JPH02232920A - Method and device for electron beam lithography - Google Patents

Abstract

PURPOSE:To make it possible to improve both pattern dimensional accuracy and through put by a method wherein a raster scanning method and a vector scanning method are conjointly used. CONSTITUTION:The data of patterning format which are inputted by a data input part 18 are divided into two parts of the profile part of pattern and the internal pattern located inside, they are data-converted by a data conversion and control section 19 and they are fed to a pattern control section 20. The electron beam 5, emitted from an electron gun, is passed through the first diaphragm 8, the second diaphragm 11 and the first reduction lens 12, the beam 5 is formed into a spot light of circular beam by the third diaphragm 13 of a circular beam aperture, the beam passes through the second reduction lens 14 and a projection lense 16, the subject to be patterned 1 on a stage 2 is raster- scanned by a fixed spot beam 22, and a highly precise profile is patterned. The internal pattern inside the profile pattern is drawn by a vector scanning method in the same manner as above using a high through-put rectangular beam, and a highly precise patterning having a high through-put can be conducted using two different methods of scanning in accordance with the state of patterning section.

Description

Detailed Description of the Invention [Industrial Technical Field] The present invention relates to semiconductor device manufacturing technology, and in particular, to synergistically improves the throughput of electron beam lithography for masks, reticles, and semiconductor wafers, and improves the dimensional accuracy of lithographic patterns. The present invention relates to electron beam lithography technology that can be realized virtually.

[Conventional technology]

Regarding electron beam lithography technology in the manufacture of semiconductor devices,
For example, Press Journal Co., Ltd., published February 20, 1986, monthly rsemiconductor [or
ld (Semiconductor World)” March issue, P75~
P83 and Kogyo Kenkyukai Co., Ltd., March 1, 1986.
Published by Japan, “Electronic Materials J March 1988 issue, P43-P
50.

As described in these documents, representative examples of this type of electron beam lithography technology include the so-called vector scan method using a spot beam and the so-called raster scan method using a rectangular beam. .

[Problem to be solved by the invention]

However, according to the studies of the present inventors, each of the above two drawing methods has the following problems.

First, in the vector scanning method using a spot beam, as the pattern figure to be drawn becomes finer, the spot width of the beam must be made smaller, so there is a problem that the throughput of the drawing process is reduced.

On the other hand, in the raster scan method using a rectangular beam, if the beam size is changed according to the pattern design dimension size, the throughput improves, but due to the physical Coulomb effect etc., the dimensional accuracy of the pattern varies depending on the beam size. Due to the difference, there is a problem that the dimensional accuracy of the pattern decreases.

The above-mentioned problems are becoming more prominent as masks, reticles, and patterns drawn directly onto devices become finer, and as semiconductor devices continue to become more highly integrated, sufficient It is assumed that it will be difficult to achieve improvements in pattern dimensional accuracy and throughput using conventional techniques.

An object of the present invention is to provide a technique that can improve the throughput and pattern dimensional accuracy of electron beam lithography on an object.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means to solve the problem]

A brief overview of typical inventions disclosed in this application is as follows.

That is, according to the electron beam lithography method of the present invention, when drawing a graphic pattern, a raster scan lithography method using a spot beam and a vector scan lithography method using a rectangular beam are used in combination.

Further, the electron beam writing apparatus of the present invention includes a rectangular beam forming section that forms an electron beam generated from an electron beam source as a rectangular beam, and a spot beam forming section that forms the electron beam as a spot beam. This is what we have in place.

[Effect]

According to the electron beam lithography method of the present invention described above, by selectively implementing a raster scan lithography method using a spot beam and a vector scan lithography method using a rectangular beam depending on the purpose, the pattern size of the former lithography method can be improved. A synergistic effect can be obtained by combining the improvement in accuracy and the improvement in throughput due to the latter drawing method.

Further, according to the above-described electron beam lithography arrangement of the present invention, by having both a rectangular beam forming section and a spot beam forming section, raster scan lithography and vector scan lithography can be performed with one device depending on the purpose. This can be done selectively, and the cost of the device can be greatly reduced compared to the case where both drawing methods are performed by separate devices.

[Embodiment 1] FIG. 1 is a schematic explanatory diagram of an electron beam lithography apparatus as an example of the present invention, and FIG. 2 is a schematic explanatory diagram showing an embodiment of the electron beam lithography method according to the present invention.

The electron beam lithography apparatus shown in the embodiment of FIG.
The structure is such that an electron beam 5 is generated and irradiated from an electron gun 4 provided at the top of the column 3 above the column 3 to form a desired graphic pattern.

The electron gun 4 is equipped with a thermionic emission cathode (not shown), and the material of the cathode is, for example, single crystal LaBs (
Lanthanum hexaboride) etc. are used.

The shape and scanning method of the electron beam 5 may be, for example, a vector scanning method using a rectangular beam, as will be explained later.
It also employs a rask scanning method using a spot beam.

