SPIN-COATING DEVICE

Abstract

Provided is a spin-coating device including a film thickness measurement unit (1) and an operation adjustment unit (2). The film thickness measurement unit (1) measures a real-time thickness of a film formed of coating liquid by means of interferometry. The operation adjustment unit (2) adjusts operation of the spin-coating device in accordance with the real-time thickness of the film formed of the coating liquid.

Claims

1. A spin-coating device comprising: a film thickness measurement unit (1); and an operation adjustment unit (2), wherein the film thickness measurement unit (1) measures a real-time thickness of a film formed of coating liquid by means of interferometry, and the operation adjustment unit (2) adjusts operation of the spin-coating device in accordance with the real-time thickness of the film formed of the coating liquid.

2. The spin-coating device according to claim 1, wherein the film thickness measurement unit (1) includes a light source (101), an irradiation unit (102), a light receiving unit (103), a spectroscopic unit (104), and a film thickness calculation unit (105), and the operation adjustment unit (2) includes a memory (201) and a control unit (202).

3. The spin-coating device according to claim 1, wherein the film thickness measurement unit (1) measures a real-time thickness of a film formed of a resist material by means of optical interferometry, the operation adjustment unit (2) stops rotation of the spin-coating device when the real-time thickness of the film formed of the resist material reaches a predetermined range, and the spin-coating device is for applying the resist material onto a substrate.

4. A spin-coating method which uses the spin-coating device according to claim 1.

5. A method of selecting optimum spin-coating conditions which uses the spin-coating device according to claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0032] FIG. 1 schematically shows a spin-coating device of the present invention.

[0033] FIG. 2 schematically shows the way in which irradiation with light and detection of light are performed by the spin-coating device of the present invention.

[0034] FIG. 3 schematically shows an example of the spin-coating device of the present invention.

[0035] FIG. 4 is a graph that shows a change with time in real-time thickness of a resist material in Example 1.

DESCRIPTION OF EMBODIMENTS

Example 1

[0036] A film formed of a resist material was formed on a substrate by means of a spin-coating device of the present invention.

[0037] (Spin-Coating)

[0038] By means of the spin-coating device of the present invention, spin-coating was performed while measuring the film thickness of the resist material. FIG. 3 shows the spin-coating device used here. A nozzle (5) drips 6 ml of a resist material (6) onto a central portion of a substrate. The dripped resist material (601) is spread to reach an end portion of the substrate because of a centrifugal force caused by rotation of a rotary table (8) (rotation speed: 3200 rpm), so that a film (602) is formed. A film thickness measurement unit (1) irradiates the film (602) formed of the resist material (6) with light having a wavelength equal to or larger than 400 nm and equal to or smaller than 700 nm three times per second at regular intervals. The film thickness measurement unit (1) calculates the real-time thickness of the resist material (6) on the substrate from the thickness of the film (602) at a point irradiated with the light. Note that FIG. 3 is a schematic diagram for helping understanding of this example, and does not precisely reproduce the shape or disposition of the actual device. For example, the rotary table, a portion of a material on the rotary table, a member to which the nozzle is connected, a portion of communication connection means, a power source, and the like are not shown.

[0039] The real-time thickness of the resist material (6) on the substrate which is output from the film thickness measurement unit (1) is stored in a memory (201) of a PC (2) functioning as an operation adjustment unit (2) together with other data related to coating. The PC (2) converts stored data into display data by means of a predetermined program.

[0040] In the operation adjustment unit (2), a desired thickness of the resist material (6) on the substrate is prescribed as target values. In a case where the real-time thickness of the resist material (6) on the substrate that is received from the film thickness measurement unit (1) matches the target values, the operation adjustment unit (2) transmits a rotary table stoppage command to the spin-coating device. In the present example, as the target values, a minimum value was set to 1100 nm and a maximum value was set to 1250 nm so that the resist material forms a film having a thickness of 1000 nm on the substrate in the end after baking. A control unit of the PC (2) compared the real-time thickness of the resist material (6) generated on the substrate with the target values (the minimum value and the maximum value) and stopped the rotary table (8) when the real-time thickness of the resist material (6) generated on the substrate reached a target range (a range of 1100 nm to 1250 nm).

[0041] A screen (301) of the PC which functions as a display unit (3) displays a change with time in real-time thickness of the resist material (6) on the substrate in accordance with the display data output from the PC (2). In the present example, a graph shown in FIG. 4 was displayed on the screen (301) for purpose of observing a change with time in real-time thickness of the resist material (6). The vertical axis of the graph in FIG. 4 represents the thickness (nm) and the horizontal axis represents time (seconds).

