JP2907220B2 - Electron beam exposure equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] A pair of electrodes facing each other is installed inside each of a plurality of two-dimensionally provided openings, and each pair of electrodes is determined depending on whether a voltage is applied between the pair of electrodes. The present invention relates to an electron beam exposure apparatus in which the trajectory of an electron beam passing through an opening is changed in two ways to turn on and off the electron beam to perform two-dimensionally patterned exposure. The purpose of the present invention is to reduce the number of electrodes between openings to facilitate the formation of the electrodes, and to increase the efficiency of electron beam deflection by narrowing the electrode spacing while leaving one pixel as it is. Are configured such that a common electrode exists.

[Industrial applications]

The present invention relates to an electron beam exposure apparatus, and in particular, sets a pair of electrodes facing each other inside each of a plurality of openings provided two-dimensionally, and determines whether or not to apply a voltage between the pair of electrodes. The present invention relates to an electron beam exposure apparatus in which the trajectory of an electron beam passing through an opening is changed in two ways, and the electron beam is turned on and off to perform two-dimensionally patterned exposure.

[Conventional technology]

In recent years, the degree of integration and functions of ICs have been increasingly improved, and they are expected to play a role as a core technology of technological progress in a wide range of industries such as computers, communications, and machines.

A major pillar of IC process technology is high integration by fine processing. Optical lithography is said to have a limit of about 0.3 microns, but electron beam exposure
Fine processing of 0.1 micron or less is possible with an alignment accuracy of 0.05 micron or less. Therefore, if an electron beam exposure apparatus that exposes 1 cm ² in about 1 second is realized, fineness,
Regardless of alignment accuracy, completion speed, and reliability,
It cannot be followed by other lithography means. This makes it possible to manufacture 1 to 4 gigabit memories and 1-megagate LSIs.

Before describing the direct prior art of the present invention, a rough review of the electron beam exposure apparatus will be made.

Generally, in a point beam exposure apparatus, since the beam diameter is constant, the throughput becomes extremely low particularly when the exposure pattern becomes large, and such an exposure apparatus is used only for research and development and practical use. On the other hand, the variable rectangular beam (the amount of deflection of the electron beam passing through the first slit is changed to change the position where the image of the electron beam passing through the first slit is projected on the second slit, and the first and second An electron beam exposure apparatus using an electron beam passing through a slit and changing the shape of the image of the electron beam in the X and Y directions to form various rectangular beams)
Even a large exposure pattern can be exposed with a small shot amount, and the throughput is increased by one to two digits compared to the point beam. However, even in this case, when exposing a pattern in which a fine pattern of about 0.1 micron is packed with a high degree of integration, the throughput also decreases. This means that, for example, when rendering a 1 gigabit DRAM, the throughput is about three digits insufficient.

Therefore, as a means to expose any pattern,
There is an exposure unit using a blanking aperture array proposed by the present inventors. As shown in FIG. 6, a large number of openings 1 'are arranged two-dimensionally on a substrate, and blanking electrodes 2' and 3 'are formed on both sides of the openings 1'. Whether or not a predetermined voltage is applied between 'and 3' is controlled by pattern data. For example, of the electrodes 2 'and 3', the potential of one electrode 3 'is fixed (for example, ground potential), and a predetermined voltage different from the potential of the one electrode 3' is applied to the other electrode 2 '. When applied, the electron beam passing therethrough is bent, so after passing through the lens installed under the blanking aperture array, it is cut by the aperture provided under the blanking aperture array and the electron beam is cut on the data surface (wafer). Does not reach. On the other hand, if the same voltage as that of the electrode 3 'is not applied to the other electrode 2', the electron beam passing therethrough is not bent, so that the electron beam passes through a lens provided below the blanking aperture array. The electron beam reaches the data surface without being cut by the aperture provided below.