In addition to the electron gun 4, the electron optical system in the electron beam drawing apparatus of this embodiment includes a planking electrode 6 made of two parallel metal plates, an irradiation lens 7, a first aperture 8, a shaped deflector 9, and a shaped lens. 10, second aperture ll1, a first reduction lens 12, a third aperture 13, a second reduction lens 14, a projection lens 15, a positioning deflector 16, and the like.

The first diaphragm 8 and the second diaphragm 11 can change how the former image and the latter image overlap, and the first diaphragm 8 and the second diaphragm 11 can change the way the former image and the latter image overlap. After passing through 1 1, the third aperture 13
The shape of the photoelectron surface of the electron beam 5 can be set continuously or fixedly.

In this embodiment, the first aperture 8, the shaping deflector 9, the shaping lens 10, and the second aperture 1l form a rectangular beam forming section. In this rectangular beam forming section, in order to form a rectangular beam, the rectangular beam is continuously formed by changing the way in which the image of the electron beam 5 that has passed through the first aperture 8 and the image of the second aperture l1 overlap. can be formed into

Further, in this embodiment, the third aperture 13 and the like constitute a spot beam forming section. In this spot beam shape corner, the electron beam 5 that has passed through the first aperture 8 and the second aperture 11 is formed as a circular spot beam by the third aperture 13. In this spot beam forming section, the electron beam 5 that has passed through the second aperture 11 and the third aperture 13 is reduced by the first reduction lens l2 and the second reduction lens 14, respectively, and focused by the projection lens 15. be exposed.

Further, the positioning deflector 16 is configured to control the arrival position of the electron beam 5 that has passed through the projection lens 15 with respect to the object to be drawn.

Further, the drive stage 2 is configured by combining drive stages in the X direction and the Y direction, which are movable in mutually orthogonal directions, in a stacked manner.

As a method of moving the drive stage 2, for example, a step-and-repeat method can be adopted.

Note that a loader l7 that supplies the object 1 to be drawn to the drive stage 2 is located on the side of the drive stage 2.

Furthermore, the drive stage 2 and the electron optical system (projection lens 1
(including lens systems such as 5) includes a manual input B18 for manually inputting data for drawing, and a data conversion/control unit 1.
9 and a drawing control section 20.

The operation of this embodiment will be explained below.

First, before drawing an unconventional pattern, the data manual section 18 manually inputs data in a drawing format. Then, this data is transferred to the data conversion/control unit l9.
The data conversion process is performed by the lithography controller 20, and the lithography is performed while controlling each mechanism of the electron beam lithography apparatus.

At this time, in the electron beam drawing of this embodiment, the pattern figure to be drawn is divided into an outline part forming the outline of the pattern figure 21 and an internal pattern inside the outline part, as shown in FIG.

When drawing the outline of the divided pattern figure 2l, the electron beam 5 generated from the electron gun 4, which is the electron beam source, passes through the first aperture 8, the second aperture 11, and the first reduction lens 1.
2, etc., when passing through the third aperture 13 constituting the spot beam forming section, it is made into a circular beam by the circular beam aperture of the third aperture 13, further reduced by the second reduction lens l4, and then, Projection lens l5
, to the outline of the pattern figure 21 to be drawn on the object 1 on the drive stage 2 through the positioning deflector 16.
It is irradiated as a fixed spot beam 22 using a raster scan method.

This spot beam 22 draws the outline of the pattern figure 21 on the object 1 to be drawn, and the pattern figure 2l
Framing is done.

When drawing the pattern figure 21 using the raster scan method using the fixed spot beam 22, the spot beam 22 is characterized by the fact that fluctuations in pattern dimensional accuracy due to the effects of the so-called proximity effect and Coulomb effect do not occur, so it is extremely effective. dimensional accuracy can be obtained.

On the other hand, when drawing the internal pattern of the pattern figure 21, since dimensional accuracy is not required for drawing the internal pattern or the rectangular part, a vector scanning method using a continuously variable shaped rectangular beam 23 is used. Draw with throughput.

That is, in this case, the electron beam 5 generated from the electron gun 4
The first aperture 8, the molded deflector 9, the molded lens 10, the second
In a rectangular beam forming section consisting of a diaphragm 11, a rectangular beam 23 is continuously variably shaped by a first diaphragm 8 and a second diaphragm 11 having rectangular beam apertures, and is irradiated onto the internal pattern of the pattern figure 21. Thereby, the internal pattern of the pattern figure 21 is drawn by the vector scanning method using the rectangular beam 23 that is continuously variably shaped, so that the drawing throughput is greatly improved.

As described above, in this embodiment, out of the pattern figure 21 to be drawn, the portion that requires dimensional accuracy, that is, the contour part, is drawn by the raster scanning method using the spot beam 22 with high dimensional accuracy, and dimensional accuracy is not required. Part ie internal pattern or rec H? B is drawn by the vector scan method using the rectangular beam 23 with good throughput, so the pattern figure 21 can be drawn with good dimensional accuracy and throughput.

