JPS5971246A - Electron beam defining device - Google Patents

Abstract

PURPOSE:To improve the processing ability of a fine pattern definition, by making each electron beam emitted out of plural cathode electrodes disposed in matrix form turn on or off independently in a way of changing the service voltage to be fed to a blanking electrode group. CONSTITUTION:Acicularly formed cathode electrodes 11-14 are disposed in matrix form, and an anode electrode 20 provided with a through hole, a group of blanking electrodes 51-54 deflecting the forward direction of each electron beam and a stop aperture 60 are all disposed beneath these cathode electrodes, while a group of switches 101-108 for changing the service voltage to be fed to these blanking electrodes 51-54 over to the power source side and the ground side separately in an independent manner, thus a power source part is made up. And afterward, an accelerating electrode 25, electron lenses 30 and 40 and a deflector 70 are all installed whereby an image is formed on a sample 80. Accordingly, with each electron beam out of matrix-form cathode electrodes 11-14 controlled independently, the amount of 'throughput' can be sharply improved.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an electron beam lithography apparatus that uses an electron beam to form fine circuit patterns on a wafer sample such as an LSI (large scale integrated circuit) at high speed and with high precision. In particular, throughput (processing capacity) was increased by using an electron source equipped with a large number of cathode electrode groups arranged in a two-dimensional IJ box shape and operating each electron beam separately. It is something.

[Prior art]

Conventionally, fine patterns of about 0.1 to 0.2 μm are the first
It was created using an electron beam lithography system equipped with a field emission type electron gun as shown in the figure.ゞ1st
In the figure, 1 is an electron beam, 10 is a needle-shaped cathode electrode, and 20
25 is an anode electrode, 25 is an accelerating electrode, 30 and 40 are electron optical lenses, and 50 is a blanking electrode.

60 is a stop aperture, 70 is a deflector, and 80 is a sample to be drawn. The operation of this device is as follows.

That is, a voltage is applied between the cathode 10 and the anode 20.

A high electric field is applied to the cathode to extract the electron beam from the cathode 10 by the Tornel effect, and the electron beam is focused by the electron optical lenses 30 and 40 and deflected by the deflector 70.

At the same time, a predetermined pattern is drawn on the sample 80 by selectively passing the electron beam through the stop aperture 60 by applying or not applying a voltage to the blanking electrode 50.

However, the prior art described in Section 1 has the following problems. In other words, field emission type electron guns have high brightness (
, it is possible to generate an electron beam with a minute diameter, but the total current value as an electron beam is small.

When applied to pattern drawing for LSI, etc., there is a problem in that the time required to finish drawing is extremely long.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electron beam lithography apparatus that can solve the above-mentioned problems of the prior art and significantly improve the throughput of fine pattern lithography.

[Summary of the invention]

The present invention is characterized by a plurality of cathode electrodes, each made in the shape of a needle, arranged in a matrix, and through-holes formed at positions corresponding to the arrangement positions of these cathode electrodes. an anode electrode arranged insulated from the electrode, a blanking electrode group that biases the traveling direction of the electron beam drawn from each cathode electrode through the through hole for each electron beam, and a supply to these blanking electrodes. A group of switches that change the voltage to bias the traveling direction of each electron beam or keep it straight, and a stop that is placed outside the blanking electrode group and allows only the electron beam that continues to travel straight to pass through. an electron source formed by an aperture, and an accelerating electrode for accelerating the electron beam, an electron lens for focusing the electron beam, and a deflector for deflecting the electron beam, which are arranged downstream of the stop aperture. , and further, for each switch in the group of changeover switches.

