JPH0214512A - Resist removal apparatus for semiconductor wafer - Google Patents

Abstract

PURPOSE:To reduce a defect of a pattern which is caused by a defect of a resist and by a dust particle and to enhance a yield of a product by adopting a constitution that a peripheral edge part of a wafer is immersed in a tank of a removal liquid. CONSTITUTION:A spin shaft 10 is arranged in a vertical direction by means of a driving shaft 13; a wafer 14 is fixed onto a vacuum chuck 11. Then, a resist 21 is dropped onto the wafer 14 from a resist discharge nozzle 20. Then, the shaft 10 is turned; the wafer 14 is set to a desired thickness. The number of revolutions is reduced; in succession, the shaft 10 is set in a horizontal direction by means of the driving shaft 13. Thereby, an outer peripheral edge of the wafer 14 can be immersed in a resist removal liquid 12a. On the other hand, a peripheral edge part of the wafer 14 which has been lifted from the resist removal liquid 12a can be dried immediately by N2 gas discharged from a nozzle 16. Accordingly, a problem that the resist removal liquid 12a drips to the central part of the resist 21 does not arise.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resist removal apparatus used in a resist coating process to a semiconductor wafer during the manufacture of semiconductor integrated circuits.

[Prior Art] A process using a conventional resist coating apparatus is schematically shown in FIGS. 6A to 6D. In FIG. 6A, wafer 1 is attracted onto vacuum chuck 2. In FIG. The vacuum chuck 2 is attached to the upper end of the rotating shaft 3. A resist 5 is dropped onto the wafer 1 from the discharge nozzle 4 as shown in FIG. 6B. Then, the rotating shaft 3 is rotated at high speed to obtain a desired resist film thickness as shown in FIG. 6C. Thereafter, the solvent 7 is discharged from the discharge nozzle 6 while the wafer 1 is rotated at a low speed as shown in FIG. 6D. This solvent 7 is applied to prevent dust from being generated due to resist peeling in a later step.

[Problems to be Solved by the Invention] In the conventional apparatus described above, the solvent discharged around the wafer periphery bounces off the wafer surface and scatters toward the wafer center, resulting in a pattern as shown in FIGS. 7 and 8. There is a problem in that holes 8 that cause defects are formed in the resist 5.

Furthermore, a portion of the resist 5 melted by the discharge of the solvent swells toward the center of the wafer as shown in FIG. There is also the problem that this raised portion peels off in a later process, causing pattern defects. Furthermore, since the solvent is discharged from the narrow nozzle 6, the peripheral edge of the resist 5 does not have an ideal curve as in the case of patterning using a photomask, but has an irregular shape as shown in FIG. . There is also the problem that film peeling occurs due to the irregular shape, which becomes foreign matter and causes pattern defects.

An object of the present invention is to provide a resist removal device that does not cause the scattering of a solvent toward the center of a wafer, does not cause a bulge on the periphery of the resist after removing the resist, and does not create an irregular shape.

[Means for solving the division report] The semiconductor wafer resist removal apparatus according to the present invention includes a rotating shaft having a horizontal center line, a wafer holding section provided on the rotating shaft, and a wafer holding section disposed below the holding section. and a resist removal tank containing a resist removal solution in which the peripheral edge of the wafer is immersed.

[Function] In the resist removing apparatus according to the present invention, instead of applying a resist removing liquid to the resist using a nozzle, a configuration is adopted in which the peripheral edge of the wafer is immersed in a removing liquid tank. Therefore, in the resist removing apparatus according to the present invention, there is no problem that the resist removing liquid bounces off the wafer surface and scatters, forming holes in the resist that cause pattern defects. Further, since the wafer is immersed in the removal liquid tank, there is no problem that the peripheral edge of the resist on the wafer is raised or the shape of the peripheral edge is irregular. Therefore, resist defects and pattern defects caused by dust generated by the resist are reduced, and the yield of products can be improved.

[Embodiment] In FIG. 1 showing an embodiment of the present invention, a resist removal device includes a rotating shaft 10, a vacuum chuck 11 provided at the tip of the rotating shaft 10, and a vacuum chuck 11 disposed below the vacuum chuck 11. and a removal liquid tank 12.

The base of the rotary shaft 10 is supported by a drive shaft 13 extending perpendicularly to the main surface in FIG. It is designed to be driven between. In addition, the drive shaft 13
is also movable in the vertical direction, and based on this, the rotating shaft 10 is also movable in the vertical direction. Further, the rotating shaft 10 can be rotated around the center line of the rotating shaft 10 by a drive mechanism (not shown).

