JPS6133640Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam exposure apparatus, and more particularly to a structure of an electron beam exposure apparatus that can prevent heat generated in an electron beam control system from being transmitted to an object to be processed.

As the level of integrated circuits changes from LSI to VLSI, highly accurate patterns are required, and electron beam exposure methods have become widely used.

As the accuracy of the electron beam exposure apparatus improves, it has become important to eliminate the influence of temperature errors on objects to be processed, such as mask substrates and semiconductor substrates.

In order to eliminate the above-mentioned temperature error, a method is generally used in the mask manufacturing process to precisely control the indoor temperature by setting the mask use process and the indoor temperature to the same temperature (reference temperature).

That is, the electron beam exposure apparatus is installed in a room whose temperature is precisely controlled to a reference temperature, and the object to be processed is also kept in the same room for a long period of time, so that electron beam exposure is performed with both the apparatus and the material kept at the reference temperature.

However, the temperature inside the electron beam exposure device is slightly higher than the room temperature due to the heat generated by the device, so after placing the object to be processed on the stage inside the electron beam exposure device, the temperature of the object to be processed becomes stable. After leaving it for a while, it is then exposed to light.

In the above-described method, it takes several tens of minutes to several hours for the temperature of the object to be processed to stabilize, resulting in a lot of wasted time, resulting in poor work efficiency and low utilization rate of the apparatus.

An object of the present invention is to provide a structure of an electron beam exposure apparatus that does not require standing time for stabilizing the temperature of the object to be processed during the electron beam exposure.

A feature of the electron beam exposure apparatus of the present invention is that a heat shield having an electron beam passage window and a water cooling mechanism is provided in the middle of the electron beam path toward the stage on which the object to be processed is placed. There is a particular thing.

An embodiment of the electron beam exposure apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic structure of an electron beam exposure apparatus of the present invention in which a heat shield is provided between an electron beam control system and a stage.

In the figure, 1 is an electron gun consisting of a cathode, grid, and anode, 2 is a blanking deflector for blanking the electron beam during unnecessary times, 3 is a converging lens, and 4 is a first aperture. , 5 is a rotation control lens for controlling the rotation of the electron beam around the axis, 6 is an electron lens, 7
is a deflector for controlling the imaging position of the image of the first aperture 4 formed on the second aperture 8 by the electronic lens 6, 9 is a rotation control lens, 10 is a converging lens, and 11 is a position control device. The deflector 12 is used for processing an object such as a glass substrate or a semiconductor substrate coated with a resist, and 13 is a stage on which the processing object 12 is placed.

In the electron beam control system consisting of the above-mentioned lens system and deflection system, many coils are used for electromagnetic lenses, electromagnetic deflectors, and the like.

Therefore, during operation of the electron beam exposure apparatus, a large amount of heat is generated by the many coils that constitute the control system, and this heat is transmitted to the object to be processed and the stage by radiation or the like, raising the temperature thereof.

This temperature rise reaches 2 to 3 [°C], so if the object to be processed is a mask substrate made of glass, for example, the linear expansion coefficient is 0.9×10 ^-5 [°C ^-1 ], so the drawing range is 80 [mm]. This results in an error of 1.44 to 2.16 [μm].

Therefore, in this embodiment, a heat shield equipped with a water cooling mechanism is provided between the electron beam control system and the stage 13, that is, on the path of the electron beam heading toward the stage 13, so that radiation from the coil of the electron beam control system is provided. The object to be processed 12 and the stage 13 are
This prevents the temperature from rising.

As shown in FIG. 2, the heat shield 21 consists of a base body 22 made of a non-magnetic material such as copper (Cu) with good thermal conductivity, and a cooling water introduction pipe 23 connected to the base body 22. Become.

The outer shape of the base body 22 may be any shape as long as it can be accommodated in a lens barrel (not shown) that accommodates an electron beam control system, and in this embodiment, it is circular. Further, an electron beam passing window 24, which is slightly larger than the deflection range of the electron beam, is provided at the center of the base body 22. Since the deflection range of the electron beam is extremely small, in this embodiment, the size of the electron beam passing window 24 is a circle with a diameter of 2 mm.

A cooling water passageway is provided inside the base body 22 and is introduced from a cooling water introduction pipe 23 connected to the side surface of the base body 22. By flowing the cooling water, the base body 2
Keep the temperature of step 2 constant. In the heat shield 21 of this embodiment, the water cooling mechanism is constituted by the water passage and the cooling water introduction pipe 23.

The above cooling water is supplied to a constant temperature water tank 25 as shown in Fig. 3.
The water is stored in the water pump 26, sent to the heat shield 21, and returned to the constant temperature water tank 25 through a water passage provided in the heat shield.

The temperature of the constant temperature water bath 25 is preferably controlled to the same temperature as the stage 13, that is, the same temperature as the room temperature.

By doing so, during electron beam exposure, the electron beam 31 reaches the object to be processed 12 through the electron beam passing window 24, but the radiant heat 32 from the coil is absorbed by the heat shield 21 and is absorbed by the cooling water. carried outside. Therefore, the heat shield 21
The temperature is always maintained at approximately the water temperature, that is, room temperature, and the radiant heat 32 does not reach the object to be processed 12 and the stage 13.

As explained above, according to the electron beam exposure apparatus of the present invention, the temperatures of the object to be processed and the stage hardly change even during electron beam exposure.
Electron beam exposure can be started immediately after placing the object to be processed on the stage. Therefore, work efficiency and usage efficiency of the electron beam exposure apparatus are greatly improved.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the electron beam exposure apparatus of the present invention, and FIGS. 2 and 3 are perspective views and side views of essential parts showing the heat shield of the present invention used in the above embodiment. It is a diagram. 12...Object to be processed, 13...Stage, 21...
... Heat shield, 22 ... Base, 23 ... Cooling water introduction pipe, 24 ... Electron beam passage window.

Claims (1)

[Scope of utility model registration request] A heat shield having an electron beam passing window for passing the electron beam and having a water cooling mechanism is provided in the middle of the path of the electron beam toward the stage on which the object to be processed is placed. Electron beam exposure equipment.