JPS60175352A - Multiple electron beam gun - Google Patents

Abstract

PURPOSE:To form a multiple electron beams gun by providing, on a substrate, multiple metallic wires formed in parallel with each other through the intervention of an insulating thin film and multiple metallic thin films intersecting said multiple metallic wires with a constant angle, and using each intersecting position of them as an electron beam source. CONSTITUTION:The multiple wires of a metallic wiring part (Al) 4 with aninsulating thin film 2 are formed in X-direction on a substrate 5 and the interspaces between said wires are filled with insulators 3. Furthermore, wiring parts 1 made of metallic thin film (Au) are arranged in Y-direction perpendicular to the wiring part 4 in the form of a grating and thus, cathodes 7 are formed. A multiple electron beams gun is formed by applying 10 volts between the wiring parts 1 and 4, and accelerating electrons emitted from the tunnel current generated in each region 6 corresponding to the grating intersecting points by the positive electrode 9. Therefore, at the time of describing a pattern of a semiconductor element, it is possible to generate multiple electron beams having any arbitrary form with any arbitrary irradiation period and also, greatly improve the productivity of an exposure unit.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a multiple electron beam gun that generates a plurality of electron beams, and is used, for example, for baton drawing when manufacturing semiconductor devices.

[Background of the invention]

The prior art and its problems will be explained with reference to FIGS. 1 and 2. FIG. 1 is a schematic diagram of a conventional electron gun, and FIG. 2 is a diagram showing an example of a conventional electron beam exposure apparatus.

As shown in FIG. 1, conventional electron guns use a method in which electrons emitted into a vacuum from a heated cathode tip 61 are accelerated by an anode 62, or the tip of the cathode tip is sharpened to concentrate the electric field. This method used a tunnel effect to extract electrons. In Figure 1, there is only one electron beam, but even if you try to arrange multiple can-1 chips close together to obtain multiple beams using this method, the voltage shown at 63 will exceed several KV. That it is necessary,
It has been virtually impossible to stably extract a large number of beams due to manufacturing problems and the difficulty of ensuring uniformity when the electric field is concentrated. As a result, the current high-speed electron beam exposure apparatus using a conventional electron gun uses an electron gun 31 that generates one beam and shapes the beam with an irradiation lens 32, as shown in FIG. In accordance with the aperture, a shaping system consisting of shaping apertures 33, 36, shaping lens 35, and shaping deflector 34 creates a shaped image of the beam, which is reduced by a reduction lens 37, and a blanker is formed according to the required irradiation time. 42 to turn the beam on and off, and finally irradiate the sample surface 40 with an objective deflection system consisting of three objective lenses and an objective deflector 38. In addition,
43, 44. , 45 are irradiation figure control circuits,
These are a blanking control circuit and an irradiation position control circuit. As a result, as can be seen from FIG. 2, in order to draw the desired bump on the sample surface, irradiation with only one shaped beam image was repeated for each irradiation operation.

As a result, there has been a problem in that productivity is significantly lowered due to an increase in the number of tabs associated with the increase in the density of integrated circuits. Furthermore, an electron optical system for an electron beam exposure apparatus using a conventional electron gun requires an irradiation lens, a molding system, and a blanker, and has the problem of being expensive.

[Purpose of the invention]

An object of the present invention is to solve the above-mentioned problems in the prior art, and to be able to generate a plurality of electron beams having an arbitrary shape corresponding to the desired irradiation button shape in an arbitrary irradiation time. Therefore, it is an object of the present invention to provide a multiple electron beam gun that can significantly improve the productivity of an electron beam exposure apparatus and reduce the cost of the apparatus.

[Summary of the invention]

The present invention is characterized in that, in order to achieve the above object, (1) a plurality of metal wirings are formed in parallel on the surface of an insulating substrate, and a plurality of metal thin film wirings are formed on the surface of these metal wirings via an insulating thin film; are parallel to each other and intersect with the metal wiring at a certain angle, and each area at each intersection point where the metal wiring and the metal thin film wiring intersect in a lattice pattern is used as an electron beam source. (2) A plurality of wirings made of a P-type semiconductor are formed in parallel on the surface of an insulating substrate with or without metal wiring, and an N-type semiconductor is formed on the surface of these wirings. A plurality of thin film wirings made of the above are formed in parallel and in a direction intersecting the wiring made of the P-type semiconductor at a certain angle, and the wiring made of the P-type semiconductor mentioned above and the thin film made of the N-type semiconductor mentioned in 2. A plurality of electron beam guns are provided in which the regions at the intersection points where the wiring lines intersect in a lattice pattern serve as electron beam sources. That is, the present invention enables arbitrary irradiation with a plurality of electron beams having an arbitrary shape corresponding to the desired irradiation button shape, based on the tunnel effect between thin film layers of metal and insulator, or the tunnel effect between semiconductor layers. It is intended to occur over time.

