JPH01158730A - Electron beam lithography - Google Patents

Abstract

PURPOSE:To eliminate the thinning of a pattern, the disconnection of the pattern, etc., even if an alignment error occurs between fields by devising the pattern shape near a field boundary. CONSTITUTION:The pattern width of at least one field side is enlarged with respect to wiring patterns L1-L6 exceeding boundaries I-X-IV-X of a plurality of divided fields A-D thereby to form first margin patterns L1m-L6m. Further, the pattern of other field side is extended in a predetermined length at one field side, thereby forming second margin patterns L1l-L6l. Accordingly, even if the alignment error of the fields due to the moving accuracy of a stage 6 occurs, malfunctions, such as the thinning of the pattern, the disconnection of the pattern, etc., can be avoided as long as the error does not exceed the widths of the patterns L1m-L6m and the predetermined length of the patterns L1l-L6l.

Description

[Detailed Description of the Invention] [Summary] Regarding the step-and-repeat electron beam lithography method, by devising the pattern shape near the field boundary, even if a field alignment error occurs, pattern thinning or pattern breakage can be avoided. The purpose of the present invention is to provide an electron beam lithography method that does not cause defects, and in an electron beam lithography method in which a predetermined pattern is divided into a plurality of fields and lithography is repeated for each field to form a predetermined pattern. When drawing a pattern that exceeds the field, the pattern width on at least one field side is slightly expanded to form a first margin pattern, and the pattern on the other field side is extended to one field side to form a second margin pattern. forming a pattern.

[Industrial application field]

The present invention relates to an electron beam lithography method for pattern formation in a semiconductor manufacturing process, and particularly to a step-and-repeat electron beam lithography method.

The feature of pattern forming technology that uses electron beams is that it can not only draw micron-sized or smaller patterns, but also does not require the mask used in pattern forming technology using ultraviolet rays or X-rays, and has the ability to generate patterns at high speed by itself. That's true. Therefore, we are developing high-speed masks and reticles that take advantage of the high-speed writing capabilities of electron beam lithography.
Furthermore, "electron beam direct writing" is performed to draw fine patterns directly onto the resist on the wafer. This ``electron beam direct writing'' can omit the mask and reticle manufacturing process, so it has a great effect on shortening the development period of semiconductor devices. In addition, the pattern generation function is, for example, computer aided design (CAD).
sign) system etc., so
Pattern data of a compound LSI or the like having a large-area pattern constructed in a CAD system can be flexibly transferred onto a wafer.

[Conventional technology]

FIG. 2 is a diagram showing an electron beam lithography apparatus.

In the figure, an electron beam drawing apparatus 1 includes an electron beam E
an electron gun 2 that irradiates the electron beam B, a blanking electrode 4 that blanks the electron beam EB in the mask portion according to the pattern data PT from the pattern generator 3, and a deflector 5 that deflects the electron beam EB according to the writing position information of the pattern data PT. and a stage 6 on which the wafer W is placed, and exposes a desired position on the wafer W indicated by the pattern data PT to an electron beam EB to insolubilize or dissolve the resist to form a pattern. are doing.

By the way, when drawing a large-area pattern on the wafer W using such an electron beam drawing apparatus 1, the area that can be drawn in -degrees is limited by the maximum deflection angle of the deflector 5. Step
Therefore, the stage 6 of the electron beam lithography apparatus 1 can be moved in the X and Y directions by a drive mechanism (not shown) according to a predetermined control signal, and the desired position of the wafer W is centered on the field. The pattern in the field is drawn according to the pattern, and then the stage 6 is moved to draw the pattern in the adjacent field.This operation is repeated, and finally a large-area pattern is drawn.

[Problem that the invention seeks to solve]

However, in such conventional electron beam lithography methods, the width of the pattern beyond the boundary of each field is the same as the width of the pattern within the field. If there is a large misalignment between a field and an adjacent field, so-called alignment error between fields, problems such as the bonding surface of a pattern that crosses the field boundary may shift (pattern thinning) or may not be bonded (pattern disconnection). was there.

The present invention was made in view of these problems, and
It is an object of the present invention to provide an electron beam lithography method that does not cause defects such as thinning of the pattern or disconnection of the pattern even if a field alignment error occurs by devising the pattern shape near the field boundary.

[Means for solving problems]

In order to achieve the above object, the present invention provides an electron beam drawing method in which a predetermined pattern is divided into a plurality of fields and drawing is repeated for each field to form a predetermined pattern. When drawing, the pattern width on at least one field side is slightly expanded to form a first margin pattern, and the pattern on the other field side is extended to one field side to form a second margin pattern. ing.

[For production]

In the present invention, first and second margin patterns are formed near the boundaries of patterns that exceed the boundaries of each field.

