KR102539964B1 - Electrostatic Chuck And Substrate Inspection Apparatus Using The Same - Google Patents

Abstract

A substrate irradiation device that facilitates substrate unloading and inspects for defects in a substrate processing unit is introduced. The substrate irradiation device includes a chuck plate 110; a transparent or translucent diffuser 200 disposed below the substrate adsorption area of the chuck plate 110; and a carrier 400 supporting the chuck plate 110 and accommodating the diffuser 200 . An elongated groove 112 for supplying gas to the back side of the substrate B is formed on the adsorption surface of the substrate. The light of the light source is irradiated upward through the diffuser 200 .

Description

Electrostatic Chuck And Substrate Inspection Apparatus Using The Same}

The present invention relates to an electrostatic chuck (ESC) and a substrate inspection device using the electrostatic chuck for processing and post-processing inspection of a substrate.

An electrostatic chuck electrostatically chucks a substrate such as a wafer, glass, display panel, or the like. An electrostatic chuck can fix substrates without applying physical force and is widely used in semiconductor or display manufacturing processes.

Electrostatic chucks may be classified into ceramic electrostatic chucks, polyimide electrostatic chucks, thermal spray coating electrostatic chucks, and the like, depending on materials or manufacturing methods. Electrostatic chucks may be classified into a Coulomb type and a Johnson-Rabeck type according to induction characteristics of a clamping force, and a monopolar type and a bipolar type according to the number or structure of electrodes.

A bipolar electrostatic chuck has an insulating or dielectric chuck plate and two electrodes electrically separated and embedded in the plate. When voltages of opposite polarities are applied to the electrodes, charges of opposite polarities are charged to portions of the substrate facing the electrodes, and the substrate is adsorbed by dielectric polarization. A high-voltage DC power supply or AC power supply may be used as a power source.

Since the bipolar electrostatic chuck can constitute a self-contained circuit, it can clamp the substrate with or without plasma. Since the clamping force of the electrostatic chuck is proportional to the area of the electrode, the electrode is formed in various types of patterns to cover a large area. A monopolar electrostatic chuck with a single electrode makes electrical contact to a substrate for induction of an electrostatic force, or a plasma provides such contact.

An OLED display displays a screen by forming pixels with an organic material that emits light by an electric field and controlling the pixels. Forming pixels is called color patterning, and a desired screen can be accurately displayed only when subpixels of red (R), green (G), and blue (B), which are the three primary colors, are accurately patterned. A shadow mask called a fine metal mask is used for such color patterning, and a plurality of fine holes are processed in the shadow mask for deposition of an organic material for forming pixels. High-precision processing of micro-hole patterns using lasers has recently been attempted in order to process the micro-holes of the shadow mask smaller and with higher density as the resolution of the display increases. The processing quality of the fine hole pattern is evaluated using an inspection device.

In the display manufacturing process, many processes are involved, such as cutting, cleaning, and bonding, including hole processing for a substrate, and quality inspection is performed after the processes. For example, when processing a hole for a camera lens or sensor on a display panel on which OLED is deposited, the size or shape of the processed hole is accurate, whether the cut surface is smooth, whether particles scattered during cutting adhere to the surface of the substrate, etc. need to be checked The inspection is performed in such a way that a camera photographs light reflected from the substrate while irradiating light on the substrate, and analyzes the photographed image to determine the presence or absence of a defect.

On the other hand, electrostatic chucks often suffer from dechucking. Even after turning off the clamping power supply, the substrate may not be easily unloaded from the electrostatic chuck due to charges remaining in the electrostatic chuck. When the substrate is made of a thin and light material such as a polyimide film, the substrate is not easily unloaded from the electrostatic chuck due to surface pressure. This dechucking problem of the substrate causes a delay in transfer time between processes.

Republic of Korea Patent Registration No. 10-0863341 (Announced on October 15, 2008)

SUMMARY OF THE INVENTION The present invention is based on the recognition of the prior art as described above and is intended to provide an electrostatic chuck and a substrate inspection device capable of inspecting the quality or defects of a substrate processing unit.

In addition, the present invention is to provide an electrostatic chuck and a substrate inspection device capable of easily unloading a substrate.

