KR101661641B1 - Large size electrostatic chuck - Google Patents

Abstract

An embodiment of the present invention relates to a large area electrostatic chuck, and a technical problem to be solved is to provide a large area electrostatic chuck for a display for an eighth generation that is light in weight, small in deflection phenomenon, and unaffected by a process temperature .
To this end, the present invention provides a semiconductor device comprising: a base substrate made of a titanium material having a first surface and a second surface opposite to the first surface; An insulating layer of a ceramic material coated on a first surface of the base substrate; And an anti-sag structure of aluminum attached to the second surface of the base substrate.

Description

Large area electrostatic chuck {LARGE SIZE ELECTROSTATIC CHUCK}

One embodiment of the present invention relates to a large area electrostatic chuck.

The display industry is mainly developing technology to increase the size (area) and sharpness (image quality). One of the notable technologies for this is display technology using OLED (Organic Light Emitting Diode).

The current OLED technology is mainly applied to mobile smart devices, and the sizes are increasing to be applied to the smart TV and large display markets, which are large displays of the household appliance industry.

The key to such OLED technology is the technology of evaporating fluorescent organic materials to uniformly deposit thin films, and a bottom-up evaporative deposition process is generally used for the efficiency of the deposition process.

In the bottom-up evaporative deposition process, it is very important to act as a face-down type supporting device for fixing and transferring the glass to the supporting device. Conventionally, as the supporting device, the cohesive chucking method and the ceramic electrostatic chucking method have been used in the size of 5 generation or less.

However, in the 8th generation (for example, 2200 mm x 2500 mm) size, it is difficult to perform uniform chucking in the conventional adhesive chucking method, and dechucking due to over chucking ) There was a problem that the glass was broken.

In addition, the ceramic type electrostatic chuck has a problem in that it is difficult to manufacture a large ceramic material, and even if the ceramic type electrostatic chuck is manufactured by an assembling method, the phenomenon of sagging due to an increased self weight occurs.

Korean Registered Patent No. 10-1189815 (Publication Date October 10, 2012)

One embodiment of the present invention is a lightweight large area electrostatic chuck having a weight of less than about 400 kg (preferably 320 kg) despite chucking an eighth generation glass that is about four times larger in size or area than the fifth generation .

In addition, one embodiment of the present invention provides a large-area electrostatic chuck having chucking of an eighth generation glass with a self-weight deflection of about 3 mm or less.

In addition, an embodiment of the present invention provides a large-area electrostatic chuck capable of preventing warpage and peeling between components due to a small difference in thermal expansion coefficient even at a high temperature process of about 50 ° C to 120 ° C.

A large area electrostatic chuck according to an embodiment of the present invention includes: a base substrate made of a titanium material having a first surface and a second surface opposite to the first surface; An insulating layer of a ceramic material coated on a first surface of the base substrate; And an anti-sag structure of aluminum attached to a second side of the base substrate.

The sag prevention structure may have a planar shape in the form of a lattice pattern.

The sagging prevention structure may include a plurality of transverse structures arranged in a horizontal direction and a plurality of longitudinal structures arranged in a longitudinal direction and intersecting the transverse structure.

The slack prevention structure may have a shape of a cross section of a square, a rectangle, a T shape, an I shape or a ⊥ shape.

The deflection preventing structure may be fixed to the base substrate by bolts.

The sag preventing structure may have a thickness of 30 mm to 45 mm.

The base substrate may have a thickness of 5 mm to 7 mm.

The insulating layer may have a thickness of 0.6 mm to 1.2 mm.

The insulating layer may include Al ₂ O ₃ .

The base substrate may be the same as the 8th generation glass having a width of 2200 mm x 2500 mm.

The electrostatic chuck is disposed such that the insulating layer faces downward, and the deflection amount due to the self weight of the electrostatic chuck may be less than 3 mm.

The electrostatic chuck may have a weight of less than 400 kg.

