JP7238218B2 - Mask pattern manufacturing apparatus and mask pattern manufacturing method - Google Patents

Description

The present invention relates to a mask pattern manufacturing apparatus and a mask pattern manufacturing method.

In the manufacture of semiconductors, especially in the manufacture of LSIs, the optical proximity effect (OPE) has become conspicuous and complicated with the progress of miniaturization technology, and large-scale correction has become essential. A correction process called OPC (Optical Proximity Correction) has been developed to restore a mask pattern that has been deformed by OPE to approximate the original mask pattern.

In order to perform the correction process more accurately, it is necessary to reduce the grid size, which is the minimum unit of correction. OPC is performed based on layout data of circuit elements, but there is a problem that OPC takes a lot of time when the amount of data related to the object becomes enormous. In addition to this, since the amount of data after OPC is also enormous, there is a problem that the disk capacity becomes large and the size and cost of the apparatus are increased.

It is known that as the scale and pattern increase, the amount of variation in the OPE is greater in the outer side than in the inner side, while the central portion has a constant amount of variation.

In view of the above, Japanese Unexamined Patent Application Publication No. 2002-100003 discloses a mask pattern design method aiming at cost reduction by shortening the OPC processing time and the turnaround time of semiconductor device manufacturing. According to the technique of Patent Document 1, OPC processing is performed on a cell library pattern in advance, and a semiconductor chip is created using the OPC-processed cell library pattern. At this time, the mask pattern design method includes a cell library pattern design process in which a proximity effect correction process for correcting a shape change that occurs when a mask pattern is exposed to form a pattern is performed for each cell library; It includes a step of arranging a library and designing a mask pattern, and a step of changing the correction amount of the proximity effect correction applied to the cell library in consideration of the influence of the cell library patterns arranged around.

Further, Patent Document 2 discloses a mask manufacturing method for reducing the time required for OPC processing. This mask making method includes the steps of dividing the layout of a semiconductor integrated circuit into a plurality of unit areas, defining a processing area including each unit area, and defining an optically affected area that optically affects each unit area. creating an OPC layout comprising: extracting from the processing area; performing OPC processing on the geometry in the processing area to create an OPC layout; and fabricating a mask based on the OPC layout. If the figure in the area overlaps the optically affected area and includes an abnormal portion violating the design criteria, the OPC process is performed after removing the abnormal portion from the figure.

Furthermore, Patent Document 3 discloses a mask for manufacturing semiconductor devices having a first mask layer and a second mask layer. The first mask layer includes first exposure areas in which a first halftone pattern is formed to define first pattern areas. Also, the second mask layer includes a second exposure area in which a binary pattern area and a second halftone pattern are formed to define a second pattern area. By using a second mask layer composed of a binary pattern and a halftone pattern, after the first exposure using the first mask layer, misalignment and registration of the halftone film and the light blocking film induced Abnormal exposure in primary exposure can be corrected by secondary exposure.

Non-Patent Document 1 discloses library-based OPC in which pre- and post-OPC patterns calculated by model-based OPC are registered in a correction library, and when the same pattern is corrected again, the patterns in the correction library are reused. It is Further, an OPC tool is disclosed that can perform correction with a small number of simulations by combining this library-based OPC with rule-based OPC that is normally performed. Furthermore, a technique called DFM (Design for Manufacturability), which is a technique for predicting and solving problems that occur at the stage of transition from design to manufacturing, is also disclosed. It is stated that the improvement of shape prediction accuracy and the reduction of calculation time, which are contradictory issues, should be overcome.

JP 2006-276079 A Japanese Patent Application Laid-Open No. 2008-145600 JP 2006-106757 A

Toshiya Kotani, 2 others, "OPC Technology and DFM Technology Supporting Miniaturization of Semiconductor Devices", Toshiba Review, Vol. 67, No. 4 (2012), p. 11-15

SUMMARY OF THE INVENTION It is an object of the present invention to overcome and further promote the contradictory issues of improving the accuracy of pattern shape prediction and shortening the calculation time.