In order to achieve the above object, a substrate inspection apparatus according to the present invention includes a chuck plate having a substrate adsorption area and capable of transmitting light in at least a partial area; a transparent or translucent diffuser disposed below the substrate adsorption area of the chuck plate; a carrier supporting the chuck plate and accommodating the diffuser; and a light source disposed on the carrier and radiating upward light from below the diffuser so that the light is diffused in the diffuser and irradiated to the back surface of the substrate placed in the substrate adsorption area.
According to the present invention, the diffuser has an upper rim; a slope that becomes narrower from the upper rim to the lower part; And a dust collector in the center of the lower part.
In addition, according to the present invention, a processing hole is formed in the chuck plate, and the processing hole is formed at a position corresponding to a hole being processed in the substrate. The diffuser is placed below the processing hole to collect particles falling from the processing hole through the dust collector.
According to the present invention, a long groove is formed in the substrate adsorption area, and a communication hole penetrating the chuck plate 110 is provided at one end of the groove. The groove is formed with a deep depth at the through hole side and a smaller depth toward the other end side so that the gas introduced from the through hole blows out toward the other end side of the groove 112 and provides a dechucking force to the substrate.
In addition, according to the present invention, a distribution plate is provided in close contact with or attached to the lower part of the chuck plate, and a gas channel is formed on the upper surface of the distribution plate to allow gas to flow in from the outside and be supplied to the communication hole.

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The carrier communicates with the dust collector and further includes an outlet for external discharge of the cutting plate, and is installed to move from the processing stage of the substrate to the inspection stage. can

As described above, according to the present invention, processing holes and grooves are processed in the electrostatic chuck, so that the cutting pieces and particles cut and separated from the substrate are discharged downward through the processing holes, and the gas discharged through the grooves is charged with remaining static electricity. There is an effect that the separation of the substrate can be easily performed by pushing the substrate adsorbed to the electrostatic chuck by the method.

In addition, the electrostatic chuck and the diffuser are made transparent, and the light source under the diffuser irradiates light upward to transmit light through the diffuser and the electrostatic chuck, so that the light of the light source passes through the diffuser and becomes even, Since the light is irradiated almost perpendicularly to the electrostatic chuck and the substrate rather than obliquely, shadows due to holes, cracks, scratches, and particles are not generated on the substrate, so that the accuracy of the inspection rate can be maximized.

The electrostatic chuck, the diffuser, and the light source with the processed holes and grooves are moved from the substrate processing stage to the substrate inspection stage by the carrier, so that the substrate can be processed and inspected while the electrostatic chuck adsorbs the substrate. It has the effect of shortening the time and simplifying the work process.

The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention serve to further understand the technical idea of the present invention, the present invention is limited only to those described in the drawings. and should not be interpreted.
1 is a schematic perspective view of an inspection device including an electrostatic chuck according to a preferred embodiment of the present invention.
FIG. 2 is a cross-sectional view along line AA of FIG. 1 .
3a and 3b are images and photographs showing the diffuser shown in FIG. 2 .
4 is a plan view illustrating the inspection device of FIG. 1;
FIG. 5 is a plan view illustrating a state in which a substrate is raised on the electrostatic chuck of FIG. 1 .

Hereinafter, examples will be described in more detail so that various characteristic aspects of the present invention can be understood. In the drawings, the same or equivalent components may be denoted by the same reference numerals, and the drawings may be exaggerated or schematically illustrated for an intuitive understanding of the features of the present invention.

In this document, unless otherwise limited or inherently unacceptable, expressions for explaining the relationship between two elements, for example, expressions such as 'phase' and 'connection' are used when two elements are in direct contact with each other. It is of course allowed for a third element to be interposed between the elements of the first and second elements. Directional indications such as front and rear, left and right, or up and down are only for convenience of description and are not intended to limit the scope of the present invention.

Hereinafter, an inspection device according to a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4 .

The distribution plate 120 and the diffuser 200 shown in the drawings are, for example, made of transparent or translucent light. Substrate B is, for example, a display panel.

FIG. 4 is a plan view of the electrostatic chuck 100, in which the distribution plate 120 and the gas channel 121 are visible through the chuck plate 110. In FIG. 4 , the chuck plate 110 is illustrated as being transparent to help an intuitive understanding of the chuck plate 110 and components placed thereunder. The chuck plate 110 is made of a transparent or translucent material so that light can pass through.

FIG. 5 schematically shows that a substrate B is placed on the electrostatic chuck 100 .

As shown in FIGS. 1 and 2 , the inspection apparatus according to the embodiment includes an electrostatic chuck 100 , a diffuser 200 , a light source 300 and a carrier 400 .