One embodiment of the present invention is a lightweight large area electrostatic chuck having a weight of less than about 400 kg (preferably 320 kg) despite chucking an eighth generation glass that is about four times larger in size or area than the fifth generation . That is, according to the present invention, a base substrate of a relatively thin titanium substrate is provided with a relatively high strength aluminum sag preventing structure in the form of a lattice pattern, thereby providing an electrostatic chuck with a minimized or reduced weight.

In addition, one embodiment of the present invention provides a large-area electrostatic chuck having chucking of an eighth generation glass with a self-weight deflection of about 3 mm or less. That is, in the present invention, a sag preventing structure in the form of a lattice pattern is further provided on the base substrate, so that the deflection due to its own weight is limited to about 3 mm or less, preferably 2 mm or less, more preferably 1 mm or less.

In addition, an embodiment of the present invention provides a large-area electrostatic chuck capable of preventing warpage and peeling between components due to a small difference in thermal expansion coefficient even at a high temperature process of about 50 ° C to 120 ° C. That is, in the present invention, since the base substrate made of titanium and the insulating layer made of the ceramic material have similar thermal expansion coefficients, the electrostatic chuck is not bent or the insulating layer is not peeled off from the base substrate in the organic material deposition process, which is a relatively high- .

1A and 1B are a cross-sectional view and a plan view showing a large area electrostatic chuck according to an embodiment of the present invention.
2A to 2E are cross-sectional views illustrating various structures of a sag preventing structure of a large area electrostatic chuck according to an embodiment of the present invention.
3 is a cross-sectional view illustrating an example of using a large area electrostatic chuck according to an embodiment of the present invention.
4A to 4E are views simulating the amount of deflection by the self weight of the large area electrostatic chuck according to the embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are described in order to more fully explain the present invention to those skilled in the art, and the following embodiments may be modified in various other forms, The present invention is not limited to the embodiment. Rather, these embodiments are provided so that this disclosure will be more faithful and complete, and will fully convey the scope of the invention to those skilled in the art.

In the following drawings, thickness and size of each layer are exaggerated for convenience and clarity of description, and the same reference numerals denote the same elements in the drawings. As used herein, the term "and / or" includes any and all combinations of one or more of the listed items. In the present specification, the term " connected "means not only the case where the A member and the B member are directly connected but also the case where the C member is interposed between the A member and the B member and the A member and the B member are indirectly connected do.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a," "an," and "the" include singular forms unless the context clearly dictates otherwise. Also, " comprise "and / or" comprising "when used herein should be interpreted as specifying the presence of stated shapes, numbers, steps, operations, elements, elements, and / And does not preclude the presence or addition of one or more other features, integers, operations, elements, elements, and / or groups.

Although the terms first, second, etc. are used herein to describe various elements, components, regions, layers and / or portions, these members, components, regions, layers and / It is obvious that no. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section described below may refer to a second member, component, region, layer or section without departing from the teachings of the present invention.

1A and 1B are a cross-sectional view and a plan view showing a large area electrostatic chuck 100 according to an embodiment of the present invention.

1A and 1B, an electrostatic chuck 100 according to the present invention includes a base substrate 110, an insulating layer 120, an electrode 130, and a sag prevention structure 140.

The base substrate 110 includes a first surface 111 (bottom surface) that is substantially flat or completely flat and a second surface 112 (top surface) that is substantially flat or completely flat as the opposite surface of the first surface 111. The base substrate 110 may be formed of any one selected from the group consisting of titanium, titanium alloy, and the like having a small difference in thermal expansion coefficient from the insulating layer 120 to be formed. However, the titanium base substrate 110 has a relatively larger weight compared to the same area and thickness as the conventional aluminum base substrate. Therefore, the thickness of the base substrate 110 should be limited to approximately 5 mm to 7 mm, preferably approximately 6 mm, so that the weight of the electrostatic chuck 100 is minimized or reduced in the present invention. Further, the thickness of the base substrate 110 should be within a range of approximately 5 mm to 7 mm, and the bolts 144 to be formed should be formed on the base substrate 110 without affecting the flatness of the base substrate 110 Can be suitably combined.