The vacuum chuck 11 has a distal end surface that is a flat surface extending in a direction perpendicular to the center line of the rotating wheel. Therefore, when the wafer 14 is held by the vacuum chuck 11, the wafer 14 is held in a vertical position.

In the removal liquid tank 12, a resist removal liquid 12a is stored. As shown in FIG. 2, the removal liquid tank 12 has a removal liquid inlet 15a and an outlet 15b, and the resist removal liquid 12a in the removal liquid tank 12 can be exchanged through these ports 15a and 15b. ing. Also,
The removal liquid tank 12 is provided with a N2 blow nozzle 16.

The nozzle 16 is located on the lower side of the wafer 14 in the rotational direction.
It is placed near the part of the wafer 14 that has come up from the resist removal liquid 12a, so that the part can be dried by the N2 gas discharged from the nozzle]6.

Next, the operation of the above embodiment will be explained.

First, the rotation shaft 10 is vertically arranged by the drive shaft 13, and the wafer 14 is fixed on the vacuum chuck 11 as shown in FIG. 3A. Next, as shown in FIG. 3B, a resist 21 is dropped onto the wafer 14 from the resist discharge nozzle 20. Then, the wafer 14 is rotated by rotating the rotating shaft 10, and the resist 21 on the wafer 14 is made to have a desired film thickness depending on the rotation speed (usually 3000 to 6000 rpm).

The number of rotations is reduced, and then the rotation shaft 10 is set in the horizontal direction by the drive shaft 13. Thereby, the outer peripheral edge of the wafer 14 is immersed in the resist removal liquid 12a. On the other hand, nozzle 1
N2 gas is discharged from 6, and resist removal liquid 12
The peripheral portion of the wafer 14 that has come up from a is immediately exposed to N2.
Dry with gas. Therefore, the problem that the resist removing liquid 12a drips toward the center of the resist 21 does not occur. Note that when the orientation flat portion 14a of the wafer 14 is immersed in the resist removal liquid 12a, the rotation shaft 10 is driven downward by the drive shaft 13. As a result, the orientation flat part 1
4a, the resist 2 is similar to the other wafer peripheral areas.
1 is removed. Note that in order to detect the position of the orientation flat portion 14a in advance, the present device performs the following steps.
It has a clear alignment function so that the orientation flat portion 14a is always in the same position (not shown in the figure).

When the resist removal work is completed, the drive shaft 13 returns the rotating shaft 10 to the vertical direction again, and the wafer 14 is placed in a horizontal position. Then, the wafer 14 is transported to the next step by a transport mechanism (not shown).

FIGS. 4 and 5 show the state of a wafer from which the resist has been removed using the apparatus according to this embodiment.

In the above embodiment, the rotating shaft 10 is driven between the horizontal direction and the vertical direction, but the inclination can also be set at any other arbitrary angle. Further, in the embodiment, the removal of the resist 21 at the orientation flat portion 14a is performed by
Although this was done by moving the rotating shaft 10 up and down, it can also be done by using a cam having the same shape as the wafer and interlocking the rotating shaft 10 and the cam.

[Effects of the Invention] According to the present invention, since the resist is removed by immersing the wafer in the resist removal solution, the scattering of the removal solution and the swelling and unevenness of the resist that occur when the resist removal solution is discharged are avoided. It disappears. Therefore, pattern defects caused by resist defects and dust generation are reduced.
Product yield can be improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of one embodiment of the present invention. FIG. 2 is a view taken in the direction of the ■ arrow in FIG. FIGS. 3A and 3B are partial schematic side views showing the operating state of the embodiment. FIGS. 4 and 5 are a front view and a side view of a wafer obtained in this example. FIGS. 6A to 6D are partial schematic side views showing the operating state of the conventional example. FIG. 7 and FIG. 8 are a partial schematic side view and a schematic plan view showing problems in the conventional example. FIG. 9 is a partial schematic side view showing another problem in the conventional example. FIG. 10 is a schematic plan view showing still another problem in the conventional example. 10 is a rotating shaft, 11 is a vacuum chuck, 12 is a removal liquid tank,
12a is a resist removing liquid, and 14 is a wafer.

Claims (1)

[Scope of Claims] A rotating shaft having a horizontal centerline; a wafer holding part provided on the rotating shaft; and a resist removing liquid disposed below the holding part and into which the periphery of the wafer is immersed. A resist removal device for semiconductor wafers, comprising: a removal liquid tank containing a liquid;