KR100689189B1 - A vessel for particle deposition system and particle deposition system using the same - Google Patents

Abstract

The present invention relates to a container for a particle deposition system (PDS) and a particle deposition system (PDS) employing the same. The vessel for Particle Deposition System (PDS) according to the present invention stores a mixture of particles and a solution to be deposited on a wafer surface, and heats the outlet tube for discharging the aerosol of the mixture, a stirrer for stirring the mixture and the mixture. It characterized in that it comprises a heater for.

Wafer, deposition

Description

A container for a particle deposition system and a particle deposition system employing the same {A VESSEL FOR PARTICLE DEPOSITION SYSTEM AND PARTICLE DEPOSITION SYSTEM USING THE SAME}

1 is a schematic illustration of a Particle Deposition System (PDS) for fabricating a standard wafer by depositing conventional standard calibration particles onto a wafer.

2 is a view showing a method of manufacturing a standard wafer (Reference Wafer) using a conventional PDS.

Figure 3 is a schematic cross-sectional view showing the internal configuration of the container for PDS in accordance with a preferred embodiment of the present invention.

Figure 4 is a schematic cross-sectional view showing the internal configuration of a container for a PDS according to another embodiment of the present invention.

Figure 5 is a schematic cross-sectional view showing the internal configuration of the container for PDS according to another preferred embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

101, 301... Container 103.. dryer

105... Heavy weapon 107... (Move Deviation Sorter) DMA

109... Chamber 111... (Application Nucleus Counter) CNC

201, 303... Sprayer 304... agitator

305... Impeller 307... Driving means

309... Stirrer controller 401... heater

403... Electrothermal coil 405... Heater controller

501... Barrier

The present invention relates to a container for a particle deposition system (PDS) and a particle deposition system (PDS) employing the same.

In the semiconductor industry, it is often necessary to measure the number of particles on a wafer using a wafer inspection device. Such devices generally operate based on scattering principles and measure the particle size on the wafer by the amount of light scattered by each particle when the laser beam is projected across the wafer surface. In order to standardize such an inspection apparatus, a particle of a predetermined size must be deposited on the wafer, and the wafer is placed in the inspection apparatus to measure the reaction from the reference wafer particle for comparison with a predetermined set point corresponding to the inspection apparatus. . In addition, it is important to know the number of particles on the wafer and to have an appropriately uniform distribution of particles on the wafer surface. This is essentially a calibration process to ensure that the results obtained from the wafer inspection apparatus are accurate or can in some way be correlated with standard readings.

In addition, the first calibration of the inspection apparatus is based on the use of particles of a predetermined size on the wafer. The most commonly used orthodontic particles are polystyrene latex (PSL) spheres. In addition, to determine the response of the inspection device to different material particles, uniformly sized particles of titanium (Ti), tungsten (W), silicon, silicon dioxide, silicon nitride, aluminum oxide, titanium oxide, and the like Must be deposited on the wafer. A conventional method of depositing standard calibration particles on a wafer will be described with reference to FIG. 1.

1 is a schematic view showing a particle deposition system (PDS) for fabricating a standard wafer by depositing a conventional standard calibration particle on a wafer.

Referring to FIG. 1, a conventional PDS stores a mixture of particles such as PSL and DI water and sprays them by injection of compressed air, a dryer 101 for removing moisture from the generated particles. ), The neutralizer 105 to neutralize the irregularly charged state of the particles passing through the dryer, the movement is applied to the particles passing through the neutralizer to classify only particles having a certain size and a certain charge for the particles having a certain polarity Differential Mobility Analyzer (DMA) 107, chamber 109 for depositing particles of the same size and constant charge passing through a moving deviation classifier on bare wafer 115 and a Condensation Nucleus Counter; CNC, 111).

Referring to the conventional PDS configuration, a process of manufacturing a standard wafer by depositing particles on a bare wafer will be described as follows. A suspension, which is a mixture of particles such as PSL and DI water stored in the container 101, is sprayed by injecting compressed air through a pipe installed in the container 101 to form a spray (aerosolization). The formed spray (aerosol) is moved to the dryer 103 and diffused to dry to remove moisture. Particles such as PSL from which water is removed are often charged irregularly and are neutralized in the neutralizer 105. Thereafter, particles such as neutralized PSL pass through a charging device (not shown) to have a charge of a constant polarity (mainly a cathode). Particles, such as PSL, that have passed through the charging device, are extracted only in the DMA 107 with particles having the same electrical mobility. The DMA 107 classifies only particles having a certain size and a constant charge. The DMA 107 applies an electric field to the passing particles to use an electrostatic force caused by the electric field and a fluid resistance force due to the relative speed of the particles and the fluid. Particles having the same electrical fluidity are supplied to the chamber 109 and deposited on the bare wafer or delivered to the CNC 111. Particles having the same electrical flowability supplied to the chamber 109 are deposited on the bare wafer to produce a standard wafer.