In the embodiment of the present invention, pre-OPC mask position information before performing optical proximity correction in the full-scale cell is associated with a simulation size region having an area obtained by reducing the area of one full-scale cell for manufacturing semiconductors. OPC means for performing optical proximity correction using simulation size area information; dividing the simulation size area into influence degree corresponding areas according to the degree of influence of the optical proximity effect in the full-scale cell; (b) influence-corresponding area mask information group creating means for creating an influence-corresponding area mask information group configured by assigning post-OPC mask position information after optical proximity correction obtained by said OPC means and said pre-OPC mask position information; selects required influence corresponding area mask information from the influence corresponding area mask information group according to the influence of the optical proximity effect in each area of the influence corresponding area of all areas in the full size cell, and selects the necessary influence corresponding area mask information map generating means for arranging degree-corresponding region mask information in corresponding areas to generate an influence-corresponding region mask information map for all regions in the full-scale cell; and design rule check means for performing a design rule check for verifying at least a size and space deviation in the full-scale cell based on the area mask information.

1 is a configuration diagram of a mask pattern manufacturing apparatus according to an embodiment of the present invention; FIG. FIG. 4 is an explanatory diagram of simulation size region information used in the mask pattern manufacturing apparatus according to the embodiment of the present invention; FIG. 4 is a diagram for explaining the first type of simulation size area segmentation used in the mask pattern manufacturing apparatus according to the embodiment of the present invention; FIG. 4 is a diagram for explaining a second type of simulation size area segmentation used in the mask pattern manufacturing apparatus according to the embodiment of the present invention; FIG. 5 is a diagram for explaining a third type of simulation size area segmentation used in the mask pattern manufacturing apparatus according to the embodiment of the present invention; FIG. 4 is a diagram for explaining a fourth type of simulation size area segmentation used in the mask pattern manufacturing apparatus according to the embodiment of the present invention; 4 is a flow chart for explaining the operation of the mask pattern manufacturing apparatus according to the embodiment of the present invention; FIG. 4 is a diagram for explaining how the mask pattern manufacturing apparatus according to the embodiment of the present invention divides the simulation size area into influence degree corresponding areas according to the influence degree of the optical proximity effect in the full-scale cell. In the mask pattern manufacturing apparatus according to the embodiment of the present invention, each divided area includes pre-OPC mask position information PM indicated by a dashed frame and post-OPC mask position after optical proximity correction indicated by a solid square mark. The figure explaining that information is matched. FIG. 4 is an explanatory diagram of an influence-corresponding region mask information group created by the mask pattern manufacturing apparatus according to the embodiment of the present invention; FIG. 4 is a diagram showing an influence degree corresponding area mask information map of all areas in a full-scale cell generated by the mask pattern manufacturing apparatus according to the embodiment of the present invention;

A mask pattern manufacturing apparatus and a mask pattern manufacturing method according to embodiments of the present invention will be described below with reference to the accompanying drawings. In each figure, the same components are denoted by the same reference numerals, and overlapping descriptions are omitted. FIG. 1 shows a configuration diagram of a mask pattern manufacturing apparatus according to an embodiment of the present invention. A computer unit 10 includes a CPU, a main memory, an external storage device, and has all the programs necessary for manufacturing a semiconductor mask pattern.

An input device 20 and an output device 30 are connected to the computer section 10 . The input device 20 is used to input commands and various data to the computer unit 10, and includes a keyboard, a pointing device such as a mouse, a touch panel, and the like. It includes all input means such as those for inputting data. However, not all input means need to be connected, and appropriate input means can be connected.

The output device 30 is for externally outputting all data and information output from the computer unit 10, and includes all output means such as various display devices, printer devices, storage media devices, and audio output devices. shall include However, not all the output means need to be connected, and appropriate output means can be connected.

