JP3505717B2 - Method and apparatus for developing resist - Google Patents

Description

TECHNICAL FIELD The present invention relates to a resist developing method and a developing apparatus in lithography.

BACKGROUND ART As a mounting technology for semiconductor elements, TAB (Tape Automated Boa
nding) technology has been put to practical use. This technique has many features such as a semiconductor device mounted on a flexible circuit board, suitable for mass production, downsizing, and precise pattern formation.

Here, the flexible circuit board is manufactured through many processes. That is, a step of attaching a metal foil such as copper to a long flexible film mainly made of a resin, a step of applying a photoresist, a step of exposing a circuit pattern, a step of developing a circuit pattern, and a circuit pattern remains. The flexible circuit board is manufactured through the steps of etching, removing the photoresist, and plating.

Of these steps, the step of developing the circuit pattern is shown in FIG. In the figure, the flexible film 104 wound around the reel 102 is formed by applying a photoresist (not shown) and exposing the circuit pattern. Flexible film 104 is a sprocket 10
It passes through the inside of the developing container 108 guided by 6, 112 and 114.
A developing solution 110 is stored in the developing container 108, and the exposed portion of the photoresist applied to the flexible film 104 is dissolved and removed by the developing solution 110. A positive type photoresist is used here. Then, the flexible film 104 is washed by the washing machine 118 via the sprocket 116, dried by the drying machine 120, and then wound on the reel 122.

In the above process, as the development of the flexible film 104 progresses, the developing solution 110 deteriorates, especially near the flexible film 104, and the concentration decreases. That is, even if they exist in the same developing container 108, the concentrations of the developing solutions 110 are partially different, and the degree of development varies. Especially when the pitch of the circuit pattern is fine, when the subsequent etching step is performed,
Due to the variation, the circuit pattern is broken or short-circuited. Further, as the number of times of use increases, the concentration of the developing solution 110 decreases not only partially but entirely, and the developing speed becomes slow. To avoid this, flexible film
Since it is necessary to adjust conditions such as the delivery speed of 104 and the temperature of the developing solution, the work becomes complicated.

The present invention has been made focusing on the above problems,
It is an object of the present invention to provide a developing method and a developing apparatus that improve patterning accuracy of resist development in lithography and can avoid work delay and complexity.

DISCLOSURE OF THE INVENTION (1) The present invention relates to a method for developing a resist in lithography, wherein a long object to be developed coated with a resist is conveyed in its longitudinal direction while a part of the object to be developed is stored in a container. And injecting the developing solution stored in the container in order to apply the hydraulic pressure by the developing solution to the developing object. Do it above.

According to the present invention, the object to be developed is immersed in the developer stored in the container to perform the development. Therefore, the developer is in contact with air only at the liquid surface, so that the area is small and carbon dioxide in the air is difficult to dissolve in the developer. By doing so, the neutralization reaction between carbonic acid generated by dissolving carbon dioxide in the developer and the alkali, which is the main component of the developer, is small, and a decrease in the alkali concentration of the developer can be suppressed.

In this respect, when the developer is used as a shower, the developer becomes a small mist, so the contact area of the developer with the air becomes very large, and much more carbon dioxide in the air becomes the developer. It dissolves and the developer deteriorates quickly. Further, according to the present invention, bubbles are not generated unlike when a developer is used as a shower.

Further, according to the present invention, the liquid pressure of the developing solution is applied to the object to be developed. By this liquid pressure, not only the developing speed can be increased, but also the developing solution can be stirred to make the concentration uniform, and defects such as disconnection and short circuit in the subsequent etching step can be reduced. Further, since the development proceeds in the direction of hydraulic pressure, anisotropic development is possible, and the resist can be developed almost at right angles from the surface to obtain an excellent resist pattern.

(2) The object to be developed may be a flexible film to which a metal foil is attached and which is irradiated with the resist corresponding to a circuit pattern. Such flexible films are used in TAB technology.

(3) The liquid pressure may be applied by circulating the developer stored in the container. By doing so, the developer can be stirred in the container to make the concentration uniform.

(4) The liquid pressure is preferably adjusted according to the concentration of the developing solution. In this way, the developing speed can be adjusted by changing the liquid pressure of the developing solution. For example, when the developing solution is new and the alkali concentration is high, the developing speed is high in the first place, so the liquid pressure is made small, and when the developing solution deteriorates as the development is performed, the liquid pressure is increased to suppress the decrease in the developing speed. it can. In this way, regardless of the state of the developing solution, development can be carried out for a fixed developing time.

