JPH065501A - Manufacture of semiconductor - Google Patents

Abstract

PURPOSE:To correct pattern data and thereby to widen a process window by executing plotting after the amount of change in a plotting density is decreased by correcting a plotting pattern by addition of a supplementary pattern or partial deletion of the pattern. CONSTITUTION:In the case when a change in a plotting density is reckoned as large, it is decreased by correcting a pattern. By adding a supplementary pattern 2a to a signal line 2, in other words, the line width is enlarged from Ws to Ws'. In this way, the value of the dimensional ratio between the line widths Wm and Ws (Wm/Ws') of a power supply trunk line before correction is made smaller. Thereby a plotting density of a part of proximity of the power supply trunk line 1 and the signal line 2 to each other is increased, the relative change in the plotting density is lessened, a process window is widened and stable machinability can be obtained. Accordingly, it is prevented that the signal line 2 is reduced or disconnected due to failure in maintenance of a necessary dimension.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing method, and more particularly to a method of correcting a drawing pattern in an electron beam direct drawing technique.

[0002]

2. Description of the Related Art When drawing a fine pattern using an electron beam drawing technique, pattern accuracy cannot be ensured unless the drawing data is corrected in consideration of the proximity effect. The proximity effect is a phenomenon in which incident electrons are backscattered from the substrate and are returned to the resist to be exposed, and the size is reduced between adjacent patterns, and conversely, the size is increased in isolated patterns (in the case of a negative resist). On the other hand, conventionally, it has been usual to make corrections by methods such as line width classification and contour correction.

[0003]

As a result of examining these correction methods, the present inventor has found that the following problems occur. That is, with these correction methods, it is difficult to sufficiently perform correction in a portion where the pattern density or dimension of the drawing pattern changes drastically. For example, the power supply main line (line width 100 μm) and the signal line (line width 1 μm) , The process window (the optimum range of process processing conditions) is narrowed, it is difficult to secure the dimensional accuracy of the signal wiring, and stable workability cannot be obtained.

Further, since the EB direct drawing is affected by the step difference of the background, it is necessary to optimize the proximity effect correction.
Also in this respect, it is difficult to secure a process margin. In particular, in the case where the influence of the step difference of the underlying layer also overlaps in a place where the change of the pattern density is large, it may lead to disconnection failure of the signal wiring, which is a serious problem.

An object of the present invention is to correct pattern data and widen the process window. Another object of the present invention is to enable stable processing accuracy of the minimum processing size. The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0006]

In order to achieve the above object, the present invention corrects a drawing pattern by adding a reinforcing pattern or deleting a part of the pattern to reduce the amount of change in drawing density and then perform drawing. It was done like this.
In the above case, a rectangular pattern or a pattern formed by combining rectangles is preferably used as the addition of the reinforcing pattern. Further, in the above case, the partial deletion of the pattern is preferably performed in a rectangular shape or a combination of rectangles.

[0007]

According to the above means, the drawing pattern is corrected,
By reducing the amount of change in the drawing density, the influence of the proximity effect in the low density drawing area where the conventional high density drawing area is close is suppressed, which makes it possible to widen the process window and always provide stable machining accuracy. You will be able to secure. Also, in suppressing the amount of change in drawing density,
By adding a reinforcement pattern to the low density drawing portion to increase the drawing density of the portion, the influence of the proximity effect can be relatively suppressed.

Further, in order to suppress the change amount of the drawing density, by deleting a part of the pattern from the high density drawing portion to reduce the drawing density of the portion, the influence of the proximity effect can be relatively suppressed. Moreover, by adding a reinforcing pattern and deleting a part of the pattern in a rectangular shape,
The correction of the drawing data of the deleted portion can be performed very simply and at high speed, and the decrease in throughput can be minimized.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 3 is a diagram showing a pattern before the correction according to the present invention is applied. As shown in FIG. 3, in this pattern,
Thick power supply trunk line 1 with a line width Wm = 100 μm and a line width W
A thin signal line 2 having a size of s = 1 μm is arranged in close proximity. If drawing is performed as it is, the line width of the signal line 2 cannot receive the required dimensional accuracy due to the proximity effect from the power supply trunk line 1 as described in the prior art. Because
While the power supply main line 1 having a high drawing density is being drawn, the line width is reduced by direct exposure due to drawing and indirect exposure due to scattering generated during drawing of the adjacent portion, while the signal line 2 with a low drawing density is obtained. This is because the line width is enlarged in the drawing of since it is not subjected to such indirect exposure.