[Embodiments of the invention]

The present invention will be explained in detail below with reference to the drawings.

FIG. 3 is a diagram for explaining the electron gun according to the present invention. The overall structure of the electron gun section is as shown in FIG.
It is accelerated by For this reason, a voltage of several kilovolts or more is applied between the reference potential of the cathode section and the anode section. (1) of the high voltage power supply for acceleration applied between the cathode and anode parts.
4 or almost the same as a conventional electron gun. The feature of the present invention lies in the cathode section. This is shown in the same figure +a+-; tb+
, (This will be explained using C1. (a) is a partial view of the cathode section viewed from the direction in which electrons are emitted, and its X, Y
The cross-sectional views in each direction are (b) and (C). That is,
In the cathode part, a metal wiring part (M) 4 having an oxide film (insulating thin film) 2 with a thickness of about 100 angstroms on the surface is formed in the Y direction on a substrate 5 made of an insulating material, and the space between the wirings is S. ], 02. A metal thin film (
A wiring portion 1 made of (Au) is formed to have a thickness of about 1.50 angstroms and has a lattice-like shape.

Now, if a voltage of about IOV is applied between 1 and 4,
According to the principle described later, a tunnel current flows through the insulating film 2 in the region 6 corresponding to the lattice points, and a portion of the tunnel current is emitted into the vacuum. These emitted electrons are accelerated by the aforementioned anode. That is, according to the present invention, it is possible to obtain a plurality of beams from each area of lattice points.

Next, a method for obtaining multiple beams of arbitrary shapes according to the present invention will be explained using FIG. 4. Figure 4(a) shows the third
The cathode section and the multiplexer for applying voltage thereto are shown when viewed from the same direction as in Figure (a). The multiplexer 21 has a connection function for setting the Y-direction metal wiring 4 to the reference voltage of the cathode section. The multiplexer 22 connects the X-direction metal thin film wiring 1 to 1. It has a connection function to apply a voltage of about OV diameter. In this figure, since the only lattice points where the voltage is set are the circles (◯) in the figure so that the tunnel current flows, two rectangular beams are obtained from the cathode section. If this is reduced and projected by ζ on the sample surface, it becomes possible to give the sample a dose as shown in FIG. 4 fbl. Here, 23 indicates the maximum area that can be irradiated in one irradiation operation, and 24 indicates the area that can be dosed on the sample surface in the (al) connected state.More generally, the multiplexer 21 and 22 You can draw any shape by changing the connection status of each switch over time.If you want to turn off the beam (blanking), turn one or both of the multiplexers on. All the switches need to be disconnected.

Now, FIG. 5 shows a schematic diagram of an electron beam exposure apparatus constructed using an electron gun according to the present invention. That is, the electron optical system consists only of the electron gun 50 according to the present invention, the reduction lens 37, the deflector 38 and the objective lens 39, and the electron gun is equipped with an irradiation pattern control circuit and a blanking control circuit (these are collectively referred to as 59) A plurality of beams of a predetermined shape are emitted at arbitrary times and at arbitrary time intervals upon input of signals from the .

Similar to the conventional type, the irradiation position signal is inputted to the deflector from the irradiation position control circuit 45.

Next, using FIG. 6, we will explain the principle of emitting electrons into vacuum by the tunnel effect, on which the present invention is based, and also explain another embodiment of the present invention using a P-N junction electrode. . In the same figure (a), the insulating film 52 has a number of tens of
In the case of a thin film, some of the electrons in the metal base 51 leak out over the potential energy barrier of the insulating film due to the wave nature of the electrons, and reach the metal film 53. This effect can be increased by applying a voltage of about 10 V (indicated by a battery ■ in the figure) between the metal films 51 and 53. Some of the electrons that reach 53 have enough energy to jump out from 53 into the vacuum, and are emitted into the vacuum. A diagram of energy levels corresponding to the above explanation is shown in the lower part of the figure (a).

