JPH0442791A - electrostatic chuck board - Google Patents

Abstract

PURPOSE:To eliminate a gap between an object and an attracting plane and have an attracting force applied to the object wastelessly and securely by a method wherein the circumferential edge parts of the attracting plane are provided closer to the base side than the attracting plane. CONSTITUTION:Tapered pats 21 are provided along the edge parts of a base 2. After electrodes 2 are formed on the flat part of base 2 by a method such as deposition, an insulating film 3 is formed by a method such as spin-coating. With this process, protrusions 31 are formed along the edge parts like with a conventional process. However, the crests of the protrusions are provided closer to the base side than an attracting plane. Therefore, an object is attracted tightly by the attracting plane without touching the protrusions 31 along the edge parts, so that a necessary attracting force can be ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrostatic chuck substrate that moves an object while holding it therein.

[Prior Art] Generally, when attaching a certain object to a target object, the target object is brought into contact with the target object and fixed by a method such as adhesion. However, when converting objects one after another, a means such as vacuum suction, which requires a short attachment and detachment time, is used. However, although this method has no problems in air, it cannot be used in a vacuum, so in this case an electrostatic chuck that utilizes the attractive force of an electric field is used.

As shown in FIG. 6, the electrostatic chuck has an electrode 1 on a base 2 covered with an insulating film 3, and this insulating film is formed by spin coating for reasons such as economic efficiency. Then, an electric field is generated by the voltage elements E and -E supplied to the electrodes, so
The electric field applies an attractive force to the object 4.

[Problem M to be solved by the invention] However, since the insulating film is made by adhering a liquid insulator to the electrode surface and then solidifying it, the actual insulator is
It cannot be formed into the ideal shape as shown in the figure, and the seventh
As shown in the figure, a bulge 31 is formed on the peripheral edge, and due to this bulge 31, when an object is attracted, a gap of distance d is created between the object and the plane of the electrostatic chuck, and therefore, the electrode is separated from the electrode. There was a problem in that the distance to the object became longer and the adsorption force decreased. For example, when making an insulating film of 20 μm using polyimide as an insulating coating agent, the protrusion at the outer edge will be about 6 μm, and only 25% of the force will be applied to the object compared to when there is no gap.

[Means for Solving the Problem] In order to solve this problem, the present invention is configured such that the peripheral edge of the suction surface is located closer to the base than the suction surface.

[Operation] There is no gap between the object and the suction surface, and the suction force is reliably applied to the object without wasting it.

[Example] FIG. 1 shows an example of the present invention, in which a base 2, an electrode 1,
It is composed of an insulating film 3 and has a hole in the center for attaching and detaching the object. To explain this structure using a cross-sectional view taken along the line A-A in FIG. 1, for example, as shown in FIG.
After forming the electrode 1 on the flat surface of the base by a method such as vapor deposition, the insulating film 3 is formed by a method such as spin coating. By doing this, a bulge will be created at the end as before, but the top of this bulge will be located closer to the base than the suction surface, so the object will not come into contact with the bulge 3□ on the peripheral edge. Since it comes into close contact with the suction surface, the necessary suction force is ensured.

FIG. 3 shows another embodiment, in which the base 2 has an insulating property and the electrode 1 is provided with a tapered portion 11. In this example, the electrodes are made of a plate-like material and can be formed by cutting the ends of the material, so it is easy to manufacture.

FIG. 3 shows another embodiment in which the end of the base 2 is formed into a tapered shape, and the electrode 1 is formed by spin coating a conductive coating agent such as silver paste on the base. An insulating film 3 is formed by spin coating an insulating coating agent. In this method, both the electrode and the insulating film are manufactured by spin coating, so that they are easy to manufacture and can easily be formed with a small thickness.

FIG. 5 is a plan view showing another embodiment, in which the hatched portion is an inclined portion.

Although the above examples use an insulating film as the outer film, an electrostatic chuck substrate utilizing the Johnson-Rahbek effect can be formed by coating a conductive or semiconductor film instead of the insulating film. Also, the shape of the taber may be a curved taber (R) instead of a simple linear taber.

[Effects of the Invention] As described above, in this invention, the peripheral edge of the suction surface is located closer to the base than the suction surface, so the adhesion between the suction surface and the object is improved, and the necessary suction force can be achieved. This has the effect that it can be ensured.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing one embodiment of the present invention, Figs. 2 to 4 show different application examples, and Fig. 5 is a sectional view taken along the line A-A in Fig. 1. A plan view showing another embodiment, and FIGS. 6 and 7 are cross-sectional views showing a conventional example. 1...-electrode, 2...-base, 3...-insulating film 4
····Object.

Claims (1)

[Claims] In an electrostatic chuck substrate in which a film serving as an attraction surface is formed on the top surface of the base using a spin coating method, at least a part of the peripheral edge of the attraction surface is formed to be located closer to the base than the attraction surface. Characteristic electrostatic chuck substrate.