JPS63100728A - X-ray stepper - Google Patents

Abstract

PURPOSE:To increase the X-ray brightness of a lithography equipment by a method wherein X-ray laser induction-discharged by means of entering the X-rays into plasma in excited state is led to a semiconductor substrate. CONSTITUTION:The charge of capacitors 2 charged by a high voltage power supply 1 actuates trigger electrodes 5 to be discharged between a pair of electrodes 31-41. Thus, discharged plasma is produced between respective electrodes to bring about an excited state of atoms in plasma. A part of X-rays emitted from spot plasma between the electrodes 31 and 41 become incident x-rays into electrodes 32, 33 inducing induction discharge phenomenon to emit x-rays in the same direction as that of the incident rays so that the induction discharge may take place successively to emit X-rays 9. Finally, the X-rays 9 are picked up on an exposure part through a window 10 to transfer the pattern of a mask 12 on a holder 11 to the Si wafer 13 on an aligner 14. In such a constitution, an X-ray output in high brightness can be generated enabling a fine pattern to be transferred.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an X-ray source for an XM lithography apparatus for LSI manufacturing, and more particularly to an X-ray exposure apparatus with improved XS and brightness.

[Conventional technology]

In recent years, in order to manufacture higher performance semiconductor integrated circuits,
There is an increasing demand for forming fine patterns having dimensions of 0.5 μm or less on semiconductor substrates. X-rays (mainly 4~
X is a pattern transfer technology using soft X-rays)
With the line exposure method, the accuracy of the transferred pattern is extremely high;
In particular, it is considered to be a powerful technology in submicron pattern formation.

By the way, in order to carry out the X-ray exposure method, a high-power and stable
Requires a line generator. So recently.

X-ray generators using discharge plasma as an X-ray source are being researched. As shown in Fig. 6, this device discharges the electric charge of a capacitor 2 charged by a high voltage power supply 1 between a pair of electrodes 3 and 4, generates discharge plasma between the electrodes 3 and 4, and generates energy generated in the plasma. It utilizes X-rays emitted by transitions. Note that 5 in FIG. 6 indicates a trigger electrode.

[-As such conventional technology, for example, Japanese Patent Application Laid-open No.
5g-188040.

[Problem that the invention seeks to solve]

The above-mentioned conventional technology does not take into consideration the control of energy transition in plasma, and has a problem in that only a weak X-ray output can be obtained. In other words, to explain the mechanism of X-ray generation, an atom consists of an atomic nucleus and electrons that revolve around it with a certain energy level. If the kinetic energy of the incident electron becomes greater than the electron's binding energy, the electron is knocked out of its shell (photoelectric effect)
.

When an electron in the outer orbit enters the empty space, the energy difference held by the electron is emitted as X-rays.

The situation is shown in Figure 7, where high-energy electrons are spontaneously emitted and transitions occur accidentally, and X-rays are irregularly emitted and utilize the energy transitions of spontaneous emission. It was difficult to control because of the

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the drawbacks of the prior art described above and to provide an exposure apparatus having an X-ray source that can output high-intensity X-rays.

[Means for solving problems]

In the present invention, in order to achieve the above object, the X-ray generation source includes:
They used an X-ray laser that uses stimulated emission by injecting X-rays into an excited plasma.

[Effect]

Figure 8 shows MM. When an incident x-ray acts on an excited atom, the incident x-rays move in the same direction, have the same frequency phase,
Furthermore, it utilizes the phenomenon that X-rays with the same polarization characteristics are stimulated to be emitted and are emitted in proportion to the intensity of the incident X-rays.

The X-ray laser that produces this phenomenon has a plurality of X-ray generating sections arranged in a straight line, and forms the above-mentioned excited state by high-speed, large-current discharge. At this time, when X-rays are incident, high-intensity X-ray output can be obtained by stimulated emission.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. Here, the same components as in the conventional example shown in FIG. 6 are given the same numbers. Opposing pairs of electrodes 31, 41, 32, 42, . ... 46 are cylindrical conductive paths 8
1.82..., 86 are joined. (Figure 2 shows the external appearance of one electrode pair, 16 is the opening through which X-rays pass) Electrodes 31.32. ... 36 and the capacitor 2 via the trigger electrode 5, and the conductive paths 81, 82 .・
... One side of 86 is also connected to capacitor 2. The discharge time control of the trigger electrode 5 is adjusted by a trigger hour controller 7. An X-ray extraction window 10 is installed at the bottom of the vacuum container 6 in the drawing.

