JPS6324619A - X-ray exposure equipment - Google Patents

Abstract

PURPOSE:To clarify the profile of an X-ray projected image by deflecting the course of secondary electrons between the exposure mask and the wafer. CONSTITUTION:A deflecting electrode 14 is provided between an exposure mask 4 and a wafer 9 of a silicon substrate applied with an X-ray resist 10. With this, secondary electrons E radiated from a mask 4 are deflected and become difficult to provide their effect, so the profile of the projected image of a gold pattern 7 becomes clear, improving the resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an X-ray exposure apparatus used for wafer exposure.

(Prior Art) With the increasing density of LSIs, the establishment of submicron pattern transfer technology has become a major issue, and X-ray exposure technology is being considered as one of the solutions.

According to X-ray exposure technology, it is possible to transfer patterns of 0.5 μm or less, but in order to particularly increase productivity, an X-ray exposure device that uses high-temperature, high-density plasma and uses characteristic X-rays from this plasma Development is also being considered.

In such an X-ray exposure apparatus, a wafer in a vacuum state and an X-ray exposure mask are placed facing each other with a small distance between them, and after the wafer is aligned, the wafer is placed behind the X-ray exposure mask. For example, an X-ray resist on the wafer is exposed to X-rays from a plasma X-ray source.

High-energy particles such as electrons and ions are also emitted from the plasma X-ray source, and these can damage the beryllium window for X-ray extraction and the X-ray exposure mask, or emit secondary X-rays that are harmful to exposure. Therefore, deflection magnets and reflectors are used to remove these particles before they reach the beryllium window.

(Problem to be Solved by the Invention) By the way, even if the charged particles emitted from the plasma X-ray source are removed in this way, the plasma X-rays may subsequently irradiate, for example, a metal part of an X-ray exposure mask. There is a problem in that secondary electrons are emitted due to the photoelectric effect, and these secondary electrons blur the outline of the portion of the wafer that is shielded by the gold pattern, resulting in a reduction in resolution.

Although it is possible to use a deflecting magnet to remove high-energy particles such as electrons A') ions from plasma X-rays, the distance between the X-ray exposure mask and the wafer is usually 1.
Since the width is as narrow as 0 to several tens of micrometers, it is virtually impossible to use such means.

The present invention has been made to solve these conventional problems, and it is an object of the present invention to provide an X-ray exposure apparatus that eliminates pattern blur caused by secondary electrons.

[Structure of the Invention] (Means for Solving the Problems) That is, the X-ray exposure apparatus of the present invention includes a deflection electrode that deflects the path of secondary electrons between an X-ray exposure mask and a wafer that are arranged to face each other. It is characterized by the placement of

Note that a thin annular electrode consisting of ten electrodes is suitable for the deflection electrode, but one electrode or a counter electrode of ten electrodes and one electrode may also be used as required. In addition, as mentioned above, the distance between the X-ray exposure mask and the wafer is usually narrow, 10 to several tens of micrometers, so this deflection electrode is not configured as an independent electrode, but rather, for example, on a mask support formed integrally with the X-ray exposure mask. It is desirable to form it integrally with the inner surface of the body or the inner surface of the X-ray passage section of the mask stage.

Roughly speaking, it is desirable that the applied voltage be a voltage that deflects the path of the secondary electrons approximately parallel to the wafer, and that the voltage is approximately 1q.
It is sufficient that the voltage is such that the secondary electrons are deflected and incident on the wafer in an oblique direction, and as a result, the intensity of the secondary electrons irradiated onto the outline of the gold pattern on the wafer is reduced to about 1710 nm.