The computer unit 10 has the following units implemented by programs. That is, they are OPC means 11 , influence degree corresponding area mask information group creating means 12 , map creating means 13 and design rule checking means 14 . The OPC means 11 creates a simulation size region in which the simulation size region having the reduced area of one full-scale cell for manufacturing semiconductors is associated with pre-OPC mask position information before optical proximity correction in the full-scale cell. The area information is used to correct the optical proximity effect. The OPC processing method by the OPC means 11 is not limited as long as it generates correction data according to the degree of influence of the OPE.

The influence corresponding area mask information group creating means 12 divides the simulation size area into influence corresponding areas according to the influence of the optical proximity effect in the full-scale cell, and the OPC means for each influence corresponding area. A group of influence-corresponding area mask information is created by allocating post-OPC mask position information after optical proximity effect correction obtained by and the pre-OPC mask position information.

The map generating means 13 selects required influence corresponding area mask information from the influence corresponding area mask information group according to the influence of the optical proximity effect in each area of the influence corresponding area of all the areas in the full size cell. Then, the influence corresponding area mask information is arranged in the corresponding area to generate an influence corresponding area mask information map of the entire area in the full size cell.

The design rule check means 14 performs a design rule check for verifying at least the size and space deviations in the full-scale cell based on the influence degree corresponding area mask information of the generated influence degree corresponding area mask information map.

Since each of the above means needs to perform processing, information on the area S of one full-scale cell for semiconductor manufacturing and information on the area s obtained by reducing the area S of the full-scale cell are provided in advance from the input device 20 . Further, the input device 20 provides in advance simulation size region information in which pre-OPC mask position information before optical proximity correction in the full-scale cell is associated with the simulation size region of the area s. When pre-OPC mask position information before optical proximity correction in the full-scale cell is given in advance from the input device 20, this simulation size area information is based on this pre-OPC mask position information and the information on the area s. The computer section 10 may create it.

The simulation size region information is obtained by associating the pre-OPC mask position information PM with the rectangular region which is the simulation size region E having the area s as shown in FIG. In this figure, the pre-OPC mask position information PM is indicated by a square mark, but depending on the contents of the OPC processing performed by this apparatus, it is not limited to a mark and may be a numerical value. The simulation size area information specifies the coordinates in the rectangular area that is the simulation size area E of the area s and the size (vertical and horizontal dimensions) of the layer (lattice) to determine the OPE influence at that position (coordinates). There is no particular limitation as long as the information can be calculated and the OPC can be appropriately corrected.

It should be noted that the rectangular area (that is, the layer corresponding to the mask), which is the simulation size area E of the area s, is preferably repeated to some extent regularly (periodically) like a memory element. It suffices if it has a length that stably reflects the influence of the OPE in . For example, the simulated size region E of area s above preferably includes an area reflecting the effects of several typical OPEs in a full scale cell. Of course, the simulated size region E of area s above may be an area all reflecting the effects of some typical OPE in a full scale cell.

Specifically, as shown in FIG. 3, the simulation size area E can be composed of four corner areas EA, EB, EC, and ED of a predetermined area at the four corners of a rectangle, and the other area CC ( the first type). Among the four corners of the predetermined area, the area existing between two pairs of two corners existing at the ends of the first two parallel sides of the rectangle (rectangle of areas EA, EB, EC, and ED) is defined as the degree of influence. It can be divided into corresponding areas. For example, as shown in FIG. 4, the first two sides are one side (strip-shaped area) formed by area S1 connecting area EA and area ED and one side (strip-shaped area) formed by area S2 connecting area EB and area EC. area). Each of the regions S1 and S2 can be equally divided (for example, divided into three equal parts, four equal parts, etc.) (referred to as a second type).

Further, among the four corners of the predetermined area, an area existing between two pairs of two corners existing at the ends of the second two sides different from the first two parallel sides of the rectangle corresponds to the degree of influence. It can be divided into multiple areas. For example, as shown in FIG. 5, two pairs of areas (areas A pair of EA and area EB and a pair of area EC and area ED). At this time, for example, as shown in FIG. 5, the first two sides are defined as one side by region S3 connecting area EA and area EB and one side by region S4 connecting area EC and area ED. can be done. Each of the regions S3 and S4 can be equally divided (for example, divided into three equal parts, four equal parts, etc.) (referred to as a third type).

