JPS6089922A - Electron beam radiating device - Google Patents

Abstract

PURPOSE:To effect easy and simple patterning by providing an electron beam generating means in one of a plurality of vacuum chambers opened toward a table for receiving an article to be radiated and by enabling the opening to come close to the article to be radiated. CONSTITUTION:A semiconductor substrate 37 is vacuum adsorbed to a notch 36 on a Z table 34 which is a tri-directional table. Each of chambers 38-40 arranged to form concentric circles is evacuated of air with respective pumps while intaking air through an opening facing to the substrate 37. When the distance between the opening and the substrate is about 2mum, less air is intaken than the discharged air, whereby a desired degree of vacuum can be maintained. The chamber 38 is connected to a booster-provided rotary pump and the cham-bers 39 and 40 are connected respectively to molecular flow pumps so as to realize a higher degree of vacuum as it goes to the central portion. Thus, the degree of vacuum in the chamber 40 can be about 10-6Torr and electron beams are emitted from the chamber 40 to the opening. The gap between the opening and the substrate is detected by 41 with piezoelectric elements 35 so as to keep it constant. The gap is made about 20mum in order to prevent the effect of the electric charge stored on the surface of the substrate. According to such a constitution, the precision of radiating position and the treating speed can be improved.

Description

Detailed Description of the Invention (1) Technical field to which the invention pertains The present invention relates to a single beam irradiation device, and in particular to an electron beam irradiation device that can perform drawing without inserting an object to be irradiated, such as a semiconductor wafer, into a vacuum chamber. Regarding equipment.

(2) Description of the prior art Drawing of a pattern of a semiconductor integrated circuit device fIt, (IC) (
1) The original side light is widely used. However, it is difficult to draw fine patterns using light, so in recent years exposure using electron beam irradiation has come to be used. Exposure equipment that uses electron beam irradiation is suitable for VLSI because it can easily perform extremely fine patterning, for example, 1μ771 or less, but it is suitable for VLSI, but it is not suitable for semiconductor wafers coated with photoresist, which must be placed in an empty chamber. There are drawbacks such as the fact that it takes time to put in and take out the wafer, which does not improve the processing speed, and the stage on which the wafer is placed is installed in a vacuum, making it difficult to move.

FIG. 1 is a block diagram of a conventional electron beam exposure apparatus. A filament 2 is provided in a vacuum chamber 1, and an electron beam 3 is irradiated toward a wafer 4 by a high voltage source of, for example, about 50 KV. The electron beam 3 passes through an electromagnetic lens 5. Its focus is adjusted by fl, 7, and the deflection electrode 9
The wafer 4 is scanned by. 8 is a blanking electrode. Note that voltages to the high-voltage power supply and each electromagnetic lens are supplied by (2) the power supply circuit 10. The wafer 4 is placed on an XY stage 11, and the XY stage 11 is controlled by a controller 12 together with a blanking electrode 8 and a deflection electrode 9. Further, the beam irradiation system is placed on a seismic stand 13 to eliminate the influence of vibrations.

In such a conventional electron beam processing device, it is extremely difficult to accurately drive the XY stage 11. In other words, if the drive system of the XY stage is enclosed in a vacuum, the friction of the bearings becomes extremely large in the vacuum, resulting in a large backlash, making it difficult to move the stage to an accurate position. Become.

Therefore, it was considered to install the drive system outside the vacuum as shown in FIG. That is, a stage 21 connected to an external box 23 by an arm 22 is provided in the vacuum chamber 1, and this external box 23fX)
4. The XY stage 21 is being moved by being driven by the Y torque motor 25. The external case 23 is held by an X air bearing (3) 26, 27 and a Y air bearing 28, 29, and is separated from the X empty chamber 1 by a bellows 30 as the atmosphere. Although such a configuration solves the problem of stage movement in vacuum, it complicates the drive system and ultimately does not improve accuracy.

(3) Purpose of the Invention The purpose of the present invention is to provide an electron beam irradiation device R1- which solves the above-mentioned conventional drawbacks.

(4) Features of the Invention A feature of the present invention is that in an electron beam irradiation device that irradiates a substrate with an electron beam, a stage is provided with a placement part for an irradiated object to be irradiated with the electron beam, and a stage is provided opposite to this placement part. a plurality of vacuum chambers having apertures are provided;
At least one of the plurality of vacuum chambers is provided with an electron beam generating means, and the electron beam irradiation apparatus is such that the irradiated surface of the irradiated object and the opening of the vacuum chamber can be very close to each other.

Preferably, the plurality of vacuum chambers are arranged concentrically (4), and the electron beam is irradiated from inside the vacuum chamber provided in the center toward the open end. Furthermore, it is preferable that the degree of vacuum of the plurality of concentric X nitrogen chambers is higher in the vacuum chambers Pi closer to the center.

In addition, a concentric gas outlet is provided on the outermost side of the concentric chamber, and the shape of the outlet is modified to blow the gas outward to generate negative pressure in the center using Bernoulli's theorem. You can also take revenge.

(5) Effects of the Invention According to the present invention, it is possible to perform electron beam irradiation without placing the irradiated object in a vacuum chamber, and the accuracy of the electron beam irradiation position and processing speed have been greatly improved. Being done □.

(6) Embodiment FIG. 3 is a partial sectional view of an electron beam irradiation apparatus according to a first embodiment of the present invention. Stage 31 is X stage 32, Y
It is constructed by combining a stage 33 and a Z-Kf-ji 34, and the Y stage 33 and the second stage 34 are composed of a piezoelectric element 31.
Combined by 5.

