JP3307485B2 - Foreign matter removal device - Google Patents

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 fine particles adhering to a wafer or a glass substrate in a semiconductor or liquid crystal manufacturing process, and more particularly to a removing apparatus which does not involve a cleaning step.

[0002]

2. Description of the Related Art In a semiconductor device manufacturing process, there is a process of removing foreign matter (particles) attached to a wafer surface at a stage prior to each process in order to improve the yield. Generally, wet cleaning with a chemical solution or ultrapure water is used to remove the foreign matter.

[0003]

However, in the wet cleaning, since a chemical solution or ultrapure water is used, there has been a problem that the cost increases due to the management thereof and the installation of a cleaning device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and does not require a cleaning step using a chemical solution or ultrapure water to reduce the cost. It is intended to collect / aggregate in a state of being closed.

[0005]

Configuration of the present invention Means for Solving the Problems To solve the above problems, in claim 1, and a aspirator tip of the nozzle by passing the air body is made to be negative pressure, wherein A position control device that is disposed near the tip of the nozzle and moves the stage relative to the tip of the nozzle;
And a container for storing the ionized gas.
The aspirator is filled with the gas, and the surface of the object placed on the stage is swept by the aspirator to suck in foreign matter attached to the object and blow out from one end of the aspirator. .

[0006] In the second aspect, by arranging a filter downstream of the aspirator which is characterized in that the collecting / aggregating the foreign substance, in claim 3, by the flowing gas Reno An aspirator in which the tip of the nozzle has a negative pressure, and an aspirator arranged near the tip of the nozzle,
A position control device for relatively moving the tip of the nozzle and the stage, and a container for storing the tip of the nozzle, the stage, and the subject, wherein the container is filled with ionized gas; The surface of the object placed on the stage is swept by the aspirator to suck foreign matter attached to the object, and is blown out from one end of the aspirator. Detects each existing foreign substance one by one,
Characterized by inputting position information storing the position of each foreign object, arranging the subject in accordance with the coordinate position of the position information, and selectively sweeping only the position where the foreign object is present. It is.

[0007]

According to the first aspect, the ionized gas is exposed to the gas.
Decreases the adsorption power of the foreign matter attached to the sample due to static electricity
At the same time, the tip of the nozzle at the negative pressure sweeps the surface of the subject, so that the foreign substances attached to the subject are removed by suction.
According to the second aspect, the sucked foreign matter is collected / concentrated by a filter disposed at a subsequent stage, and thus is in a state suitable for composition analysis. In claim 3, since the position information in which the position of each of the foreign matter on the subject is stored is input to the position control device, the foreign matter can be efficiently removed by selectively sweeping according to the position information. It becomes possible.

[0008]

1 is a block diagram showing one embodiment of a foreign matter removing apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes an aspirator having a suction nozzle 2 and one end of the aspirator 1 is provided with a flow control valve 3 at one end. A pipe is connected, and a flow meter 4 is connected to the other end. Reference numeral 5 denotes a stage arranged in the vacuum vessel 7, on which, for example, a semiconductor wafer or an LCD is mounted.
A subject 8 such as a (liquid crystal display) is placed. Reference numeral 9 denotes a driving device which moves and sweeps the stage 5 while keeping the surface of the subject 8 and the tip of the nozzle 2 at a predetermined distance by moving the stage 5 in the X, Y, and Z directions or by giving a rotational movement.

Reference numeral 11 denotes a position control device for controlling the moving speed of the driving device based on the signal of the flow meter 4. Reference numeral 12 denotes a vacuum pump, and reference numeral 13 denotes an electromagnetic valve for exhausting air in the vacuum container 7. 14 fills the vacuum vessel with the gas ionized by the ionizer 15. FIG. 2 shows an embodiment of the aspirator shown in FIG. 1, in which a through hole 23 having a diameter of, for example, about 3 mm is formed in a body 20 having a length of about 30 mm. A nozzle 2 having a through hole 23 having a diameter of about 1 mm and having a diameter of about 6 mm and having a diameter of about 6 mm and having a diameter tapered in the middle of the through hole 23 and being substantially perpendicular to the hole. Are formed.

