JP2523910B2 - Electronic beam drawing method - Google Patents

Description

The present invention relates to an electron beam writing method.

In the conventional electron beam writing method, the method of moving the sample table
Step-and-repeat method and continuous movement method 2
There are types.

In the step-and-repeat method, for example, the drawing areas are connected while repeating the step movement in the X direction, the step ends are moved once in the Y direction at the end of the sample, and then −
Repeat the step movement in the X direction. When it reaches the end of the sample, it moves once in the Y direction. The above operation is repeated to draw the entire surface of the sample.

In the continuous movement method, for example, a striped area having a constant width is drawn while continuously moving the sample table in the X direction, and when the sample edge is reached, step movement is performed in the Y direction. continue,
-Move continuously in the X direction. The above operation is repeated to draw the entire surface of the sample.

In either method, the entire writing operation divides the sample into striped regions that are long in the X direction and connects these regions to perform the entire writing.

In order to improve the drawing accuracy, it is important to prevent the accuracy deterioration due to the step movement of the sample table in both drawing methods.
From this point of view, an attempt has been proposed in which the step movement amount is made smaller than the stripe width so that the stripes are overlapped and multiple writing is performed to improve the accuracy.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In such a conventional electron beam drawing method, drawing in the X direction is continuous in time, whereas drawing in the Y direction is not necessarily continuous, and the sample and the sample table are not necessarily continuous. Since various error factors such as the occurrence of a positional deviation with and the expansion due to the change in the sample temperature during drawing occur in the connecting portion in the Y direction, it is difficult to improve the accuracy unless the number of overlapping stripe-shaped drawing regions is increased.
Therefore, there is a problem that the drawing time becomes extremely long and the throughput decreases.

Means for Solving the Problems In order to solve the above problems, the electron beam drawing method of the present invention includes a first sample movement in which a sample continuously moves in one direction or an opposite direction or step movement is repeated, and A first drawing in which the entire surface of the sample is drawn by repeating a second sample moving in which a step moves in a direction orthogonal to the first sample moving direction at the end of the sample; and the first sample moving, The third sample movement which moves continuously in the orthogonal direction or repeats the step movement and the fourth sample movement which moves stepwise in the direction orthogonal to the direction of the third sample movement at the end of the sample are repeated. The second drawing for drawing the entire surface of the sample is overlapped.

By this method, drawing in the Y direction can be provided with temporal continuity, and highly accurate drawing can be realized with a small number of superimpositions.

Embodiments FIGS. 1A and 1B are drawing pattern diagrams for explaining an embodiment of an electron beam drawing method of the present invention.

In this embodiment, the sample moving method is a continuous moving method, and the number of times of superposition is once in the X direction and once in the Y direction for a total of two.
In each of FIGS. 1 (a) and 1 (b), 1 is a sample and 2, 3
Is a drawing pattern, and 4 to 9 are stripe-shaped drawing areas.

The first drawing is performed by connecting stripe-shaped drawing regions in the Y direction, as shown in FIG. That is,
The pattern 2 and the like are drawn while moving the sample on the stripe 4 in the -Y direction (arrow B ₁ ). When reaching the sample end, the stripe 5 is drawn while stepwise moving in the X direction (arrow A ₁ ) and then continuously moving the sample in the Y direction (arrow B ₂ ). Thereafter, the same operation is repeated to draw the entire surface of the sample.

The second drawing is performed by connecting stripe-shaped drawing regions in the X direction as shown in FIG. 1 (b). That is,
The movement of the sample is such that the first drawing and the X and Y are exchanged as indicated by arrows D ₁ , C ₁ , D ₂ , C ₂ , and D ₃ . Then, the entire surface of the sample is drawn.

Each drawing is performed with an exposure amount that is half the optimum exposure amount of the electron beam resist used. Therefore, the pattern to be resolved becomes an overlapping portion of each drawing, and the position accuracy is high. This will be described with reference to FIG.

In FIG. 2, 11a to 14a represent patterns drawn by the first drawing, 11b to 14b represent patterns drawn by the second drawing, and 11c to 14c represent patterns to be resolved.

Since the patterns 11a to 14a drawn by the first drawing are drawn continuously in time in the Y direction, the positional accuracy in the Y direction is extremely high, but the positional accuracy in the X direction is slightly inferior.
On the other hand, the patterns 11b to 14b drawn by the second drawing are X
The positional accuracy is high in the Y direction and slightly inferior in the Y direction.
Therefore, the overlapping portions 11c to 14c are resolved, but the positional errors of both are averaged to be 1/2. Compared with the case where only stripes in the same direction are superimposed, in the present invention, the highly accurate drawing pattern in the X direction and the highly accurate pattern in the Y direction are overlapped, so the degree of improvement in the position error is extremely large.

Even in the step-and-repeat method,
A great improvement in accuracy can be obtained in exactly the same manner.

It should be noted that, in each drawing, if the conventional method in which the step movement amount connecting the stripe-shaped drawing regions is made smaller than the stripe width and the stripes in the same direction are superposed together, the accuracy can be further improved.

EFFECTS OF THE INVENTION According to the electron beam writing method of the present invention, it is possible to perform writing with high pattern position accuracy by averaging errors due to sample movement.

[Brief description of drawings]

FIG. 1 is a drawing pattern diagram showing an electron beam drawing method in one embodiment of the present invention, and FIG. 2 is a plan view showing a drawing pattern in one embodiment. 1 ... Sample, 11a-14a ... First drawing pattern, 11b-14b
...... Second drawing pattern, 11c to 14c ...... Resolution pattern.

Claims (1)

(57) [Claims] 1. A first sample movement in which a sample continuously moves in one direction or an opposite direction or repeats step movement, and a step moves in an end portion of the sample in a direction orthogonal to the direction of the first sample movement. A first drawing in which the entire surface of the sample is drawn by repeating the second sample movement, and a third sample movement in which the first movement is repeated or a step movement is repeated in a direction orthogonal to the first sample movement and the sample At the end of the third
An electron beam drawing method, characterized in that the fourth sample movement of stepwise moving in a direction orthogonal to the sample movement direction is repeated to overlap a second drawing of the entire surface of the sample.