As a result, a set of point beams that can be turned on and off independently is arranged on a two-dimensional surface on the data surface. For example, 200 × 200 = 40,000 beams (equivalent to the number of apertures 1 ′ arranged two-dimensionally) arranged on a document surface at a size of 0.02 μm square are arranged in a 4 μm × 4 μm area on the document surface. In this way, an electron beam capable of forming a pattern can be formed in one shot.

Usually, the spherical aberration of the final lens of the electron beam exposure device,
Since the chromatic aberration can be suppressed to only about 0.02 microns, the individual beams passing through the blanking aperture array are irradiated overlapping on the wafer surface, and the individual electron beams of 0.02 microns are separated. It won't.

When a specific structure of a blanking aperture array is considered, a 7 μm square opening 1 ′ (for example, a 10 μm pitch and a 7 μm square image is reduced on a substrate having a thickness of 30 μm, As described above, for example, a 0.02 micron square is formed by etching, a thin (about 3000 °) insulating film is formed on the surface thereof, and tungsten or the like is formed on two opposing surfaces of the opening 1 ′ on the insulating film. The electrodes 2 'and 3' are formed of metal.

As a result, only a grid-like portion having a width of 3 μm (10 μm−7 μm) remains on the substrate. It is necessary to apply an independent electric signal to the electrode of each opening on the 3-micron grid through a metal wiring pattern.

Also, with a one-dimensional blanking aperture array, a minimum beam of 0.02 microns will cause a 1 cm ²
Cannot be drawn in one second, and therefore, the electron beam exposure using the one-dimensional blanking aperture array does not have the throughput applicable to the IC manufacturing line.

Now, in the conventional blanking aperture array as shown in FIG. 6, since the beam is deflected at each opening independently, a pair of electrodes 2 ', 3 is provided at both ends of each opening 1'. 'Were formed individually. Then, for example, 10
Forming 7 micron openings at a micron pitch gives 3
Two electrodes and an insulating film (unnecessary if the insulating film substrate interposed between each electrode and the substrate is an insulator) must be formed in a micron space, which is not easy to form. In general, a larger potential difference is required to deflect a beam as the electrode gap is larger. Therefore, it is better that the electrode gap is smaller, but there is also a demand that a wider aperture itself allows a larger beam passage amount.

[Problems to be solved by the invention]

The present invention has been made in order to solve such a problem, and is capable of performing electron beam exposure using a blanking aperture array that does not allow other lithography means to follow, regardless of fineness, alignment accuracy, completion speed, and reliability. In order to make it possible, a blanking aperture array is formed which forms a realistically possible two-dimensional patterned beam.

Further, the number of electrodes formed in the lattice portion between two adjacent openings is reduced to facilitate the formation of the electrodes, and the spacing between the electrodes is narrowed while one pixel remains unchanged to increase the deflection efficiency.

[Means for solving the problem]

According to one embodiment of the present invention, there is provided an electrode to which a constant potential is applied to two adjacent openings among a plurality of two-dimensionally provided openings, and Means for changing the trajectory of an electron beam passing through each of the two apertures in two ways according to the potential applied to the common electrode, provided with a common electrode whose potential applied according to the data changes. An electron beam exposure apparatus is provided, comprising means for turning on and off the electron beam by changing the electron beam in two ways, and means for forming one pixel with each of the two adjacent openings.

According to another aspect of the present invention, among a plurality of two-dimensionally provided openings, for each of a plurality of adjacent openings,
Electrodes to which a constant potential is applied are provided at both ends,
In addition, a first common electrode whose potential applied according to data changes and a second common electrode to which a constant potential is applied are alternately provided between the adjacent openings. Means for changing the trajectory of an electron beam passing through each of two openings sharing the first common electrode among the plurality of openings in two ways in accordance with a potential applied to the first common electrode; An electron beam exposure apparatus is provided, comprising: means for turning on and off the electron beam by changing the electron beam in two ways; and means for forming one pixel with each of the two apertures.

