JPS61245454A - Ion beam lithography apparatus - Google Patents

Abstract

PURPOSE:To improve the focus performance thus to improve the machining accuracy by forming an ion beam lithography apparatus while employing an electromagnetic lens as ion beam focus means and a deflection coil as ion beam deflection means. CONSTITUTION:An ion source 3 is arranged at the upper end of high vacuum body 1 to convert the ions from said source 3 into desired beam through triode structure ion gun 4 then passed through a blanking electrode 5 and an objective restrictor 6. Thereafter, it is focused through a focus electromagnetic coil 21 then deflected magnetically through a deflection coil 22 and irradiated onto a sample 9. In such ion beam lithography apparatus, electrostatic lens such as Einzel lens having inferior focus performance is not employed as focus means while magnetic deflection means is employed in place of electrostatic deflection means, thereby highly accurate ion beam can be obtained while the entire size can be reduced.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to an ion beam lithography apparatus.

<Prior Art> As a conventional ion beam lithography apparatus, one having a configuration as shown in FIG. 2 is widely used. An ion source 3 heated by a heater 2 is provided at the top end of the ion beam lithography apparatus main body 1 kept in a high vacuum. formed into an ion beam and accelerated. The ion beam is connected to the blanking electrode5. Objective aperture #)6
The light is focused by the electrode structure 7 constituting the Einzel lens, and the direction is controlled by the XY deflection electrode 8.
A desired position on the sample 9 is irradiated.

In FIG. 2, IO is a heater power source, 11 is a noisy power source that applies a predetermined noisy voltage to the three-electrode ion gun, 12 is an accelerating power source that applies a voltage to the ions,
13 is a focus power supply, 14 is a current amplifier, 15 is an optical fiber for noticing signals, 16 is a power supply for blanking electrodes, 17 is a deflection power supply that generates voltages for the XY deflection electrodes, and 18 is a scanning A signal generator 19 is a high-speed current amplifier for detecting the ion current, and 20 is a cathode ray tube display for observing the ion current.

FIG. 3 shows the detailed structure of the Einzel lens in comparison with the corresponding optical lens system. %71m 7s in Figure 3
s 7s is an electrode that forms a potential distribution that focuses ions,
4 #12 #z= is an optical lens system corresponding to the Einzel lens effect of the ion beam, and the dotted line represents the accelerated ion travel path.

<Problems to be Solved by the Invention> In the conventional ion beam lithography apparatus shown in FIG. 2, the ion beam is focused using an einzer, which is formed by an electrostatic lens to which a high voltage is applied, as shown in FIG. using a lens. However, the aberration of ion beam focusing is large. When the potential of the stain electrode becomes unstable due to the discharge, floating particulates that become dirt are attracted to the electrode by the strong electric field inside the lens, which becomes electrically charged and changes the potential of the lens, impairing its stability. As a result, there are disadvantages in that the ion beam convergence is shifted, the ion beam becomes unstable, the processing accuracy is not improved, and the reliability of the ion beam processing is lacking.

The present invention has been made in view of the above drawbacks of the prior art, and it is an object of the present invention to provide an ion beam lithography apparatus using an electromagnetic lens/ET-based ion beam that has excellent focusing properties and has high processing accuracy.

<Means for Solving the Problems> The configuration of the ion beam lithography apparatus according to the present invention that achieves the above object is characterized in that an electromagnetic lens is used as the ion beam focusing means, and a deflection coil is used as the ion beam deflection means. It is a sign.

<Embodiment> An embodiment of an ion beam lithography apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention.

According to the ion beam lithography apparatus according to the present invention shown in FIG. 11, compared to the conventional ion beam lithography apparatus shown in FIG. That is, whereas the Einzel lens 7t was used, the one of the present invention uses a focusing means by a focusing electromagnetic coil 21, and the conventional XY which electrostatically deflects an ion beam is used as an ion beam deflection means. There are nine differences in that a deflection coil 22 for magnetically deflecting the ion beam is used in place of the deflection electrode 8)'. The other constituent parts are the same as the conventional one shown in FIG. 2, and the same numbers indicate the same parts. Note that the drive power source 17' for the deflection coil 22 outputs a current to the deflection coil 22.
There is nothing special about it other than the fact that it is being supplied to

By the way, in the case of an ion beam consisting of very heavy ions, a strong focusing magnetic field and a deflecting magnetic field are required, but it is effective to use superconducting magnets and magnets because they can obtain strong magnetic fields. be.

Further, in the present invention, the deflection coil 22 of the ion beam deflection means can be installed within the length range of the focusing electromagnetic coil 21 of the ion beam focusing means, as shown in FIG. There is an advantage that the length of the main body 1 can be shortened. In addition, the focusing electromagnetic coil 21
It is also possible to construct a structure in which the deflector 22 and the deflector 22 are integrated.

<Effects of the Invention> According to the ion beam lithography apparatus according to the present invention,
Since an electromagnetic coil is used as the ion beam focusing means and a deflection coil is used as the ion beam deflection means, the aberration coefficient is several times that of the conventional method using an electrostatic lens with poor convergence. can get. In addition, there is no problem of unstable electrode potential, and stable and highly accurate ion beam processing can now be achieved. Furthermore, the deflection coil can be installed within the length of the focusing electromagnetic coil, resulting in miniaturization. Further, the focusing electromagnetic coil and the deflection coil can be made into an integrated structure, in which case it can be made into a vertical structure.

[Brief Description of the Drawings] Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is a block diagram of a conventional ion beam lithography apparatus, and Fig. 3 is a portion of the Einzel lens of the apparatus shown in Fig. 2. FIG. In the drawing. 1 is an ion beam lithography apparatus body, 2 is a heater, 3 is an ion source, 4 is a triode ion gun, 5 is a blanking electrode, 6 is an objective aperture, and 9 is a sample. 10 is the heater power supply. 11 is a noise power source, and 12 is an acceleration power source. 13 is the focus power supply. 14 is a current amplifier, 15 is an ex-Fino. 16 is a power supply for the blanking electrode, 17' is a deflection power supply for the deflection coil, 18 is a scanning signal generator, and 19 is a high-speed current amplifier. 20 is a cathode ray tube display, and 21 is a focusing electromagnetic coil. 22 is a deflection coil.

Claims (3)

[Claims] (1) Using an electromagnetic lens as an ion beam focusing means,
An ion beam lithography apparatus characterized in that a deflection coil is used as an ion beam deflection means. (2) The ion beam lithography apparatus according to claim 1, wherein at least one of the electromagnetic lens and the deflection coil is a superconducting magnet. (3) The ion beam lithography apparatus according to claim 1, wherein a deflection coil is installed within the length of the ion beam focusing electromagnetic lens.