KR100251136B1 - Stripping apparatus of photoresist - Google Patents

Abstract

PURPOSE: An apparatus for stripping a photoresist is provided to reduce the process time and the manufacturing cost by stripping the photoresist without performing a photoresist ashing process. CONSTITUTION: A wafer is loaded in an inner container(11) installed in an outer container(8). A photoresist formed on the wafer is removed by a stripper(5). A stripper passage(20) is formed at a bottom of the outer container(8). A wafer holder(15) is coupled to one end of a shaft(14) connected to a motor(13). The motor(13) is mounted on a cover(12) of the outer container(8). The wafer is fixed on the wafer holder(15). The stripper(5), which is circulated through a tube(10), is injected onto the wafer in the inner container(11) by means of the motor(21), thereby removing the photoresist.

Description

Photoresist Stripping Device

1 is a schematic diagram of a conventional photoresist stripping device.

2 is a schematic diagram of a photoresist stripping device according to the present invention.

* Explanation of symbols for main parts of the drawings

1,8: Outer container 2,11: Inner container

5: stripper 7: wafer

9: filter 10: teflon tube

13: motor 14: shaft

15: wafer holder 18: wafer holding pin

19: silicone rubber

The present invention relates to a photoresist stripping apparatus, and more particularly to the unnecessary photoresist mask on a wafer after dry etching by rotating the wafer mounted in the container and simultaneously ejecting the stripper to the wafer in the thin film wafer manufacturing process. It is to be able to remove efficiently at room temperature.

In the thin film wafer manufacturing process, the thin film wafer is formed by stacking unit layers of metal films or insulating films having a complex structure, and a photoresist, which is a conventional photolithography process, to form a complex pattern of such unit layers. (Photo-resist) A process of forming a photo-resist mask using application, exposure, and development and then etching is required. At this time, a process of removing the unnecessary photoresist mask after etching is called photo-resist stripping.

The etching process can be roughly divided into wet and dry processes. Common dry etching processes use IBE (Ion Beam Etching) or RIE (Reactive Ion Etching), and these processes are used to completely remove unnecessary photoresist masks from wafers with dry etching processes that are difficult to strip. Since it is impossible to use wet stripping by commercial strippers, it is used in parallel with the photoresist etching process using oxygen plasma (O ₂ Plasma).

In the case of using such dry etching process, the stripping process is complicated, which leads to a problem of increasing process time and cost, and how the photoresist is hardened and damaged during the etching process and thus the photoresist stripping process is performed. Whether to practice is a big problem.

On the other hand, since it is difficult to remove photoresist on the wafer after dry etching, the stripper commercialized in the strip process is used to remove the unnecessary photoresist mask of the wafer. FIG. 1 illustrates such a conventional wet photoresist stripping apparatus. It is shown schematically.

As shown in the figure, a conventional photoresist stripping device has an inner container filled with a stripper 5 inside an outer container 2 having a hot plate 1 for providing heat to the stripper 5. (3) is provided, and water (4) is filled between the outer container (2) and the inner container (3), and the wafer (7) attached to the dipper (6) is attached to the inner container (3). It is configured to remove unnecessary photoresist masks on the wafer 7 by submerging the filled stripper 5 during a few minutes of reception.

The stripping process through such a photoresist stripping device tends to gradually require a stripping temperature up to 120 ° C. so that the unnecessary photoresist mask of the wafer can be removed more reliably, and the stripping time is extended for a long time. (Up to about an hour). This high temperature and long time stripping is a problem that if the stripping is not completed within a given time, the lower photoresist causes a baking phenomenon in which the adhesion with the underlying layer becomes larger, which makes the stripping process impossible. Have. In addition, since the stripper rapidly deteriorates at a high temperature, the stripper is consumed severely, and thus, it is very difficult to secure reproducibility of the stripping condition.

In the case of wet etching, the fine pattern width is difficult to control due to the undercut phenomenon during nicking, and thus the utilization thereof is limited. Even in wafers subjected to wet etching and wet stripping, the complete removal of the photoresist is difficult to ensure reproducibility.

In addition, when the photoresist is not completely removed and the process proceeds to the next process, there is a problem that partial swelling phenomenon due to poor adhesion between the films, peeling and defective wafer characteristics are caused.

Accordingly, the present invention was created to solve the above problems, and thus can save the stripping process time and cost by performing the photoresist stripping without the photoresist etching process by O ₂ plasma after the dry etching process. It is an object of the present invention to provide a photoresist stripping device.

Another object of the present invention is to provide a photoresist stripping device that can minimize damage to the underlying film as compared to the conventional high temperature stripping process by performing the stripping process at room temperature.

Still another object of the present invention is to provide a photoresist stripping device that can ensure stripping reproducibility because stripping does not occur during stripping.

A feature of the present invention for achieving the above object is a photoresist stripping apparatus for removing a photoresist of a wafer through a stripper by installing a wafer on an inner container installed in an outer container in a thin film wafer manufacturing process, the outer A stripper passage is formed at the bottom of the container, and a wafer holder is mounted at one end of a shaft connected from a DC motor mounted on a cover of the outer container, and inside the inner container on a wafer fixed to the wafer holder. In the photoresist stripping device formed to remove the photoresist by ejecting the stripper circulated through the Teflon tube by the magnetic motor, the configuration of the present invention with reference to the accompanying drawings in more detail as follows. .

