrate W. At this time, from time point t9 to time point t10 that is earlier than time point t11, the rotation speed of the substrate W is reduced to s4, which is lower than s3, and is maintained for a fixed period. Then, the supply of the solvent to the substrate W is stopped, and the rotation speed of the substrate W is changed to s5, which is higher than s4 and lower than s3, and is maintained for a fixed period.

The above-mentioned processing from time point t9 to time point t11 is so-called post-rinsing. By post-rinsing, the resist liquid R1 or the solid matter of the resist adhered to the lower surface of the substrate W is removed by the solvent.

Finally, from time point t11 to time point t12, the rotation speed of the substrate W is adjusted step by step without supplying processing liquid (rinsing liquid, resist liquid, etc.) to the substrate W. Thereby, the entire substrate W is dried, and the coating process is completed.

[4] End time of the liquid supply period (period p2)

As described above, the end time point (time point t7) of the liquid supply period (period p2) is set before the film thickness distribution determination time point (time point t8). Here, for example, in the example of FIG. 5 , when the rotation speed of the substrate W is maintained constant at s3 during the liquid film drying process, before the entire resist liquid R1 on the substrate W loses fluidity, the liquid film The flowing resist liquid R1 in the upper layer will cause interference stripes. This interference fringe can be visually recognized based on the rotation speed of the substrate W and the type of resist liquid R1.

Therefore, the time point when the interference fringes generated on the substrate W disappear can be regarded as the film thickness distribution determination time point. Therefore, when the above-mentioned interference streaks can be confirmed, the end time of the liquid supply period (period p2) is preferably set to a time point after starting the liquid film drying process and before the interference streaks generated on the substrate W disappear.

[5] The supply start time of flushing liquid in the liquid film drying process

In order to confirm whether there is a better time point to start supplying the rinse liquid in the liquid film drying process, the inventors used three coating processing methods to form the resist film R2 on three substrates W1, W2, and W3. . The three coating treatment methods are basically the same as the coating treatment method in Figure 5 except that the supply start time of the rinse liquid in the liquid film drying process is different from each other. In the following description, the start time point of supplying the rinse liquid to the substrate W in the liquid film drying process is referred to as the rinse start time point.

Specifically, the present inventors performed a coating process on the substrate W1 using the time point 3 seconds after the start time point of the liquid film drying process (time point t6 in FIG. 5 ) as the flushing start time point. In addition, the present inventors performed a coating process on the substrate W2 using the time point 6 seconds after the start time point of the liquid film drying process as the flushing start time point. Furthermore, the present inventors performed a coating process on the substrate W3 using a time point that was 9 seconds after the start time point of the liquid film drying process as the flushing start time point. The substrates W1 to W3 have a common outer shape. Furthermore, in the coating process of the substrates W1 to W3, the length of the liquid supply period was set to 6 seconds.

Then, the present inventors measured the film thickness distribution of the resist film R2 on the straight line passing through the center of each substrate on the substrates W1 to W3 after the coating process. FIG. 6 is a diagram showing the film thickness distribution of the resist film R2 on the three substrates W1 to W3 subjected to a coating process for confirming a preferable flushing start time point.

In FIG. 6 , the film thickness distribution of the resist film R2 on the substrates W1 to W3 is represented by a graph. In the graph of FIG. 6, the vertical axis represents the film thickness of the resist film R2, and the horizontal axis represents the position on a straight line passing through the center of each substrate W1 to W3. In addition, on the horizontal axis, "0" represents the center of the substrates W1 to W3. In addition, "150" represents one end of a straight line passing through the center of the substrates W1 to W3 on the surface of the substrates W1 to W3, and "-150" represents the end of a straight line passing through the center of the substrates W1 to W3 on the surface of the substrates W1 to W3. the other end.

Furthermore, in the graph of FIG. 6 , the solid line represents the film thickness distribution corresponding to the substrate W1 , the single-dot chain line represents the film thickness distribution corresponding to the substrate W2 , and the dotted line represents the film thickness distribution corresponding to the substrate W3 . In addition, in the graph of Figure 6, the numerical values "60" and "-60" are marked on the horizontal axis. The range CA from “60” to “-60” on the horizontal axis of FIG. 6 represents the portion (contact portion) of the substrates W1 to W3 held by the suction holding portion 11 .

