JPH0642070B2 - Method for creating exposure data for mask ROM integrated circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Outline] A method for creating exposure data for a mask ROM integrated circuit, which creates an exposure data file for exposing a mask ROM integrated circuit by data processing, and shortens the time for creating the exposure data. Exposure for manufacturing a mask ROM integrated circuit with a single exposure device, in which only the pattern of the ROM section differs depending on the data to be written, and the pattern of the peripheral circuit section other than the pattern of the ROM section is the same In a method of creating exposure data for a mask ROM integrated circuit for creating data, cell placement information of a plurality of ROM cells forming the ROM section is processed in advance to a form used in the exposure apparatus regardless of the value of write data, and cell placement is performed. The pattern is registered as an information conversion file, and the pattern of the peripheral circuit section of the exposure apparatus is registered based on the pattern arrangement information of the peripheral circuit section. Bulk exposure data to be used for exposure is generated in advance and registered as a bulk exposure data file, and when the data to be written is given, the data is written from the truth value for each bit of the data to be written and the cell information conversion file. The exposure apparatus is configured to generate ROM pattern exposure data to be used for exposing the pattern of the ROM section, and to obtain the exposure data of the entire mask ROM integrated circuit by combining it with the bulk exposure data from the bulk exposure data file.

[Industrial application field]

The present invention relates to a method of creating exposure data for a mask ROM integrated circuit, and more particularly to a mask R for creating an exposure data file for exposing a mask ROM integrated circuit by data processing.
The present invention relates to a method of creating exposure data for an OM integrated circuit.

The use amount of mask ROM integrated circuits is rapidly increasing due to higher performance, higher reliability, and lower prices, and for the generation of Kanji patterns such as printers and CRT displays due to the rapid development of Japanese information processing. The use amount of a large-capacity mask ROM integrated circuit as a memory is increasing.

Under such circumstances, it is desired to shorten the delivery time of mask ROM integrated circuit products.

[Conventional technology]

As shown in FIG. 3, the exposure pattern of the mask ROM integrated circuit comprises a main pattern 11 and an alignment peripheral pattern 12 which form the integrated circuit. Main pattern 11
A ROM pattern 13 and other bulk patterns such as a decoder pattern 14, a sense amplifier pattern 15, an input / output circuit pattern (not shown), and the like are arranged therein.

Cell Forming Layer Here, in order to manufacture a mask ROM integrated circuit, a multilayer mask 16 is required as shown in FIG. Mask ROM
Different types of masks have different multilayer masks 16, but
In the same type, even if the data to be written in the mask ROM is different, the mask 1 of the cell formation layer of the multilayer mask 16
The same mask can be used for the other masks, _except that 6 _n is different.

In the ROM pattern 13 of FIG. 3, as shown in FIG.
A plurality of ROM cells 17 are arranged in a matrix, and word lines 18a and bit lines 18b are provided above them. The mask 16 _n of the cell forming layer is used for each ROM cell 17 in the ROM pattern 13 by the bit line 18 b.
This is a mask for forming a pattern of a cell forming window (that is, a via hole) 19 for connecting to each other. This cell forming window 19
For example, the ROM cell 17 having a value of 1 stores a value of 1, and the ROM cell 17 having no cell forming window 19 stores a value of 0.

Of course, also in the decoder 14 and the sense amplifier 15, etc., the mask of the cell formation layer 16n has a pattern of cell formation windows for connecting the word line 18a and the bit line 18b to the decoder 14 and the sense amplifier 15, respectively. It is fixed for each variety.

FIG. 6 shows a system flowchart of an example of a conventional exposure data creating method for a mask ROM integrated circuit. This flowchart relates to the cell forming layer.

In the figure, in the input data processing of job step 21, write data file 2 which is data to be written in the mask ROM
2 is edited in accordance with the edit instruction information 23 input to the card, and data check is performed to generate a truth value data file 24 as shown in FIG. 7 (A).

In the ROM pattern generation process of job step 25, the truth value data file 24 and cell arrangement information 26 regarding the ROM pattern 13 as shown in FIG. 7 (B) which is input to the card (in the figure, x is x coordinate, y is y). From the coordinates, π is the rotation angle, and * is the address in the memory), a ROM pattern as shown in FIG. 7C corresponding to the write data is generated. Further, the decoder pattern, the sense amplifier, etc. are generated from the bulk information file 27 concerning the decoder pattern 14, the sense amplifier pattern 15, etc. to generate the exposure data first intermediate file 28.

In this exposure data first intermediate file 28, the ROM pattern is expanded in layers, but since the other bulks have a hierarchical structure, these hierarchical expansion processes are performed in job step 29, and the exposure data second intermediate Get the file 30.

Thereafter, the exposure data second intermediate file 30 is field-divided and sub-field-divided for electron beam exposure, and the scanning order of the electron beam in the sub-field is determined to supply the exposure data to the electron beam exposure apparatus. Generate the file 32.

[Problems to be Solved by the Invention]

If the mask ROM integrated circuit is of the same kind, the patterns of layers other than the cell formation layer are the same, and the pattern obtained from the bulk information is also the same in the cell formation layer, only the ROM pattern of the cell formation layer. Is different.

