JPH0674717A - Resist film thickness measuring method - Google Patents

Abstract

(57) [Summary] [Purpose] The film thickness of the resist coated on the substrate surface is measured in a short time and the coating equipment is adjusted. [Structure] The film thickness of the resist applied to the substrate surface is measured immediately after the resist is applied, without waiting for the resist to dry, and the solvent amount of the resist contained in the resist is measured in a non-contact manner, and the measured value has a constant relationship. The film thickness of the resist in the dry state is calculated, and the resist coating amount in the resist coating step is adjusted based on the obtained film thickness data. [Effect] It is possible to measure the resist film thickness in real time and adjust the coating film thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for rapidly measuring the film thickness of a resist forming a predetermined pattern when a shadow mask, a lead frame or the like is manufactured by etching a thin metal plate. The present invention relates to a method for measuring the film thickness of.

[0002]

2. Description of the Related Art For etching a shadow mask, lead frame, etc., a resist is applied to the surface of a thin metal plate such as mild steel or iron-nickel alloy, dried, and then exposed by a mask having a predetermined pattern to form a pattern on the resist. Is formed. In the production of shadow masks and lead frames, after continuously applying a resist to at least one surface of a long metal thin plate, each step of drying, exposing, developing and etching is performed.

Since making the thickness of the resist applied to the substrate constant has a great influence on the etching characteristics, and eventually the quality of the shadow mask and lead frame obtained, it is required to keep the resist film thickness constant. . Therefore, the film thickness of the resist is accurately measured, and the obtained measurement data of the resist film thickness is fed back to the resist coating process to maintain the coating thickness at a predetermined value.

FIG. 3 is a diagram for explaining an example of a conventional method for measuring the resist film thickness. Coating device 22 for thin metal plate 21
After applying the resist 23 by the method, in a drying step 24, the resist was dried by a dry air flow and an infrared heating device 25, and the film thickness of the dried resist was measured by an optical interference type film thickness measuring device 26 or the like. The measurement data is fed back to the coating device 22 to maintain the coating amount at a predetermined value. However, it takes time to measure the film thickness of the resist after the drying step, and in the manufacturing process of the shadow mask and the lead frame, the resist is continuously applied to a long thin metal plate, so When the data of the film thickness is sent to the coating process, the resist coating has already been applied to the next part, so there is a time delay and it is necessary to maintain the resist thickness at a predetermined value accurately in real time. I couldn't.

[0005]

The measurement of the film thickness of the resist after drying requires a time from coating to measurement, and if the resist thickness is accurately controlled based on the measured data, the next resist It is necessary to wait until the drying is completed for the measurement of 1. On the other hand, in the case where the resist coating and the drying are continuously performed, when the data of the film thickness is sent to the resist coating step, the measurement of the next portion is already performed. Since the resist is applied, a time delay occurs and it is difficult to control the film thickness in real time. An object of the present invention is to quickly measure the resist film thickness and feed back the film thickness measurement data to the coating process in real time to enable efficient manufacturing.

[0006]

The present invention provides a method for measuring the film thickness of a resist applied on a substrate surface, in which the amount of the solvent of the resist contained in the resist is measured immediately after the application of the resist, and the obtained solvent is obtained. Is a method of measuring the film thickness of the resist from the measured value of. When the resist is a water-soluble resist that can be developed with water or warm water, such as casein with added substances such as ammonium dichromate, gelatin, etc., measure the water content in the resist with a moisture meter and obtain The film thickness of the resist can be measured based on the obtained measurement data.

Further, according to the measuring method of the present invention, since the film thickness of the resist can be known immediately after coating the resist without waiting for the drying, the time from the coating of the resist to the film thickness measurement can be shortened. Since it becomes possible to immediately feed back the measurement data of the thickness to the resist coating process, after waiting for drying to measure the resist film thickness and then performing the next measurement, or when continuously coating, The measurement data of the film thickness can be immediately reflected in the coating process. In particular, water-soluble resists use water as the main solvent,
Since it takes longer time to dry than a resist using a volatile organic solvent, the method of the present invention which does not require drying is highly effective when a water-soluble resist is used.