In addition, the base substrate 110 has a width or size of approximately 2200 mm x 2500 mm, so that the present eighth-generation glass can be chucked. In addition, the base substrate 110 made of titanium is advantageous in comparison with a base substrate made of Invar or stainless steel except the base substrate made of aluminum. That is, the base substrate made of invar or stainless steel is relatively larger in weight compared to the base substrate 110 made of titanium at the same area and thickness.

For reference, the first-generation glass is 270 mm × 400 mm, the second-generation glass is 370 mm × 470 mm, the third-generation glass is 550 mm × 650 mm, the fourth-generation glass is 730 mm × 920 mm, The glass has a width or a size of 1100 mm x 1300 mm, the glass for sixth generation is 1500 mm x 1850 mm, the glass for seventh generation is 1870 mm x 2200 mm, and the glass for eighth generation is 2200 mm x 2500 mm.

The insulating layer 120 is formed by coating on the first surface 111 of the base substrate 110. Insulating layer 120 is, for example, may be a ceramic, may preferably be alumina (Al ₂ O _3). The insulating layer 120 of the ceramic material may be coated on the first surface 111 of the base substrate 110 by the plasma spraying method. However, the present invention is not limited to the method of forming such an insulating layer 120. The insulating layer 120 is formed to have a thickness of approximately 0.6 mm to 1.2 mm.

Here, the base substrate 110 made of titanium has a thermal expansion coefficient of about 8 占 퐉 m ^-1占^{-1 -1} at about 25 占 폚 to 150 占 폚, preferably 50 占 폚 to 120 占 폚, and an insulating layer 120 ) because it is substantially about 25 ℃ to 150 ℃, preferably to 50 ℃ to the thermal expansion coefficient at 120 ℃ about 5 ~ 6 ㎛ · m ^-1 · K ^-1 to, relatively high-temperature process (for example, approximately 50 ℃ 120 deg. C), the bending phenomenon of the electrostatic chuck 100 is small, so that the insulating layer 120 does not peel off from the base substrate 110.

Since the aluminum base substrate used in the prior art has a thermal expansion coefficient of approximately 22 to 23 탆 · m ^-1 · K ^-1 at approximately 25 캜 to 150 캜 or 50 캜 to 120 캜, The bending phenomenon of the chuck largely occurred, and the insulating layer of the ceramic material was easily peeled off from the base substrate made of the aluminum material. In addition, since the electrostatic chuck made of Invar or stainless steel used in the prior art has a relatively heavy weight, it is difficult to use the electrostatic chuck in face down type electrostatic chuck.

Meanwhile, the insulating layer 120 may be substantially divided into a first insulating layer 121 and a second insulating layer 122. A first insulating layer 121 coated on the first surface 111 of the base substrate 110 and a second insulating layer 122 covering the plurality of electrodes 130 formed on the first insulating layer 121, . The first insulating layer 121 and the second insulating layer 122 may be formed of alumina as described above. In addition, the surface of the second insulating layer 122 may be ground after the coating process of the second insulating layer 122 so that the flatness is improved.

In addition, in the present invention, in addition to the above-described alumina, the insulating layer 120 may be formed of a material selected from the group consisting of Y ₂ O ₃ , Al ₂ O ₃ / Y ₂ O ₃ , ZrO ₂ , AlC, TiN, AlN, TiC, MgO, CaO, CeO ₂ , TiO _{2 , BxCy, BN, SiO 2,} SiC, YAG, Mullite, 1 or two or more from the group consisting of AlF ₃ are mixed, each may be the insulating layer (120). Substantially, the insulating layer 120 can be formed by all known ceramic materials.

