JP3921746B2 - Electrostatic chuck - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bipolar electrostatic chuck, and more particularly, to an electrostatic chuck that can be provided with a plurality of concentric electrode patterns of positive and negative alternately, thereby facilitating pattern formation and obtaining a uniform attracting force on a wafer. Is.
[0002]
[Prior art]
For example, in a semiconductor manufacturing process such as an etching process or a CVD / PVD process, the wafer is subjected to various processes while being attracted and fixed to an electrostatic chuck.
[0003]
As such an electrostatic chuck, both positive and negative electrodes are installed in an insulator in the upper part of a jacket having a cooling water pipe or the like, and a wafer placed on the insulator is attracted and held by an electrostatic force generated between both electrodes. Bipolar electrostatic chucks are used. As electrodes of such a bipolar electrostatic chuck, those having a mosquito-repellent incense type consisting of one continuous electrode in a spiral shape and a radial type electrode pattern consisting of a plurality of electrodes arranged in the radial direction are known. .
[0004]
In the case of the electrostatic chuck having the conventional electrode pattern, it is difficult to produce the electrode pattern and it is difficult to obtain a uniform attracting force on the wafer. For example, if a uniform adsorption force to the wafer is not obtained in the etching process, the temperature distribution is non-uniform for each adsorbed wafer, and uniform processing dimensions and various treatments cannot be performed on each wafer. On the other hand, since the pattern size of the wafer will be further reduced in the future, a more uniform attracting force to the wafer is required in the bipolar electrostatic chuck.
[0005]
On the other hand, it is conceivable that the electrode pattern is formed concentrically, which is easy to manufacture and is expected to obtain a uniform adsorption force on the wafer. The following are known.
[0006]
That is, (1) an electrostatic adsorption device having a flat plate electrode provided inside a dielectric layer and a plurality of concentric conductor layers provided on the surface of the dielectric layer and conducted by a radial bridge. And a reactive ion etching apparatus using the same (see Japanese Patent Application Laid-Open No. 2-234426), (2) applying a low frequency voltage using, for example, a portion of a plurality of distributed electrodes embedded in a concentric pattern as a chuck electrode, On-site real-time area resistance measurement sensor system and measurement method (see Japanese Patent Laid-Open No. 6-177217) having an electrostatic chuck to which a high-frequency excitation signal is applied using the remaining electrodes as sensor electrodes, and (3) an electrostatic chuck In an electrostatic fixing method (see Japanese Patent Laid-Open No. 5-190654), (4), in which at least one electrode of the electrostatic chuck electrode is disposed on the outer periphery of the wafer. There is a plasma processing apparatus (refer to Japanese Patent Laid-Open No. 6-177081) etc. that constitutes an electrostatic chuck sheet by sandwiching a first electrode and a second electrode arranged concentrically between two polymer films. Proposed.
[0007]
[Problems to be solved by the invention]
However, in the electrode pattern in the electrostatic adsorption apparatus (1) and the reactive ion etching apparatus using the same, one electrode is formed concentrically, but the corresponding electrode is shifted downward and planar. As a result, the entire electrode becomes thick, making it difficult to manufacture, and sufficient electromagnetic holding power cannot be obtained. In addition, in the electrode pattern in the field real-time area resistance measurement sensor system and measurement method of (2) above, the structure is complicated because a part of the concentric circle is used as the chuck electrode and the remaining electrode is used as the sensor electrode. Inevitable. The electrode pattern in the electrostatic adsorption method of (3) and the plasma processing apparatus of (4) is concentric, but forms one positive and one negative electrode on the outer periphery and inner periphery. It is difficult to obtain a uniform adsorption force over the entire area.
[0008]
The present invention has been made in consideration of the above prior art, and has an electrode that has a simple structure and can be easily manufactured, and provides an electrostatic chuck capable of obtaining a uniform attracting force on a wafer. With the goal.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, in a bipolar electrostatic chuck having both positive and negative electrodes in an insulator, one of the positive and negative electrodes has a semicircular shape as a whole. A plurality of semicircular arc-shaped electrode patterns arranged concentrically and spaced apart from each other, and a radial linear connection pattern that connects the plurality of concentric electrode patterns through the center of each concentric electrode pattern Two concentric electrode patterns spaced apart and facing each other so as to form a circular shape as a whole, the concentric electrode patterns on the outermost periphery of the two semicircular patterns are connected to each other, and the positive and negative The other electrode of the electrodes is disposed between the concentric electrode patterns of the one electrode, and is arranged in a semicircular shape different from the semicircular pattern of the one electrode by 90 ° as a whole. A semicircular pattern having a plurality of arc-shaped concentric electrode patterns and a radial linear connection pattern connecting the plurality of concentric electrode patterns through the center of each concentric electrode pattern so as to be circular as a whole The two connection patterns of the two semicircular patterns are connected to each other at the center of a circle.