(5) It is preferable that the liquid pressure increases as the concentration of the developing solution decreases. By doing so, even if the concentration of the developing solution decreases, the developing ability can be maintained by increasing the liquid pressure.

(6) According to the present invention, in a developing device for developing a resist in lithography, a container for accommodating a developing solution and a long object to be developed with a resist applied to at least a part thereof are immersed in the developing solution. A guide for laterally guiding inside the container, a first guide arranged inside the container, and a guide for guiding the developing object outside the container, the guide being arranged inside the container. And a pump for applying a liquid pressure by the developing solution to the object to be developed which is still immersed in the developing solution. The pump sucks the developing solution stored in the container. The liquid is discharged onto the object to be developed, and the suction position of the developer is above the discharge position.

The developing method can be carried out by using this developing device.

(7) The development target is a flexible film to which a metal foil is attached and which is irradiated with the resist corresponding to a circuit pattern, and an unwind reel that unwinds the flexible film, And a take-up reel for winding the flexible film.

By doing so, the resist can be efficiently developed on the flexible film used in the TAB technology.

(8) The developing device according to the present invention may have a valve for adjusting the liquid pressure of the developing solution. With this valve, the liquid pressure of the developing solution can be adjusted to maintain a constant developing time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a developing device according to an embodiment of the present invention, FIG. 2 is a diagram showing a developing device according to another embodiment of the present invention, and FIG. FIG. 8 is a diagram showing a conventional developing device.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a developing device according to an embodiment of the present invention. This developing device includes a take-up reel 10 and a developing container.
It has 20, a washing machine 30, a dryer 40 and a take-up reel 50.

A flexible film 12 used in the TAB technology is wound around the unwind reel 10. A copper foil, for example, is attached as a metal foil to the flexible film 12, and a photoresist is applied on the copper foil. Further, the photoresist is exposed in accordance with the circuit pattern. Therefore, the flexible film 12 is in a state of waiting for the developing process in lithography, and the developing process is performed by the developing device shown in FIG.

The flexible film 12 is wound around the unwind reel 10 so that the photoresist coating surface faces outward.

A developer 22 is stored in the developer container 20, and the flexible film 12 can be immersed in the developer 22 for development. That is, the guide 14 is provided above the developing container 20 on the unwind reel 10 side, and the flexible film 12 is guided inside along the inner peripheral surface of the developing container 20. Further, at the bottom of the developing container 20, the flexible film 12 is laterally guided via the guide 16. Further, the flexible film 12 is guided upward through the guide 18 and sent out of the developing container 20. In this way, the flexible film 12 is immersed in the developing solution 22 stored in the developing container 20 and developed.

In the present embodiment, the liquid pressure of the developing solution 22 is applied to the flexible film 12 in the developing container 20.
That is, the pump 26 sucks the developer 22 from the pipe 24 provided in the lower portion of the developer container 20, and discharges the developer 22 from the discharge port 28a provided at the tip of the pipe 28. In this way, by applying liquid pressure to the flexible film 12, the developing ability can be enhanced and the developing solution 22 can be stirred.

The opening position of the pipe 24 with respect to the developing container 20 is set so that the developing solution 22 can be sucked from a position above the discharge port 28a. By doing so, the developer 22 can be agitated by suction through the pipe 24 even at a position above the discharge port 28a.

The discharge port 28a faces the photoresist application surface of the flexible film 12, and the developer 22 to be discharged hits the photoresist. For more information,
The flexible film 12 is guided by the guides 14 and 16 so that the photoresist coating surface faces the center of the developing container 20. Therefore, at the bottom of the developer container 20,
Since the coating surface faces upward, the discharge port 28a is arranged so as to face downward.

A valve 60 is provided in the pipe 28 so that the liquid pressure of the developer 22 discharged from the discharge port 28a can be adjusted.

In this way, the flexible film 12 that has passed through the developing container 20 is sent under the washing machine 30 by the guide 32. The washing machine 30 showers the washing solution on the flexible film 12 to wash away the developing solution 22.

Next, the flexible film 12 is sent under the dryer 40 via the guide 42 to be dried, and is wound up by the take-up reel 50 via the guide 44. Take-up reel 50
Is rotated by the motor 52. Therefore, the flexible film 12 is wound from the unwind reel 10 through the inside of the developing container 20 by the rotation of the take-up reel 50.