When generating X-rays, by operating the trigger electrode 5, the electric charge of the capacitor 2 charged by the high voltage power supply 1 is transferred between the electrode pairs 31 and 41, between 32 and 42, etc.
・Discharge between 36 and 46. As a result, discharge plasma is formed between each electrode, and atoms in the plasma become excited. A part of the X-rays generated from the spot plasma between the electrodes 31 and 41 become incident X-rays between the electrodes 32 and 33, and are induced and generated. Sequentially between electrode pairs 33 and 43, 34 and
44, . . . stimulated emission between 36 and 46 and generates X-rays 9. In order to transfer the fine pattern, the above generated Xl1
The pattern of the mask 12 supported on the support 11 is transferred onto the silicon wafer 13 on the aligner 14 .

As explained above, since an X-ray laser that utilizes the stimulated emission phenomenon is used as a light source for X-ray exposure, high-intensity X-ray output can be obtained. The incident XM generating section for stimulated emission can similarly obtain high-intensity X-ray output no matter which electrode pair shown in FIG. 1 generates the incident XM.

FIG. 3 shows another invention in which a gas puff type is applied to the electrode pair. Each electrode pair 31・41゜32・42.33
- 43, 34, and 44 are arranged in a straight line, and an opening is provided in the center of each electrode for the passage of X-rays. Each electric pi
431, 32, 33° There is a gas blowing hole 1 inside 34.
There are 8.

To generate X-rays, gas 19 is first blown out between the electrodes from the gas introduction vibrator 17 at a constant rate. 'Be biased.

The gas between the electrodes becomes a high-temperature, high-density plasma due to the magnetic pinch effect of the current, forming an excited state. At this time,
When X-rays are incident on each plasma, the stimulated emitted X-rays are amplified and generate X-rays 9. The present invention also has the effect of generating high-intensity XM, as in FIG. 1.

FIGS. 4 and 5 show another example of the invention in which an excited state is formed inside the laser condo 20 and high-intensity X-rays are generated. The ultraviolet laser beam 23 is irradiated onto a rotating target 24 through a condenser lens 22 . target 30
A high-temperature, high-density plasma is formed above, generating X-rays 21. The X-rays are incident on the cylindrical laser rod 20 and are stimulated to be emitted inside the crystal of the laser rod. Therefore, amplified X-rays 9 are generated. FIG. 4 shows the case where X-rays are incident from the axial direction of the laser rod 20.
Furthermore, in order to improve the X-ray brightness, an example in which the X-rays are incident from the radial direction is shown in FIG. 5, and both the inventions shown in FIGS. 4 and 5 can provide high-brightness X-ray output.

〔Effect of the invention〕

According to the present invention, since an X-ray laser that injects X-rays into excited plasma and utilizes stimulated emission is used as an X-ray source, high-brightness X-ray output can be obtained and throughput can be improved. It has the effect of

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is a partial structure of an embodiment of the invention, FIG. 3 is a longitudinal sectional view of another embodiment of the invention, and FIGS. FIG. 5 is a vertical sectional view of yet another embodiment of the present invention, FIG. 6 is a conventional example, FIG. 7 is a principle diagram of the conventional example, and FIG. 8 is a principle diagram of the present invention. 31・41.32・42. 〜36・46...electrode pair,
2... Capacitor, 5... Trigger electrode, 20...
・Leh 1st Mine J A Dormitory 4 Diagram 5

Claims (1)

[Claims] 1. In an X-ray exposure apparatus that forms fine patterns on a semiconductor substrate using X-rays from an X-ray source, the
An X-ray exposure apparatus characterized in that an X-ray laser is guided onto the semiconductor substrate, which stimulates and emits X-rays by making X-rays from a radiation source enter an excited plasma.