As shown in FIG. 6 , the thickness of the resist film R2 of the substrates W1 to W3 is locally increased near both ends of the contact portion in the non-contact portion. Here, if the thickness of the resist film R2 near both ends of the contact portion is compared between the substrates W1 to W3, the thickness of the resist film R2 of the substrate W1 is similar to the thickness of the resist film R2 of the substrates W2 and W3. ratio, close to the thickness of the central part of the substrate. On the other hand, the thicknesses of the resist films R2 of the substrates W2 and W3 are substantially equal to each other.

From these results, it can be seen that when the flushing start time point is set to a situation where more than 6 seconds have passed from the start time point of the liquid film drying process, the film thickness distribution of the resist film R2 formed on the substrate W is not easily uniform. . Therefore, it was confirmed that the flushing start time is preferably set within 5 seconds from the start time of the liquid film drying process, and more preferably is set to within 3 seconds from the start time of the liquid film drying process. . Thereby, the thickness of the resist film R2 formed on the substrate W can be made more uniform.

[6] Length of liquid supply period

In order to confirm whether there is a preferable length of time as a liquid supply period, the inventors used six coating processing methods to form the resist film R2 on six substrates W11, W12, W13, W14, W15, and W16. Six types The coating treatment method is basically the same as the coating treatment method in FIG. 5 except that the liquid supply period in the liquid film drying step is different.

Specifically, the present inventors set the length of the liquid supply period (period p2 in FIG. 5 ) to 3 seconds and performed the coating process on the substrate W11 , and set the length of the liquid supply period to 4 seconds and performed the coating process on the substrate W12 coating treatment. In addition, the present inventors set the length of the liquid supply period to 5 seconds and performed the coating process on the substrate W13, and set the length of the liquid supply period to 6 seconds and performed the coating process on the substrate W14. Furthermore, the present inventors set the length of the liquid supply period to 9 seconds and performed the coating process on the substrate W15, and set the length of the liquid supply period to 12 seconds and performed the coating process on the substrate W16. In addition, in the coating process of the substrates W11 to W16, the flushing start time point is set to be 3 seconds after the start time point of the liquid film drying process (time point t6 in FIG. 5).

Then, the present inventors measured the film thickness distribution of the resist film R2 on the straight line passing through the center of each substrate on the substrates W11 to W16 after the coating process. FIG. 7 is a diagram showing the film thickness distribution of the resist film R2 on the six substrates W11 to W16 that were subjected to a coating process to confirm the preferred length of the liquid supply period.

In FIG. 7 , the film thickness distribution of the resist film R2 on the substrates W11 to W16 is represented by a graph. In the graph of FIG. 7 , like the example of FIG. 6 , the vertical axis represents the film thickness of the resist film R2 , and the horizontal axis represents the position on a straight line passing through the center of each substrate W11 to W16 . In addition, in FIG. 7 , the dotted line represents the film thickness distribution corresponding to the substrate W11, the two-dot chain line represents the film thickness distribution corresponding to the substrate W12, and the thick solid line represents the film thickness distribution corresponding to W13. Furthermore, the thick single-dot chain line represents the film thickness distribution corresponding to the substrate W14, the single-dot chain line represents the film thickness distribution corresponding to the substrate W15, and the solid line represents the film thickness distribution corresponding to the substrate W16. In the graph of FIG. 7 , similarly to the example of FIG. 6 , the range CA from “60” to “-60” on the horizontal axis represents the portion of the substrates W11 to W16 held by the suction holding portion 11 ( contact part).

As shown in FIG. 7 , the thickness of the resist film R2 of the substrates W11 to W16 is approximately the same at the center of the substrate, and has a large difference near both ends of the contact portion in the non-contact portion. According to the example of FIG. 7 , the thickness of the resist film R2 near both ends of the contact portion becomes smaller as the substrate is coated with a shorter liquid supply period. On the other hand, the thickness of the resist film R2 in the vicinity of both ends of the contact portion increases as the substrate is coated with a longer liquid supply period. As a result, large unevenness in the film thickness distribution of the resist film R2 was confirmed between the substrates W11 to W16.