As shown in FIG. 6, the simulation size area E exists at the four corners (areas EA to ED) of the predetermined area and the ends of the first two parallel sides of the rectangle in the four corners of the predetermined area. Regions S1 and S2 that exist between two pairs of two corners, and two corners that exist at the ends of the second two sides of the rectangle that are different from the first two parallel sides of the four corners of the predetermined area. It is divided into regions S3 and S4 existing between the pairs, the four corners (areas EA to ED), and the central area CC2 other than the above regions. Further, the central area CC2 is divided into small areas CCs having the same area (referred to as a fourth type).

The method of dividing the simulation size region described above is merely an example, and any dividing method may be used as long as it does not deviate from the gist of the present embodiment. For example, in the fourth type, the central area CC2 may be divided into a plurality of small areas having different sizes.

The operation of the apparatus according to this embodiment, including the setting of the simulation size area information, will be described below with reference to the flowchart shown in FIG. As already explained, the area of one full-scale cell for semiconductor manufacturing, the area obtained by reducing the area of this one full-scale cell, the pre-OPC mask position information before optical proximity correction in the full-scale cell, Simulation size area information or the like associated with the pre-OPC mask position information is set (or partially created) in the simulation size area having the reduced area (STEP 11).

Next, optical proximity correction is performed using the simulation size area information (STEP 12). The simulation size area E is divided into influence degree corresponding areas according to the influence degree of the optical proximity effect in the full-scale cell (STEP 13). FIG. 8 shows an example of division by this process. In this embodiment, the simulation size area E is divided into 9 blocks. The four corner areas EA to ED in the nine blocks are the areas where the OPE has the greatest influence. In this embodiment, the area MA between the four corner areas EA and ED and the area between the four corner areas EB and EC MB is the area where the degree of influence of OPE is the next largest, and the other areas are areas where the degree of influence of OPE is the most stable.

Each area divided in STEP 13 is associated with pre-OPC mask position information PM indicated by a dashed square frame and post-OPC mask position information after optical proximity correction indicated by a solid square mark. , which is shown in FIG. These are mask position information such as the coordinates and the size of the area surrounded by the frame lines, which are indicated by marks and filling in FIG. 9 . Therefore, each area divided in STEP 13 after OPC is assigned and set with the post-OPC mask position information and the above-mentioned pre-OPC mask position information. and the pre-OPC mask position information are assigned to create an influence-corresponding region mask information group as shown in FIG. 10 (STEP 14).

The group of influence-corresponding area mask information created in STEP 14 is shown in FIG. Impact-corresponding area mask information of influence-corresponding areas (abbreviated as "areas" in the figure) A, B, C, and D, and influence of influence-corresponding area E in the center between influence-corresponding areas A and D Degree of influence corresponding area mask information, influence corresponding area mask information of influence corresponding area F in the center between influence corresponding areas B and C, influence corresponding areas A, E and D and influence corresponding areas B and F , C, and the influence corresponding area mask information of the influence corresponding areas G, H, and I. Influence corresponding areas G, H, and I in FIG. 10(b) are the influence corresponding area mask information located at the positions of areas EG, EH, and EI in FIG. 10(a).

After the group of influence corresponding area mask information is created as described above, next, the influence corresponding area mask is generated according to the degree of influence of the optical proximity effect in each area of the influence corresponding area of the whole area in the full size cell. Required influence corresponding area mask information is selected from the information group, and this influence corresponding area mask information is arranged in the corresponding area to generate an influence corresponding area mask information map of the entire area in the full size cell (STEP 15 ).

The area of the impact corresponding area of all the areas in the full-size cell is the same size as the impact corresponding areas A, E, D, B, F, C, G, H, and I described using FIG. . Moreover, the influence corresponding area mask information group is divided into influence corresponding areas according to the influence of the optical proximity effect in the full-scale cell, and the optical proximity effect obtained by the OPC means 11 is divided for each influence corresponding area. Since the corrected post-OPC mask position information and the pre-OPC mask position information are assigned, the influence degree corresponding areas A, E, D, B, F, C, G, H, and I correspond to the actual object. It is clear to which area in the area of the influence corresponding area of all the areas in the large cell is associated.