(Function) In the X-ray exposure apparatus of the present invention, secondary electrons generated in the X-ray transmitting portion of the mask substrate are deflected by the deflection electrode and dispersed over a wide range from the outline of the portion shielded by the gold pattern. Therefore, the outline of the X-ray projected image of the portion shielded by the gold pattern becomes clear, and the resolution of the apparatus is improved.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a plasma X-ray source, which is coupled to an exposure chamber 3 via a beryllium window 2. In FIG. The X-ray exposure mask 4 has a polyimide film 6 coated on a BN substrate 5 and a gold pattern 7 formed thereon, and is held on a mask stage 8. A wafer 11 with an X-ray resist 10 formed on a silicon substrate 9 is
Mounted on the XY stage 12, an X-ray exposure mask 4
They are placed facing each other with a small distance between them. Further, on the inner surface of the X-ray passage section of the mask stage 8, a deflection electrode 14 consisting of ten annular electrodes is integrally formed with an insulating layer 13 in between, for example, by metal vapor deposition.

In the Xa exposure apparatus configured in this manner, the X-ray exposure mask 4 is first mounted on the mask stage 8, and the exposure chamber 3 is evacuated. Next, the wafer 11 is mounted on the XY stage 12 via a vacuum preliminary chamber (not shown).
Positioning with respect to the line exposure mask 4 is performed.

After that, ten potentials are applied to the deflection electrode 14, and the plasma
X-rays for exposure are emitted from a radiation source 1 in a pulsed manner.

By irradiating the plasma X-rays, a hardened pattern of the gold pattern 7 of the X-ray exposure mask 4 is formed on the X-ray resist 10 of the wafer 11. At this time, some of the secondary electrons generated when the X-ray exposure mask 4 is irradiated with plasma X-rays also pass through the X-ray exposure mask 4 and are emitted.
These secondary electrons E are transferred to the deflection electrode 14 as shown in FIG.
It is deflected by the ten potentials of the wafer 11 so that its course becomes parallel to the surface of the wafer 11, and even if it is not completely parallel, it is deflected in an oblique direction and diffused, thus blurring the outline of the cured pattern on the surface of the wafer 11. Never happened.

In the above embodiments, the deflection electrode 14 consisting of ten annular electrodes is integrally attached to the inner surface of the X-ray passing section of the mask stage 8 by metal vapor deposition, but the present invention does not apply to such an embodiment. It is not limited to this, and it is also possible to form it on the inner surface of a mask support formed integrally with the X-ray exposure mask 4, which is not shown.

Furthermore, the material and method for forming the deflection electrodes are not limited to metal vapor deposition, but may also be, for example, adhesion of metal foil or application of conductive paint.

[Effects of the Invention] As explained above, according to the present invention, the path of the secondary electrons emitted from the X-ray exposure mask is deflected to eliminate the influence thereof, so that the gold pattern projected onto the wafer is The outline of the projected image becomes clearer, and the resolution in X-ray exposure can be further improved. Furthermore, in the present invention, a deflection electrode is used as a means for deflecting secondary electrons, and since this deflection electrode can be formed thinly by any method such as vapor deposition, painting, or pasting of metal foil, X-ray exposure It is possible to arrange the wafer sufficiently even within a narrow space between the mask and the wafer.

[Brief explanation of the drawing]

FIG. 1 is a side view schematically showing the configuration of the present invention, and FIG. 2 is a diagram showing a state in which electron trajectories are deflected by an annular electrode (a diagram showing a claw). 1... Plasma X-ray source; 2... Beryllium window, 3... Exposure chamber, 4... X-ray exposure mask, 5... BN substrate, 6...
Polyimide film, 7... Gold pattern, 8...
...Mask stage, 9...Silicon substrate, 1
0...X-ray resist, 11...Wafer, 12...XY stage, 14...Deflection electrode. Applicant Tokyo Electron Co., Ltd. Representative Patent Attorney Satoshi Suyama - Figure 1 Figure 2

Claims (1)

[Claims] (1) An X-ray exposure apparatus characterized in that a deflection electrode for deflecting the path of secondary electrons is disposed between an X-ray exposure mask and a wafer that are arranged to face each other.