JPH116086A - Surface unnecessary object removal device using laser beam - Google Patents

Abstract

(57) [Problem] To prevent impurities and the like on the surface of an object to be processed from being re-contaminated by a laser light irradiation when the object to be processed and the window for introducing laser light are re-contaminated. . SOLUTION: A gas blowing cylinder 4 is arranged so as to surround the periphery of a laser beam 10 in a processing chamber 2 and gas supply means 4a for supplying gas to the blowing cylinder 4 is provided. Gas suction / discharge means 7 and 7a for sucking unnecessary substances removed from the processing target 6 and discharging the same to the outside of the processing chamber 2 are provided. [Effect] Since the removed unnecessary matter is surely removed from the laser light irradiation part, and is immediately sucked and discharged to the outside of the processing chamber, recontamination of the object to be processed and the laser light introduction window is reliably prevented. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for removing adhered impurities on a surface of an object to be processed and a thin film along a predetermined pattern from a surface portion of the object using a laser beam. The present invention relates to a surface unnecessary substance removing apparatus using a laser beam, which prevents a processing object from being recontaminated.

[0002]

2. Description of the Related Art Conventionally, in cleaning of the surface of an object to be processed, etching in forming a pattern of a semiconductor, and resist removal, unnecessary substances are mainly dissolved by using a liquid such as hydrofluoric acid, sulfuric acid or the like. A method of removing from a processing object is adopted. However, this method is dangerous when handling liquids, and has environmental problems such as waste liquid treatment. Therefore, in order to enable the above-mentioned processing without using these dangerous liquids, a laser beam having a high energy density is irradiated on the surface of the processing object to evaporate unnecessary substances and the like. Methods for removing the same have been proposed (JP-A-62-267484, JP-A-62-2).
No. 620, JP-A-61-73329, JP-A-2-86
No. 128). In addition, in these methods, in order to prevent the removed unnecessary substances from adhering to the object to be processed again and contaminating the same, re-contamination is performed in the vicinity of the laser light irradiating section by spraying gas or vaporizing by laser light irradiation. A method of sucking gas is employed.

[0003]

However, in the above-mentioned conventional apparatus, although measures are taken to prevent the re-contamination of the object to be treated by the removed unnecessary matter, all of them are only gas spraying or exhaust treatment. Only in the
In these methods, it is inevitable that the removed unnecessary substances stay in the processing chamber for a while, and it cannot be said that re-contamination is not sufficiently prevented. Further, in a device that irradiates a laser beam through an introduction window, unnecessary substances that remain in the processing chamber easily adhere to the introduction window as described above, and as a result, the transmission efficiency of the laser light decreases with time. There is. The present invention has been made in view of the above circumstances, and reliably prevents the removed unnecessary material from re-contaminating the object to be processed again. It is an object of the present invention to provide a surface unnecessary substance removing apparatus using a laser beam for preventing a decrease in light transmittance.

[0004]

Means for Solving the Problems To solve the above-mentioned problems, a first aspect of the apparatus for removing unnecessary objects using a laser beam according to the present invention is to provide a processing object placed in a processing chamber with a processing chamber. In a surface unnecessary object removal device that removes unnecessary objects from the surface of a workpiece by irradiating laser light from the outside through a laser introduction window, a gas blowing cylinder arranged so as to surround the laser light in the processing chamber And gas supply means for supplying gas into the gas blow-off tube to blow gas from the tip of the gas blow-out tube toward the object to be processed; and
A gas suction / discharge means for sucking the unnecessary matter removed from the processing object together with the gas and discharging the gas to the outside of the processing chamber. Further, a second invention is characterized in that, in the first invention, the gas blowing cylinder surrounds the laser introduction window without a gap. Further, the third invention is the first invention.
Alternatively, in the second invention, the gas suction / discharge means is characterized in that the gas suction / discharge means has an exhaust pipe which is on the outer peripheral side of the gas discharge pipe and forms a double pipe with the gas discharge pipe.