Standard wafers fabricated in this manner can be divided into full deposition or spot deposition. Full Deposition Standard wafers are standard wafers manufactured by applying PSL-like particles to the entire surface of the wafer, and Spot Deposition standard wafers are used to apply particles such as PSL to specific areas. It is a standard wafer manufactured by. Among these, a full deposition standard wafer manufactured by applying a particle such as PSL to the entire surface of the wafer is referred to as a PSL Absolute Contamination Reference wafer. A method of fabricating a standard wafer using a conventional PDS will now be described with reference to FIG. 2.

Referring to FIG. 2, a mixture of particles such as PSL and a solution such as DI water to be deposited on a wafer surface stored in a vessel 101 inside a conventional PDS is injected through compressed air through an external pipe. Sprayed by nebulizer 201 to form a spray (aerosol). The spray (aerosol) is extracted into particles such as PSL having the same electrical fluidity through a dryer, neutralizer, and DMA, and sprayed onto a bare wafer through a nozzle installed in the chamber to produce a standard wafer.

The standard wafer fabricated as described above should have a very uniform deposition of particles such as PSL on the front of the wafer. That is, a standard wafer used as a reference wafer of an inspection apparatus requires very high uniformity during the calibration of the apparatus. However, when a standard wafer is manufactured using a conventional PDS, particles settle over time in a suspension of a mixture of particles such as PSL and a solution (particularly pure water), and thus, as a result, a low concentration of PSL may be produced over time. Since the particles are deposited on the wafer, there is a problem that the uniformity of the standard wafer is very low. That is, between the initial process time T1 and the process time Te after the lapse of a certain time, there is a problem that the uniformity of the standard wafers produced differs due to the difference in the concentration of the suspension.

An object of the present invention is to provide a container for a particle deposition system in which a suspension, which is a mixture of particles and a solution, does not occur in concentration over time, and a particle deposition system employing the same.

Another object of the present invention is to provide a container for a particle deposition system in which particles in a mixture of particles and solution can maintain a single particle state, and a particle deposition system employing the same.

Another object of the present invention is to provide a container for a particle deposition system and a particle deposition system employing the same so that the suspension that is not aerosolized by the injection of compressed air is not discharged.

In order to achieve the above object, according to an embodiment of the present invention, a particle deposition system (PDS) including a discharge pipe for storing a mixture of particles and solution to be deposited on the wafer surface, and discharge the aerosol of the mixture In the container, it can provide a container for PDS further comprising a stirrer for stirring the mixture.

In a preferred embodiment the stirrer comprises an impeller located in the mixture and drive means for rotating the impeller. In addition, the discharge pipe is characterized in that the blocking film is installed to block the discharge of the aerosolized mixture.

According to another embodiment of the present invention, in the container for a Particle Deposition System (PDS) comprising a discharge pipe for storing a mixture of particles and solution to be deposited on the wafer surface, and discharge the aerosol of the mixture, the mixture It can provide a container for PDS further comprising a heater for heating the.

In a preferred embodiment, the heater is attached to the outer wall of the container. In addition, the heater is characterized in that the heat transfer coil. In addition, the discharge pipe is characterized in that the blocking film is installed to block the discharge of the aerosolized mixture.

According to another embodiment of the present invention, there is provided a particle deposition system comprising a vessel, a dryer, a neutralizer, a DMA and a chamber containing a discharge tube for storing a mixture of particles and a solution to be deposited on a wafer surface and for discharging the aerosol of the mixture. Particle Deposition System (PDS), the vessel may provide a Particle Deposition System (PDS) characterized in that it comprises a stirrer for stirring the mixture and a heater for heating the mixture.

In a preferred embodiment, the discharge pipe is characterized in that the blocking film is installed to block the discharge of the aerosolized mixture.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Figure 3 is a schematic cross-sectional view showing the internal configuration of the container for PDS in accordance with a preferred embodiment of the present invention.

Referring to FIG. 3, the PDS according to the present invention stores a mixture of particles such as PSL and DI water and sprays them by injection of compressed air, to remove moisture from the generated particles. A dryer (not shown), a neutralizer (not shown) that neutralizes the irregular charging state of the particles passing through the dryer, and a certain polarity is applied to the particles passing through the neutralizer, and has a certain size and a constant charge for the particles having a certain polarity. Differential Mobility Analyzer (DMA, not shown) for classifying particles only, chamber (not shown) and condensation nucleus for depositing particles of the same size and constant charge passing through the movement deviation classifier on bare wafers Counter; CNC, not shown).