.
[0010]
According to the above configuration, both positive and negative concentric electrode patterns in which a plurality of concentric electrode patterns of positive and negative are alternately provided and connected to each other are provided in the insulator, and a voltage is applied to both electrodes. Then, since a plurality of concentric electrode patterns are provided alternately in positive and negative directions, a stable and uniform wafer attracting force is generated almost all over the wafer attracting area. As a result, the electrostatic chuck can be easily manufactured with a simple electrode structure, can obtain a uniform attracting force to the wafer, and can reliably attract the wafer.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
In a preferred embodiment, concentric electrodes that enter a comb-like shape are formed by connecting the concentric electrode patterns of the two electrodes with a linear linear connection pattern without intersecting each other on the same plane. It is characterized by that. With this configuration, concentric electrode patterns of both electrodes are connected to each other in the insulator by a linear linear connection pattern without crossing each other on the same plane simultaneously, for example, by the same photolithography process or printing, and combed together. A pair of concentric electrodes entering the tooth shape is formed. When a voltage is applied to both concentric electrodes, a stable and uniform wafer attracting force is generated in almost the entire wafer attracting region. Thereby, a pair of positive and negative electrodes of the electrostatic chuck can be easily manufactured, and the wafer can be reliably attracted by applying a uniform attracting force to the wafer.
[0012]
In a further preferred embodiment, the widths of the concentric electrode patterns of the two electrodes are equal to each other or formed at a constant ratio.
[0013]
With this configuration, the widths of the concentric electrode patterns of both electrodes are equal to each other or formed at an arbitrary constant ratio, so that the concentric electrode patterns can be easily formed according to the required adsorption force, wafer dimensions, etc. Can do.
[0014]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an electrostatic chuck according to an embodiment of the present invention. FIG. 2 is a plan view of an electrode pattern provided on the electrostatic chuck of FIG.
As shown in FIG. 1, a bipolar electrostatic chuck 10 includes a jacket 11 having a cooling water pipe (not shown) and the like inside and an insulator 12 on the jacket 11. A pair of positive and negative concentric electrodes 13 and 14 are embedded in. For example, the positive electrode (+) of the power source 15 is connected to one concentric electrode 13, and the negative electrode (−) of the power source 16 is connected to the other concentric electrode 14.
[0015]
As shown in FIG. 2, the pair of concentric electrodes 13, 14 are disposed almost all over the surface side of the insulator 12 that becomes the wafer attracting region of the electrostatic chuck 10. The concentric electrode 13 on the positive side has a semicircular portion in which a semicircular arc-shaped concentric electrode pattern 17 is connected by a radial linear connection pattern 18 so as to be opposed to each other in a circular shape, and is arranged at the outermost periphery. Concentric electrode patterns 17 are connected and integrated. A plurality of these concentric electrode patterns 17 on the positive side are arranged concentrically so as to be semicircular as a whole without crossing each other on the same plane and being separated from each other. The concentric electrode patterns 17 are connected through substantially the center of each.
[0016]
The concentric electrodes 14 on the negative side are arranged in a comb-like shape by alternately arranging the concentric electrode patterns 19 of the concentric electrodes 14 on the negative side between the concentric electrode patterns 17 of the concentric electrodes 13 on the positive side. The semicircular portions are formed in the same manner as the concentric electrodes 13 on the positive side so that the semicircular portions are integrated by extending the connection pattern 20 to form a circular shape.
[0017]
That is, in the insulator 12, a plurality of concentric electrode patterns 17 and 19 that are positive and negative are alternately arranged positively and negatively with a predetermined interval at which a stable and uniform wafer attracting force can be obtained throughout the wafer attracting region. The pair of concentric electrodes 13 and 14 are provided with both positive and negative electrodes.
[0018]
Since the concentric electrode patterns 17 and 19 of these electrodes are continuous and integrated with each other, any one of the concentric electrodes 13 and 14 is connected to the power sources 15 and 16, respectively. A voltage can be applied to all the concentric electrode patterns 17 and 19.
[0019]
In addition, the widths of the concentric electrode patterns 17 and 19 of both electrodes can be formed to be equal to each other or at an arbitrary constant ratio by a photolithography process or printing. Therefore, the optimal concentric electrode patterns 17 and 19 can be easily formed according to the wafer size, the shape of the insulator on which the wafer is mounted, the required electrostatic attraction force, and the like. The concentric electrodes 13 and 14 using the concentric electrode patterns 17 and 19 can be easily formed by patterning at the same time.
[0020]
In the bipolar electrostatic chuck 10 having the above configuration, when a voltage is applied to both the positive and negative electrodes formed by the concentric electrode patterns 17 and 19 forming the concentric electrodes 13 and 14, the electrostatic chuck A stable and uniform wafer suction force is generated in almost all of the ten wafer suction areas.