Therefore, it is possible to select required influence corresponding area mask information, arrange this influence corresponding area mask information in a corresponding area, and generate an influence corresponding area mask information map of the entire area in the full size cell. .

FIG. 11 shows the degree-of-impact region mask information map generated as described above. In FIG. 11, it can be seen that the required influence corresponding area mask information is appropriately selected from the influence corresponding areas A, E, D, B, F, C, G, H, and I and arranged.

When the influence corresponding area mask information map for the entire area in the full-scale cell is generated as described above, at least the dimensions and space in the full-scale cell are calculated based on the influence corresponding area mask information of the influence corresponding area mask information map. A design rule check is performed to verify the deviation of (STEP 16).

According to the above embodiment, the entire processing time can be shortened compared to the case where the OPC processing is performed on the full-size cell as it is. In addition, the amount of data to be stored can be greatly reduced compared to the case where the OPC processing is performed on the full-scale cell as it is. Furthermore, even if the scale of the full-scale cell is changed, it will be possible to deal with it by repeatedly using the information of the area where the degree of influence of OPE is the most stable, which has the effect of shortening the time required for OPC processing. .

REFERENCE SIGNS LIST 10 computer section 11 OPC means 12 influence level corresponding area mask information group creating means 13 map generating means 14 design rule checking means 20 input device 30 output device

Claims (12)

