JPH06104164A - Electron beam writer - Google Patents

Abstract

(57) [Abstract] [Purpose] An electron beam lithography system equipped with an adsorption device that was developed in consideration of the unified use of wafers of different sizes, as a sample adsorption in a vacuum sample chamber. To provide. [Structure] An electrostatic adsorption device 30 that is fixed on a stage 25 in a vacuum sample chamber 15 and adsorbs a sample has an electrode layer buried in it, and can be applied to any electrode. An electron beam drawing apparatus that avoids charge-up by a cylinder 40 that wraps the electron beam 1 near the surface. [Effect] With the same sample adsorption device, an electron beam drawing device capable of adsorbing samples of various sizes can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus and, more particularly, to a semiconductor manufacturing apparatus provided with a mechanism suitable for fixing wafers of various sizes to a flat suction surface of the same holding device.

[0002]

2. Description of the Related Art In the field of manufacturing semiconductor devices, the number of processes using electron beams has increased, and the number of methods for holding and fixing a sample in a vacuum has increased. For example, when irradiating a sample such as a wafer with an electron beam, an electrostatic chuck using electrostatic attraction is known as a method of fixing the sample. Generally, an electrostatic chuck is one in which an electrode is embedded in a dielectric material having a flat sample adsorption surface, and charges are applied to the electrode and the sample. In addition, JP-A-60-95
There is also a method to divide the voltage application electrode into multiple parts, such as No. 932, but these are inventions for a sample of a certain size. I had to change the electrostatic chuck to suit. Therefore, it is necessary to prepare a plurality of types of electrostatic chucks.

[0003]

In the above-mentioned prior art, it was necessary to prepare each electrostatic adsorption device according to the size of the sample.

An object of the present invention is to provide an electrostatic adsorption device that can be used without any change even when the size of the sample is changed.

[0005]

A semi-insulating electrostatic adsorption device having a plurality of electrodes and independent voltage application to each electrode is used regardless of the size of the sample. Is made possible.

Further, the electron beam is attached to the inside of the vacuum sample chamber of a cylindrical lens barrel that wraps the sample surface up to the vicinity of the sample surface so as to avoid charge-up of the beam.

[0007]

According to the present invention, even when the size of the sample is different, it is possible to use the sample corresponding to various sizes by applying up to the electrode layer according to an arbitrary size in an independent application system. is there. Here, when a sample of a certain size is adsorbed, when a sample of a size smaller than that is tried to be adsorbed to the adsorption surface of the same electrostatic chuck, the outer peripheral portion of the adsorption surface is exposed more than before. . The exposed portion is an insulator, and if the insulator is located at a position where the electron beam directly hits, charge-up may occur in the insulated portion. Therefore, in the present invention,
A cylinder that wraps the beam sufficiently so that charge-up does not occur up to just before the irradiation surface of the sample is mounted inside the vacuum sample chamber of the lens barrel.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. The embodiment is an electrostatic chucking device for holding a sample such as a wafer (hereinafter referred to as a wafer) used in an electron beam drawing device that performs beam irradiation while continuously moving a stage,
A schematic configuration is shown in FIG. Details of the electrostatic adsorption device are shown in FIGS. 2 and 3.

In FIG. 1, an electron beam 1 generated from an electron gun 10 is converged and deflected by an electromagnetic lens 12 while passing through a lens barrel 11, passes through a cylinder 40, and
Irradiate the wafer 35. The transfer device 20 exchanges the wafer 35 between the vacuum sample chamber stage 25 and the external transfer system. In this embodiment, the wafer 35 transferred from the external transfer system is installed in the transfer device 20. The vacuum sample chamber 1 is placed on the electrostatic adsorption device 30 and the electrostatic adsorption device 30 and the wafer 35 are integrated and are evacuated by an exhaust system.
It is transported to the inside of the stage 5 and placed on the stage 25. The wafer 35, the electrostatic attraction device 30, and the stage 25 are integrated by the electrostatic force generated by the voltage application, and the stage 25
Moves.

Next, the electrostatic chuck will be described. Hereinafter, electrostatic attraction between the wafer and the electrostatic attraction device will be described.