[Embodiment 2] FIG. 3 is a schematic explanatory diagram of an electron beam lithography apparatus according to Embodiment 2 of the present invention.

In the second embodiment, the spot beam forming section and the rectangular beam forming section of the electron optical system in the column 3 of the electron beam lithography apparatus are arranged upside down compared to the first embodiment.

That is, in the second embodiment, the first aperture 8, the shaping deflector 9, the shaping lens 10, and the second aperture l1 that constitute the spot beam forming section are replaced by the third aperture 1 that constitutes the rectangular beam forming section.
It is located below 3 etc.

Also in the case of this second embodiment, the pattern figure 21 to be drawn
The outline of . This enables satisfactory electron beam lithography in terms of both dimensional accuracy and throughput.

As above, the invention made by the present inventor has been specifically explained based on Examples, but it should be noted that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Not even.

For example, it is possible to use a structure of an electron beam lithography apparatus and a lithography method other than those in the above embodiments.

In the above description, the invention made by the present inventor was mainly applied to electron beam lithography on masks and reticles for manufacturing semiconductor devices, which is the field of application of the invention, but the present invention is not limited to this, for example. It can also be applied to direct writing on semiconductor wafers, etc.

〔Effect of the invention〕

Among the inventions disclosed in this application, the effects obtained by typical inventions are briefly described below.

(1). According to the electron beam lithography method of the present invention, pattern figures are drawn using a raster scan lithography method using a spot beam and a vector scan lithography method using a rectangular beam. It is possible to improve both throughput and throughput.

(2) The figure pattern is divided into an outline part and an internal pattern inside the outline part, the outline part is drawn by raster scanning using a spot beam, and the internal pattern is drawn by vector scanning using a rectangular beam. As a result, contours that require high dimensional accuracy can be drawn without being affected by proximity effects or Coulomb effects, and high dimensional accuracy can be obtained, while internal patterns that do not require high dimensional accuracy can be drawn with high throughput. It is possible to perform good drawing due to the synergistic effect.

(3) According to the electron beam drawing apparatus of the present invention, an electron beam source that generates an electron beam for drawing, a rectangular beam forming section that forms the electron beam generated from the electron beam source as a rectangular beam, It consists of a spot beam forming section that forms the electron beam generated from the electron beam source as a spot beam, a lens system that shapes the electron beam generated from the electron beam source, and a support means that supports the object to be drawn. As a result, electron beam lithography with high dimensional accuracy and high throughput can be achieved with a single inexpensive device.

(4). According to (1) to (3) above, it is no longer necessary to create data for correcting the proximity effect, and therefore the drawing time that was conventionally required can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of an electron beam lithography apparatus according to an embodiment of the present invention, FIG. 2 is a schematic explanatory diagram illustrating an embodiment of an electron beam lithography method according to the present invention, and FIG. 1 is a schematic explanatory diagram of an electron beam lithography apparatus according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Object to be drawn, 2... Drive stage, 3... Column, 4... Electron gun, 5... Electron beam, 6... Planking electrode, 7... Irradiation lens, 8... Rod l diaphragm, 9... Molded deflector, 10... Molded lens, 11.
...Second aperture, 12...First reduction lens, 13...
3rd aperture, l4... Second reduction lens, 15... Projection lens, l6... Positioning deflector, 17... Loader, 18... Data human power department, 19... Data conversion/control 20... Drawing control unit, 21... Pattern figure, 22... Spot beam, 23... Rectangular beam. Agent Patent Attorney Daiwa Tsutsui

Claims (1)

[Scope of Claims] 1. A method for drawing a graphic pattern on an object to be drawn using an electron beam, which method includes a raster scan drawing method using a spot beam when drawing the graphic pattern;
An electron beam lithography method characterized by performing lithography in combination with a vector scan lithography method using a rectangular beam. 2. The figure pattern is divided into an outline part and an internal pattern inside the outline part, the outline part is drawn by a raster scan drawing method using a spot beam, and the internal pattern is drawn by a vector scan drawing method using a rectangular beam. 2. The electronic drawing method according to claim 1, wherein the electronic drawing method is performed by: 3. An electron beam source that generates an electron beam for drawing; a rectangular beam forming unit that forms the electron beam generated from the source into a rectangular beam; and a rectangular beam forming unit that forms the electron beam generated from the electron beam source into a spot. An electron beam lithography apparatus comprising a spot beam forming section that forms a beam, a lens system that shapes the electron beam generated from the electron beam source, and a support means that supports an object to be drawn. 4. The electron beam lithography apparatus according to claim 3, wherein the rectangular beam forming section comprises first and second aperture means arranged spaced apart from each other via a shaping lens.