The electrode 130 is formed on the surface of the first insulating layer 121, which is covered with the second insulating layer 122. The electrode 130 is formed to a thickness of about 0.03 mm to 0.1 mm, and may be formed by a spray coating method using a metal material. However, the present invention is not limited to this. In addition, the electrode 130 may be formed of any one of W, Mo, Ti, and the like. As is well known, this electrode 130 is connected to a power supply (not shown) and serves to generate an electrostatic force.

The anti-sagging structure 140 is attached to the second side 112 of the base substrate 110. For example, the anti-sag structure 140 may be coupled to the base substrate 110 by bolts 144 or equivalents thereof. However, the present invention is not limited to this combination method. In addition, the slack prevention structure 140 may have a shape of a cross section of a square shape, a rectangular shape, a T shape, a ⊥ shape, or an I shape.

The sag preventing structure 140 may have a substantially rectangular shape in cross section along the periphery of the base substrate 110 so that the electrostatic chuck 100 is light in weight. , The cross-sectional shape of the slack prevention structure 140 may be substantially T-shaped so as to prevent the electrostatic chuck 100 from being bent due to its own weight. The thickness and width of the anti-sagging structure 140 should be controlled to approximately 30 to 45 mm so that the electrostatic chuck 100 is lightweight.

In addition, a rail (not shown) made of stainless steel may be further formed along a square circumference of the base substrate 110, and in some cases, a sag preventing structure formed along the periphery of the base substrate 110 (140) may serve as a rail.

Subsequently, the sag prevention structure 140 may be formed in a substantially planar shape or a checkerboard shape, as shown in Fig. 1B. More specifically, the anti-slack structure 140 includes a rectangular frame 141 formed along the periphery of the base substrate 110, an inner region of the rectangular frame 141, And a plurality of longitudinal structures 143 arranged longitudinally and intersecting with the lateral structures 142 as inner regions of the arranged plurality of lateral structures 142 and the square frames 141. As described above, the rectangular frame 141 formed along the periphery of the base substrate 110 may serve as a rail.

The number, pitch, thickness, and / or width of the transverse structure 142 and the longitudinal structure 143 are determined by the width and / or the size of the electrostatic chuck 100, the warpage caused by the self weight of the electrostatic chuck 100 May be varied in various ways.

As described above, one embodiment of the present invention is to provide a base substrate 110 made of a thin-thickness titanium material and a base substrate 110 made of a titanium nitride material having excellent rigidity, A different material, such as an anti-sagging structure 140 of aluminum, is employed in the electrostatic chuck 100 to provide a lightweight large area electrostatic chuck 100 having a weight of approximately 400 kg (preferably 320 kg) or less do.

That is, in the case of a face-down electrostatic chuck generally used in a bottom-up evaporative deposition process, the specification is set so as to maintain a total weight of about 400 kg or less. When an electrostatic chuck is manufactured using only a titanium material having a high specific gravity, An unstable problem may occur when the electrostatic chuck is transported. Therefore, in the present invention, the anti-sag structure is made of an aluminum material which can maintain the rigidity while the specific gravity is low, and this anti-sag structure is bonded or bonded to the base substrate made of titanium, so that one electrostatic chuck is manufactured. Needless to say, the titanium material is manufactured in a plate shape capable of maintaining rigidity, and the aluminum material is manufactured in a protruded rib shape so that various parts of the rigid and electrostatic chuck can be mounted while minimizing the weight.

In addition, by using the base substrate 110 made of titanium and the ceramic insulating layer 120 made of alumina which have mutually similar thermal expansion coefficient differences, an embodiment of the present invention can prevent warping phenomenon And the large-area electrostatic chuck 100 in which the insulating layer 120 does not peel off from the base substrate 110 is provided.