The present embodiment is configured as described above, and its operation will be described below.

First, the flexible film 12 that has been subjected to photoresist coating and exposure is wound around the unwind reel 10.
Pull out this flexible film 12, guide 14,
It is attached to the take-up reel 50 while being guided by 16, 18, 32, 42 and 44. Further, the developing container 20 is filled with the developing solution 22.

Then, the take-up reel 50 is rotated and the pump is
The liquid pressure of the developing solution 22 is applied to the flexible film 12 by driving 26. At this time, the pump 26 sucks the developer 22 in the developer container 20 and at the same time, discharges the developer 22 from the discharge port 28a.
Is discharged. Therefore, the developer in the developing container 20 is agitated, so that the alkali concentration becomes uniform. Further, since the liquid pressure of the developing solution 22 is applied to the photoresist coated surface of the flexible film 12, the effect of development can be enhanced. By doing so, it is possible to uniformly develop the photoresist without variation.

Further, when the alkali concentration of the developing solution 22 decreases with the progress of development, the developing speed can be increased by increasing the liquid pressure of the developing solution 22 with the valve 60.
On the other hand, when the developing solution 22 is new, a sufficient developing speed can be secured without applying a hydraulic pressure, so the hydraulic pressure of the developing solution 22 is kept small by the valve 60. In this way, by adjusting the liquid pressure of the discharged developing solution 22, it is possible to carry out the developing in a fixed time regardless of the alkali concentration of the developing solution, and the work efficiency is greatly improved.

Next, FIG. 2 is a diagram showing a developing device according to another embodiment of the present invention. The developing device shown in the figure is the same as the developing device shown in FIG. 1 except for the configuration of the pipe 74, and therefore, the same reference numerals are given and the description thereof is omitted.

As shown in FIG. 2, the pipe 74 is arranged above the discharge port 28a, and the tip portion is inserted from the liquid surface of the developer 22. By doing so, the developer 22 is sucked and stirred at the position farthest from the discharge port 28a, so that the developer 22 as a whole can be stirred.

Next, the results of experiments conducted using the developing device will be described. Sodium hydroxide (NaOH) as developer
A solution was used, the liquid temperature was 27.0 ° C., and the thickness of the photoresist was 4 μm. Then, the relationship between the alkali concentration of the developing solution and the liquid pressure of the discharged developing solution when the same resist pattern line width as the exposure mask pattern line width was obtained in 75 seconds was examined. The results are shown in the table below.

As shown in the table above, the alkali concentration is 0.140-0.145mo.
When it was 1 / l, a new developer was used, and sufficient development was possible with a low liquid pressure. On the other hand, when the alkali concentration is 0.115 to 0.120 mol / l, the deterioration of the developer is progressing, but by increasing the liquid pressure of the developer to 2.0 kgf / cm ² ,
Development was possible in the same time as when using a new developer. Thus, the effect of the present invention was confirmed experimentally.

Claims (5)

(57) [Claims] 1. A method for developing a resist in lithography, wherein a long object to be developed coated with a resist is conveyed in its longitudinal direction, and a part of the object to be developed is added to a developer stored in a container. Dipping, and inhaling and discharging the developing solution stored in the container in order to apply a hydraulic pressure by the developing solution to the developing object, and inhaling the developing solution at a position higher than the ejection. Method for developing resists. 2. The resist developing method according to claim 1, wherein the object to be developed is a flexible film to which a metal foil is attached and which is irradiated with the resist corresponding to a circuit pattern. A method of developing a resist. 3. The resist developing method according to claim 1, wherein the liquid pressure increases as the concentration of the developing solution decreases. 4. A developing device for developing a resist in lithography, wherein a container for accommodating a developing solution, and a long object to be developed, at least a part of which is coated with the resist, are immersed in the developing solution. A guide for laterally guiding inside the container, a first guide arranged in the container, and a guide for guiding the development target to the outside of the container,
A second guide arranged in the container; and a pump for applying a liquid pressure of the developing solution to the development target that is still immersed in the developing solution, the pump collecting in the container. The developing device is sucked and discharged to the object to be developed, and the suction position of the developing liquid is above the discharge position. 5. The developing device according to claim 4, wherein the object to be developed is a flexible film to which a metal foil is attached and which is irradiated with the resist corresponding to a circuit pattern, A developing device comprising: a winding reel that winds the flexible film; and a winding reel that winds the flexible film.