Here, the mixture of particles such as PSL and a solution such as DI water to be deposited on the bare wafer surface stored in the container 301 is inside the container 301 through injection of compressed air through an external pipe. It is sprayed by the sprayer 303 installed in the form of a spray (aerosol). The particles and solution in aerosol form are extracted into particles having the same electrical flow through a dryer, neutralizer, and DMA, and sprayed onto the bare wafer through a nozzle installed in the chamber to produce a standard wafer. Particles such as PSL in the suspension stored in the vessel 301 settle over time, in order to prevent this, an agitator 304 is installed inside the vessel 301. The stirrer 304 includes an impeller 305 and a driving means 307, and is operated by a control signal of the stirrer controller 309. The drive means 307 rotates the impeller 305 in response to the control signal of the stirrer controller 309, which is rotated by being located in a mixture of particles such as PSL and a solution such as pure water. Improves dispersibility This can prevent concentration gradients due to sedimentation of fine particles, such as PSL, in the mixture over time, and maintain a constant concentration during the course of the process. By maintaining a constant concentration, it is possible to maintain the flux of fine particles such as PSL, so that fine particles such as PSL can be uniformly deposited on the entire bare wafer. In the embodiment of the present invention, the impeller 305 type, shape and rotation speed of the stirrer 304 may be adjusted according to the particles to be deposited. In addition, although the stirrer was used in the Example of this invention, as long as it is a means which can improve the dispersibility of the particle | grains in a mixture, it does not matter.

In order to discharge the spray (aerosol) to the dryer, etc., a blocking film 501 is installed at one side of the discharge port installed in the container 301 to prevent the non-aerosolized mixture from being discharged to the dryer. The blocking film 501 is a phenomenon in which the pressure inside the container 301 is excessively high in the process of generating aerosol from the mixture using compressed air, and thus the mixture itself, which is not aerosolized, is discharged to the dryer or contains too much moisture. It is installed to remove the aerosol.

Figure 4 is a schematic cross-sectional view showing the internal configuration of a container for a PDS according to another embodiment of the present invention.

Referring to FIG. 4, a mixture of particles such as PSL and a solution such as DI water to be deposited on the bare wafer surface stored in the container 301 is heated to increase the kinetic energy of the fine particles such as PSL to settle. A heater 401 for preventing movement may be installed in the container 201. The heater 401 includes heat transfer coils 403 therein to generate heat by electricity supply by a control signal of the heater controller 405. The heater 401 may be installed on an inner wall, an outer wall, or the like of the container 301, but is preferably provided on the outer wall. The heating by the heater 401 increases the mobility of the fine particles such as PSL contained in the mixture to maintain a single particle state. As a result, it is possible to prevent the deposition of particles on the wafer in a state in which particles such as PSL are aggregated. In addition, since a certain amount of evaporation is generated in the aerosol generated in the container 301 due to the heating by the heater 401, the efficiency of the dryer may be improved.

In the present embodiment, a blocking film 501 may be installed at one side of the outlet of the container 301. Since the details of the blocking film 501 are the same as those described with reference to FIG. 3, description thereof will be omitted.

Figure 5 is a schematic cross-sectional view showing the internal configuration of a container for a PDS according to another embodiment of the present invention.

Referring to FIG. 5, the container 301 may be provided with a stirrer 304, a heater 401, and a blocking film 501 at one side of an outlet of the container 301. Since the contents of the stirrer 304, the heater 401, and the blocking film 501 are the same as those described with reference to FIGS. 3 and 4, the description thereof will be omitted.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the invention.

According to the present invention, a container for a particle deposition system and a particle deposition system employing the same are provided with a stirrer which can increase the dispersibility of particles so that a suspension, which is a mixture of particles and a solution, does not occur with a concentration difference over time. Can be provided.

In addition, according to the present invention, it is possible to provide a container for a particle deposition system in which a heater is installed so that particles in a mixture of particles and a solution can maintain a single particle state, and a particle deposition system employing the same.

In addition, according to the present invention, it is possible to provide a container for a particle deposition system in which a barrier film is installed on one side of an outlet so that a suspension that is not aerosolized by injection of compressed air is provided, and a particle deposition system employing the same.

Claims (9)

A container for a particle deposition system (PDS) for storing a mixture of particles and a solution to be deposited on a wafer surface, A stirrer for stirring the mixture; A nebulizer for aerosolizing the mixture with compressed air; And A discharge pipe for discharging the aerosolized mixture, The discharge pipe is a container for a particle deposition system, characterized in that the barrier is installed to block the discharge of the non- aerosolized mixture. 2. The container of claim 1, wherein the stirrer includes an impeller located in the mixture and drive means for rotating the impeller. The container of claim 1 or 2, further comprising a heater for heating the mixture. A container for a particle deposition system (PDS) for storing a mixture of particles and a solution to be deposited on a wafer surface, A heater for heating the mixture; A nebulizer for aerosolizing the mixture with compressed air; And A discharge pipe for discharging the aerosolized mixture, The discharge pipe is a container for a particle deposition system, characterized in that the barrier is installed to block the discharge of the non- aerosolized mixture. 5. The vessel of claim 4, wherein the heater is attached to an outer wall of the vessel for the particle deposition system. 5. The container of claim 4, wherein the heater is a heat transfer coil. 4. The container of claim 3, wherein the heater is a heat transfer coil. A particle deposition system (Particle Deposition System, PDS) comprising a container, a dryer, a neutralizer, a differential mobility analyzer (DMA) and a chamber for a particle deposition system according to claim 3. delete

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