FIG. 8 is a diagram showing the uniformity of the film thickness distribution of the resist film R2 on the six substrates W11 to W16 that were subjected to a coating process in order to confirm the optimal length of the liquid supply period. In FIG. 8 , a graph is used to show the uniformity of the film thickness distribution of the resist film R2 on the substrates W11 to W16.

In the graph of FIG. 8 , the vertical axis represents uniformity, and the horizontal axis represents the type of substrate (substrates W11 to W16). In addition, in the graph of FIG. 8 , the ranges calculated as uniformity based on the thickness of a plurality of portions of the resist film R2 measured on the substrates W11 to W16 are respectively represented by hatching and dot pattern bars. and 3σ. The range and 3σ shown in Figure 8 indicate that the smaller the value, the more uniform the film thickness distribution of the resist film R2, and the larger the value, the greater the unevenness of the film thickness distribution of the resist film R2.

From the results of Figures 7 and 8, it was confirmed that the film thickness distribution of the resist film R2 of the substrate W14 has the highest uniformity (less unevenness) among the film thickness distributions of the resist films R2 of the plurality of substrates W11 to W16. . That is, it was confirmed that by setting the length of the liquid supply period to 6 seconds and performing the coating process, the film thickness distribution of the resist film R2 can be made most uniform. On the other hand, it was confirmed that the film thickness distribution of the resist film R2 of the substrate W11 has the lowest uniformity (larger unevenness) among the film thickness distributions of the resist films R2 of the plurality of substrates W11 to W16.

As described above, it can be seen that the film thickness distribution of the resist film R2 formed on the substrate greatly differs depending on the length of the liquid supply period set during the coating process. Therefore, the length of the liquid supply period is preferably determined more appropriately based on simulations, experiments, or the like so that the film thickness distribution of the resist film R2 becomes more uniform.

[7] Flush fluid supply location

In the coating processing apparatus 1 of FIG. 1 , the plurality of lower surface nozzles 17 are respectively arranged near the outer peripheral end of the adsorption holding part 11 in a plan view. Therefore, the rinse liquid sprayed from each lower surface nozzle 17 is supplied to a portion of the non-contact portion of the substrate W that is close to the outer peripheral end of the adsorption holding portion 11 and away from the outer peripheral end of the substrate W.

In the following description, the portion of the non-contact portion of the substrate W that is far away from the outer peripheral end of the adsorption holding portion 11 and close to the outer peripheral end of the substrate W is called an outer annular portion. Furthermore, when the substrate W has a diameter of 300 mm, the outer annular portion is located inside about 50 mm from the outer peripheral end of the substrate W, for example.

In order to confirm whether the film thickness of the resist film R2 can be adjusted when the rinse liquid is supplied to the outer annular portion, the inventors changed the positions of the plurality of lower surface nozzles 17 of the coating processing apparatus 1 in FIG. 1 . Specifically, the inventors arranged each lower surface nozzle 17 at a position closer to the inner peripheral end of the shield 15 than the outer peripheral end of the suction holding portion 11 in a plan view, so that the plurality of lower surface nozzles 17 eject The rinse liquid is supplied to the outer annular portion of the substrate W. In addition, the present inventors used the coating processing apparatus 1 in which the positions of the plurality of lower surface nozzles 17 were changed, and used 8 coating processing methods on 8 substrates W21, W22, W23, W24, W25, W26, W27, and W28 A resist film R2 is formed on the resist film R2. The eight coating treatment methods are basically the same as the coating treatment methods in Fig. 5 except that the liquid supply period in the liquid film drying step is different from each other.