The present invention is configured to employ a group of changeover switches whose switching is controlled in synchronization with a deflection signal applied to the deflector.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

First, the electron source used in this embodiment will be described with reference to FIGS. 2 and 3. Figure 2 is a perspective view and electrical circuit diagram.
FIG. 3 is a partial sectional view and an electric circuit diagram thereof. This electron source section was originally developed by the present inventor in Japanese Patent Application No. 57-124342.
The configuration is the same as the electron gun proposed in the issue. In the drawings, 11, 12, 13, and 14 are cathode electrodes made in substantially the same needle shape, and in the embodiment, they are arranged in a 2×2 matrix. 20 is an anode electrode made of a thin metal plate, and cathode electrodes 11-
A through hole is made at a position corresponding to the arrangement position of 14,
It is arranged electrically insulated from the cathode electrodes 11 to 14. Reference numerals 51, 52, 53, and 54 are blanking electrodes for biasing the traveling direction of the electron beams drawn through each through hole of the anode electrode 20 for each electron beam, and two opposing electrodes are provided for each electron beam. An electrode is provided. A stop aperture 60 is provided outside the blanking electrode groups 51 to 54 so as to block the deflected electron beam and allow only the undeflected electron beam to pass through.

91 is a power supply for applying a voltage between the cathode electrode and the anode electrode, 92 is a power supply for applying voltage to the blanking electrode groups 51 to 54, and 101 to 108 are the blanking power supply 92 and Each blanking electrode 51-5
This group of switches is arranged in the middle of the connection line connecting the blanking electrodes 4 to 4 and switches the voltage supplied to each blanking electrode to the power supply side or to the ground side. In addition, 1, in Figure 3
2 are electron beams emitted from the cathode electrodes 11 and 12, respectively.

In such a configuration, when a voltage Ve is applied between the cathode electrode and the anode electrode so that an electric field of IQ6 V/cm or more is applied to the cathode tip, an electron beam is emitted from the cathode tip. In Figure 3, if the blanking electrode 51.5
When the electron beam 2 is at ground potential, the electron beam 1.degree. 2 travels straight, passes through the through hole of the stop aperture 60, and is emitted downward.

However, if the changeover switch is changed so that a voltage of +Vb is applied to one of the two opposing electrodes of the blanking electrode 52 and a voltage of -Vb is applied to the other, as shown in FIG. The electron beam 2 is bent and blocked by the stop aperture 60, so that the electron beam 2 does not come out below the stop aperture 60. In this way.

By controlling each changeover switch separately, voltage can be applied or grounded to each blanking electrode independently, and each electron beam can be individually blocked or passed through a stop aperture. become able to.

FIG. 4 is a cross-sectional view and an electric circuit diagram showing the overall configuration of this embodiment, and the same reference numerals are used for the same parts as in FIGS. 2 and 3. 25 is an accelerating electrode, 93 is an accelerating power source, 30 and 40 are a first electron lens and a second electron lens for reducing the electron beam, respectively, 70 is a deflector, and 112 is a deflector 7° controlled by the control circuit 111. 80 is a sample, and 113 is a switch control circuit that receives a control command signal from a control circuit 111 and controls the changeover switch groups 101 to 104 in synchronization with the deflection signal.

The apparatus of the embodiment shown in FIG. 4 operates as follows. Cathode electrode 11
．． A voltage ve is applied between the electrode 12 and the anode electrode 20 to extract electrons. The electron beam emitted from the tip of each cathode electrode can be controlled by separately applying a voltage ±Vb to the blanking electrodes 51 and 52 or by grounding them.
Each of them can bend in the direction of travel or go straight. The electron beam traveling straight and passing below the through hole of the stop aperture 60 is accelerated to a desired speed by the accelerating electrode 25. The electron beam thus generated is narrowed down in beam diameter by the first electron lens 30 and the second electron lens 40, and is deflected by the deflector 70.

An image is formed at a predetermined position on the sample 80.