Therefore, even if an alignment error occurs between fields, as long as this error does not exceed the first and second margin patterns, pattern breakage can be avoided if the pattern becomes thinner.

〔Example〕

Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, and shows a pattern diagram near the boundary of fields A to D divided into a plurality of fields.

That is, Ll and Lz are wiring patterns placed between fields A and 8 beyond the boundary 1-X, and L3゜L is placed between fields A and C beyond the boundary 11-X. Wiring pattern, L5 crosses the boundary ■-X to fields C and D
The wiring pattern L6 placed between the two fields is a wiring pattern placed between the fields D and 8 beyond the boundary TV-X.

The wiring pattern that touches the boundary between the left side and the bottom side of each field has its pattern width slightly expanded (for example, 1.25 times the pattern width), and the expanded portion is the first margin pattern L In ~ L611+ is formed. Further, the wiring pattern in contact with the boundary between the right side and the top side of each field extends to the adjacent field by a predetermined length β, and the extended portion becomes the second margin pattern L It ”
L 6 L is formed.

Next, the effect will be explained.

Pattern data in which first and second margin patterns are formed in advance on a wiring pattern beyond the field boundary is created by, for example, a CAD system.

Then, the electron beam drawing apparatus 1 shown in FIG. 2 forms a pattern on the wafer W according to this pattern data. First, the first field formation is completed, and then the stage 6 is moved to form the second field B. At this time, if a field alignment error due to the movement accuracy of the stage 6 occurs, for example, in the direction of the arrow indicated by Z in the figure, Ll and Lz on the field B side are already aligned with the wafer W.
It is formed to be shifted in the Z direction by the alignment error amount from L1 and L2 of field A formed above.

However, the wiring pattern L+ on the field B side.

Since the first margin pattern L1m+LZm is formed in L2, the alignment error is the first margin pattern L, □, L. . As long as the width of the wiring patterns L1 and L2 on the field A side and the field B side do not exceed the width, if the pattern becomes thinner, no disconnection of the pattern will occur.

Furthermore, due to alignment error in the Z direction, field B moves away from field D, causing wiring pattern L6 to move away from boundary IV.
-X is the boundary, but the second margin pattern L61 and the first margin pattern wrinkle □ are separated by a predetermined length l.
As long as the alignment error does not exceed the predetermined length l, the wiring pattern L6 will not be separated.

In this way, according to this embodiment, for the wiring patterns L1 to L6 that cross each boundary of the plurally divided fields A to D from ■-X to IV-X, the pattern width on the field side is Enlarged first margin pattern L1m~
L6□ is formed, and the pattern on the other field side is further extended by a predetermined length β toward one field side to form a second pattern.
Since the margin patterns LIL to L6a are formed, even if a field alignment error occurs due to the movement accuracy of the stage 6, this alignment error will affect the width of the first margin patterns L1m to L6□ and the second margin pattern. As long as the predetermined length β of the margin patterns LIL to L61 is not exceeded, it is possible to avoid problems such as pattern disconnection if the pattern becomes thin.

In this embodiment, the first margin pattern is provided on one field side across the boundary; however, the first margin pattern may be provided on both field sides.

Further, the second margin pattern extending from the other field side to the one field side may also extend to both sides, or the first margin pattern may be provided on both sides, and this first margin pattern The pattern may be extended to also have the function of a second margin pattern.

Further, in this embodiment, the pattern that crosses the boundary is a wiring pattern, but it is not limited to this, and it goes without saying that other patterns, such as a resistor pattern, may be used.

〔Effect of the invention〕

According to the present invention, when drawing a pattern beyond the field boundary, the pattern width on at least one field side is slightly expanded, and the pattern on the other field side is extended to extend to the one field side. Therefore, even if an alignment error occurs between fields, as long as the error does not exceed the enlarged width of the pattern or the extended bone, it is possible to avoid pattern breakage if the pattern becomes thinner.

[Brief explanation of the drawing]

FIG. 1 is a pattern diagram of a main part near a field boundary showing an embodiment of an electron beam lithography method according to the present invention, and FIG. 2 is a configuration diagram showing an electron beam lithography apparatus. A-D...Field, I-X~IV-X...Boundary, L I" Lb...Wiring pattern, L1m~
L6□...First margin pattern, LIL~
L6L...Second margin pattern.

Claims (1)

[Scope of Claims] In an electron beam drawing method in which a predetermined pattern is divided into a plurality of fields and drawing is repeated for each field to form a predetermined pattern, at least one of the fields is drawn. An electronic device characterized in that a first margin pattern is formed by slightly expanding the pattern width on the field side of the field, and a second margin pattern is formed by extending the pattern on the other field side to one field side. Beam drawing method.