[0042] Rotation of the rotary table (8) was started 30 seconds after the start of measurement of time. After the start of the rotation, the real-time thickness of the resist material (6) on the substrate was rapidly decreased in about 10 seconds and reached the target range (a range of 1100 nm to 1250 nm) 70 seconds after the start of the measurement of time. Therefore, the PC (2) transmitted a rotation stoppage command to a main body of the spin-coating device. As a result, the operation of the rotary table (8) was stopped and the spin-coating ended. Throughout a time from the start to the end of the spin-coating, the temperature of a spin-coating atmosphere (the inside of a chamber where the rotary table of the spin-coating device was placed) and the temperature of a discharge portion of the nozzle were constant at 23° C.

[0043] (Drying and Baking) The obtained substrate was dried and heated to obtain a substrate (a substrate A1) coated with the film formed of the resist material.

[0044] (Film Thickness Measurement) At a plurality of points on the substrate A1, the thickness of the film formed of the resist material was measured by means of interferometry.

Example 2

[0045] Spin-coating, drying, and heating were performed on a new substrate in the same manner as the substrate A1 to obtain a substrate A2. In the case of the spin-coating of the substrate A2, operation of the rotary table (8) was stopped after 72 seconds from the start of measurement of time. Although there was a period, in which the temperature of the spin-coating atmosphere (the inside of the chamber where the rotary table of the spin-coating device was placed) or the temperature of the discharge portion of the nozzle changed from 23° C., within a time from the start to the end of the spin-coating of the substrate A2, there was no change in conditions set for the film thickness measurement unit (1) and the PC (2). At a plurality of points on the substrate A2, the thickness of the film formed of the resist material was measured by means of interferometry.

Example 3

[0046] Furthermore, spin-coating, drying, and heating were performed on a new substrate in the same manner as the substrate A1 to obtain a substrate A3. In the case of the spin-coating of the substrate A3, operation of the rotary table (8) was stopped after 79 seconds from the start of measurement of time. Although there was a period, in which the temperature of the spin-coating atmosphere (the inside of the chamber where the rotary table of the spin-coating device was placed) or the temperature of the discharge portion of the nozzle changed from 23° C., within a time from the start to the end of the spin-coating of the substrate A3, there was no change in conditions set for the film thickness measurement unit (1) and the PC (2). At a plurality of points on the substrate A3, the thickness of the film formed of the resist material was measured by means of interferometry.

Reference Examples 1, 2, and 3

[0047] Separately, optimum operating conditions for a spin-coating device main body were determined by means of a method in the related art such that the film formed of the resist material has a thickness of 1000 nm in the end. The above-described optimum operating conditions were determined in consideration of the temperature of the spin-coating atmosphere. Spin-coating was performed under the determined optimum operating conditions. The obtained substrate was dried and heated under the same conditions as Examples 1, 2, and 3 to obtain three substrates (substrates B1, B2, and B3) each of which was coated with a film formed of a resist material.

[0048] For each of the substrates B1, B2, and B3 as well, the thickness of the film formed of the resist material was measured by means of interferometry under the same conditions as Examples 1, 2, and 3.

[0049] [Evaluation]

[0050] No significant difference in average film thickness and degree of variation in film thickness was observed between the substrates A1, A2, and A3 and the substrates B1, B2, and B3. From this, it can be found that film thickness measurement performed during spin-coating in Examples did not damage formation of a coating liquid (resist material) film.

[0051] In the spin-coating of Examples 1, 2, and 3, a rotary table stoppage command of the PC (2) was generated without being affected by a change in temperature of the spin-coating atmosphere, and the length of spin-coating time was adjusted to an optimum length by means of the stoppage command. However, in the spin-coating of Reference Examples 1, 2, and 3, it was necessary to determine in advance the optimum operating conditions for the spin-coating device main body in consideration of the temperature of the spin-coating atmosphere. Therefore, so-called optimal condition establishment was complicated in comparison with the case of Examples.

INDUSTRIAL APPLICABILITY

[0052] The spin-coating device of the present invention, a spin-coating method using the same, and a method of selecting optimum spin-coating conditions simplify a step of manufacturing various products manufactured with spin-coating. The present invention particularly contributes to reduction of the manufacturing cost and improvement of the quality of a precision-processed product such as a resist substrate.

REFERENCE SIGNS LIST

[0053] 1: film thickness measurement unit [0054] 101: light source [0055] 102: irradiation unit [0056] 103: light receiving unit [0057] 104: spectroscopic unit [0058] 105: film thickness calculation unit [0059] 106: communication unit [0060] 2: operation adjustment unit [0061] 201: memory [0062] 202: control unit [0063] 203: communication unit [0064] 3: display unit [0065] 301: screen [0066] 4: communication means (cable) [0067] 5: nozzle [0068] 6: coating liquid [0069] 601: dripped resist material [0070] 602: film formed of the resist material [0071] 7: substrate [0072] 8: rotary table [0073] 9: rotation mechanism