An example of the drawing pattern in this case and the relationship between blanking control and deflection control will be explained with reference to FIG. Here, we will discuss the case of an electron source equipped with cathode electrodes arranged in a 2×2 matrix. Assume that the electron beams from the 2×2 cathode electrodes are separated from each other by a distance t on the sample 2. In Figure 5,
201, 202, 203, and 204 are areas scanned by four electron beams. Figure 5 (al shows the movement of the electron beam spot; all four electron beams pass through the stop aperture (hereinafter, those that pass through the stop aperture are referred to as ON, and those that are blocked by the stop aperture are referred to as OFF). ) for each t
By deflecting in the range of xt, 2t as shown in 7.
It becomes possible to draw within the range of x 2t. Fig. 5 (bl shows an example of the pattern drawing method, and the ○ mark is the irradiation position of the electron beam spot. Each area of txt has 9 rows in the direction, al b ° IC2 ... 6 rows of f 2nd row direction is also 1.
2.3. ...is divided into 6 columns of 6, so 6X6=
It is assumed that the entire area of t's<t is filled with 36 spots. One of the electron beam spots is a-1→a-2→
...proceed to a-6, then b-6→b-5→-...b
-1, and is further deflected to proceed c-1→C-2→...c-5. Since the other three electron beam spots are separated by t from each other, they move in the same way in the areas 202, 203, and 204 (.

Then, by controlling each electron beam on and off as shown in Table 1, drawing of row a shown in FIG. 5 [bl with diagonal lines] is performed. When line a is finished, line breaks are made in sequence from line b to line C...→line f, and at the same time as the line break, by changing the combinations of ON and OFF for each electron beam as shown in Table 1, 2t× The pattern drawing for the area No. 21 is completed. As described above, an example device using an electron source equipped with a group of cathode electrodes arranged in a 2×2 matrix,
By deflecting the txt area, a 21 x 2t area can be drawn, and the throughput can be increased four times.

〔Effect of the invention〕

As explained above, the electron beams from the cathode electrodes arranged in the shape of an nXn matrix are turned on independently.

By using an electron source that can be turned off and concentrating the electron beam spot image created by this electron source and deflecting the projection, the throughput can be increased by n2 times compared to conventional electron beam lithography equipment. can.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the prior art, Fig. 2 is a perspective view and electric circuit diagram of an electron source used in the present invention, Fig. 3 is a sectional view and electric circuit diagram thereof, and Fig. 4 is an embodiment of the present invention. FIG. 5, which is an overall configuration diagram of an example, is an explanatory diagram of drawing according to the present invention. Explanation of symbols ■, 2...Electron beam 10, IL 12.13.1.4...Cathode electrode 20
...Anode electrode 25...Acceleration electrode 30...
・First electron lens 40...second electron lens 50
, 51.52.53.54...Blanking electrode 60
...stop aperture 0...deflector 80...sample 91...
・Electronic draw-out power supply 92...Blanking power supply 93
...Acceleration power supplies 101 to 108...Selector switch 111...Control circuit 112...Deflection circuit 1
13... Switch control circuits 201 to 204... Electron beam scanning area patent applicant Nippon Telegraph and Telephone Corporation patent attorney Junnosuke Nakamura Junior High School 1 Sakiho 2 Figure 1 1°', 2 □□

Claims (1)

[Claims] (1) A plurality of cathode electrodes each made in the shape of a needle and arranged in the shape of an IJ box, and through holes are drilled at positions corresponding to the placement positions of these cathode electrodes, and the cathode electrodes are electrically connected. an anode electrode disposed insulated; a group of blanking electrodes that bias the traveling direction of the electron beams drawn out from each cathode electrode through the through holes described in 1 for each electron beam; A group of changeover switches that change the supply voltage to bias the traveling direction of each electron beam or keep it straight, and a group of switches arranged outside the blanking electrode group to allow only the electron beam that continues to travel straight to pass through. An electron source comprising an electron source consisting of a stop aperture, and an acceleration electrode for accelerating the electron beam, an electron lens for narrowing down the beam diameter, and a deflector for deflecting the traveling direction are arranged after the stop aperture. Line drawing device. (2. In the device according to claim 1. The group of changeover switches provided in the group of blanking electrodes is a switch that is controlled to be switched in synchronization with a deflection signal given to the deflector for each switch. An electron beam lithography device characterized by a group of switches.