Therefore, the present invention not only provides the lightweight electrostatic chuck 100, but also provides the electrostatic chuck 100 which is not affected by high temperature (25 占 폚 to 150 占 폚, preferably 50 占 폚 to 120 占 폚) .

2A to 2E are cross-sectional views illustrating various structures of a sag preventing structure of a large area electrostatic chuck 100 according to an embodiment of the present invention.

The cross-sectional structure of the sagging prevention structure formed on the second surface 112 of the base substrate 110 may include a substantially square 240 as shown in FIG. 2A, a substantially rectangular shape 340 as shown in FIG. 2B, Shaped 140 as shown in FIG. 2C, a generally I-shaped 440 as shown in FIG. 2D, and a generally L-shaped 540 as shown in FIG. 2E.

Meanwhile, the square, rectangular, T-shaped, I-shaped, or ⊥-shaped deflection preventing structures 240, 340, 140, 440 and 540 may be formed on the base substrate 110. Moreover, the thickness and width of such square, rectangular, T-shaped, I-shaped, or elliptical anti-sag structures can be the same or mutually different.

The sagging preventing structures 240, 340, 140 and 440 may be attached to the base substrate 110 by laser welding, electric resistance welding, ultrasonic welding or the like in addition to the bolts 144. In the present invention, the sagging preventing structures 240, 340, The method of connecting the substrates 110 to each other is not limited.

3 is a cross-sectional view illustrating an example of using the large-area electrostatic chuck 100 according to an embodiment of the present invention.

3, the electrostatic chuck 100 is disposed such that the insulating layer 120 faces downward, and the glass 180 is electrostatically attached to the insulating layer 120, I look down. That is, the present invention provides an electrostatic chuck 100 of a face-down type. Of course, the organic material 190 deposited on the glass 180 is positioned at the bottom and vaporized, so that the organic material 190 is deposited on the glass 180 looking downward.

As described above, in the present invention, the electrostatic chuck 100 additionally includes the slack prevention structure 140, so that the deflection amount due to the self weight of the electrostatic chuck 100 is approximately 3 mm, preferably 2 mm, more preferably 1 mm. < / RTI >

Accordingly, in one embodiment of the present invention, when chucking the eighth-generation glass 180, the deflection phenomenon due to its own weight is controlled to be within 3 mm, 2 mm, or 1 mm, so that an electrostatic chuck 100 ).

4A to 4E are views simulating the amount of deflection by the self weight of the large area electrostatic chuck according to the embodiment of the present invention.

4A is a simulation result of a deflection amount of an electrostatic chuck made of a base substrate made of a titanium material having no sag prevention structure and an insulating layer made of a ceramic material. In the drawing, it means that a large amount of deflection occurred in the order of blue <sky blue <green <yellow <red. In the case of an electrostatic chuck without such an anti-sagging structure, the deflection was measured to be approximately 3.0 mm.

Next, FIG. 4B is a simulation result of the deflection amount of the electrostatic chuck including the base substrate of titanium material and the insulating layer of the ceramic material and including the anti-sag structure having a rectangular cross section as shown in FIG. 4A. In the case of an electrostatic chuck with a sagging-type anti-sagging structure, the deflection was measured to be approximately 1.6 mm.

4c is a simulation result of the deflection amount of the electrostatic chuck including the base substrate made of titanium, the insulating layer made of the ceramic material, and the anti-sagging structure having the rectangular cross section as shown in FIG. 4b. Here, the difference from FIG. 4B is that the pitch of the anti-sag structure is relatively smaller. In this electrostatic chuck, deflection was measured to be approximately 1.4 mm.