FIG. 2 is a sectional view of the electrostatic chucking device. The electrode layer 3a has a disk shape, and the electrode layers 3b, 3c, 3d
Is a ring-shaped electrode layer that is concentric with the electrode layer 3a. These electrode layers are in the same plane along the adsorption surface, no electrode layers are in contact with each other, and these electrode layers are covered with the dielectric material 31 as shown in FIG. If this material is a perfect insulator, there is a great possibility that charge-up due to the electron beam will occur. Therefore, a semi-insulator is used to reduce the resistance value to avoid the charge-up. Also, 3a, 3b, 3c and 3d are terminals 6a,
6b, 6c, 6d are connected to the voltage power supply,
On and off of voltage application from the power source to each electrode layer are completely independent. Consider, for example, a case where a wafer 35 having a size of 6 inches is placed on the electrostatic attraction device. When the 6-inch size wafer 35 is placed, the electrode layer 3
It is assumed that the sizes of a, 3b and 3c are smaller than the size of the wafer 35, and only the electrode layer 3d is larger than the wafer 35. The wafer is grounded by the terminal 70. In this case, a voltage is applied to the electrode layers 3a, 3b, 3c,
3d should be cut off. By the way, although the number and size of the electrode layers are not particularly strict, the outermost electrode layer 3c to be applied in this case has a size corresponding to the size of the wafer as shown in FIG. 3, for example. Seems to be ideal. In addition, it is better not to open more than necessary because the electrode area will decrease and the suction force will decrease if the space between each electrode layer is widened. However, the number and size of the electrode layers should be the user's intention. It's up to you. The electrode layers 3a,
When applying to 3b and 3c, it may be good to do as follows. First, a voltage is applied to 3a. Cut off everything else. Next, a voltage is applied to the outermost 3b, and it is possible to apply positive charges as it is, but first, negative charges are applied. As a result, a force acts so that the wafer and the suction surface tend to separate from each other. At this time, if negative charges are applied to both 3b and 3c at the same time, the separating force is too strong and the wafer is displaced, so only 3b is applied. afterwards,
The application is stopped once and then a positive charge is given. Then, at this time point, the electrode layers 3a and 3b are positively charged, and the negative charges are similarly applied to 3c and then the positive charges are similarly applied. As described above, the order of voltage application can be arbitrarily operated, and the warp of the wafer can be eliminated.
By the way, in this case, the vicinity of the electrode layer 3d is exposed,
There is a possibility that the electron beam 1 may cause charge-up, but the cylinder 40 at the ground potential wraps the beam 1 near the upper surface of the wafer 35 to prevent it. Alternatively, it may be wrapped up close to the wafer surface so that there is no risk of charging up. From the above, the most effective use of the present invention is as follows. The size of the outer circumference of the electrode layer should match the wafer size.

2. The radial distance between the concentric electrode layers is not longer than necessary.

3. As a power supply to connect each electrode layer,
It is preferable that the positive and negative charges and the blocking can be controlled arbitrarily.

[0014]

As described above, according to the present invention, even in the case of a sample having a different size such as a semiconductor wafer,
The same electrostatic adsorption device can be used.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an electron beam drawing apparatus.

FIG. 2 is a cross-sectional view of an electrostatic attraction device.

FIG. 3 is a plan view of the electrostatic attraction device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electron beam, 10 ... Electron gun, 11 ... Lens barrel, 12 ... Electromagnetic lens, 15 ... Vacuum sample chamber, 20 ... Transfer device, 25 ...
Sample stage stage, 30 ... Electrostatic adsorption device, 31 ... Dielectric material, 35 ... Wafer, 40 ... Cylinder, 3a, 3b, 3c, 3
d ... Electrode layer.

Claims (3)

[Claims] 1. An electron gun for generating an electron beam, a lens barrel for converging and deflecting the electron beam, a vacuum sample chamber for irradiating the sample with an electron beam having a stage movable in X and Y. In an electron beam drawing apparatus including a transfer device that transfers a sample from the atmosphere to the XY stage and an exhaust system that evacuates the device, the inside of a flat adsorption surface formed of a semi-insulating material in the sample mounting portion. An electron beam drawing apparatus comprising an electrostatic attraction device having a plurality of electrodes arranged concentrically in a center, and having a mechanism capable of applying a voltage to an arbitrary electrode. 2. The resistance value of the adsorption surface according to claim 1,
An electron beam drawing apparatus having an electrostatic attraction device having a resistance of 10 ⁹ to 10 ¹⁴ Ω · cm. 3. The electron beam drawing apparatus according to claim 1, wherein the lens barrel has a structure in which the outside of the beam orbit is surrounded by a cylinder having a ground potential up to the vicinity of the sample.