As shown in FIGS. 1 and 2 , the electrostatic chuck 100 is mounted on the carrier 400 . When clamping power (not shown) is applied, the substrate B is electrostatically clamped to the top surface of the chuck plate 110, that is, the substrate adsorption surface. A battery providing a voltage for clamping the substrate B may be mounted on the carrier 400 .

The inspection device is movable along the process line. For example, the inspection device may be configured to be movable using a magnet moving type linear motion system as introduced in Japanese Patent Publication No. 2011-050220. The carrier 400 has a moving wheel 410, a magnet is mounted on the moving wheel 410, and a coil corresponding to the magnet is arranged along a rail. As another example, a battery for moving the test device may be mounted on the carrier 400 .

The electrostatic chuck 100 includes a chuck plate 110 and a distribution plate 120 .

The chuck plate 110 includes a lower plate, an upper plate attached to a top surface of the lower plate, and a clamping electrode interposed between the lower plate and the upper plate. The chuck plate 110, particularly the top plate, may be made of a dielectric material such as polyimide film. As another example, the chuck plate 110 may be configured as a monolithic integral plate having buried electrodes. The chuck plate 110 may be manufactured using, for example, ceramic or resin.

The upper plate and the lower plate may be made of an insulating or dielectric transparent material. For example, at least one of the upper plate and the lower plate may be made of a light-transmitting resin such as glass, quartz, or epoxy.

The electrode for clamping can be obtained by printing a conductive metal material such as copper, silver, tungsten or the like on the lower plate or on the lower surface of the upper plate.

In addition, the clamping electrode may be made of a transparent conductive material having high light transmittance. The conductive material may be a single material or a mixture of metal oxides including indium tin oxide (ITO), silver nanowires/particles, carbon nanotubes, graphene, conductive polymers, or conductive ionic liquids. For example, the transparent electrode may be manufactured by screen-printing a dispersion or paste of a conductive material, or by patterning indium tin oxide using a sputtering method.

As an example, the upper plate may have a cavity formed on its lower surface and an edge portion protruding along the edge. An electrode for clamping is printed on the surface of the cavity and can be bonded to the lower plate using an insulating adhesive. The edge portion prevents leakage of current from the electrode.

Referring to FIGS. 1 to 4 , a processing hole 111 and a groove 112 are provided in the chuck plate 110 .

The processing hole 111 is provided to allow hole processing in the substrate B in a state where the substrate B is adsorbed on the chuck plate 110 . The processing hole 111 is formed through the chuck plate 110 . Crumbs may be generated during hole processing using a laser or the like, and the debris may be collected through the processing hole 111 and the dust collection port 210 of the diffuser 200. A suction device for collecting debris may be provided in the processing stage, and the debris is collected by the suction device through the outlet 430. As an example, the substrate B is a display panel for a mobile device, and a hole processed on the substrate B may be a camera lens hole, a sensor hole, or the like.

The inspection device is movable between the processing stage and the inspection stage. When hole processing is completed on the board in the processing stage, the inspection device moves along the rail to the inspection stage. When positioned on a processing stage or an inspection stage, the voltage for adsorption of the substrate B can be supplied from outside the inspection device. When the inspection device moves, the supply of external power is cut off, and the substrate B on the chuck plate 110 is absorbed by the charge remaining on the chuck plate 110 during the movement.

The groove 112 facilitates dechucking of the substrate B placed on the chuck plate 110 . Even after the power supplied to the clamping electrode is turned off or cut off, the adsorption state of the substrate (B) can be temporarily maintained due to residual charges, its own weight, or surface pressure. When the gas blows out, the unloading of the substrate B becomes easy. The groove 112 is formed elongated so as to blow from the center side of the substrate B to the edge side at the center side of the back surface of the substrate B.

As shown in FIGS. 4 and 5 , the groove 112 is provided on the substrate adsorption surface of the chuck plate 110 . A communication hole 130 penetrating the chuck plate 110 is provided at one end of the groove 112, and gas for dechucking the substrate B is introduced from the communication hole 130 to the other end of the groove 112. it will grow The groove 112 is deep at the side of the communication hole 130 and increases in depth toward the other end. Grooves 112 may be formed in two pairs disposed in parallel. The substrate B can be easily separated from the substrate adsorption surface and picked up by the transfer device by the gas blowing from the center side of the substrate to the edge side between the substrate adsorption surface and the substrate B.