Specifically, the present inventors set the length of the liquid supply period (period p2 in FIG. 5 ) to 1 second and performed the coating process on the substrate W21 , and set the length of the liquid supply period to 2 seconds and performed the coating process on the substrate W22 coating treatment. Furthermore, the present inventors set the length of the liquid supply period to 3 seconds and performed the coating process on the substrate W23, and set the length of the liquid supply period to 4 seconds and performed the coating process on the substrate W24. In addition, the present inventors set the length of the liquid supply period to 5 seconds and performed the coating process on the substrate W25, and set the length of the liquid supply period to 6 seconds and performed the coating process on the substrate W26. Furthermore, the present inventors set the length of the liquid supply period to 9 seconds and performed a coating process on the substrate W27, and set the length of the liquid supply period to 12 seconds and performed a coating process on the substrate W28. In addition, in the coating process of the substrates W21 to W28, the flushing start time point is set to be 3 seconds after the start time point of the liquid film drying process (time point t6 in FIG. 5).

Then, the present inventors measured the film thickness distribution of the resist film R2 on the straight line passing through the center of each substrate on the substrates W21 to W28 after the coating process. FIG. 9 shows the resist films R2 of the eight substrates W21 to W28 that were subjected to a coating process to confirm whether the film thickness of the resist film R2 can be adjusted by supplying a rinse liquid to the outer annular portion of the substrate W. The film thickness distribution diagram.

In FIG. 9 , the film thickness distribution of the resist film R2 on the substrates W21 to W28 is represented by a graph. In the graph of FIG. 9 , like the example of FIG. 6 , the vertical axis represents the film thickness of the resist film R2 and the horizontal axis represents the position on a straight line passing through the center of each substrate W21 to W28 . In addition, in FIG. 9 , the dotted line represents the film thickness distribution corresponding to the substrate W21, the two-dot chain line represents the film thickness distribution corresponding to the substrate W22, the single-dot chain line represents the film thickness distribution corresponding to the substrate W23, and the solid line represents the film thickness distribution corresponding to the substrate W22. Film thickness distribution corresponding to W24. Furthermore, the thick dotted line represents the film thickness distribution corresponding to the substrate W25, the thick two-dot chain line represents the film thickness distribution corresponding to the substrate W26, the thick single-dot chain line represents the film thickness distribution corresponding to the substrate W27, and the thick solid line represents the film thickness distribution corresponding to the substrate W27. Film thickness distribution corresponding to W28. In the graph of FIG. 9 , similarly to the example of FIG. 6 , the range CA from “60” to “-60” on the horizontal axis represents the portion of the substrates W21 to W28 held by the suction holding portion 11 ( contact part).

As shown in FIG. 9 , the thicknesses of the resist films R2 formed on the non-contact portions of the substrates W21 to W28 are different from each other. Specifically, according to the graph of FIG. 9 , the thickness of the resist film R2 in the non-contact portion becomes smaller as the substrate is coated with a shorter liquid supply period. The longer the coated substrate is, the greater the thickness of the resist film R2 in the non-contact portion. Furthermore, the difference in thickness becomes larger as it approaches the outer peripheral end of the substrate W. From this, it was confirmed that when the rinse liquid is supplied to the annular portion outside the substrate W, by appropriately adjusting the length of the liquid supply period, the film thickness of the resist film R2 formed on the non-contact portion of the substrate W can also be adjusted. .

[8]Effect

(1) In the coating processing apparatus 1 of this embodiment, the resist liquid is supplied to the upper surface of the rotating substrate W during the coating processing. The resist liquid R1 supplied to the upper surface of the substrate W flows on the upper surface of the substrate W using centrifugal force. During the liquid supply period, the rinse liquid is supplied to the non-contact portion of the substrate W. At least part of the rinse liquid supplied to the substrate W during the liquid supply period is vaporized until the film thickness distribution determination time point passes. In this case, the temperature of the non-contact portion of the substrate W is adjusted with high efficiency using the vaporization heat generated as the rinse liquid vaporizes.

By appropriately adjusting the temperature of the non-contact portion of the substrate W, local changes in the movement state of the resist liquid flowing along the radial direction of the substrate W can be suppressed. Thereby, the thickness of the resist film R2 formed on the substrate W can be made uniform. The liquid supply period is shorter than the period from when the supply of the resist liquid R1 to the substrate W is stopped to the time when the film thickness distribution is determined. Therefore, in order to make the thickness of the resist film R2 uniform, it is not necessary to continuously supply the rinse liquid to the substrate W while the resist liquid R1 flows on the substrate W. As a result, regardless of the thickness of the resist film R2, the film thickness distribution can be made uniform at low cost.