Using simulation size region information in which pre-OPC mask position information before performing optical proximity correction in the full-scale cell is associated with a simulation-size region having an area obtained by reducing the area of one full-scale cell for semiconductor manufacturing. OPC means for optical proximity correction;
The simulation size area is divided into influence degree corresponding areas according to the degree of influence of the optical proximity effect in the full-scale cell, and for each influence degree corresponding area, an OPC post-OPC mask after optical proximity effect correction obtained by the OPC means influence-corresponding area mask information group creating means for creating an influence-corresponding area mask information group configured by assigning position information and the pre-OPC mask position information;
Selecting required influence corresponding area mask information from the influence corresponding area mask information group according to the influence of the optical proximity effect in each area of the influence corresponding area of all areas in the full size cell, and corresponding to this influence map generation means for arranging region mask information in corresponding areas and generating an influence degree corresponding region mask information map for all regions in the full size cell;
and design rule checking means for performing a design rule check for verifying at least a deviation of dimensions and spaces in a full-scale cell based on the influence degree corresponding area mask information of the generated influence degree corresponding area mask information map. mask pattern manufacturing equipment. 2. The influence degree corresponding area mask information group creating means configures the simulation size area by four patterns of four corners of a predetermined area at the four corners of a rectangle and one pattern of other areas. The mask pattern manufacturing apparatus described. The influence-corresponding area mask information group creating means assigns an area existing between two pairs of two corners existing at the ends of first two parallel sides of a rectangle among the four corners of the predetermined area as an influence. 3. The mask pattern manufacturing apparatus according to claim 2, wherein the group of influence-corresponding region mask information corresponding to the influence is created by dividing into a plurality of corresponding areas. The influence-corresponding area mask information group creating means is configured to create a mask between two pairs of two corners existing at the ends of second two sides different from the first two parallel sides of the rectangle among the four corners of the predetermined area. 4. The mask pattern manufacturing apparatus according to claim 3, wherein an existing region is divided into a plurality of areas corresponding to degrees of influence, and a group of mask information corresponding to regions corresponding to degrees of influence is created. The influence degree corresponding area mask information group creating means divides the simulation size area into
four corners of the predetermined area; and
an area existing between two pairs of two corners existing at the ends of first two parallel sides of a rectangle among the four corners of the predetermined area;
a region existing between two pairs of two corners existing at the ends of second two sides different from the first two parallel sides of a rectangle among the four corners of the predetermined area;
Divided into a central area other than the four corners and the area,
3. A mask pattern manufacturing apparatus according to claim 2, wherein said central area is divided into small areas having the same area, and said small areas are used as the group of influence corresponding region mask information of the same pattern. The influence degree corresponding area mask information group creating means divides the simulation size area into
four corners of the predetermined area; and
an area existing between two pairs of two corners existing at the ends of first two parallel sides of a rectangle among the four corners of the predetermined area;
a region existing between two pairs of two corners existing at the ends of second two sides different from the first two parallel sides of a rectangle among the four corners of the predetermined area;
Divided into a central area other than the four corners and the area,
3. A mask pattern manufacturing apparatus according to claim 2, wherein said central area is divided into small areas having the same area, and said small areas are used as a group of mask information corresponding to regions of influence corresponding to different patterns in a plurality of stages. Using simulation size region information in which pre-OPC mask position information before performing optical proximity correction in the full-scale cell is associated with a simulation-size region having an area obtained by reducing the area of one full-scale cell for semiconductor manufacturing. an OPC step for optical proximity correction;
The simulation size area is divided into influence degree corresponding areas according to the degree of influence of the optical proximity effect in the full -scale cell. an impact-corresponding area mask information group creating step of creating an impact-corresponding area mask information group configured by assigning the mask position information and the pre-OPC mask position information;
Selecting required influence corresponding area mask information from the influence corresponding area mask information group according to the influence of the optical proximity effect in each area of the influence corresponding area of all areas in the full size cell, and corresponding to this influence a map generation step of arranging the region mask information in the corresponding area and generating an influence degree corresponding region mask information map of the entire region in the full size cell;
and a design rule check step of performing a design rule check for verifying at least a size and space deviation in the full-scale cell based on the influence degree corresponding area mask information of the generated influence degree corresponding area mask information map. mask pattern manufacturing method. 8. The method according to claim 7, wherein, in said influence level corresponding area mask information group creation step, said simulation size area is composed of four patterns of four corners of a predetermined area at four corners of a rectangle and one pattern of other areas. The mask pattern manufacturing method described. In the influence level corresponding area mask information group creation step, an area existing between two pairs of two corners existing at the ends of first two parallel sides of a rectangle among the four corners of the predetermined area is defined as an influence level. 9. The mask pattern manufacturing method according to claim 8, wherein the group of influence-corresponding area mask information corresponding to the influence is created by dividing into a plurality of corresponding areas. In the influence degree corresponding region mask information group creation step, between two pairs of two corners existing at the ends of the second two sides that are different from the first two parallel sides of the rectangle, among the four corners of the predetermined area. 10. The method of manufacturing a mask pattern according to claim 9, wherein an existing area is divided into a plurality of areas corresponding to the degree of influence, and an influence degree corresponding area mask information group corresponding to the degree of influence is created. In the influence level corresponding area mask information group creation step, the simulation size area is
four corners of the predetermined area; and
an area existing between two pairs of two corners existing at the ends of first two parallel sides of a rectangle among the four corners of the predetermined area;
a region existing between two pairs of two corners existing at the ends of second two sides different from the first two parallel sides of a rectangle among the four corners of the predetermined area;
Divided into a central area other than the four corners and the area,
9. The method of manufacturing a mask pattern according to claim 8, wherein the central area is divided into small areas of the same size, and the small areas are used as the group of influence corresponding region mask information of the same pattern. In the influence level corresponding area mask information group creation step, the simulation size area is
four corners of the predetermined area; and
an area existing between two pairs of two corners existing at the ends of first two parallel sides of a rectangle among the four corners of the predetermined area;
a region existing between two pairs of two corners existing at the ends of second two sides different from the first two parallel sides of a rectangle among the four corners of the predetermined area;
Divided into a central area other than the four corners and the area,
9. The method of manufacturing a mask pattern according to claim 8, wherein the central area is divided into small areas of the same area, and the small areas are used as a group of mask information corresponding to regions of different pattern influence levels in a plurality of steps.

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