In the above configuration, the vacuum pump 12 is driven to discharge the air in the vacuum vessel 7, and then the gas having an atomic weight of 1 is supplied from a gas supply means (not shown) via the flow control device 14.
0 or more gas (for example, air, Ar, N ₂ gas) is filled at a pressure slightly higher than 1 atm, and then 200 m / min.
About l is injected. Next, the driving device 9 is driven by the position control device 11, and the nozzle 2 is placed on the surface of the subject 8 on the stage.
Is brought close to, for example, about 20 μm, and, for example, 30 μm
A gas having an atomic weight of about 10 or more of about 0 ml (for example, air or A
r, N ₂ gas) is supplied from one side of the through hole. As a result, the pressure of the tip of the nozzle 2 becomes negative pressure, and the surface of the subject 8 and the tip of the nozzle 2 are swept relatively to each other.
The foreign substances adhering to the surface can be removed by suction.

FIG. 3 shows the carrier gas flow rate and the suction flow rate when the gas to be injected into the aspirator 1 and the vacuum vessel 7 is N ₂ gas (atomic weight 14.0) and also when He gas (atomic weight 4.0) is used. This indicates the relationship between the carrier gas flow rate (S ₁ ) and the gas supplied in the direction of arrow A.
The gas sucked in the direction is the suction flow rate (S ₂ ).
In general, the suction efficiency of an aspirator can be represented by the ratio of the suction flow rate divided by the carrier flow rate, and is usually S ₂ / S ₁ <1.
However, it is also possible to increase the suction efficiency to approach 1 or to increase it to 1 or more.

That is, in FIG. 3, when the used gas is He, the suction flow rate (S ₂ ) is about 300 ml / min while the carrier gas flow rate (S ₁ ) is about 400 ml / min, and the suction efficiency S ₂ / S _1. Is only 0.75, but when the used gas is N ₂ , the carrier gas flow rate (S ₁ ) is 200 ml / min.
It can be seen that the suction flow rate (S ₂ ) is about 600 ml / min, the suction efficiency is 3, and the suction flow rate is dramatically improved by a factor of four. This suction flow rate (S ₂ ) decreases when the gap between the tip of the nozzle 2 and the subject 8 shown in FIG. 2 is narrowed, and the reduced amount is converted to suction power. Therefore S ₂ /
As S ₁ is greater large attractive force is obtained.

According to the present invention, an ionized gas is provided.
Weakens the adsorbing force of static electricity with foreign substances attached to the subject
Therefore, foreign substances on the subject can be removed with a relatively simple configuration. It is noted that a foreign substance position detecting device including means (for example, a CD-ROM) for detecting each foreign substance present on a subject one by one and storing each position of each detected foreign substance is known. I have. Storing positional information of the foreign matter adhered to advance the subject using the known device, captures the CD-ROM which stores the position information to the position control equipment of the foreign matter removing apparatus of the present invention. Then, if the coordinate position of the subject is aligned with the same coordinate position as that attached to the foreign matter position detecting device and only the portion where the foreign matter is present is selectively swept, the foreign matter can be efficiently removed.

Further, a microwave induced plasma proposed by the present applicant is used as an apparatus for analyzing the type and size of a foreign substance (element) in order to know the cause and location of the foreign substance attached to the subject. A known analyzer is known. An analyzer using the microwave induced plasma will be briefly described with reference to FIG. In FIG. 4, reference numeral 31 denotes a disperser, in which a filter 32 to which solid fine particles (not shown) to be measured are attached is arranged. 3
Reference numeral 3 denotes an aspirator similarly arranged in the disperser 1, which sucks solid fine particles attached to the filter 32 and supplies the fine particles to the reaction tube 4. After the air is exhausted by the suction pump 35, He gas is introduced into the disperser 31 from the replacement gas inlet 38, and is maintained at a pressure slightly higher than the atmospheric pressure. 39 is a carrier gas (He) inlet, 37
Reference numerals a to 37d denote on-off valves. 43 is a microwave source, 44
Is a cavity into which microwaves from a microwave source have been introduced.