As described above, the surface unnecessary substance removing apparatus using laser light according to the present invention can be used for removing adhering impurities on the surface of an object to be processed, removing a thin film in a predetermined pattern in a semiconductor, and the like. . Therefore, the type of the object to be processed is not limited to a specific type, and the type of the unnecessary object and the purpose of removal are not limited. As the type of the laser light, for example, excimer laser light having a high energy density can be used when removing the attached impurities. However,
In the present invention, the type of the laser beam is not particularly limited, and the type of the laser beam and its output can be appropriately selected depending on the type of the object to be processed, the type of the unnecessary object to be removed, and the like. Unnecessary matter removed as a result of the laser light irradiation is one in which the bond with the surface of the object to be processed is released by the laser light irradiation, and what state the unnecessary matter is in as a result of the removal. Depends on the type of the unnecessary object, the energy density of the laser beam, and the like, and is separated from the surface of the object to be processed in the form of gas or ultrafine particles.

In the present invention, upon irradiation with a laser beam, a gas is blown toward the object to be processed in the vicinity of the irradiated portion of the object to be processed, and the gas is sucked (preferably locally sucked in the vicinity of the irradiated portion). Unnecessary matter removed from the object to be processed as described above is reliably removed from the surface of the object to be processed by the gas flow, and is immediately transferred to the outside of the processing chamber by suction. . As a result, it is possible to effectively prevent a phenomenon that unnecessary objects stay in the processing chamber to re-contaminate the object to be processed or to contaminate the laser beam introduction window.

[0007] The above gas for spraying includes:
In order to avoid the influence on the object, an inert gas is preferably used, and a gas such as helium, nitrogen, or argon is blown toward the object at an appropriate amount and an appropriate speed.
The gas can be blown toward the object to be processed by a gas blowout tube arranged so as to surround a laser beam irradiated in the processing chamber. The gas blowing cylinder has a size and shape surrounding the periphery of the laser beam, and an appropriate shape can be selected according to the beam shape. For example, a cylindrical gas blowing tube can be used for the spot beam, and a flat gas blowing tube can be used for the line beam.

It is desirable that the gas blow-out tube extends to the vicinity of the object to be processed, and that the blow-out portion at the tip thereof is close to the irradiation portion. However, if it is too close, the flow of gas deteriorates. It is desirable to secure a gap. On the other hand, on the laser light introduction window side, it is desirable that the gas blowing cylinder surrounds the laser light introduction window without any gap. The above gas is supplied into the blowing cylinder by gas supply means,
The supply method is not particularly limited, and any method may be used as long as the gas can be supplied into the blow-out cylinder in a state where the irradiation of the laser beam is not hindered. By blowing the gas to the object to be processed through a blowing cylinder surrounding the periphery of the laser light, the gas can be accurately blown to the irradiated portion of the processed object, and the removed unnecessary matter can be reliably removed from the irradiated portion. it can. Since the pressure inside the blow-out tube is relatively increased by the supply of gas, the removed unnecessary matter rarely enters the blow-out tube and is immediately blown off to the outer peripheral side of the blow-out tube.
Therefore, the object to be processed is irradiated with the laser beam through a clean space in the blow-out tube without passing through a space where an unnecessary object floats. Furthermore, if the window for introducing laser light is surrounded by the blowing cylinder without gaps, it is possible to reliably prevent the removed unnecessary substances from adhering to and contaminating the window for introduction.