2 is a schematic diagram of a photoresist stripping device according to the present invention. In the present invention, the inner container (11) is provided in which the stripper (5) is ejected through the Teflon tube (10) by the magnetic motor (9) for continuously circulating the stripper (5) inside the outer container (8). The wafer holder 15 is mounted to one end of the shaft 14 connected to the motor 13 provided in the cover 12 of the outer container 8 adjacent to the upper part of the inner container 11.

Preferably, adjacent intervals of the wafer holder 15 installed adjacent to the inner container 11 are usefully maintained within 10 centimeters.

The wafer holder 15 is formed with a wafer mount opening 16 facing the inner container 11 through which the stripper 5 is ejected, and a wafer 7 at the inlet side of the wafer mount opening 16. Several wafer fixing pins 18 for fixing are provided, and a silicon rubber 19 for supporting one side of the wafer 7 is provided inside.

The teflon tube 10 connected to the stripper 5 to be supplied from the lower side of the inner container 11 is connected to the stripper passage 20 formed at one bottom of the outer container 8, and the stripper circulated on the connection. The Teflon filter 21 which filters (5) is attached.

Referring to the operation and effect of the photoresist stripping device according to the present invention configured as described above with reference to an embodiment of the present invention.

The user of the photoresist stripping apparatus according to the present invention is directed to the back of the wafer 7 toward the silicon rubber 19 in the wafer holder 15 for photoresist stripping, and then pushes and inserts the Turn the stainless pin 18 to fix it. At this time, the silicon lever 6 serves as a backstring by setting the wafer.

The outer container 8 is filled with a commercially available stripper 5, and then the magnetic motor 9 is operated to spray the stripper 5 on the surface of the wafer 7 at a constant flow rate and simultaneously operate the direct current motor 13. The wafer holder 15 holding the wafer 7 at a predetermined rpm is rotated. At this time, the stripper 5 acts on the wafer 7 by the centrifugal force and the frictional force acting by the pressure sprayed on the surface of the wafer 7 and the rotation of the wafer 7, and the photoridge on the surface of the wafer 7. The strip is stripped and melted and removed from the wafer surface.

For efficient stripping on the wafer 7, the separation distance between the wafers 7 from the stripper spout formed by the inner container 11 is kept within 10 cm, the wafer rotational speed is 100-1,000 rpm, and the stripper injection The speed is preferably in the range of 5,000 to 50,000 cc / min.

The results of the stripping apparatus of the present invention as described above are shown in Table 1 together with the comparative example.

The wafers used were deposited by sputtering to form Ni ₈₀ Fe ₂₀ alloys having a thickness of about 3 μm and then patterned to about 6 μm using AZ5214 photoresistor through exposure and development, which is a common photolithography process. .

After photoresist patterning, 100 minutes dry etching was performed using an IBE apparatus at 500 mA and 900 eV for etching conditions.

TABLE 1

Commercial strippers (model names: ST22, AZ 100, ALEG445) were used in the wet stripping process, and the O ₂ RIE conditions in the comparative example were gas flow rate of 98 seconds.m, pressure of 80m.ton, and RF. It was set as Power 100watt.

Stripping conditions according to the present invention were carried out under the conditions of 42 liters of stripper capacity, wafer rotation speed 400r.pm stripper ejection speed 20000cc / min, wafer / stripper spout distance 3cm, Teflon filter mesh size 0.2㎛. Magnetic motor used MAGNET MOTOR (30W, 60hg) of IWAKI IND. Of Japan.

As can be seen from Table 1, the stripping device according to the present invention was used to efficiently remove the photoresist after dry cornering in the Senate.

Therefore, the photoresist stripping device according to the present invention can be photoresist stripped after the dry etching process without the photoresist ashing process by O ₂ plasma, thereby simplifying the process and saving process time and cost, and at room temperature. Since the stripping process is performed, damage to the underlying film can be minimized compared to the existing high temperature stripping process, and since stripping deterioration hardly occurs since the stripping process is performed at room temperature, stripping reproducibility is secured.

Claims (3)

A photoresist stripping apparatus for removing a photoresist of a wafer 7 through a stripper 5 by installing a wafer on an inner container 11 installed in an outer container 8 in a thin film wafer manufacturing process. A stripper passage 20 is formed at the bottom of the outer container 8, and a wafer holder is formed at one end of the shaft 14 connected from the motor 13 mounted on the cover 12 of the outer container 8. A stripper 5 circulated through the teflon tube 10 by the motor 21 on the inside of the inner container 11 on the wafer 7 fixed to the wafer holder 15. A photoresist stripping device, characterized in that it is formed to eject to remove the photoresist. The photoresist stripping according to claim 1, wherein the wafer holder (15) holding the wafer (7) is held within 10 centimeters from the inner container (11) for ejecting the stripper (5). Device. A filter (9) is further configured on the Teflon tube (10) between the inner container (11) and the stripper passage (20), so as to continuously filter the circulating stripper (5). Photoresist stripping device.