JPS60202935A - X-ray exposure device - Google Patents

Abstract

PURPOSE:To unnecessitate the use of a pure water making device, to simplify even a countermeasure against insulation and to improve heat shielding efficiency by combining a deflection electrode with a heat shielding plate, bringing the deflection electrode to grounding potential and applying positive high voltage to a target. CONSTITUTION:A heat shielding plate 4' combining a Wehnelt 1 and a deflection electrode is brought to grounding potential, and positive high voltage is applied to a target 3. A filament 2 is heated by a filament power supply 6 under the state to generate electron rays 7. Electron rays 7 are accelerated toward the target 3 while being focussed by the action of the Wehnelt 1, and an orbit thereof is bent by the deflection electrode 4' and electron rays are projected to the desired position of the target 3 to generate X-rays 8. Heat generated at the same time as X-rays 8 are generated is cooled by cooling pipes 9 disposed to the heat shielding plate 4' acting as the deflection electrode in combination.

Description

[Detailed description of the invention] The present invention relates to an X-ray exposure apparatus that uses an X-ray tube with a built-in X-ray tube.

2. Description of the Related Art Conventionally, in the manufacturing process of semiconductor devices, an X-ray exposure apparatus has been developed and utilized as one of fine circuit pattern transfer techniques. The X-ray tube used in this type of device generally has a high-voltage power supply 5 connected to the Wehnelt l, filament 2, and deflection electrode 4, as shown in the electrical system diagram of the X-ray tube in Figure 1. It was configured to apply a high voltage and bring the target 3 to ground potential. In order to prevent damage to the filament 2 due to ion bombardment from the target 3, the deflection electrode 4 bends the trajectory of the electron beam 7 to irradiate a desired position on the target 8, thereby generating X-rays. X-ray exposure equipment, which belongs to the technology of transferring fine circuit patterns, is a technology aimed at submicron transfer, and is therefore extremely sensitive to thermal fluctuations. However, as mentioned above, since a negative high voltage is applied to the deflection electrode, the electrode part must be insulated using a high voltage resistant insulator, such as ceramics, and the contact part must be cooled. In this case, there are various problems as an X-ray tube for an X-ray exposure apparatus, such as being limited to the use of pure water with a high resistance value in order to prevent excessive current from flowing into the refrigerant used.

On the other hand, as an X-ray tube for industrial analysis (fluorescence analysis), an X-ray tube having the electrical circuit shown in Figure 2 has been proposed. This X
The radiation tube is configured to apply a high positive voltage to the target 3 and bring the Wehnelt 1 and deflection electrode 4 to ground potential. The X-ray generation process is the same as in Figure 1, but the generation of heat due to recoil electrons from the target 8 can be reduced, and cooling means for the deflection electrode can be implemented more easily than in the X-ray tube in Figure 1. can.

However, even in the X-ray tube shown in FIG. 2, there still remains a problem in heat shielding as an X-ray tube for an X-ray exposure apparatus.

SUMMARY OF THE INVENTION The present invention aims to eliminate the drawbacks of the above-mentioned conventional examples, and provides an X-ray tube for an X-ray exposure apparatus that has high heat shielding efficiency and a simple structure.

The present invention will be described below with reference to FIGS. 8 to 5 showing embodiments of the present invention.

In FIG. 3, Wehnelt 1. The arrangement of the filament 2, target 3, deflection electrode 4', etc. is similar to the conventional example shown in FIGS. 1 and 2, but the deflection electrode plate 4' in this embodiment is a heat shield that also serves as a deflection electrode. It is a board.

7 is an electron beam, 8 is an X-ray, 9 is a cooling pipe disposed on the heat shield plate according to the present invention, and IO is an opening for taking out the X-ray.

In the above configuration, the Wehnelt 1 and the heat shield plate 4', which also serves as a deflection electrode, are set to ground potential, and a positive high voltage is applied to the target 8. In this state, when the filament 2 is heated by the filament power source 6, an electron beam 7 is generated, which is accelerated toward the target 3 while being focused by the action of the Wehnelt 1. The trajectory of the electron beam 7 is bent by appropriately designing and arranging the geometrical shape and placement position of the deflection electrode 4', which also serves as a heat shield plate at ground potential. The position is irradiated with an electron beam 7 to generate X-rays 8. At the same time as the X-rays 8 are generated, a large amount of heat is also generated. A cooling medium is passed through one or more cooling pipes 9 disposed at appropriate positions on the heat shield plate 4' which also serves as a deflection electrode, and a cooling device (not shown) transfers the generated heat to the outside of the X-ray apparatus. is removed, cooled, and recirculated to continue the cooling action. The shape of the heat shield plate 41 is not necessarily limited to a plate shape, and any arbitrary shape can be used as long as the heat shielding effect can be obtained while ensuring its basic function of deflection. The generated X-rays pass through the opening 10 and reach the mask 11 in the exposure chamber to expose the wafer 12.

Since the heat shield plate 4', which also serves as a deflection electrode, is set to the ground potential as described above, when attaching a cooling means to it, the heat shield plate 4', which also serves as a deflection electrode, is placed at a ground potential. There is no need to limit the refrigerant used to prevent current flow; any fluid such as water, oil, or air may be used, and the material of the cooling pipe 9 may be copper, aluminum, or stainless steel. Materials such as steel are selected and used depending on the purpose, taking safety, atmosphere, cooling efficiency, etc. into consideration.

In the embodiment shown in FIG. 3, a pipe 9 is used to cool the heat shield plate 4' which also serves as a deflection electrode, but any shape and structure can be used as long as a cooling effect can be obtained. For example, As shown in FIG. 4, the cooling path 9' can be integrated with a heat shield plate 4' which also serves as a deflection electrode.

Heat shield plate 4 that also serves as a deflection electrode for extracting X-rays
As shown in FIG. 5, the openings 10 formed in ' can be provided at a plurality of locations, selecting positions suitable for the purpose as required.

As described above, the heat shield plate that also serves as a deflection electrode according to the present invention does not require insulation measures for high voltage resistance, and the cooling medium is not limited to pure water, if it is set to the ground potential. Furthermore, since the heat shield plate also serves as a deflection electrode that can freely deflect the trajectory of the emitted electron beam, the performance of X-ray exposure equipment can be improved by using a compact, highly efficient X-ray tube with a simple structure and low cost. It has a remarkable effect.

[Brief explanation of the drawing]

Fig. 1 is an electrical system diagram of a conventional X-ray tube used in an X-ray exposure device, Fig. 2 is an electrical system diagram of an X-ray tube for industrial analysis (fluorescence analysis), and Fig. 8 The figure is a principle diagram of an embodiment of a heat shield plate that also serves as a deflection electrode according to the present invention, and FIG. 4 is a sectional view of another embodiment of a cooling path of a heat shield plate that also serves as a deflection electrode.
FIG. 5 is a sectional view showing an embodiment of an opening in a heat shield plate that also serves as a deflection electrode. 1... Wehnelt 2... Filament 8... Target 4... Deflection electrode 4'... Heat shield plate that also serves as a deflection electrode 5... High voltage power source 6... Filament power source 7... Electron beam 8...X-ray 9...Cooling pipe 9'...Cooling path 10...X-ray extraction opening 11...Mask 12...Ueno 1 patent applicant Canon Corporation Figure 1 Figure 2

Claims (2)

[Claims] (1) An X-ray exposure apparatus characterized by comprising an X-ray tube having a heat shield means. (2) The X-ray exposure apparatus according to claim 1, wherein the heat shield means of the X-ray tube has a function of controlling the trajectory of thermoelectrons emitted from the filament.