JPH11176812A - Method and apparatus for removing resist - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the throughput of resist elimination by ashing. SOLUTION: Light 'h' is cast on a resist applied on the surface of a wafer 'W' held by a carrier arm 13 from a light source 21 located face to face with a wafer holding face 13a of the carrier arm 13 for decomposing the constituent molecules of the resist. After that, the wafer W is carried into a processing chamber 11 by means of the carrier arm 13, and then the resist is ashed in the processing chamber 11. Through this method, the time required for ashing can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for removing a resist, and more particularly to a method for removing a resist on a wafer in a semiconductor device manufacturing process and a resist removing apparatus used for the method.

[0002]

2. Description of the Related Art In a manufacturing process of a semiconductor device, ion implantation and etching are performed using a patterned resist as a mask. After the completion of these processes, an ashing process in a dry process using oxygen plasma or ozone as an oxidation source is performed as a step of removing the resist.

FIG. 6 is a perspective view of a resist removing apparatus used for removing the resist by the ashing process. The resist removing device 6 includes a processing chamber 11 in which an ashing process is performed, and a carrier 1 for accommodating a wafer.
2, and a transfer arm 13 for transferring a wafer between the processing chamber 11 and the carrier 12. When the resist on the wafer is removed using the resist removing device 6 having such a configuration, the wafer stored in the carrier 12 after the processing using the resist as a mask is completed, and the transfer arm 13 moves the wafer into the processing chamber 11. Insert Next, an ashing process is performed by supplying an oxidation source to the wafer surface in the processing chamber 11 to remove the resist from the wafer surface.

[0004]

In recent years, in response to the demand for large-diameter wafers and high-mix low-volume production of semiconductor devices, single-wafer type resist removal apparatuses are becoming mainstream. For this reason, in the resist removal process, there is a concern that the throughput may be reduced due to a reduction in the wafer processing capacity,
There is a demand for further improving the throughput by further reducing the time required for one wafer processing. However, in the range of the resist removal method, besides improving the individual functions of the resist removal apparatus, such as improving the ashing ability in the processing chamber and shortening the transfer time of the wafer into the processing chamber, the resist removal step is not limited. The throughput cannot be improved.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resist removing method capable of reducing the time required for one ashing process without relying only on the individual functions of the resist removing device, and a resist removing device used in this method. Aim.

[0006]

According to the present invention, there is provided a method of removing a resist, which comprises irradiating a resist with light to decompose constituent molecules of the resist, and then performing an ashing process on the resist. Features.

In the above-described resist removing method, ashing is performed on a resist in which constituent molecules are decomposed into lower molecules by light irradiation. Therefore, in the ashing process, the constituent molecules of the resist are more easily oxidized. Therefore, the time required for resist ashing is reduced.

The resist removing apparatus according to the present invention is a resist removing apparatus having a processing chamber for performing an ashing process on a resist on a wafer, and a transfer arm for loading the wafer into the processing chamber. A light source is provided to face the wafer holding surface of the transfer arm. The light source emits light for decomposing the constituent molecules of the resist.

In the above resist removing apparatus, the surface of the wafer held by the transfer arm is irradiated with light from a light source, and the wafer is inserted into a processing chamber to perform an ashing process. Since the light decomposes the constituent molecules of the resist on the wafer surface, the ashing process is performed on the resist in which the constituent molecules are decomposed by the light irradiation in the processing chamber.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment to which a resist removing method and a resist removing apparatus of the present invention are applied will be described below with reference to the drawings. FIG. 1 is a perspective view for explaining an embodiment of a resist removing apparatus for carrying out the resist removing method of the present invention, and FIG. 2 is a schematic sectional view of a processing chamber of the resist removing apparatus. -A 'section. First, an embodiment of a resist removing apparatus will be described with reference to these drawings. Here, the same components as those of the resist removing apparatus described in the related art will be described with the same reference numerals.