Various methods can be used as a method for non-contactly measuring the amount of the solvent in the resist. By irradiating the solvent with an electromagnetic wave having an absorption wavelength and the solvent with an electromagnetic wave having no absorption wavelength, the film thickness can be known by obtaining the amount of the solvent from the difference in the reflection intensity of both wavelengths. An example of the film thickness measuring method of the present invention will be described with reference to the drawings in FIG. Before the resist is dried on the substrate 2 coated with the resist 1, light having an absorption wavelength that is not absorbed by the resist but is absorbed only by the solvent of the resist is emitted from the light emitting element 3, and reflected light is detected by the light receiving element 4. The A signal 5 and the B signal 6 detected by the light receiving element by irradiating light having a wavelength which is not absorbed by the solvent of the resist in the vicinity thereof are supplied to the film thickness calculation device 7 and undried from the ratio of the A signal and the B signal. Obtain the film thickness in the state.

On the other hand, the relationship between the film thickness in the undried state and the film thickness after drying the resist is known by measuring the film thickness of the resist after drying the resist. However, since the relationship between the film thickness of the resist in the undried state and the film thickness of the resist in the dried state differs depending on the characteristics of the resist, it is advisable to measure both for each target resist to prepare a calibration curve or the like. Furthermore, the film thickness in the dry state is automatically obtained by the dry film thickness calculating device 8 using a microcomputer or the like having a memory storing the relationship between the thickness in the non-dry state and the thickness in the dry state, and the film thickness in the coating device 9 is calculated. By adjusting the coating amount adjusting mechanism, the film thickness can be adjusted immediately.

[0010]

Since the film thickness of the resist is obtained by non-contactly measuring the amount of the solvent in the undried resist immediately after coating, it is possible to know the film thickness of the resist without waiting for the drying. Since the resist coating amount can be adjusted without causing a time delay with the resist coating process, it is possible to continuously form a resist having a uniform thickness.

[0011]

EXAMPLES Examples of the present invention will be described below. Example 1 A casein resist was applied to a strip-shaped metal substrate having a width of 650 mm,
As shown in FIG. 1, the thickness of the resist is changed, and the thickness of the resist immediately after the application is reciprocated in the width direction while maintaining a constant gap between the metal substrate and the sensor portion including the light emitting element and the light receiving element. The water content in the casein resist was measured. The water content is measured by calculating the water content from the ratio of the measured intensity of infrared light of a wavelength that is absorbed by water and the measured intensity of infrared light that is not absorbed by water adjacent to the infrared light, and undried based on the measured value. The thickness in the state was calculated, and then the thickness of the dry resist was measured. From these results,
The relationship between the resist thickness in the undried state and the resist thickness in the dried state was determined. In FIG. 2, when the film thickness is measured using a moisture meter, the horizontal axis shows the reading of the moisture meter and the vertical axis shows the relationship between the film thickness in the undried state and the film thickness in the dried state.

[0012]

EFFECT OF THE INVENTION The resist film thickness measuring method of the present invention measures the content of the solvent in the undried resist in a non-contact manner and determines the film thickness after drying from the measurement results. In the method of measuring with a film thickness meter, it takes 5 to 15 minutes to measure the film thickness within a time that can be ignored, and the coating amount of the resist coating device is immediately adjusted based on the measurement result of the film thickness. Therefore, it is possible to efficiently obtain a substrate coated with a resist having a predetermined film thickness.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a film thickness measuring method of the present invention.

FIG. 2 is a diagram illustrating an example of measurement results of a film thickness before and after drying.

FIG. 3 is a diagram illustrating a conventional film thickness measuring method.

[Explanation of symbols]

1 ... Resist, 2 ... Substrate, 3 ... Light emitting element, 4 ... Light receiving element, 5 ... A signal, 6 ... B signal, 7 ... Film thickness calculation device, 8 ...
Dry film thickness calculation device, 9 ... Coating device, 21 ... Metal thin plate, 2
2 ... Coating device, 23 ... Resist, 24 ... Drying process, 25
... Infrared heating device, 26 ... Film thickness measuring device

Claims (3)

[Claims] 1. A method for measuring a resist film thickness applied to a substrate surface, which comprises measuring the amount of a solvent in a resist which is in an undried state. 2. The resist film thickness measuring method according to claim 1, wherein the film thickness of the water-soluble resist is determined by the amount of water measured by a moisture meter. 3. The film thickness in a dry state is calculated from the film thickness of the resist in a non-dried state by referring to the relationship between the film thickness in the non-dried state and the film thickness in the dried state obtained in advance. 1. The resist film thickness measuring method described in 1.