Further, if an exhaust pipe constituting a double cylinder with the gas blow-off cylinder is provided on the outer peripheral side of the gas blow-off cylinder, unnecessary matter blown out by gas blowing from the gas blow-out cylinder is blown out. The gas is immediately sucked through the gap between the gas blow-out tube and the exhaust tube together with the discharged gas, and is discharged out of the processing chamber. Therefore, the removed unnecessary material hardly stays in the processing chamber and reattaches to the object to be processed or the laser light introduction window, and the unnecessary material can be reliably and quickly removed from the processing chamber. In addition, since the amount of gas that leaks to the outside of the exhaust pipe can be reduced, there is an advantage that the atmosphere in the processing chamber can be easily adjusted. Further, since the exhaust pipe is arranged in a double cylindrical shape with the blow-out pipe, the gas flows almost uniformly toward the outside, so that the flow of the gas is deviated, and unnecessary substances adhere to the blow-out pipe. Problems can also be avoided.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. It should be noted that the present invention is not limited by this. FIG. 1 is a schematic view of a laser cleaning device 1 according to an embodiment of the present invention. The present apparatus 1 is applicable to all atmospheres, specific gas atmospheres, and vacuum atmospheres. Each atmosphere is formed by using a vacuum exhaust duct (not shown) provided in the processing chamber 2 or an atmosphere gas inlet 2a. Can be formed. A rectangular cylindrical projection 2b is formed on the ceiling of the processing chamber 2, and a glass-made elongated laser light introduction window 3 is provided on the top plate of the projection 2b. . On the lower surface of the top plate portion, the upper end of the gas blowing cylinder extending downward is fixed without any gap so as to surround the laser light introducing window 3.
The lower end of the gas blowing cylinder 4 has a shape narrowed to a narrow width, and reaches near the upper surface of the processing target 6 placed on the base 5 in the processing chamber 2. Further, the side wall of the protruding portion 2b extends further down through the ceiling of the processing chamber 2 to form an exhaust pipe 7, and the lower end of the exhaust pipe 7 has substantially the same shape as the gas blowing pipe 4. Has reached the position. In addition, at the lower end of the blowing cylinder 4, a gas flow is secured.
At the lower end of the exhaust pipe 7, the lower end of the exhaust pipe 7 can be made closer to the workpiece 6 in order to minimize gas leakage. An exhaust port 7a is formed in the upper side wall of the exhaust pipe 7, and the exhaust port 7a is connected to a suction device (not shown). These exhaust stacks 7,
A gas suction / discharge means is constituted by the exhaust port 7a and the suction device. Further, a gas supply pipe 4a is connected to a side wall of the gas blowing cylinder 4, and the gas supply pipe 4a penetrates a side wall of the exhaust pipe 7 and is externally connected to a gas supply device (not shown). Gas supply means is constituted by the gas supply pipe 4a and the gas supply device.

Hereinafter, a method of using the above embodiment will be described. Laser light 10 oscillated from an excimer laser irradiation device (not shown) is introduced into the processing chamber 2 of the laser cleaning device 1 through the laser introduction window 3 and irradiates the object 6 to be processed. The object 6 moves in the processing chamber 2 by the movement of the base 5, and the laser light 10
Thus, the desired surface is cleaned. At the same time, the inert gas 40 is supplied from the gas supply device to the gas supply pipe 4a, and the inside of the exhaust pipe 7 is sucked through the exhaust port 7a by the suction device. As described above, the introduced gas 40 passes through the same path as the laser beam 10 and is blown from the tip of the blow-out tube 4 to the laser irradiation portion of the processing target 6 and its vicinity. In the laser irradiation unit, the bond between the impurity adhering to the surface of the object 6 and the surface is cut. The impurities are removed from the surface by the gas 40 and move together with the gas.
And is carried out of the processing chamber 2 through the exhaust port 7a as the exhaust gas 70. In addition,
As shown in the figure, it is also possible to provide an ionic substance suction electrode 11 in the blowing cylinder 4 and / or the exhaust cylinder 7.
The impurities removed as described above can be positively collected by the suction electrode 11. According to the above-described apparatus, since the impurities removed from the object to be processed by the irradiation of the laser beam are reliably and quickly carried out of the processing chamber together with the gas, the object to be processed and the window for introducing laser light are recontaminated by the removed impurities. Can be prevented. In addition, since the laser beam introduction window is covered with the outlet cylinder without any gap, and is completely isolated from the exhaust path, the adhesion of impurities is reliably prevented.

