JPS58154200A - X-ray exposure apparatus - Google Patents

Abstract

PURPOSE:To provide a plasma X-ray source having enhanced X-ray generating efficiency and increase X-ray exposure efficiency by providing features pinching timely high temperature plasma. CONSTITUTION:When the first switch S1 is closed, an arc discharge is conducted between a main discharge cathode 3 and an anode 2 by charges accumulated in the first charge accumulating capacitor C1. High temperature and high density plasma is formed (main discharge) in the vicinity of the anode 2 by vapor of Al of the anode material generated by the arc discharge. At this point of time, the second switch S2 connected to the second cathode 5 is closed, the second discharge is conducted between the second cathode 5 and the anode 2 by charges accumulated in the second charge accumulating capacitor C2. The high temperature and high density plasma 4 generated by main discharge is pinched in the small zone in the vicinity of the anode 2 by magnetic field formed in the circumference of the discharge area, and a large amount of characteristic X-ray of Al which is an anode material from this plasma 4 is generated.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention is directed to )! -Regarding improvements to plasma X-ray sources in exposure equipment.

(b) Background of technology As semiconductor devices become more highly integrated, 4-submicron and
It became necessary to form a pattern. For this reason, it has become necessary to further improve the pattern resolution in pattern transfer technology, and the light source for pattern transfer has been changed from conventional ultraviolet light to short, deep ultraviolet light with multiple wavelengths. Recently, as an even higher resolution transfer technology, an X-ray exposure technology having wavelengths as short as 2 to 50 (phantom) has begun to be used.

(c) Prior art and problems Initially, an electron beam impact type X-ray source was used for X-ray exposure.

However, in the electron beam bombardment method, the characteristic The level of radiation was extremely low, requiring a large amount of power to generate X-rays17, and the efficiency of the lightning was poor.

Therefore, recently, plasma X-ray sources have been provided that eliminate the above-mentioned drawbacks.

In this plasma X-ray source, for example, an anode and S
An arc discharge is caused between the electrodes, and X generated from the target material vapor plasma formed by the arc discharge.
A ray was used as the XM source, and the rice stimulator had the schematic structure of the main part as shown in FIG. In the Hjt diagram, 1 is a vacuum vessel, 2 is an anode, 3 is a single pole, an sFi switch, C is a discharge charge storage capacitor, R is a power supply retention resistor, and Hv is a voltage LI! 1IM source, G represents ground and 7.

As shown in the figure, in a plasma X-ray source with a conventional structure, only a pair of electrodes (anode 2 and one electrode 3) facing each other are arranged in a vacuum chamber L, and a condenser C for accumulating discharge charges is provided. When a predetermined charge is IMed, S is closed, and the charge of C causes an arc discharge between the electrodes, and the heat of the arc discharge forms a body plasma 4 of the evaporated anode material, and the high temperature plasma 4 is transferred to the anode. Characteristic X-rays of the material are emitted.

By pinching the high-temperature plasma using a magnetic field, a high-temperature, high-density plasma is formed.
1l! i! However, at 411 mK, the pinch of high-temperature plasma is caused by the magnetic field formed by the Zuma current itself, so the timing of the pinch cannot be controlled, and therefore There was not necessarily enough pinch.

(d) Object of the Invention In view of the above problems, the object of the present invention is to provide a plasma '/Ii
A: The purpose is to improve the efficiency of exposure.

(e) Structure of the Invention In other words, the present invention is a glass which generates X-rays by generating high-temperature plasma by discharging charges accumulated in a capacitor between an opposing cathode and an anode in an X-ray exposure apparatus. -V A plasma X-ray source connected to a second discharge circuit is used as an exposure energy source.

(f) Example of @Akira The following is an example of the present invention, and the plasma X shown in FIG.
The plasma X-ray source of the present invention will be explained in detail using a schematic cross-sectional view of the main part of one embodiment of the radiation source and a schematic cross-sectional view of the main part of another embodiment shown in Figure 3. For example, as shown in the second evil,
A desired length of Xl1tIJt (2 to 50 [λ
])) A main discharge anode 2 made of aluminum (Aj), for example, having a characteristic X@wavelength (about stA)
The anode 2 and the cathode 3 are connected at a predetermined distance (for example, about 10 [m2) &), the anode 2 is grounded G, and the cathode 3 is connected to the switch S1 and #! of the order of [MΩ]. l power supply protection resistor R.