(2) As mentioned above, the time point when the interference fringes generated on the substrate W disappear can be regarded as the time point when the film thickness distribution is determined. Therefore, by confirming the occurrence and disappearance of interference fringes in advance, the liquid supply period can be easily and appropriately set.

(3) In the coating process using the coating processing apparatus 1 of this embodiment, the length of the liquid supply period is preferably 10 seconds or less. Thereby, the consumption of flushing fluid can be further reduced. Therefore, the film thickness distribution of the resist film R2 can be made uniform at a lower cost.

(4) As mentioned above, the flushing start time point is preferably set within 5 seconds from the start time point of the liquid film forming process. In this case, the temperature of the substrate W can be adjusted more appropriately. Thereby, the film thickness distribution of the resist film R2 formed on the substrate W can be made more uniform.

(5) In the coating processing device 1 of FIG. 1 , the rinse liquids sprayed from the plurality of lower surface nozzles 17 are supplied to the non-contact portion of the substrate W close to the outer peripheral end of the adsorption holding portion 11 and away from the outer periphery of the substrate W. The position of the end. That is, the rinse liquid is supplied to the area on the lower surface of the substrate W between the contact portion of the substrate W and the outer peripheral portion. Thereby, the temperature of the portion of the non-contact portion of the substrate W located near the contact portion can be adjusted more appropriately.

[9]Other implementations

(1) In the coating processing device 1 of the above embodiment, the plurality of lower surface nozzles 17 are fixed to the casing of the coating processing device 1, but the present invention is not limited to this. FIG. 10 is a schematic cross-sectional view showing an example of the configuration of the coating processing apparatus 1 according to another embodiment. The coating processing apparatus 1 of FIG. 10 has the same structure as the coating processing apparatus 1 of FIG. 1 except that it is provided with the lower surface nozzle drive part 81.

As shown by the thick arrow in FIG. 10 , the lower surface nozzle drive unit 81 is configured to move the plurality of lower surface nozzles 17 in the radial direction of the substrate W, and is controlled by the control unit 30 . According to this configuration, the supply position of the rinse liquid on the lower surface of the substrate W can be adjusted according to various conditions such as the type of substrate W and the type of resist liquid. Furthermore, the supply position of the rinse liquid can also be moved during the liquid supply period. Therefore, the degree of freedom in temperature adjustment of the substrate W is improved.

(2) In the coating processing apparatus 1 of the above embodiment, the temperature of the rinse liquid supplied to the substrate W from the plurality of lower surface nozzles 17 is higher than the temperature of the adsorption holding part 11, but the present invention is not limited to this. The temperature of the rinse liquid supplied to the substrate W may be lower than the temperature of the adsorption holding part 11 .

Furthermore, the coating processing apparatus 1 may be configured to be able to adjust the temperature of the rinse liquid supplied to the substrate W. FIG. 11 is a schematic cross-sectional view showing another structural example of the coating processing apparatus 1 according to another embodiment. The coating processing apparatus 1 of FIG. 11 has the same structure as the coating processing apparatus 1 of FIG. 1 except that it is provided with the temperature adjustment part 82.

As shown in FIG. 11 , the temperature adjustment unit 82 is configured to adjust the temperature of the flushing liquid supplied from the flushing liquid supply system 18 to the lower surface nozzle 17 to a preset temperature, and is controlled by the control unit 30 . According to this configuration, the temperature of the rinse liquid supplied to the lower surface of the substrate W can be appropriately adjusted according to various conditions such as the type of substrate W and the type of resist liquid.

(3) In the coating process of the above embodiment, the rinse liquid is continuously supplied to the lower surface of the substrate W during the liquid supply period, but the present invention is not limited to this. The rinse liquid may be intermittently supplied to the lower surface of the substrate W during the liquid supply period.

(4) In the coating process of the above embodiment, a solvent is used as a rinse liquid in order to adjust the temperature of the non-contact portion of the substrate W, but the present invention is not limited to this. As a rinse liquid for adjusting the temperature of the non-contact portion of the substrate W, pure water that cannot dissolve the resist film R2 may be used instead of the solvent.