As shown in the above figures, a resist removing apparatus 1 includes a processing chamber 11, a carrier 12, a transfer arm 13, and a light source 2 characteristic of the resist removing apparatus of the present invention.
1 is provided.

The processing chamber 11 is for ashing and removing the resist on the wafer W in the inside thereof. Here, an RF down-flow type plasma processing chamber is shown as an example. A gas introduction pipe 15 and a gas exhaust pipe 16 are connected to the processing chamber 11, and a plasma generation unit 17 is provided on a side circumference of the processing chamber 11.

Oxygen (O ₂ ) is supplied from the gas introduction pipe 15.
A mixed gas obtained by adding methane tetrafluoride (CF ₄ ) to oxygen or oxygen is introduced as an oxidizing gas. Gas exhaust pipe 1
Numeral 6 is provided with a vacuum pump, whereby the pressure in the processing chamber 11 can be reduced to about 60 Pa to 200 Pa. Then, the plasma generating means 17
Is composed of, for example, a magnetic coil connected to an RF power supply, and is provided in a state where the magnetic coil is wound around the plasma generation chamber 12b. The output of the RF power supply is about 800 W to 2000 W.

The carrier 12 accommodates a plurality of wafers W therein. This carrier 12
A resist used as a mask for etching or a mask for ion implantation in the previous process is provided on the surface of the wafer W stored in the wafer.

The transfer arm 13 is connected to the carrier 12
The wafer W stored in the processing chamber 11 is loaded into the processing chamber 11, and the wafer W in the processing chamber 11 is taken out and stored in the carrier 12. It is provided between. The transfer arm 13 has a wafer holding surface 13a for holding the wafer W mounted thereon.

The light source 21 is connected to the processing chamber 1.
The transfer arm 13 is provided on a passage of the wafer holding surface 13 between the carrier 1 and the carrier 12. The light source 21 generates light having a wavelength capable of decomposing constituent molecules of the resist to be removed by using the resist removing device 1. Here, the resist is mainly composed of a resin polymer such as a polymethyl methacrylate resin or a polyvinyl alcohol resin, and has a specific wavelength that is easily decomposed by its composition. Therefore, as the light source 21, a light source that generates light h having a wavelength suitable for decomposing the constituent molecules of the resist to be removed is applied, or a light source such as white light is used in order to correspond to a plurality of types of resists. Alternatively, a light source 21 that emits light of a plurality of wavelengths may be used.

A resist removing method using the resist removing apparatus 1 will be described below with reference to FIG. 3 together with FIGS. First, the wafer W in the carrier 12 is taken out while being held on the wafer holding surface 13a of the transfer arm 13. Next, the light h from the light source 21 is applied to the wafer holding surface 1.
Irradiate the resist R on the surface of the wafer W held on 3a. Thereafter, the wafer W is inserted into the processing chamber 11 by the transfer arm 13. Thereafter, the inside of the processing chamber 11 in which the wafer W is stored is reduced to a predetermined pressure by exhaustion from the gas exhaust pipe 16. Next, the gas exhaust pipe 1
An oxidizing gas is introduced from the gas introduction pipe 15 while the exhaust from the gas generator 6 is continued. As a result, the wafer W is introduced into the flow path of the oxidizing gas flowing down from the gas introduction pipe 15 to the gas exhaust pipe 16.
Place.

In the above state, by applying an RF voltage to the magnetic coil constituting the plasma generating means 17, the electrons of the oxygen gas molecules in the oxidizing gas flowing down are excited to decompose the oxygen gas molecules. To generate oxygen plasma. This oxygen plasma is supplied to the surface of the wafer W arranged in the flow path between the gas introduction pipe 15 and the gas exhaust pipe 16. Then, the resist R on the wafer W is ashed by the radicals in the oxygen plasma, and the resist R is removed from the wafer W.