In this embodiment, in order to easily evaluate the amount of change in the drawing density, attention is paid to the line width of lines that are close to each other. That is, firstly, a sudden change in the drawing density causes a problem in the vicinity of a plurality of lines (circuit patterns), and even if the drawing density suddenly changes during drawing of isolated lines, it does not cause a problem. This is because the line width of each line is simple to show the amount of change in the drawing density at the adjacent points of the plurality of lines. Therefore, in this embodiment, attention is paid to the dimensional ratio of Wm and Ws, and when Wm / Ws is equal to or greater than a predetermined value (R), correction is performed assuming that the drawing density change is large. R
The smaller the value of, the more the change in pattern drawing density can be suppressed. However, since the correction work takes time, R = 20 in this embodiment.

If it is recognized that the change in the drawing density is large according to the above determination conditions, the pattern is corrected and reduced. FIG. 1 and FIG. 2 are diagrams showing patterns after correction is applied. FIG. 1 shows a case where correction is performed by adding a reinforcing pattern, and corresponds to claim 2. FIG. 2 shows a case where correction is performed by partially deleting the pattern.
It corresponds to.

That is, in FIG. 1, the tip width is changed from Ws to Ws' by adding the reinforcing pattern 2a to the signal line 2.
Has been expanded to. Thus, if the value of the dimensional ratio of Wm and Ws (Wm / Ws') is set to a small value, the power supply trunk line 1
The drawing density of the portion close to the signal line 2 becomes high, the relative change of the drawing density becomes small, the process window becomes wide, and stable workability can be obtained. Therefore, the signal line 2 cannot be reduced in size or broken without maintaining the required dimensions.

Further, in FIG. 2, power supply trunk lines 1 to 1
As shown in a, the line width is changed from Wm to W by deleting a part in a rectangular shape.
It has been reduced to m '. Of course, the deletion at this time is performed within the limit range such as power supply migration.
Thus, the dimensional ratio of Wm 'and Ws (Wm' / Ws)
With a small value, the drawing density in the vicinity of the power supply main line 1 and the signal line 2 becomes low, the relative change in the drawing density becomes small, and the process window becomes wide and stable workability can be obtained. Like Therefore, the signal line 2 cannot be reduced in size or broken without maintaining the required dimensions.

As described above, in the above-described embodiment, the drawing pattern is corrected by adding the reinforcing pattern or deleting the part of the pattern to reduce the change amount of the drawing density and then perform the drawing. Conventionally, the influence of the proximity effect in the low-density drawing portion where the high-density drawing portion is close to is suppressed, so that the process window can be widened, and stable processing accuracy can always be ensured. Further, in order to suppress the change amount of the drawing density, by adding a reinforcing pattern to the low density drawing portion to increase the drawing density of the portion, the effect of the proximity effect can be relatively suppressed. Moreover, by adding the reinforcing pattern and partially deleting the pattern in a rectangular shape, the correction of the drawing data of the deleted part can be performed very simply and at high speed, and the decrease in throughput can be minimized. Become.

It is needless to say that the present invention is not limited to the above embodiment and can be applied to all elements other than the power supply trunk line and the signal line. Further, the correction of the present invention may be performed at the time of designing the pattern, or may be performed simultaneously with the drawing by the drawing device, and the point is that the actually drawn pattern may be corrected. . Although only the amount of change in the pattern density has been described as the correction condition, the pattern may be reinforced by taking the base level difference into consideration as the correction condition.

[0016]

As described above, according to the present invention, it is possible to widen the process window by alleviating the abrupt change of the pattern drawing density, so that the stable processing accuracy can be obtained regardless of the line width. There is an effect that can be secured.

[Brief description of drawings]

FIG. 1 is a diagram showing a pattern after a correction according to the present invention is added.

FIG. 2 is a diagram showing a pattern after a correction according to the present invention is added.

FIG. 3 is a diagram showing a pattern before correction according to the present invention is applied.

[Explanation of symbols]

 1 Power supply trunk line 1a Part deleted by correction 2 Signal line 2a Part added by correction Wm Line width of power supply trunk line before correction Wm 'Line width of power supply trunk line after correction Ws Line width of signal line before correction Ws' After correction Line width of signal line

Claims (3)

[Claims] 1. A semiconductor manufacturing method, wherein when a pattern is drawn by an electron beam direct drawing technique, the pattern is corrected to reduce the amount of change in drawing density and then the drawing is performed. 2. The semiconductor manufacturing method according to claim 1, wherein the correction of the pattern is performed by adding a reinforcing pattern. 3. The semiconductor manufacturing method according to claim 1, wherein the correction of the pattern is performed by partially deleting the pattern.