JPH0563038U - Spin coater - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] Regardless of the unevenness of the wettability of the substrate surface, surely apply photoresist to the entire substrate surface with a uniform film thickness.
It also improves the use efficiency of the resist. A substrate 100 is placed on a turntable 30, a photoresist from a resist supply system 40 is discharged onto the surface of the substrate 100 through a coater nozzle 50, and is rotated by an electric motor 20 to rotate the photoresist uniformly. Is formed on the surface of the substrate by coating. In this case, the photoresist spread on the surface of the substrate 100 is detected by the sensors 60 and 61, and the developing speed is obtained by the calculation unit 70. Since this developing speed is related to the wettability of the substrate surface, the amount of photoresist discharged from the coater nozzle 50 is adjusted based on this.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a spin coater for coating and forming a uniform thin film on a wafer or a glass substrate, and in particular, it is possible to detect the developing speed of the coated thin film material and automatically adjust the discharge rate. The present invention relates to a spin coater.

[0002]

[Prior Art]

 Conventionally, a spin coater is used to coat and form a uniform thin film on a wafer, a glass substrate, or the like. A general method of applying, for example, a photoresist or the like by this conventional spin coater will be described below with reference to FIG. First, the substrate 2 placed on the rotary table 1 is rotated at low speed (10 to 100 rpm), and a predetermined amount of photoresist is applied to the substrate from the coater nozzle 3 of the spin coater. Discharge and drop. Next, low-speed rotation is continued to spread the dropped photoresist to a certain range, and when the photoresist spreads to the specified range by the centrifugal force, the substrate 2 is rotated at a high speed and the surface of the substrate is rotated. The photoresist that has been spread to a certain area is further spread, and this is continued for a certain period of time. How the normal photoresist spreads on the substrate surface at this time is shown in FIGS. 2 (a) and 2 (c).

[Problems to be solved by the device]

By the way, a substrate on which a thin film such as a photoresist is formed on the surface may not be able to form a uniform thin film on the entire surface by the above method if the surface has poor coatability. For example, if a substrate having a slightly poor wettability is mixed in the lot, the dropped photoresist does not spread evenly at low rotation on the surface of this substrate, as shown in Fig. 2 (b). In addition, the boundary surface becomes sharply protruding, that is, it becomes jagged. In this state, when the rotation speed is further increased, the photoresist flows only in the easy-to-flow portion, and in a conventional spin coater that supplies a fixed amount of photoresist, as shown in (d) of FIG. In addition, there will be a portion of the substrate surface where the photoresist is not applied.

On the other hand, when the wettability is better than the average, the desired coating amount can be achieved with a resist amount smaller than the set value, but since a fixed amount of resist has already been supplied, it is not used. There is a problem in that resist is generated, which deteriorates the utilization efficiency of the material. In view of the above-mentioned problems in the prior art, the present invention can form a uniform thin film on the entire surface even if the coatability of the surface is uneven, and the coating material can be used efficiently. The object is to provide a spin coater that can be used well.

[0005]

[Means for Solving the Problems]

 That is, according to the present invention, in order to achieve the above object, a rotary table for mounting and rotating a substrate, a rotating means for transmitting a rotary driving force to the rotary table, and a surface of the substrate mounted on the rotary table. In a spin coater equipped with a coating material supply nozzle that discharges the coating material for forming a thin film on the substrate, the spreading speed of the coating material coated on the substrate is further measured along the surface of the rotary table. A spin coater comprising a detecting means, and controlling the amount of the coating material discharged and supplied from the coating material supply nozzle based on the developing speed of the coating material detected by the detecting means. provide.

[0006]

[Action]

 According to the above-described spin coater of the present invention, by providing the spreading speed detecting means provided along the rotary table, the wettability of the coating material discharged and supplied onto the substrate surface can be improved. It becomes possible to detect in advance. Therefore, based on this, by controlling the amount of coating material that is further discharged and supplied from the coating material supply nozzle, an amount of coating material that matches the wettability of the substrate surface is supplied, and the substrate is reliably It is possible to apply the coating material with a uniform film thickness on the entire surface.

[0007]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, FIG. 1 shows a spin coater according to an embodiment of the present invention. In this figure, a substrate 100 on which a coating material such as photoresist is to be coated in a thin film is placed on a rotary table 20 which is driven to rotate by an electric motor 10. On the other hand, the applied photoresist is discharged onto the surface of the substrate 100 through the coater nozzle 50 by the control unit 30 and the resist supply system 40.