(5) In the coating processing apparatus 1 of the above embodiment, four lower surface nozzles 17 are provided to supply the rinse liquid to the lower surface of the substrate W, but the present invention is not limited to this. The number of the lower surface nozzles 17 for supplying the rinse liquid to the lower surface of the substrate W may be one, two or three. Alternatively, the number of lower surface nozzles 17 may be five or more.

(6) In the coating processing apparatus 1 of the above embodiment, the resist liquid R1 is supplied to the substrate W as the coating liquid, but the present invention is not limited to this. In the coating processing apparatus 1, the antireflection film coating liquid may be supplied to the substrate W. Alternatively, in the coating processing device 1, a SOC (Spin On Carbon) film, a SOG (Spin On Glass) film or a SiARC (Si-rich Anti Reflective Coating) film can also be used. The coating liquid for the coating film is supplied to the substrate W.

(7) In the coating processing apparatus 1 of the above embodiment, the plurality of lower surface nozzles 17 are used as the rinse liquid supply device for post-rinsing, but the present invention is not limited to this. In addition to the plurality of lower surface nozzles 17 described above, the coating treatment device 1 may also have one or a plurality of nozzles dedicated to post-rinsing. In this case, the plurality of lower surface nozzles 17 can be provided at a position more suitable for adjusting the temperature of the substrate W. In addition, one or a plurality of nozzles dedicated to post-rinsing can be provided at a position more suitable for removing the resist liquid R1 or the resist film R2 adhered to the lower surface of the substrate W. As a result, the film thickness uniformity of the resist film R2 formed on the substrate W can be improved, and the lower surface of the substrate W can be kept cleaner.

[10] Correspondence between each component of the technical solution and each element of the implementation

Hereinafter, examples corresponding to each component of the technical solution and each component of the embodiment will be described. In the above embodiment, the contact portion of the substrate W is an example of the center portion of the lower surface of the substrate, the rotation holding device 10 is an example of the rotation holding portion, the liquid supply device 20 is an example of the coating liquid supply portion, and the non-contact portion of the substrate W is The portion is an example of an annular portion on the lower surface of the substrate, and the plurality of lower surface nozzles 17 and the rinse liquid supply system 18 are examples of a rinse liquid supply portion.

In addition, the time point when the supply of the resist liquid R1 is stopped in the liquid film forming process (time point t4 in FIG. 5 ) is an example of the first time point, and the film thickness distribution determination time point (time point t8 in FIG. 5 ) is an example of the second time point. As an example of the time point, the control unit 30 is an example of the control unit, and the coating processing device 1 is an example of the coating processing device. The time points are the end time point of the liquid film forming process and the start time point of the liquid film drying process (Fig. Time point t6 in 5) is an example of the third time point. As each component of the technical solution, various other elements having the configuration or function described in the technical solution can also be used.

1: Coating processing device 10: Rotation holding device 11: Adsorption and holding part 11u: Upper surface 12:Rotation axis 13: Rotary drive part 14:Suction device 15: Protective cover 15d: Drainage port 15x: bottom 15y: Peripheral wall 16: Drainage guide tube 17: Lower surface nozzle 17b: Liquid ejection port 18: Flushing fluid supply system 20:Liquid supply device 21:Resist nozzle 22: Coating liquid supply system 30:Control Department 81: Lower surface nozzle driving part 82: Temperature adjustment department h: suction hole R1: Resist liquid R2: Resist film vp: air intake path W: substrate

