JPS592046A - Object to be irradiated with x rays - Google Patents

Abstract

PURPOSE:To make secure further the copying of a pattern having a submicron width and to provide a large degree of technical freedom to an X-ray mask and an exposure atmosphere by providing electrode impressed with positive and negative potential near the X-ray mask and the work. CONSTITUTION:Electrodes 7, 8 are installed near an X-ray mask and the work, and positive and negative potentials are applied thereto to form the electric field region between the electrodes 7 and 8 within an exposure atmosphere. Then, all the generated secondary electrons 9 are gathered to an anode 10 and do not arrive on a resist surface; therefore, the over-exposure of the resist is obviated. The fine patterning of the resist is thus further made secure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an X-ray beam projector in the field of XI chrysometry, which is effective in producing multiples of fine patterns of 1μn1 to 1'.

According to X-green lithography using soft X mA, it is possible to copy high-resolution patterns with ease.
=, Kuss Letters (Electronics Let
ters) Vol. 8, No. 4, pp. 102-104 (1972
Since its publication in 2010, research and development on X-ray phosphorography has been vigorously pursued. X-ray source, X-ray mask,
The technology in each of the alignment methods, X-ray resists, and X-ray M optical devices is 17L, and it can be said that we have come quite close to practical Jψ spinning.

The present invention uses X, l1lil mask, 11 and A on the mask.
n1+! Regarding the effects of photoelectrons and audioelectrons emitted from several bodies. The point that exceeds the Mitsunari-Auger Boron emission by 1 degree was found in a publication published in 1975, Journal of Vacuum Science and Technology (Journal of Vacuum 5cie).
nce and Technology) No. 12, No. 6, x32c>J3:n BY. That is, when RhLa, $ (wavelength 4.6 characteristic X,
It has been pointed out that there are shadows. This continuous X-ray causes the mask contrast to be low F, and furthermore, the Au on the mask
It has been reported that light and Auger electrons are emitted from the absorber pattern and the resist substrate and affect the patterning of the resist.

However, the inventor is A7? By studying X-ray exposure using targets, we discovered the following interesting experimental facts. Its characteristics are shown in FIG.

This figure shows the dependence of the residual film (V) of the negative resists (PG) to (IA) on the vacuum degree of the exposure atmosphere. Exposure z< 1141
Air means MFin air in the space between the mask and the wafer. Figure 1 Ma'! 1 shows exposure atmosphere true F degree dependence -C. Wow, 9 light W! i1J Qi and 11, meaning the atmosphere of the space between the mask and the wafer. 1st
．． From IA to Dew::1 When the atmospheric density deteriorates, the PGM residual film thickness gradually decreases (without X-ray mask), the thickness], 7n + mask with Au film When using (data marked with ・), P(Jλ, I
It can be seen that the amount of A remaining month 1p gradually increases. At this time, the dose of klKait#o for PGIA is 3
Q! nJ/7, -q The gap between the fabric and the wafer was fixed at 20 μff+. Due to the tendency in the case without an X-ray mask, it is rumored that the crosslinking reaction is inhibited by oxygen in the air. The problem occurs when a mask having a 17 nm thick Au film is used. The remarkable increasing tendency of PGM,A shallow AJ film thickness (9) due to the deterioration of the vacuum degree of the exposure atmosphere is a newly discovered experimental fact, and the tendency for the patterning of cysts to increase. There are 8 major issues regarding the above.In other words, as the remaining film thickness increases, it becomes impossible to transfer the pattern on the mask with high accuracy.Especially, from the perspective of realizing accurate reproduction of sub-micron width patterns. In this case, such an increase in the remaining PGMA film thickness is a serious point of failure.

The major difference 1ρ between the experimental conditions of the former two experiments (marked with * and marked with ○) is the presence or absence of a thin Au film. The presence of a young Au film means that the X-rays (alpha rays) emitted from the AI digits are absorbed by the Au film and
・This means that light is emitted from Auger electrons (ζ゛). This -ρ emission of photoelectrons and Auger electrons due to the so-called photoelectric effect 1''C is the same for all fist data points.Nevertheless, as the vacuum level of the exposure atmosphere worsens, the remaining PGMA film thickness increases. To do it means
This is thought to be because the ionization of the air in the exposure atmosphere by photoelectrons and Auger Seiko increases as the degree of vacuum deteriorates.

