JPS5929331A - X-ray generating device - Google Patents

Abstract

PURPOSE:To make it possible to raise the utilization rate of an X-ray by using no special valve so as to reduce absorption loss by gas. CONSTITUTION:A vessel 11, made of metal such as iron, is partitioned by a screen 12 into an X-ray generating chamber 13 and an X-ray irradiation chamber 14, each of which is equipped with glass introducing holes 15 and 16 and exhaust holes 17 and 18 respectively. A cathode 19 made of a metal with high melting point such as tungsten or tantalium is mounted in the X-ray generating chamber 13 via an insulating material 20. Further, an opening part 21 for allowing X-rays to pass therethrough is provided on a part of the screen 12 facing the cathode 19, a taper adapted to open toward the X-ray irradiation chamber side 14 is formed on said opening part in the thickness direction thereof, and a ring-shaped plate 22 is glued to the peripheral part of said opening part on the X-ray generating chamber 13 side so a to cover the surface of the screen 12. Moreover, Kr is introduced as discharge gas having high efficiency of X-ray generation into the X-ray generating chamber 13, and He as gas having small coefficient of X- ray absorption into the X-ray irradiation chamber 14 through the gas introducing holes 15, 16 respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an X-ray generator, and more particularly to a gas plasma type X-ray generator that utilizes X-rays generated from plasma generated by gas discharge.

(b) Background of the Technology It is expected that it will be put to practical use as a device that can shorten the X-ray exposure time in patterning fine patterns, etc.

(c) Conventional technology and problems In conventional gas plasma type X-ray generators, gas is directly introduced into the plasma generation chamber, and plasma that generates X-rays is generated by discharging the gas. .

Generally, in order to efficiently generate X-rays from gas plasma, it is necessary to ionize gas atoms or molecules to a required high energy state and to make the ion density sufficiently high.

Furthermore, in order to efficiently extract the generated X-rays, it is necessary to minimize the absorption by the neutral gas atoms or molecules.

In order to satisfy these conditions, it is necessary to localize the gas and plasma, give sufficient energy to the plasma, make it dense, and prevent the generated X-rays from passing through the gas layer. It is conceivable to make it removable.

Conventionally, an X-ray generator having a structure as shown in FIG. 1 has been used for the purpose described above.

In FIG. 1, a valve 2 attached to one end of a gas reservoir 1 is reciprocated in the direction of the arrow to intermittently eject gas from a nozzle 3. On the other hand, a capacitor 5 and a switch 6 are connected in series between the gas reservoir 1 and the outer cylinder 4.

When the capacitor 5 is charged with a high voltage and the switch G is opened and closed in synchronization with the opening and closing of the valve 2, the ejected gas flow 7 is discharged and ionized, and the ion flow self-contracts due to the magnetic field generated by the charge flow. , high-density plasma column 8
form. As a result, the temperature of the plasma column 8 increases,
This leads to the generation of X-rays.

In the conventional method described above, the purpose of spatially localizing the neutral discharge gas and plasma has been achieved, but it is necessary to open and close the valve at high speed in synchronization with the discharge cycle. However, there are still some issues that need to be resolved in this regard.

That is, there is a limit to the speed at which the valve can open and close, the mechanism becomes complicated, and sufficient durability cannot be obtained.

Furthermore, in the above conventional method, impurity components in the residual gas, especially organic gases, are prevented from being activated by plasma bombardment and adhering to the irradiated sample and contaminating it.
．． -J, the sample to be irradiated was placed outside the apparatus and was irradiated with X-rays taken out from the X-ray extraction window. For this reason, an absorption loss occurs due to the X-ray extraction window, which has the disadvantage of reducing the efficiency of X-ray utilization.

(d) Purpose of the Invention The present invention provides a gas plasma type X-ray generator that makes it possible to reduce gas absorption loss and increase X-ray usage efficiency without using special valves as in the conventional method. The purpose is to provide.

(e) Structure of the Invention The present invention provides a gas plasma type X-ray generator, which is provided with an X-ray generation chamber and an X-ray irradiation chamber connected by an opening, and a cathode is installed in the X-ray generation chamber. A gas for generating a gas plasma that generates X-rays is flowed into the X-ray irradiation chamber, and a gas having low X-ray absorption and approximately the same pressure as the gas flowing into the X-ray irradiation chamber is flowed into the X-ray irradiation chamber. It is considered an insult.