The chuck plate 110 may be configured to simultaneously adsorb two or more substrates B. A processing hole 111 and a groove 112 are provided in each substrate adsorption area. Electrodes for adsorption of the substrates B may be provided to be common throughout the adsorption areas or may be provided separately in each area.

As shown in FIGS. 2 and 4 , the distribution plate 120 is in close contact with the lower surface of the chuck plate 110 . A gas channel 121 is provided on the upper surface of the distribution plate 120 to supply gas for blowing the substrate B to the communication hole 113 of the chuck plate 110 . Gas supplied from the outside is supplied through the gas channel 121 of the distribution plate 120 and supplied to the groove 112 through the communication hole 113 .

Referring to FIG. 4, the gas channel 121 includes an intake line 122 through which gas is introduced from the outside, a connection line 123, and an exhaust line 124 connected to the groove 112 through a communication hole 113. It consists of As indicated by arrows, the gas is blown through the groove 112 through the intake line 122, the connection line 123, and the exhaust line 124 in sequence. The intake line 122 may be formed so that gas can be supplied from a side of the inspection device.

When the chuck plate 110 has a region for adsorbing two substrates B, the gas channel 121 of each region uses a connection line 123 in common and has an intake line 122 and an exhaust line 124. formed to be mutually symmetrical. As another example, the gas channel 121 may be provided in the chuck plate 110 . However, considering the manufacturing cost of the chuck plate 110, it would be better to form the gas channel 121 using a separate distribution plate 120.

Referring to FIGS. 2 to 4 , the diffuser 200 is positioned directly below the electrostatic chuck 100 , more specifically, the substrate adsorption area. The diffuser 200 is used to collect debris generated during substrate hole processing and to inspect the quality of the substrate processing unit.

As shown in FIG. 2 , the diffuser 200 is seated in the receiving groove 420 provided on the carrier 400 . An accommodation hole 130 for preventing interference with the diffuser 200 and mounting the diffuser 200 is provided in the distribution plate 120 .

As shown in FIGS. 2 to 3B , the diffuser 200 has an upper quadrangular rim 220 , an inclined surface 230 gradually narrowing downward from the rim 220 , and a dust collector 210 in the lower center. The lower edge of the inclined surface 230 forms the dust collector 210 . The upper edge 220 is raised over the carrier 400, and the lower surface of the diffuser 200 is spaced apart from the bottom surface of the receiving groove 420. A light source 300 is disposed on the bottom surface of the receiving groove 420 .

The diffuser 200 is provided with a bolt hole 221 at the upper edge 220 to which a bolt for fixing the diffuser 200 to the carrier 400 is fastened. When a hole is drilled in the substrate (B), an air suction pipe is positioned under the dust collector 210, and particles generated during hole processing are collected through the dust collector 210 through the suction pipe. Accordingly, contamination of the substrate (B) due to particles generated during processing of the substrate (B) can be prevented.

The diffuser 200 is translucent or transparent. Preferably, the diffuser 200 is configured to function as a diffusion plate for diffusing light from the light source 300 .

When the inspection device moves from the processing stage to the inspection stage, defects and quality inspection of the substrate processing unit is performed. When the light source 300 is turned on for inspection, light is diffused from the diffuser 200 and irradiated to the back surface of the substrate B via the transparent or translucent electrostatic chuck 100 .

As shown in FIG. 2 , the light source 300 is located below the diffuser 200 and is installed to emit light upward toward the diffuser 200 . The light source 300 is fixed to the bottom of the receiving groove 420 of the carrier 400.

The light source 300 may be disposed avoiding the dust collector 210 and the outlet 430 where particles are collected, or may have a hole corresponding to the area of the dust collector 210 and the outlet 430 . An LED is used as the light source 300, and a hole may be provided in a substrate on which the LED is installed.

The light irradiated from the light source 300 passes through the diffuser 200, the distribution plate 120, and the chuck plate 110 to illuminate the back side of the substrate B, and is photographed with a camera from the upper side of the substrate B Through one image, it is possible to inspect defects or quality of the substrate processing part, and furthermore, whether the substrate is damaged or has particles on it.

The carrier 400 is a device for moving the electrostatic chuck 100 on which it is placed. For example, the carrier 400 may be installed to move along a rail through a moving wheel 410 mounted on a lower portion. The carrier 400 may include a receiving groove 420 in which the diffuser 200 is accommodated, and an outlet 430 positioned at the dust collector 210 of the diffuser 200 .