FIG. 1 is a schematic cross-sectional view of a coating processing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic plan view of the coating processing apparatus of FIG. 1 . FIG. 3 is a plan view showing an example of a resist film in which uneven film thickness distribution occurs. FIG. 4 is a cross-sectional view illustrating a mechanism presumed to cause uneven film thickness distribution in FIG. 3 . FIG. 5 is a diagram illustrating a specific example of the coating process according to one embodiment of the present invention. FIG. 6 is a diagram showing the film thickness distribution of the resist films on three substrates subjected to a coating process for confirming a preferable flushing start time point. FIG. 7 is a diagram showing the film thickness distribution of the resist films on six substrates subjected to a coating process to confirm the optimal length of the liquid supply period. FIG. 8 is a graph showing the uniformity of the film thickness distribution of the resist films on six substrates subjected to coating processing in order to confirm the optimal length of the liquid supply period. FIG. 9 is a diagram showing the film thickness distribution of the resist films on eight substrates subjected to a coating process to confirm whether the film thickness of the resist film can be adjusted by supplying a rinse liquid to the outer annular portion of the substrate. . FIG. 10 is a schematic cross-sectional view showing a structural example of a coating processing apparatus according to another embodiment. FIG. 11 is a schematic cross-sectional view showing another structural example of a coating processing apparatus according to another embodiment.

Claims (10)

A coating treatment method, which includes the following steps: The rotation holding part is used to hold the substrate adsorbed at the center of the lower surface of the substrate in a horizontal position and rotate it around the vertical axis; The coating liquid is supplied to the upper surface of the substrate rotated by the rotation holding portion; and In a state where the substrate held by the rotation holding unit is rotated, the liquid flow period from the first time point when the supply of the coating liquid ends to the second time point when the coating liquid on the substrate loses fluidity is longer than the liquid flow period. During the liquid supply period before the second time point, the volatile rinse liquid is supplied to at least a part of the annular portion of the lower surface of the substrate rotating by the rotation holding portion surrounding the central portion of the lower surface. The coating treatment method of claim 1, wherein the second time point is the time point when the interference fringes generated on the surface of the coating liquid supplied to the upper surface of the substrate disappear after the first time point has passed. The coating treatment method of claim 1 or 2, wherein the length of the liquid supply period is 10 seconds or less. The coating processing method of Claim 1 or 2, wherein the step of rotating the substrate includes: after the passage of the above-mentioned first time point to a third time point earlier than the above-mentioned second time point, so as to rotate the substrate supplied to the substrate. The coating liquid on the upper surface covers the entire upper surface of the substrate to rotate the substrate, The start time point of the liquid supply period is set within 5 seconds from the third time point. The coating treatment method according to claim 1 or 2, wherein the annular lower surface portion is located on the lower surface of the substrate rotated by the rotation holding portion, and the annular lower surface peripheral portion including the outer peripheral end portion of the substrate and the lower surface are between the center of the surface. A coating processing device equipped with: A rotation holding part that holds the substrate in a horizontal position by adsorbing the center portion of the lower surface of the substrate and rotates it around the vertical axis; a coating liquid supply unit that supplies the coating liquid to the upper surface of the substrate rotated by the rotation holding unit; A rinse liquid supply unit that supplies a volatile rinse liquid to at least a part of the annular portion of the lower surface of the substrate that is rotated by the rotation holding portion and surrounds the central portion of the lower surface; and A control unit that controls the rotation holding unit, the coating liquid supply unit, and the rinse liquid supply unit to supply the coating liquid to the upper surface of the substrate while the substrate held by the rotation holding unit is rotated. In the liquid flow period from the first time point when the supply of the coating liquid ends to the second time point when the coating liquid on the substrate loses fluidity, the liquid supply period that is earlier than the above-mentioned second time point will be flushed. The liquid is supplied to the annular portion of the lower surface of the substrate. The coating processing device of claim 6, wherein the second time point is the time point when the interference fringes generated on the surface of the coating liquid supplied to the upper surface of the substrate disappear after the first time point has passed. The coating processing apparatus of Claim 6 or 7, wherein the length of the liquid supply period is 10 seconds or less. The coating processing apparatus according to claim 6 or 7, wherein the control unit controls the rotating holding unit so that the amount of water supplied to the substrate is supplied to the substrate at a third time point that is earlier than the second time point after the passage of the first time point. The coating liquid on the upper surface covers the entire upper surface of the substrate, The start time of the liquid supply period is set within 5 seconds from the third time. The coating processing apparatus according to claim 6 or 7, wherein the annular lower surface portion is located between an annular lower surface peripheral portion including an outer peripheral end portion of the substrate and the lower surface of the substrate rotated by the rotation holding portion. between the center of the surface.