[0021]
For this reason, the temperature distribution does not become uneven for each wafer (not shown) adsorbed to the electrostatic chuck 10, and for example, in the etching process, the CVD / PVD process, etc., each wafer is uniform according to a desired processing dimension. This makes it possible to process fine wafer patterns. In addition, it is possible to sufficiently secure a more uniform adsorption force with respect to the wafer, which is required as the pattern size of the wafer is further refined in the future.
[0022]
That is, a plurality of concentric electrode patterns 17 and 19 are alternately arranged positive and negative by the semicircular arc concentric electrode patterns 17 and 19 and the radial linear connection patterns 18 and 20, respectively. Since the concentric electrode patterns 17 and 19 are arranged over almost the entire surface side of the insulator 12, the pattern formation is facilitated and sufficient electromagnetic holding force is obtained, and the structure is not complicated. A stable and uniform adsorption force can be obtained over the entire region. Therefore, the bipolar electrostatic chuck 10 can be easily manufactured with a simple electrode structure, and can obtain a uniform and sufficient attracting force on the wafer.
[0023]
In the above embodiment, the concentric electrode patterns 17 and 19 are connected and integrated by the connection patterns 18 and 20 to form both the concentric electrodes 13 and 14. For example, the concentric electrode patterns 17 and 19 may be connected to each other, or the concentric electrode patterns 17 and 19 may be independent from each other. When the concentric electrode patterns 17 and 19 are made independent, each concentric electrode pattern 17 and 19 is connected to a power source.
[0024]
Further, circular concentric patterns that are completely continuous with each other positive and negative may be alternately arranged, and the positive and negative patterns may be connected to each other with a wire, or the above-described connection pattern 18, 20 may be formed.
[0025]
【The invention's effect】
As described above, according to the electrostatic chuck of the present invention, both positive and negative concentric electrode patterns in which positive and negative concentric electrode patterns are alternately provided in the insulator and the positive and negative concentric electrode patterns are connected to each other are provided. When a voltage is applied to both electrodes, a stable and uniform wafer attracting force is generated over almost the entire wafer attracting area. Therefore, the electrostatic chuck has an electrode that is simple in structure and can be easily manufactured. In addition, a uniform suction force to the wafer can be obtained, and the wafer can be reliably suctioned to perform uniform processing dimensions and various processes on each wafer.
[0026]
Further, by connecting the concentric electrode patterns of both electrodes on the same plane without crossing each other in a radial linear connection pattern, a concentric electrode entering a comb-tooth shape is formed. A pair of concentric electrodes that are interdigitated into a comb shape are formed in the insulator, and when a voltage is applied to both the concentric electrodes, a stable and uniform wafer attracting force is generated almost over the entire wafer attracting area. The pair of positive and negative electrodes of the electrostatic chuck can be easily manufactured in the same patterning process.
[0027]
Furthermore, if the widths of the concentric electrode patterns of the two electrodes are equal to each other or formed at a constant ratio, the concentric electrode patterns can be easily formed according to electrostatic force or the like that requires wafer dimensions. In addition, both concentric electrodes using this concentric electrode pattern can be easily formed.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an electrostatic chuck according to an embodiment of the present invention.
2 is a plan view of an electrode pattern provided on the electrostatic chuck of FIG. 1. FIG.
[Explanation of symbols]
10: electrostatic chuck, 11: jacket, 12: insulator,
13: Positive concentric electrode, 14: Negative concentric electrode, 15: Power supply, 16: Power supply,
17: Positive concentric electrode pattern, 18: Positive connection pattern,
19: Negative concentric electrode pattern, 20: Negative connection pattern.

Claims (2)

In a bipolar electrostatic chuck with both positive and negative electrodes in an insulator,
One of the positive and negative electrodes has a plurality of semicircular arc electrode patterns arranged concentrically and spaced apart from each other so as to form a semicircular shape as a whole, and the plurality of concentric electrode patterns Two semicircular patterns having a linear linear connection pattern that connects through the center of each concentric electrode pattern, spaced apart from each other so as to form a circular shape as a whole, and the two semicircular shapes The concentric electrode patterns on the outermost periphery of the pattern are connected to each other,
Of the positive and negative electrodes, the other electrode is disposed between the concentric electrode patterns of the one electrode, so that the semicircular pattern different from the semicircular pattern of the one electrode by 90 ° as a whole is formed. A semicircular pattern having a plurality of concentric electrode patterns having a semicircular arc shape arranged in a radial linear connection pattern connecting the plurality of concentric electrode patterns through the center of each concentric electrode pattern, The electrostatic chuck is provided with two spaced apart and facing each other so as to form a circle, and the connection patterns of the two semicircular patterns are connected at the center of the circle . The widths of the concentric electrode patterns of the electrodes are equal to each other or formed at a constant ratio.
The electrostatic chuck according to claim 1 .

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