Next, FIG. 4D is a simulation result of the deflection amount of the electrostatic chuck including a base substrate made of a titanium material, an insulating layer made of a ceramic material, and a sag preventing structure having a T-shaped cross section, as shown in FIG. The deflection of the electrostatic chuck with the anti-sagging structure with a T-shaped cross section was measured to be approximately 1.2 mm. Here, the electrostatic chuck of FIG. 4D has a T shape in which the cross-sectional shape of the anti-seizure structure is not rectangular as shown in FIGS. 4B to 4C, and the total weight of the electrostatic chuck is reduced by about 10 kg or more. In addition, it is noted that the structure formed in the form of a ring in the figure is a hook for fixing the electrostatic chuck to another member, and does not greatly affect the deflection amount.

4E is a simulation result of the deflection amount of the electrostatic chuck including a base substrate made of a titanium material, an insulating layer made of a ceramic material, and a sag preventing structure having a T-shaped cross section as shown in FIG. 4D. Here, the difference from FIG. 4D is that the pitch of the anti-sag structure is relatively smaller. In this electrostatic chuck, deflection was measured to be approximately 1.0 mm.

Here, the electrostatic chuck shown in Fig. 4A has a circular shape at a substantially central portion, and the electrostatic chuck shown in Figs. 4B to 4E extends in a substantially horizontal direction to cause deflection. Since the amount of deflection formed at the center portion is measured to be approximately 3.0 mm, the risk of falling of the glass substrate from such an electrostatic chuck is large, but since the amount of deflection formed in the horizontal direction is approximately 1.0 mm to 1.6 mm, The risk of falling is reduced.

As described above, in the present invention, a lightweight large-area electrostatic chuck having a weight of about 400 kg (preferably 320 kg) or less despite chucking an eighth-generation glass which is about four times larger in size or area than the fifth generation Lt; / RTI &gt;

Also, in the present invention, when chucking an eighth-generation glass, it is possible to provide a large-area electrostatic chuck having a deflection phenomenon due to its own weight of about 3 mm or less.

In addition, the present invention provides a large-area electrostatic chuck capable of preventing warpage and peeling between components due to a small difference in thermal expansion coefficient even at a high temperature process of about 50 to 120 캜.

As described above, the present invention is not limited to the above-described embodiments, but may be applied to a large area electrostatic chuck according to the present invention, It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

100; The electrostatic chuck
110; A base substrate 111; The first side
112; Second surface 120; Insulating layer
121; A first insulating layer 122; The second insulating layer
130; Electrode 140; Anti-sagging structure
141; A square frame 142; Transverse structure
143; A longitudinal structure 144; volt

Claims (12)

A base substrate made of a titanium material having a first surface and a second surface opposite to the first surface;
An insulating layer of a ceramic material coated on a first surface of the base substrate; And
And an anti-sag structure of aluminum attached to the second surface of the base substrate. The method according to claim 1,
Wherein the sag preventing structure has a planar shape in the form of a lattice pattern. The method according to claim 1,
Wherein the deflection preventing structure includes a plurality of transverse structures arranged in a horizontal direction and a plurality of longitudinal structures arranged in a longitudinal direction and intersecting the transverse direction structures. The method according to claim 1,
Wherein the sag preventing structure has a shape of a cross section of a square, a rectangle, a T shape, an I shape, or a ellipse shape. The method according to claim 1,
Wherein the anti-sag structure is fixed to the base substrate by bolts. The method according to claim 1,
Wherein the sag preventing structure has a thickness of 30 mm to 45 mm. The method according to claim 1,
Wherein the base substrate has a thickness of 5 mm to 7 mm. The method according to claim 1,
Wherein the insulating layer has a thickness of 0.6 mm to 1.2 mm. The method according to claim 1,
Wherein the insulating layer comprises Al ₂ O ₃ . The method according to claim 1,
Wherein the base substrate has a width equal to the width of the glass for 8th generation having a width of 2200 mm x 2500 mm. The method according to claim 1,
Wherein the electrostatic chuck is disposed such that the insulating layer faces downward, wherein an amount of deflection by the self weight of the electrostatic chuck is less than 3 mm. The method according to claim 1,
Wherein the electrostatic chuck is less than 400 kg in weight.

Images