In the above embodiment, an apparatus for removing impurities has been described. However, as described above, the present invention is also applicable to a laser processing apparatus or the like used for removing an unnecessary thin film when patterning a semiconductor. Applicable. In the above-described embodiment, the gas from which impurities have been removed is sucked and exhausted by the exhaust cylinder that forms a double cylinder with the blow-out cylinder. However, a suction pipe is provided outside the blow-off cylinder, or the suction port is formed in the wall of the processing chamber. A device for performing suction / exhaust by providing a device is also within the scope of the present invention.

In the above-described embodiment, the blowing cylinder 4 having a narrowed tip is used to increase the blowing speed from the blowing cylinder. However, the blowing pressure, the speed, and the distribution thereof are adjusted. As shown in FIG.
The tip shapes of a to 14d can be appropriately changed.
For example, in the blowing cylinder 14b having the shape of B, a throttle is provided in the middle of the tip and the opening has a shape that the opening area gradually increases, so that the gas pressure is increased by the throttle, and then the tip goes outward at the tip. Therefore, it is possible to more reliably prevent the removed impurities from flowing back to the blowout cylinder and contaminating the laser light introduction window.

[0014]

As described above, the surface unnecessary object removing apparatus using laser light according to the present invention comprises a gas blow-out tube arranged so as to surround the laser light in the processing chamber, and a tip of the gas blow-out tube. Gas supply means for supplying gas into the gas blow-out cylinder to blow gas toward the processing target from outside, and outside the gas blow-out cylinder, the unnecessary matter removed from the processing target is sucked together with the gas and out of the processing chamber. A gas suction / discharge means for discharging gas is provided, so that unnecessary substances can be removed from the surface of the processing object without danger of the processing solution and adverse effects on the environment, which has been a problem in the past. It is possible to prevent the object to be processed and the laser light introduction window from being re-contaminated by the unnecessary material. In addition, if the gas introduction cylinder surrounds the laser introduction window without any gap, contamination of the laser light introduction window by the removed unnecessary matter is more reliably prevented. Furthermore, if an exhaust pipe that forms a double cylinder with the gas exhaust pipe on the outer peripheral side of the gas blow-off pipe is provided as a part of the suction / exhaust means, the gas containing unnecessary substances that have been removed can be immediately recovered and taken out of the processing chamber. The object to be processed and the laser beam introduction window can be more reliably prevented from being recontaminated.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a laser cleaning apparatus according to an embodiment of the present invention.

FIG. 2 is a partial plan view similarly including a laser light introduction window.

FIG. 3 is a partial side view similarly including a window for introducing laser light.

FIG. 4 is a partial cross-sectional view showing a modified example of the outlet cylinder.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 laser cleaning device 2 processing chamber 3 laser light introduction window 4 blowing cylinder 4 a gas supply pipe 6 workpiece 7 exhaust cylinder 7 a exhaust port 10 excimer laser light 11 ionic substance suction electrode 14 a blowing cylinder 14 b blowing cylinder 14 c blowing cylinder 14 d Outlet cylinder 40 Inlet gas 70 Exhaust gas

Claims (3)

[Claims] 1. A surface unnecessary object removing apparatus for removing an unnecessary object from a surface portion of an object to be processed by irradiating the object to be processed placed in the processing chamber with laser light from outside the processing chamber through a laser introduction window. A gas blowing cylinder disposed so as to surround the periphery of the laser beam in the processing chamber, and gas supply means for supplying gas into the gas blowing cylinder to blow gas from the tip of the gas blowing cylinder toward the object to be processed. A gas suctioning / discharging means for sucking together with the gas the unnecessary matter removed from the object to be processed and discharging the same to the outside of the processing chamber outside the gas blow-out cylinder. apparatus 2. The apparatus according to claim 1, wherein the gas blowing cylinder surrounds the laser light introducing window without any gap. 3. The laser beam as claimed in claim 1, wherein the gas suction / discharge means has an exhaust pipe on the outer peripheral side of the gas blow-off pipe and forms a double pipe with the gas blow-off pipe. Surface unnecessary material removal equipment used