In the resist removing apparatus having the above configuration and the resist removing method using the apparatus, the light h from the light source 21 is applied to the surface of the wafer W held by the transfer arm 13 before being loaded into the processing chamber 11. Is irradiated. The light h emitted from the light source 21 has a wavelength that decomposes constituent molecules of the resist R on the surface of the wafer W. Here, the constituent molecule r of the resist is a resin polymer as described above (see FIG. 4 (4)), and by irradiating the resist with light h from the light source 21, the molecule r has a smaller molecular weight. It is decomposed into a molecule r ′ (see FIG. 4 (2)).

Then, the wafer W irradiated with the light h as described above is inserted into the processing chamber 11, and an ashing process is performed in the processing chamber 11. Therefore, in the processing chamber 11, an ashing process is performed on the resist R decomposed into lower molecules. Therefore, in this ashing process, the oxidation of the resist R is apt to progress, and the ashing process can be performed in a shorter time.

In the above embodiment, the resist removing apparatus provided with the RF downflow type plasma processing chamber and the resist removing method using this apparatus have been described. But,
The resist removing apparatus of the present invention is widely applicable to a resist removing apparatus having a processing chamber for performing an ashing process in a dry process, and may be an apparatus having a processing chamber for performing an ashing process using high-concentration ozone. Also,
The resist removing method of the present invention can be widely applied to a resist removing method of performing an ashing process by a dry process, and may be applied to a method of performing an ashing process using high-concentration ozone.

The resist removing method of the present invention is not limited to the method using the resist removing apparatus as long as the step of irradiating the surface of the wafer provided with the resist with light as a pretreatment of the ashing process is performed. Absent. For example, FIG.
As shown in (1), the surface of the wafer W set on the carrier may be irradiated with light h. In this case, the light h is applied to the surface of the wafer W from an oblique direction so that the light h is applied evenly to the entire surface of the plurality of wafers W arranged to be overlapped in the carrier 12. This makes it possible to perform the pre-processing by irradiating the surface of the wafer W with the light h at a time during the waiting time of the ashing processing.

As still another method of removing the resist, light h may be applied to the surface of each wafer W after the processing step using the resist as a mask and before the wafer W is stored in the carrier 12. .

The time for irradiating the resist R on the surface of the wafer W with light is set so that the constituent molecules of the resist R are sufficiently decomposed and the irradiation of the light h does not limit the rate of the resist removing step. Shall be done.

[0025]

As described above, according to the resist removing method of the present invention, since the ashing process is performed on the resist in which the constituent molecules are decomposed by light irradiation, the time required for the ashing process is reduced. It becomes possible to shorten. Therefore, the throughput in removing the resist can be improved.

According to the resist removing apparatus of the present invention, the light source is provided so as to face the wafer holding surface of the transfer arm for transferring the wafer into the processing chamber, so that the wafer surface before the ashing process is performed. It becomes possible to irradiate the resist with light. Therefore, in the processing chamber, an ashing process can be performed on the resist whose constituent molecules have been decomposed by light irradiation,
The time required for the ashing process can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an embodiment of a resist removing apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional configuration diagram of a processing chamber.

FIG. 3 is a view for explaining a resist removing method of the present invention.

FIG. 4 is a schematic diagram for explaining decomposition of constituent molecules of a resist by light irradiation.

FIG. 5 is a diagram for explaining another example to which the present invention is applied.

FIG. 6 is a perspective view illustrating an example of a conventional resist removing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Resist removal apparatus, 11 ... Processing chamber, 13 ... Transfer arm, 13a ... Wafer holding surface, 21 ... Light source, h ...
Light, W ... wafer

Claims (2)

[Claims] 1. A method of removing a resist, comprising: performing a first step of irradiating a resist with light to decompose constituent molecules of the resist; and a second step of performing an ashing process on the resist. 2. A resist removing apparatus comprising: a processing chamber for performing an ashing process on a resist on a wafer; and a transfer arm for transferring the wafer into the processing chamber, wherein a wafer holding surface of the transfer arm is provided. A light source for irradiating light that decomposes the constituent molecules of the resist in opposition to.