By the way, along the surface of the substrate 100, sensors 60 and 61 having insensitive wavelengths are arranged above the substrate 100 at different distances in the radial direction of the rotary table 30. The outputs of these sensors 60 and 61 are input to an arithmetic unit 70 composed of, for example, a microcomputer, where a predetermined arithmetic operation is performed, and the arithmetic result is output to the control unit 30 and the resist supply system 40. .. That is, the control unit 30 controls the rotational speed of the electric motor 10 that rotationally drives the rotary table 20. On the other hand, the resist supply system 40 discharges the resist from the resist supply system 40 through the coater nozzle 50 onto the surface of the substrate 100 based on the photoresist development speed and rotation speed information calculated by the calculator 70. Controls the amount of photoresist applied. In addition, reference numeral 80 in the drawing is a fence provided so as to surround the turntable 20.

Next, the operation of the spin coater according to the present invention having the above construction will be described. First, a predetermined amount of photoresist is discharged from the resist supply system 40 through the coater nozzle 50 onto the surface of the substrate 100. Then, the supplied photoresist spreads on the substrate surface by the low speed rotation of the rotary table 20. That is, the resist discharged onto the surface of the substrate 100 spreads to the periphery as the rotary table 20 rotates (low speed rotation), and the outermost peripheral portion of the spread photoresist has passed a predetermined radius. Is detected by the sensors 60 and 61, and the developing speed of the photoresist is calculated by the arithmetic unit 70 from the passage time of these sensors 60 and 61 to obtain the wettability of the photoresist on the substrate surface.

In addition, the arithmetic unit 70 inputs an average value in advance as the comparison data using the wettability data, compares the data obtained above with the comparison data, and determines the surface of the substrate. Then, the increase / decrease of the amount of photoresist discharged upward is determined. In other words, the wettability of the substrate 100 is checked and the discharge amount of the photoresist is automatically adjusted. More specifically, the speed at which the outermost peripheral portion of the photoresist on the substrate 100 passes through the sensors 60, 61 is detected, and the developing speed of the photoresist is calculated by the arithmetic unit 70, and the data and the data are stored in advance. The average value of the development speed is input to the calculation unit as comparison data, and the two data are compared to determine the increase / decrease in the discharge amount and automatically adjust. That is, when the expansion speed is higher than the average value, the discharge amount is reduced, and when the expansion speed is slow, the discharge amount is increased. Thereafter, the control unit 30 increases the rotational speed of the electric motor 10 that rotationally drives the rotary table 20 and spreads the discharged and supplied photoresist over the entire surface of the substrate 100 to form a thin film. It is the same.

Therefore, in the case of a substrate whose surface wettability is inferior to the average, it is possible to uniformly apply the photoresist onto the substrate surface by increasing the discharge amount of the photoresist, and vice versa. In the case of a substrate having good properties, the discharge amount can be reduced and the utilization efficiency of the photoresist can be improved. Specifically, in the conventional method in which the discharge amount of the photoresist is set in advance and a fixed amount of the photoresist is supplied to the substrate, the resist coating failure is caused at a rate of 1 to 4%. Had occurred. On the other hand, when the photoresist was applied by the spin coater according to the above-mentioned embodiment of the present invention, the application failure disappeared. The spin coater of the present invention can be applied not only to the photoresist described as an example in the above embodiment, but also to spin coating of various kinds of coating films. Needless to say, the substrate can be applied not only to wafers and glass but also to various substrates such as plastics and metals.

[0012]

[Effect of the device]

 As is clear from the above detailed description, according to the spin coater of the present invention, defective coating of the photoresist when the wettability of the substrate is lower than the average is eliminated, and the wettability of the substrate is good. In this case, since it is possible to reduce the amount of photoresist that is discharged and supplied in vain, it is possible to form a thin film over the entire surface regardless of the unevenness of the wettability of the substrate surface, and The effect is that the use efficiency of the photoresist can be improved.

[Brief description of drawings]

FIG. 1 is a functional block diagram of a spin coater according to an embodiment of the present invention.

FIG. 2 is a substrate surface view for explaining a photoresist coating state on a substrate surface in a conventional technique.

FIG. 3 is a functional block diagram of a spin coater as an example of the above conventional technique.

[Explanation of symbols]

 10 electric motor 20 rotary table 30 control unit 40 resist supply system 50 coater nozzle 60, 61 sensor 70 arithmetic unit 100 substrate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Tetsuo Fukuda 6-16-20 Ueno, Taito-ku, Tokyo Taiyo Induction Co., Ltd.

Claims (2)

[Reference number] 0030767-01 [Claims for utility model registration] 1. A rotary table for mounting and rotating a substrate,
Rotating means for transmitting rotational drive force to the rotary table;
A spin coating apparatus comprising a coating material supply nozzle for discharging a coating material for forming a thin film on the surface of a substrate placed on the rotary table, further comprising: And a means for detecting the developing speed of the coating material applied to the coating material, and controlling the amount of the coating material discharged and supplied from the coating material supply nozzle based on the developing speed of the coating material detected by the detecting means. A spin coater characterized by the above. 2. The detecting means for detecting the developing speed of the coating material according to claim 1, comprising at least two sensors, and these sensors are arranged at different distances from the center of rotation of the rotary table. The spin coater is characterized in that