A similar phenomenon is also possible using a PN junction made of P-type and N-type semiconductors, both of which have high impurity concentrations. however,
In this case, the N layer is made thinner and a reverse bias voltage as shown in FIG. 6(b) is applied. Based on this principle, embodiments of the present invention are shown in FIG. 3(C), (d), and (e). These are plan views corresponding to FIG. 6(d) and te), in which P-layer and N-layer interconnects are formed in the Y direction and X direction, respectively, to form a grid-like plural cathode region. In FIG. 6(d) and te), Although the wiring made of a P-type semiconductor formed on the insulating substrate 5 in the Y direction is shown as being formed on a previously formed metal wiring 65, this metal wiring 65 is not necessarily necessary. It's not a thing.

〔Effect of the invention〕

As explained above, by using the electron gun according to the present invention, it is possible to obtain multiple beams with arbitrary shapes, so the number of irradiations when drawing semiconductor patterns can be reduced, and as a result, the productivity of the exposure equipment can be improved. can be significantly improved. Furthermore, since the blanking operation can be performed at a low voltage of about 10 V, it is possible to reduce wasted time in the operation of the electric circuit, and from this point of view as well, productivity can be improved. Furthermore, as can be seen by comparing FIG. 2, which shows a conventional exposure apparatus, and FIG. 5, which shows an electron gun according to the present invention, when the electron gun of the present invention is used,
A molding system and a blanker are no longer required, and the electron optical system mirror body can be extremely simplified, making it possible to significantly reduce the cost.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a conventional electron gun, Fig. 2 is a diagram showing an example of a conventional electron beam exposure apparatus, and Fig. 3 is a diagram showing an electron gun according to an embodiment of the present invention. figure. (b) is a sectional view in the X direction, (C) is a sectional view in the Y direction, FIG. 4 is an explanatory diagram of the operation of the electron gun according to the present invention, (a) is a plan view, and (b) is the connection state of (a). 5 is a schematic diagram of an electron beam exposure apparatus constructed using an electron gun according to the present invention, and FIG. 6 is a diagram showing the region where a dose is applied on the sample surface. The present invention using a diagram explaining the principle of emission into vacuum and a PN junction electrode! (a) is an explanatory diagram of the emission principle, (b) is an example diagram using a PN junction electrode, FC+ is a plan view, (d
) is a sectional view in the X direction, and (e) is a sectional view in the Y direction. [Explanation of symbols] l...Metal thin film wiring 2...Insulating thin film layer 3...Insulator 4...Metal wiring part 5...Insulating substrate 6...Lattice point region 7 - Cathode part 8 ... Insulating support body 9 ... Drawer anode 10 ...
High-voltage power supplies for acceleration 21, 22...Multiplexer 31... Conventional electron gun 32... Irradiation lens 33.
36... Molded aperture 34... Molded deflector 35... Molded lens 37...
・Reducing lens 38...Deflector 39...Objective lens 40...Sample surface 41...Beam trajectory J 42...-
Blanker 43... Irradiation figure control circuit 44... Blanking control circuit 45... Irradiation position control circuit 50... Electron gun 51 according to the present invention... Metal base 52... Insulating film 53...
・Metal film 54...P-type semiconductor 55...N-type semiconductor 61...Cathode chip 62...Beam extraction anode 63...High voltage power supply for acceleration 65...Metal wiring patent applicant Nippon Telegraph Telephone Public Corporation agent (patent attorney) Junnosuke Nakamura 1 Figure f2 Tsuko 3 (d) Figure 17'4 (b) Figure t5

Claims (2)

[Claims] (1) A plurality of metal wirings are formed in parallel on the surface of an insulating substrate, and a plurality of metal thin film wirings are formed in parallel on the surface of these metal wirings with an insulating thin film interposed therebetween, and at a constant angle with respect to the metal wirings. A plurality of electron beam guns formed in intersecting directions, each of which uses a region at each intersection point where the metal wiring and the metal thin film wiring intersect in a grid pattern as an electron beam source. (2) A plurality of wirings made of P-type semiconductor are formed in parallel on the surface of an insulating substrate with or without metal wiring, and a plurality of thin-film wirings made of N-type semiconductor are formed in parallel on the surface of these wirings. , and is formed in a direction that intersects with the wiring made of the P-type semiconductor at a constant angle, and the area at each intersection point where the wiring made of the P-type semiconductor and the thin film wiring made of the N-type semiconductor intersect in a lattice shape is A plurality of electron beam guns, each of which serves as an electron beam source.