JPS6212506B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing the occurrence of gaps in a mask pattern, and particularly to a method for preventing the occurrence of gaps in a mask pattern in a mask exposure apparatus that creates a mask pattern by dividing an exposure pattern into rectangular shapes and performing exposure. Regarding prevention methods.

Recently, variable aperture exposure apparatuses have been used as exposure apparatuses for creating etching masks for fine patterns of LSIs, hybrid ICs, and other devices. The exposure device divides the pattern to be exposed into a plurality of rectangles and performs the exposure.
Exposure of each rectangle is performed by forming a rectangular opening corresponding to given rectangular data representing the rectangle using a mechanical shutter.

However, in such exposure equipment, due to the shutter dimensions of the exposure equipment and the limits of the mechanical precision of shutter alignment, gaps of about 1 micron may occur where the rectangular patterns meet. If a film such as an LSI is formed using a mask with large gaps, defects such as pattern breakage may occur.

In order to prevent the occurrence of such gaps, conventionally,
A mask approximately 10 times the size of the desired mask is created using the exposure apparatus, and this mask is reduced to create a mask of the desired size, thereby absorbing and erasing the gap.

However, in the conventional type, when creating a mask of a desired size, it is necessary to reduce the size of the mask, so there is an inconvenience that extra effort is required to create the mask.

SUMMARY OF THE INVENTION In view of the above-mentioned problems with the conventional type, an object of the present invention is to provide a mask pattern gap prevention method based on the concept of correcting rectangular data input to an exposure device in advance according to a predetermined procedure. To eliminate troubles such as pattern breakage in film formation for LSI, etc. by eliminating the trouble of absorbing gaps in mask patterns by using small particles, automatically and reliably preventing the generation of gaps in mask patterns by a simple procedure. It is in.

The present invention provides a method for preventing gaps in a mask pattern in a mask exposure apparatus that creates a mask pattern by dividing an exposure pattern into rectangles and exposing each rectangle based on pattern data corresponding to each rectangle. If one side of the first rectangle among mutually adjacent rectangles is included within one side of the second rectangle, move one piece of the first rectangle outward by a slight width. Expand the first rectangle,
When a part of one side of a first rectangle and a part of one side of a second rectangle among mutually adjacent rectangles touch, a rectangle with a slight width that includes the side of the touching part in the center. It is characterized by generating new pattern data.

An embodiment of the present invention will be described below with reference to the drawings. In the present invention, for example, a pattern to be exposed as shown in FIG. 1 is divided into rectangles A, B, and C as shown in FIG. Coordinate data representing two diagonal points of a rectangle (X ₁ , Y ₁ ; X ₂ , Y ₂ ), (X ₃ , Y ₃ ;
X ₄ , Y ₄ ), _{(X 5 , Y 5 ;} However, if exposure is performed using such coordinate data as is, there is a risk that a gap G1 or G2 will be created between each rectangle A, B or B, C, as shown in FIG. 3, for the reason mentioned above. Therefore, in the present invention, according to the principle described in detail later, the rectangle B is expanded so that the side of the rectangle B that adjoins the rectangle A is slightly moved toward the rectangle A side, as shown by the dotted line in Figure 4. The coordinate data of rectangles A and B are corrected to prevent a gap G1 from occurring between rectangles A and B. Furthermore, the gap G2 between the rectangles B and C can be created by adding and exposing a new rectangle D, as shown by diagonal lines in FIG. It is prevented.

FIG. 5 shows a pattern data processing apparatus for implementing the method of the invention. The device shown in the figure includes memories 1, 2, and 3 for storing pattern data at each processing stage, a recognition circuit 4 for recognizing the pattern data stored in the memory 1 and creating data necessary for rectangular division, and a memory 2. a dividing circuit 5 that divides the pattern data stored in the memory into rectangles; a comparing circuit 6;
A first correction circuit 7, a second correction circuit 8, and a conversion circuit 9 are provided.

The operation of the pattern data processing device shown in FIG. 5 will be explained. Input pattern data D _IN automatically generated by a computer or the like or created by a digitizer or the like is input and stored in the memory 1 . The input pattern data D _IN is given as data representing the coordinates of each corner point in the exposure pattern shown in FIG. 1, for example. Next, in the recognition circuit 4, the memory 1
Data necessary for rectangular division is recognized and extracted from the coordinate data stored in the memory 2 and stored in the memory 2. That is, the diagonal 2 of each rectangle as shown in Figure 2
Point coordinate data X ₁ , Y ₁ ; X ₂ , Y ₂ ; X ₃ , Y ₃ ; X ₄ ,
Y ₄ ; X ₅ , Y ₅ ; X ₆ , Y ₆ are recognized and stored in the memory 2. Furthermore, the coordinate data stored in the memory 2 is sent to the dividing circuit 5 for each rectangle A, B,
The information is divided and organized by C and stored in the memory 3.
That is _, the coordinate data stored in the memory 3 are: Rectangle A...X ₁ , Y ₁ and X ₂ , Y ₂ Rectangle B...X ₃ , _{Y 3} and X ₄ , Y ₄ Rectangle C... They are classified and stored by rectangle, such as X ₆ and Y ₆ .