[Action]

According to the above configuration, an electrode between two adjacent openings is shared, so that it is not necessary to form two electrodes in a region between the openings as in the related art. In addition, if the distance between the electrodes is narrowed with two openings as one pixel, the deflection efficiency of the electrode beam (the degree of deflection of the electron beam with respect to a predetermined applied voltage to the electrode) can be improved accordingly.

〔Example〕

FIG. 1 illustrates the basic structure of one embodiment of a blanking aperture array used in an electron beam exposure apparatus according to the present invention.
The point that an electrode 2 common to the two openings 1 is provided between the two openings 1. An electrode 3 is formed on each opening 1 on a surface facing the common electrode 2.

FIG. 2 shows a specific example in which an electrode between two adjacent openings is shared as described above, and a potential applied to a common electrode 21 existing between the two openings 11 is changed according to data. A steady potential (for example, a ground potential) is applied to each electrode 31 provided on the surface of the opening 11 facing the common electrode 21. In this manner, each of the electrodes 31 is connected to the common electrode 21.
If a predetermined potential different from the voltage that is constantly applied to the common electrode 21 is applied, the electron beam passing through the two openings 11 is deflected together, while if the predetermined potential is not applied to the common electrode 21, The electron beams passing through the two openings are not deflected together, and thus one pixel is formed by the two adjacent openings.

FIG. 3 shows another specific example in which the electrode between the two openings adjacent to each other is shared, a steady voltage is applied to the common electrode 32 existing between the two openings 12 and The potential applied to each electrode 22 provided on the surface facing the common electrode 32 is changed according to data. Thereby, depending on whether or not to apply a predetermined potential different from the voltage constantly applied to the common electrode 32 to each of the electrodes 22,
Whether or not the electron beam passing through each opening 12 is deflected can be independently controlled for each opening.

By providing a common electrode between two adjacent openings as described above, the number of electrodes formed in one lattice portion existing between the two openings can be reduced, and the formation of the electrodes can be facilitated. Further, when one pixel is formed by the two openings, the electrode interval can be narrowed without changing one pixel, and the deflection efficiency (degree of beam deflection with respect to a predetermined applied voltage) can be improved accordingly. Further, by providing the common electrode (the electrode is shared by two openings),
Since the area of the opening can be widened accordingly, the beam passage amount can be increased. Moreover, the above-mentioned 20
The area of 0 × 200 openings can be reduced as a whole.

FIG. 4 shows another embodiment of the blanking aperture array used in the electron beam exposure apparatus according to the present invention. In the case of this embodiment, all the electrodes between the openings are alternately arranged. An electrode existing between two openings 13 adjacent to each other is used as a common electrode for the two openings, and an electrode 33 to which a constant potential is applied and an electrode 23 whose potential changes according to data are alternately arranged as the common electrode. Is done.

Also in the case of this embodiment, one pixel is formed in the two openings 13 which share the electrode 23 whose potential changes according to data, and a predetermined potential different from the steady potential applied to the electrode 33 is applied to the electrode 23. Whether or not to deflect the beam passing through the two apertures 13 is controlled depending on whether or not to perform the operation.

FIG. 5 is a view exemplifying the overall configuration of the apparatus of the present invention, in which 51 is an electron gun for emitting an electron beam, 52 is a first slit, 53 is an electron lens, and 54 is a deflector to form a variable rectangular beam. When forming, the electron beam that has passed through the first slit is deflected by a predetermined amount. 55 is an electron lens, 56 is a deflector for passing an electron beam passing through the electron lens 55 through a blanking aperture array provided in an aperture portion 57 or for forming a variable rectangular beam separately provided in the aperture portion 57 A predetermined deflection is made depending on whether the light passes through the second slit. 58, 60, 62 and 65 are electron lenses, 59 is a deflector connected to a blanking control circuit 80 described later, 61 is an aperture portion, and the electron beam deflected by the blanking aperture array or the like is used for the aperture. It does not pass through the portion 61 and is thereby prevented from reaching the material (wafer) 66. 63 and 64 are deflectors connected to a deflection control circuit 82 described later, and 67 is a stage on which a material (wafer) 66 is placed.