This idea is extremely reasonable because a deterioration in the degree of vacuum means an increase in the density of air.

That is, the photoelectrons and Auger electrons emitted from the ALL film ionize the air in the exposure atmosphere, and as a result, all the secondary electrons generated promote crosslinking of PGllviA, which is due to the effect of inhibiting crosslinking due to oxygen in the air. It is interpreted that this is to outweigh the effects.

The object of the present invention is to eliminate such conventional problems, avoid the adverse effects of photoelectrons and Auger electrons generated from an #jI The object is to be exposed to light.

According to the invention, Xfj! An X-ray mask consisting of an absorber pattern and a mask substrate, a workpiece facing the x,1 mask at a constant distance, and positive and negative An object to be exposed to X-rays is obtained which includes at least one pair of electrodes to which a voltage is applied.

EMBODIMENT OF THE INVENTION Hereinafter, the present invention will be described in detail with reference to drawings showing embodiments. FIG. 2 is a schematic diagram of a light irradiated object on the X machine side, showing one embodiment. An X-ray mask 3 having an AuXd absorber band 2 on an X-ray mask substrate 1 and a workpiece consisting of a wafer 5 coated with a resist 4 are kept at a predetermined distance. There is. In this state, X-ray 6 is irradiated and X111! The pattern on the mask is copied into the resist.

At this time, the space between the X-ray mask 3 and the workpiece, that is, the exposure atmosphere is usually atmospheric air or He or N.

Inert gas such as Therefore, as mentioned above,
Photoelectrons and Auger electrons are emitted from the Au absorber pattern on the M mask, the exposure atmosphere is ionized by these electrons, and a large number of secondary electrons are generated.

As explained in FIG. 1, overexposure of the resist occurs due to the action of all the secondary electrons. In order to avoid this, in the present invention, as shown in FIG. 2, an electrode 78 is installed near the X-ray mask and the workpiece. Positive and negative potentials are applied to these electrodes to create an electric field region in the exposure atmosphere between the electrodes 7 and 8.

In this way, all the secondary electrons 9 generated are collected at the anode 10 as shown in FIG. Reference numeral 11 is a power source that provides a potential. Therefore, all secondary electrons do not reach the resist surface, so overexposure of the resist does not occur. .

As explained and clarified above, by using an X-ray exposed object equipped with an electrode for collecting photoelectrons and Auger electrons, overexposure of the resist can be avoided and fine pattern processing of the resist can be made more reliable, and the present invention can achieve the purpose of

Another embodiment of the invention is shown in FIG.

In FIG. 3, two electrodes are arranged, but in FIG. 4, four electrodes are arranged. In this way, the travel distance of the secondary electrons 12 to the anode 13.14 is reduced, and the overall collection efficiency of the secondary electrons can be increased. With this configuration as well, the object of the present invention can be achieved.

As explained above, if the present invention is applied, first
It is possible to more reliably reproduce submicron width patterns in fiber lithography, and secondly, it is possible to provide a greater degree of technical freedom regarding the X-ray mask and exposure atmosphere.

It goes without saying that the X-rays are hotly affected by the application of the electric field.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the dependence of the PGMA residual film thickness on the vacuum degree of the exposure atmosphere, which is a problem in the prior art, and FIG. 2 is a schematic diagram of an object to be exposed to X-rays, which is an embodiment of the present invention. , 3rd
The figure is a diagram showing the electrode configuration in the same embodiment, and FIG. 4 is a diagram showing the electrode configuration in another embodiment.
・Au absorber pattern, 3・・・・・・・・・)l mask, 4・・・・・・・・・Resist, 5・・・・・・・・・
...Wafer, 6...X-ray, 7,8...
...... Electrode, 9. 12......All secondary electrons, 10.13.14...Anode,
11......Power supply. Trigram 2 Symbol J Roga 4μs

Claims (1)

[Claims] An X-ray mask consisting of an X-ray absorption body pattern and a mask substrate, a workpiece facing the X-ray mask with a constant distance of ff1l, and a workpiece adjacent to the X-ray mask and the workpiece. and at least one pair of LL buckets to which positive and negative voltages are applied.