The coordinate data stored in the memory 3 in this manner is read out to the comparator circuit 6, and it is determined whether correction is necessary and the type of correction. To explain in more detail, the comparison circuit 6 compares the coordinate data of each rectangle stored in the memory 3 and determines whether there are adjacent rectangles (for example, whether the X coordinate values match), and Determine the state of adjacent sides of adjacent rectangles. That is, when the sides of one rectangle B are included in the sides of the other rectangle A, as in rectangles A and B in FIG. 2 (Y ₁ ≦Y ₃ ≦Y ₂ ,
If Y ₁ ≦Y ₄ ≦Y ₂ ), each coordinate data and correction command signal are input to the first correction circuit 7 . On the other hand, when the sides of one rectangle B partially overlap the sides of the other rectangle C, such as rectangles B and C in FIG. 2 (Y ₃ ≦Y ₆ ≦Y ₄ , Y ₅ ≦Y ₃ ≦
In the case of _Y6 ), each coordinate data and correction command signal are input to the second correction circuit 8.

The first correction circuit 7 expands the left side of the rectangle B as shown by the arrow in FIG. 4, that is, moves the left side of the rectangle B to the left by a slight width, as shown by the dotted line. In this case, the expansion width is set to a value that can correct the maximum gap width expected from the alignment accuracy of the shutter of the exposure device. The first correction circuit 7 generates new coordinate data of the rectangle B expanded in this way.
X _{3 ′} , _{Y 3} ;
It is replaced with the original coordinate data (X ₃ , Y ₃ ; X ₄ , Y ₄ ) and stored.

The second correction circuit 8 generates a new rectangle D having a very small width similar to that described above, which includes the sides of the mutually overlapping portions of the rectangles B and C in the center, and uses the coordinate data (X ₇ , Y ₃ ; X ₈ , Y ₆ ) are newly written to memory 3.

In this way, the coordinate data of the rectangle A, the expanded rectangle B, the rectangle C, and the added rectangle D are stored in the memory 3, and the conversion circuit 9 converts these coordinate data into output data D suitable for the exposure apparatus. _OU
It is converted into _T and input to the exposure device.

Although the above description has been made regarding the case where the exposure pattern is divided into rectangular patterns along the Y axis, that is, the axis in the vertical direction of the drawing, the present invention is not limited to this. It is clear that it can be done.

As described above, according to the present invention, by correcting the exposure data input to the exposure apparatus in advance, it is possible to eliminate the trouble of absorbing gaps between mask patterns due to reduction of the mask, etc. Through this procedure, it is possible to automatically and reliably prevent the occurrence of gaps in mask patterns, and it is possible to eliminate defects such as pattern breakage in film production for LSI and the like.

[Brief explanation of the drawing]

FIG. 1 is a pattern diagram showing an example of a pattern to be exposed, FIG. 2 is a pattern diagram showing an example of a method of dividing the pattern in FIG. A pattern diagram showing a state where a gap has occurred,
FIG. 4 is a pattern diagram for explaining a gap generation prevention method according to an embodiment of the present invention, and FIG. 5 is a pattern data processing diagram for carrying out a gap generation prevention method according to an embodiment of the present invention. FIG. 2 is a block circuit diagram showing the device. 1, 2, 3...memory, 4...recognition circuit, 5...
...Dividing circuit, 6... Comparison circuit, 7... First correction circuit, 8... Second correction circuit, 9... Conversion circuit.

Claims (1)

[Claims] 1. In a method for preventing gaps between mask patterns in a mask exposure apparatus in which a mask pattern is created by dividing an exposure pattern into rectangles and exposing each rectangle based on pattern data corresponding to each rectangle, the first of the rectangles
If one side of the rectangle is included within one side of the second rectangle, expand the first rectangle so that the one piece of the first rectangle is moved outward by a slight width, and When part of one side of a first rectangle and part of one side of a second rectangle among adjacent rectangles touch, a rectangular pattern with a minute width that includes the side of the adjacent part in the center. A method for preventing gap generation in a mask pattern, characterized by generating new data.