The outlet 430 is processed to communicate with the dust collector 210 of the diffuser 200. Cutting pieces and particles that have passed through the dust collector 210 may be discharged to the outside through the outlet 430 . A suction pipe for sucking in particles may be positioned below the outlet 430 . Particles generated during processing of the substrate B by the suction pressure of the suction pipe may pass through the outlet 430 and the dust collector 210 and be collected to the outside through the suction pipe.

When the processing of the substrate (B) is completed, the carrier 400 moves to the inspection stage of the substrate (B). When the carrier is placed on the inspection stage, electricity is applied to the light source 300 to emit light, and the light passes through the diffuser 200 and the electrostatic chuck 100 to illuminate the back surface of the substrate B, and the substrate ( A camera located on top of B) takes pictures of the substrate (B). By analyzing the acquired image, it is possible to determine whether there are cracks or scratches on the substrate (B) and whether particles are attached to the substrate (B).

The substrate processing part is well observed from the upper side of the substrate by shining light on the back side of the substrate (B). In particular, in the case of a hole, the contour of the hole is clearly displayed in light and dark contrast by light shining from the back side of the substrate (B), so that whether or not the substrate is processed or whether there is a processing defect can be diagnosed more accurately and quickly.

The electrostatic chuck and substrate inspection device according to the embodiment can move between processing stages and inspection stages, and necessary processes can be performed in each stage. Since a single electrostatic chuck can be shared without using separate electrostatic chucks for each of the processing stage and the inspection stage, it is possible to reduce process costs and to perform continuous processes. The process line may be designed such that the electrostatic chuck does not simply reciprocate between the processing stage and the inspection stage, but the electrostatic chuck cycles through the processes to continuously perform them.

Having described embodiments of the present invention, these embodiments will be helpful in understanding various aspects and features of the present invention. Elements presented in these embodiments may be selectively combined with each other, and another embodiment not previously described in this document may be presented by such a combination.

Hereinafter, claims for defining the scope of the present invention are described. The element(s) recited in the claims may be variously changed, modified, and replaced with equivalents without departing from the technical spirit of the invention. The reference numerals in the claims, if any, are intended to aid easy and intuitive understanding of the claimed inventions or their elements, and do not limit the scope of the claimed inventions.

100: electrostatic chuck
110: chuck plate 111: processing hole
112: groove 120: distribution plate
121: gas channel 122: intake line
123: connection line 124: exhaust line
200: diffuser
210: dust collector 220: bolt hole
300: light source
400: carrier
410: moving wheel 420: receiving groove.
430: outlet.

Claims (5)

a chuck plate 110 having a substrate adsorption area and capable of transmitting light in at least a portion of the area;
a transparent or translucent diffuser 200 disposed below the substrate adsorption area of the chuck plate 110;
a carrier 400 supporting the chuck plate 110 and accommodating the diffuser 200; and
A light source 300 provided on the carrier 400 and arranged to irradiate upward light from under the diffuser 200 so that the light is diffused in the diffuser 200 and irradiated to the backside of the substrate placed in the substrate adsorption area. ) Board inspection device comprising a. The method according to claim 1, wherein the diffuser 200,
the upper rim 220;
an inclined surface 230 that becomes narrower from the upper edge toward the lower part; and
A substrate inspection device having a dust collector 210 in the lower center. The method according to claim 1, wherein a processing hole 111 is formed in the chuck plate 110, and the processing hole 111 is formed at a position corresponding to a hole processed in the substrate B,
The diffuser 200 is placed at the bottom of the processing hole 111 to collect particles falling from the processing hole 111 through the dust collector 210. The method according to any one of claims 1 to 3, wherein an elongated groove (112) is formed in the substrate adsorption area,
A communication hole 113 passing through the chuck plate 110 is provided at one end of the groove 112,
The groove 112 has a deep depth at the side of the communication hole 130 and is gradually increased toward the other end so that the gas introduced from the communication hole 130 blows toward the other end of the groove 112 and provides a dechucking force to the substrate. A substrate inspection device formed with a small depth. The method according to claim 4, provided with a distribution plate 120 closely attached or attached to the bottom of the chuck plate 110,
A substrate inspection device having a gas channel 121 formed on the upper surface of the distribution plate 120 so that gas can flow in from the outside and be supplied to the communication hole 113.

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