Reference numeral 71 denotes a CPU coupled to the magnetic disk 72 or the magnetic tape 73, and information for controlling a beam path (whether or not to pass through the aperture portion 61) via the interface 74, the data memory 75, the pattern controller 76, and the like. Such as the above deflector via DA converter and amplifier 78
, And to each electrode of the blanking aperture array via a two-dimensional on / off information generating or accumulating device 79, and further to the deflector 56. The blanking control circuit 80 performs control to deflect the beam so as not to irradiate the beam at all when the stage is moved or when exchanging materials. The DA converter is controlled by information from the pattern controller 76 and a sequence controller 77 described later. And the deflector 59 is controlled via the amplifier 81.

On the other hand, information sent via the sequence controller 77 is supplied to the blanking control circuit 80 and also to the deflection control circuit 82 and the stage control unit 86. The deflection control circuit 82 includes a DA converter and amplifiers 83 and 84.
By controlling the deflectors 63 and 64 through the, the beam is irradiated to a predetermined position on the document, and the stage control unit 86 controls the movement of the stage. Then, the position of the stage is read out by the laser interferometer 85, and when the position shift of the stage is detected, the deflection control circuit 82 corrects the beam irradiation position.

〔The invention's effect〕

According to the present invention, it is possible to easily realize electron beam exposure using a blanking aperture array that does not allow other lithography means to follow any of fineness, alignment accuracy, completion speed, and reliability.

Further, the electrodes between the openings can be easily formed, and the beam deflection efficiency can be improved. Further, since the area of the opening can be widened, the amount of beam passing can be increased. In addition, the area of the entire two-dimensionally provided opening can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration of an embodiment of a blanking aperture array used in the apparatus of the present invention, FIG. 2 is a diagram showing an example of a specific example of the basic configuration shown in FIG. FIG. 3 is a diagram showing another example embodying the basic configuration shown in FIG. 1, FIG. 4 is a diagram showing another embodiment of the blanking aperture array used in the device of the present invention, FIG. Is a diagram illustrating the overall configuration of the apparatus of the present invention, and FIG. 6 is a diagram illustrating the configuration of a conventional blanking aperture array. (Explanation of reference numerals) 1,11,12,13,1 '... opening, 2 ... common electrode, 3 ... electrodes opposed to common electrode 2, 21, 22, 23, 2' ... potentials depending on data Changing electrode, 31, 32, 33, 3 '... An electrode to which a constant potential is applied.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-3220 (JP, A) JP-A-1-278725 (JP, A) JP-A-1-248617 (JP, A) JP-A-60- 106130 (JP, A) JP-A-60-49626 (JP, A) JP-A-63-314832 (JP, A) JP-A-61-187334 (JP, A) JP-A-61-187234 (JP, A) JP-A-60-31226 (JP, A) JP-A-59-189627 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01L 21/027

Claims (2)

(57) [Claims] In one embodiment, a plurality of two-dimensionally provided openings are provided.
For each two adjacent openings, an electrode to which a constant potential is applied is provided, and a common electrode to which a potential applied according to data changes is provided, and an electron beam passing through each of the two openings is provided. Means for changing the trajectory in two ways according to the potential applied to the common electrode;
An electron beam exposure apparatus comprising: means for turning on and off the electron beam by changing the electron beam in a manner as described above; and means for forming one pixel by each of the two adjacent openings. 2. A plurality of two-dimensionally provided openings.
For each of the plurality of adjacent openings, an electrode to which a constant potential is applied is provided at both ends thereof, and a potential applied between the plurality of adjacent openings varies according to data. A common electrode and a second common electrode to which a constant potential is applied are provided alternately, and an electron beam passes through each of the plurality of openings that shares the first common electrode. Means for changing the trajectory of the electron beam in two ways according to the potential applied to the first common electrode.
An electron beam exposure apparatus comprising: means for turning off; and means for forming one pixel with each of the two openings.