<r>Embodiments of the invention Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 2, a container 11 is made of metal such as iron, and is divided into an X-ray generation chamber 13 and an X-ray irradiation chamber 14 by a partition plate 12, each having gas introduction holes 15 and 16 and an exhaust hole 17. and ]8 are provided.

A cathode 19 made of a high melting point metal such as tungsten or tankle is attached to the X-ray generating chamber 13 with an insulator 20 interposed therebetween. Also, partition plate 1
An aperture 21 for allowing X-rays to pass is provided in the portion facing the cathode 19 of No. 2. This aperture 21 is tapered in the thickness direction so as to open toward the X-ray irradiation chamber 14 side, and the surface of the chemical cutting plate 12 is provided at the peripheral portion that goes down to the X-ray generation chamber 13 side. A ring-shaped plate 22 is bonded to cover it.

In the configuration shown in FIG. 2, the X-ray generation chamber 13 contains a discharge gas having high X-ray generation efficiency, such as the crib 1-
In addition, in the X-ray irradiation chamber 14, there is a material such as helium (Kr), which has a small absorption coefficient for X-rays.
) are introduced through gas introduction holes 5 and 16, respectively.

In this case, the gas pressure in the ÷τ X-ray generation chamber 13 and the gas pressure in the X-ray irradiation chamber 14 are kept approximately equal by adjusting the exhaust speed of the paths of the exhaust holes 17 and 18.

In the above configuration, if a DC high voltage is applied between the container 11 and the cup 1'19 with the container 11 on the negative side, and no discharge occurs, the opening provided between the cathode 19 and the partition plate 12 A plasma column 23 is generated with the line connecting the hole 21 as an axis, and X-rays are emitted from this plasma column 23.

[j11 The plasma column 23 is the opening Ffl; 21”-
Because it extends on the opposite axis, the radiation intensity distribution of X-rays increases around this axis. therefore,
In the X-ray irradiation chamber 14, the sample 24 to be irradiated placed on the nIJ axis is most efficiently irradiated with X-rays.

Furthermore, since the atmosphere inside the X-ray generation chamber 13 is a gas such as helium having a small X-ray absorption coefficient, the loss of X-rays reaching the irradiated sample 24 can be suppressed to a small level.

Note that the X-ray generation chamber 13 through the opening 21
The influence of mutual diffusion between the discharge gas inside the X-ray irradiation chamber 14 and the gas inside the X-ray irradiation chamber 14, such as helium, can be suppressed to a negligible level by sufficiently increasing the gas flow rate in both chambers.

As mentioned above, in the gas plasma type X-ray generator according to the present invention, it is possible to suppress the absorption loss of X-rays, thereby increasing the utilization efficiency of X-rays. Since it is not used, the structure of the device is simplified and the reliability of operation can be improved.

(g) Effects of the Invention According to the present invention, it is possible to provide a highly efficient and reliable gas plasma type X-ray generator suitable for use in exposure for patterning fine patterns of electronic devices and the like.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a conventional gas plasma type X-ray generator, and FIG. 2 is a diagram showing an outline of the configuration of the gas plasma type X-ray generator according to the present invention. In the figure, I is a gas reservoir, 2 is a valve, 3 is a nozzle, and 4
1 is an outer cylinder, 5 is a condenser, 6 is a switch, 7 is an ejected gas flow, 8 and 23 are plasma columns, 11 is a container, 12 is a partition plate, 13 is an engineering/nox hanging spring generation chamber, 14 is an X-ray irradiation chamber, Spaces have been introduced from 15 and 164 L, 17 and 18 are exhaust holes, 19 is a cutout, 201 colored object, 21 is an opening, 22 is a ring-shaped plate, and No. 24 is covered!! @
H,) Shoko v, wood 1. 1st mouth single 2 mouth 0 ノ4 2+

Claims (1)

[Claims] A gas plasma type X-ray generator is provided with an X-ray generation chamber and an X-ray irradiation chamber connected by an aperture, the X-ray generation chamber is provided with a cup 1', and a gas plasma generating X-ray is provided. X-ray generation characterized in that a gas for generation is flowed into the X-ray irradiation chamber, and a gas having low X-ray absorption and approximately the same pressure as the gas flowed into the X-ray irradiation chamber is flowed into the X-ray irradiation chamber. Device