A notch 36 is provided on the main surface of the second stage 34, and a semiconductor wafer 37 is fitted into this notch 36. In this example, the semiconductor wafer 37V14.00 μm
The depth of the notch 36 is also set to 400 μm. The semiconductor wafer 37 is vacuum-adsorbed (
(not shown), and its lifting is completely prevented. The semiconductor wafer 87 is covered with photoresist and is irradiated with an electron beam from an opposing vacuum chamber.The vacuum chamber consists of a first chamber 38, a second chamber 39, and a third chamber 40 stacked concentrically. They are each sucked by a vacuum pump (not shown) K. Each chamber holds a semiconductor wafer 37
An opening is provided in a portion facing the wafer, and air molecules are sucked from this portion by vacuum suction. In this embodiment, the distance between the semiconductor wafer 37 and the opening is 2 μm.
Since the amount of air entering through the gap is small compared to the capacity of the vacuum pump, the % vacuum degree is maintained.

(6) In this embodiment, each of the first chambers 38 is
rr, second chamber 39 k 10-' Torrs
The third chamber 40 is brought to a vacuum level of about 10-' Torr.

In this way, by configuring the vacuum degree to be different for each chamber and gradually change, the load on each vacuum pump is greatly reduced, and the third chamber can easily
A high vacuum of about 6 Torr can be achieved.

In this embodiment, the first chamber 38 is connected to a rotary pump with a booster, and the second and third chambers are each connected to a molecular flow pump, but since these pumps are all well-known, we will not explain them here. It probably won't be necessary.

It should be noted that the gap between the irradiated object and the chamber closing part can be widened depending on the capacity of the pump.
If there is a possibility of contact, the width can be increased to about 20 μm. Note that the gap is determined by measuring the distance between the semiconductor wafer 37 and the semiconductor wafer 37 using the gap sensor 41. The gap sensor 41 is a general type that measures the capacitance between the conductor wafer 37 and the conductor wafer 37, so that the influence of the electric charge accumulated on the surface of the conductor wafer 37 can be ignored. Therefore, it is desirable to have a gap of about 20 μm and as large an area as possible. Gear knob sensor 4
A control circuit (not shown) for the pressure Vit element 35 operates according to the detected value of 1, and as a result, the gap is always kept constant.

When the deuteron beam ejection is completed, the stage moves to a position where the semiconductor wafer 37 is removed from the vacuum chamber, but at this time, the surface below the vacuum chamber is at the same level as the main surface of the semiconductor wafer 37 on the stage. , the degree of vacuum inside the vacuum chamber does not decrease. Note that when replacing the semiconductor wafer, it is also possible to raise the two stages and completely close the opening of the vacuum chamber.

FIG. 4 is a partial cross-sectional view of a second embodiment of the invention. In this embodiment, instead of the first vacuum chamber 38 of the first embodiment, pressurized air is sent into this part and is blown out from the tip in the outward direction K of the chamber.

This generates a Bernoulli negative pressure (8) between the chamber and the semiconductor wafer. With such a configuration, a maximum of 10-2 Tor
Achieves a degree of vacuum of approximately r. The other configurations are the same as in the embodiment of Tate 1.

In addition, although these examples show examples of devices in which a plurality of vacuum chambers are arranged concentrically, an electron beam is A structure in which .

In addition, in this example, the outer diameter of the chamber on both sides is 15su+
(diameter), the aperture diameter of the part where the electron beam exits is 3mm, but by making the outer diameter larger, the burden on the pump is reduced, and by reducing the central aperture diameter to about 1.7 ga A stable electron beam can be obtained. On the other hand, if the aperture diameter is increased, the degree of vacuum in the vacuum chamber from which the electron beam is emitted will decrease, and the arc discharge voltage will eventually be reached, so care must be taken.

[Brief explanation of drawings]

Fig. 1 is a block diagram of a conventional electron beam exposure apparatus, Fig. 2 is an example of a conventional stage drive system, Fig. 3 is a partial sectional view of the first embodiment of the present invention, and Fig. 4 is a book (9 ) is a partial cross-sectional view of a second embodiment of the invention; In the figure, 1...vacuum chamber, 2...
...Filament, 3...Electron beam, 4...
・Unino-15, 6, 7... Electromagnetic lens, 8
...Blanking electrode, 9 ... Deflection electrode, lO ... Power supply circuit, 11 ... XX stage, 12 ... Controller L-o-ra , 13... Earthquake prevention table, 21... Stage, 22... Arm, 23... External box, 24... X torque motor, 25... ...X torque motor, 26.
27...X air bearing, 28, 29...
... Y air bearing, 30... bellows, 31.
...Stage, 32 ...X stage, 33
...X stage, 34...2 stage, 35
...Piezoelectric element, 36...Notch, 37
......Semiconductor sea urchin'・-138...1st
vacuum chamber, 39... second vacuum chamber, 40... third vacuum chamber, 41...
... Gap sensor, 42 ... Pressurized air chamber. Tokken Applicant Chill Parian Co., Ltd. 101 Figure 1 Figure 25! I

Claims (1)

[Claims] In an electron beam irradiation device that irradiates a substrate with an electron beam, a mounting part for an irradiated object to be irradiated with the electron beam is provided on a stage, and a plurality of vacuum chambers each having an opening facing the mounting part are provided. An electron beam irradiation apparatus characterized in that at least one of the plurality of vacuum chambers is provided with an electron beam generating means, and the irradiation surface of the irradiation object and the opening are extremely close to each other.