Reference numeral 46 denotes a detection window provided at the other end of the reaction tube 4, and reference numeral 47 denotes an optical window provided toward the detection window 46. Reference numeral 48 denotes a light condensing system, which includes a concave mirror 48a and a reflecting mirror 48b.
have. Reference numeral 49 denotes a slit for guiding the light reflected by the reflecting mirror 48b to the signal processing unit 50. The signal processing unit 50 includes four spectrometers 50b that receive light via four optical fibers 50c, respectively, and a CPU to which outputs of these spectrometers are input.

In the above configuration, a microwave having a frequency of 2.45 GHz is supplied from the microwave source 43 to the cavity 4.
4, plasma of 4000 ° K or more is generated in the reaction tube 34. On the other hand, from the disperser 31 to the reaction tube 3
The solid fine particles guided into 4 are atomized in the plasma and excited to emit light when falling to the ground state. The emission spectrum is taken out of the reaction tube 34 in the axial direction, guided through the optical window 47 into the light collection system 48, collected, and then passed through the slit 49 to be separated by the spectroscope 50b to be separated into the CP.
The signal is processed by U, and the element in the sample is measured and displayed. By the way, in such an analyzer, elements which cannot be analyzed stochastically appear when the number of fine particles on the filter is small. According to the present invention, a filter is disposed at the subsequent stage of the aspirator and is not used only for removing foreign substances, but foreign substances sucked from a plurality of subjects are collected / concentrated through the filters. And
By analyzing the captured foreign matter (fine particles) with a known analyzer, the composition and element of the foreign matter can be specified, and fine control such as identification of a dust generation source can be performed.

[0017]

According to the present invention as described in detail above, the ionized gas is filled in the container and adheres to the subject.
The aspirator sucks and blows out the sample microparticles placed on the flat plate, which reduces the adsorption force due to the static electricity caused by the contaminated foreign matter, and reduces the cost by eliminating the need for a cleaning step using a chemical solution or ultrapure water. At the same time, a filter can be disposed downstream of the aspirator to collect / concentrate foreign substances (fine particles) sucked from a plurality of subjects. Further, by combining with a known foreign matter position detecting device, foreign matter can be removed in a short time.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory view showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of an aspirator.

FIG. 3 is a diagram showing a comparison of a suction flow rate when an N ₂ gas flows through an aspirator and a He gas flow.

FIG. 4 is a configuration diagram showing a known analyzer using microwave induced plasma.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Aspirator 2 Nozzle 3 and 14 Flow control device 4 Flow meter 5 Stage 7 Vacuum container 8 Subject 9 Drive device 11 Position control device 12 Vacuum pump 13 Solenoid valve 15 Ionizer

Claims (3)

(57) [Claims] 1. A and aspirator tip of the nozzle by passing the air body is such that a negative pressure is arranged in the vicinity of the tip of the nozzle, the position for relatively moving the tip and the stage of the nozzle Control device and tip of the nozzle
Part, a stage, and a container for accommodating the subject , wherein the container is filled with ionized gas,
A foreign matter removing apparatus, wherein a surface of the subject mounted on the stage is swept by the aspirator to suck foreign matter attached to the subject and blown out from one end of the aspirator. 2. The foreign matter removing device according to claim 1, wherein a filter is arranged at a stage subsequent to the aspirator to collect / aggregate the foreign matter. 3. A aspirator tip of Reno nozzle by the flowing gas was made to be a negative pressure, it is disposed in the vicinity of the tip of the nozzle, for relatively moving the tip and the stage of the nozzle And a container for accommodating the tip of the nozzle, the stage, and the subject, wherein the container is filled with ionized gas.
The surface of the object placed on the stage is swept by the aspirator to suck foreign matter attached to the object, and is blown out from one end of the aspirator. Detects existing foreign substances one by one, inputs position information that stores the position of each detected foreign substance, and arranges the subject in accordance with the coordinate position of the position information. A foreign matter removing apparatus characterized by selectively sweeping only a portion to be removed.