The anode 2 and cathode 3 are connected to a high voltage DC power supply -HV of several tens of kilovolts (KV) through a first charge storage capacitor C1 of about several 10 [μF] outside the switch S1. In the structure of the present invention, the terminals are connected in parallel through the main discharge cathode 3, as shown in the figure, near the tip of the main discharge cathode 3 (as close as possible, and in close contact with each other via an insulator). A second cathode 5 for plasma pinch made of the same material as the KM cathode is disposed so as to surround the main discharge cathode 3. Similarly to the main discharge cathode, the second cathode 5 is connected via the second switch 81 and the 20th power protection resistor R6.
J2 is connected to the high voltage DC power supply -HV, and the #
It is connected in parallel with the anode 2 via the charge storage capacitor of the housing 2 on the outside of the switch S of I2.

The above plasma X-ray source moves inside the vacuum chamber at '0-(Torr
), the main discharge electrode BK* and the subsequent first switch S are closed, and the charge accumulated in the first charge storage capacitor C1 causes the main discharge cathode 3 to
An arc discharge occurs between the anode 2 and the anode 2, and high-temperature, high-density plasma is formed near the anode 2 by the vapor of the anode material Aj generated by the arc discharge (1 discharge). At this point, the switch Sl of the irises 2 connected to the second cathode 5 is closed, and the electric charge accumulated in the second charge storage capacitor C8 causes a second discharge between the second one electrode 5 and the anode 20. Due to the magnetic field formed around the axillary discharge region, the nine high-temperature, high-density summer plasma 4 formed in the main discharge is pinched into a small region near the anode 2, and the high-temperature, high-density plasma 4 is transferred to the anode material. Special PI of a certain AA': A large amount of X M is released. When performing exposure using skeleton X-rays, as shown in the figure, the exposure mask 6 is placed at a distance of, for example, 100 to 50 Cw from the bright temperature density plasma formation area in the vacuum chamber 1. The stacked exposure-sensitive substrates 7 are placed facing the plasma, and the high-temperature, high-density plasma formation operation is performed in step 1.
It is repeated a desired number of times at a frequency of ~10 times/second.

The timing of the second discharge for pinching the main discharge plasma is experimentally selected so as to maximize the amount of X-rays emitted, as determined by spectrophotometric intensity 1 or exposure conditions.

FIG. 3 shows another embodiment, and each symbol in the figure represents the same part as in FIG. 2.

This structure eliminates the second switch from the external circuit of the second switch 5 in the first embodiment. a,. ID
IImKN□F□″2 pieces., □, 3 and K cause main group anode 3 and 151m2 main discharge, and discharge of electric field between electrodes 2 produced by wrinkle main discharge is fermented. The high-temperature plasma generated by the main discharge is further pinched by the magnetic field formed by the second discharge, and a high-temperature, high-density plasma 4 that emits a large amount of X-rays is formed near the anode, as in the wJl embodiment6. As described in the detailed description of the invention, in the plasma The plasma is further pinched in a smaller area by the magnetic field generated by the second discharge between the second cathode and the anode.Therefore, an extremely high-density, high-temperature plasma is formed. XM generation/radiation efficiency is 1
It can be improved to about 0-1.

As described above, the present invention provides X□ 111i! with high generation and radiation efficiency. XII! The exposure efficiency of the exposure device is improved.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of the main part of a conventional plasma X-ray source, and FIG. 2 is a diagram of the plasma X-ray source. In the figure, l is a vacuum vessel, 2 is an anode, 3 is a cathode, 4 is high-temperature high-density plasma, 5 is a second cathode, 6 is an exposure mask, and 7
is the substrate to be exposed, G is ground, S, , S. is switch 7, R, R is the power supply resistance, C,, C,
indicates a charge storage capacitor, and -HM, -HV indicate a high voltage DC power supply. Figure 1 Leather 2 Sendai 3 Figure 1-1v2 1

Claims (1)

[Claims] A second cathode is disposed near the main discharge dovetail in the cathode facing the electric charge accumulated in the capacitor, and a connection between the second cathode and the anode is integrated with the cathode of JI2. A second discharge comprising a capacitor 1! 1. An X-ray exposure apparatus characterized in that a plasma X-ray source formed by connecting -11 is used as an exposure energy source.