However, conventionally, even when the exposure data of the same type of mask ROM is created, all the patterns of the cell formation layer are generated in the job step 25. For this purpose, in job step 25, the Ebisdic code for the cell arrangement information is converted to a binary code, the layer is expanded for each pattern, the reticle magnification is multiplied, the proximity effect correction is shifted, the multiple exposure portion is removed, and the field is removed. Various complicated processes such as division and subfield division, and determination of scan order must be performed.

Therefore, in the conventional method, it takes a lot of time to create the exposure data, and there is a problem that the shortening of the delivery time of the product is limited.

The present invention has been made in view of the above points, and an object of the present invention is to provide an exposure data creation method for a mask ROM integrated circuit that shortens the time for creating exposure data.

[Means for Solving the Problems]

The mask ROM integrated circuit exposure data generation method of the present invention is different in accordance with the data to be written in only the pattern (13) of the ROM section in a single type, and the pattern of the peripheral circuit section other than the pattern (13) of the ROM section. An exposure data creating method of a mask ROM integrated circuit for creating exposure data for manufacturing a mask ROM integrated circuit (10) having the same (14, 15) by an exposure apparatus, comprising: The cell placement information (50) is processed in advance to a form used in the exposure apparatus regardless of the value of the write data, and the cell placement information conversion file (52)
(51), bulk exposure data used for exposure of the patterns (14, 15) of the peripheral circuit section is generated in advance by the exposure apparatus from the arrangement information of the pattern of the peripheral circuit section, and the bulk exposure data file (5
5) is registered (54), and when the data to be written is given, the pattern (13) of the ROM section in the exposure device is read from the truth value for each bit of the data to be written and the cell information conversion file (52). R used for exposure
OM pattern exposure data is generated and combined with the bulk exposure data from the bulk exposure data file (55) to obtain exposure data for the entire mask ROM integrated circuit (10) (60).

[Action]

In the method of the present invention, the cell layout information conversion file (5
2) and the bulk exposure data file (55) are generated and registered, and when the write data is given, the ROM pattern exposure data is simply generated using the cell arrangement information file (52). Then, the bulk exposure data of the bulk exposure data file (55) are combined to obtain the exposure data of the entire mask ROM integrated circuit.

Therefore, the processing when write data is given becomes much simpler than in the conventional case, and the processing time is greatly shortened.

〔Example〕

FIG. 2 shows a block diagram of a system for realizing the method of the present invention.

In the figure, 40 is a CPU, and 41 and 42 are storage devices. A program for each job step shown in FIG. 1 is stored in the storage device 41, and is sequentially read and executed by the CPU 40. The storage device 42 stores the files shown in FIG. Further, the card reader 43 reads the input card and supplies it to the CPU 40.

FIG. 1 shows a system flow chart of an embodiment of the method of the present invention. This flowchart relates to the cell forming layer, and the exposure data creation is divided into three in the method of the present invention.

In FIG. 1 (A), the cell placement information 50 input to the card is first converted from an Ebisdic code to a binary code in the cell placement information translation process of job step 51. After that, in job step 51, the pattern is expanded hierarchically, the reticle magnification is multiplied for all the cell patterns, that is, the patterns of the cell formation windows, and the shift (correction of the pattern) such as the proximity effect correction is performed. Field division is performed, the scan order of cell patterns in each divided subfield is determined, and the cell arrangement information conversion file 52 is generated.

This cell arrangement information conversion file 52 has an arrangement position on the chip and an address in the memory for each cell pattern, and is shown in FIG. 7C except that the presence or absence of the cell formation window is indefinite. It is the exposure data itself of the ROM pattern 13 as shown.

In FIG. 1B, the bulk information file 53 stores bulk information about the bulk of the decoder 14, the sense amplifier 15 and the like excluding the ROM pattern 13 in the main pattern 11.

This bulk information file 53 is subjected to bulk exposure data creation processing at job step 54. Here, the patterns are hierarchically developed, the reticle magnification is multiplied for each pattern, and a shift such as a proximity effect correction is performed. Further, a multiple exposure portion between adjacent patterns is removed, and field division and subfield division are performed. The scanning order of the patterns in each of the divided and divided subfields is determined, and the bulk exposure data file 55 for exposing the bulk of the decoder 14, the sense amplifier 15, etc. is generated.

A mask R is newly added to the cell placement information translation process and the bulk exposure data creation process shown in FIGS.
The cell placement information file 52 obtained by this is executed only at the beginning of developing one kind of OM integrated circuit.
The bulk exposure data file 55 is stored in the library registered.

In FIG. 1C, the write data file 56 stores the data to be written in the mask ROM by the user. In the editing instruction information 57 input to the card, the write data file 56 has, for example, 4 files of 1 word and 8 bits each, and the type of mask ROM to be manufactured is, for example, 1 word of 32 bits and 1 file of 4 M bits. In this case, it is composed of information for instructing the editing, a model name of the mask ROM to be manufactured, and a user number for specifying the data to be written in the mask ROM.

In the input data processing of the job step 58, the write data file 56 is edited according to the edit instruction information 57, and data check is performed using the error detection code added to the write data to generate the truth value data file 59.

This truth value data file 59 has a truth value of 1 or 0 (for example, 1 for each bit of the write data) indicating an address in the memory and the presence or absence of a cell formation window.
Indicates that there is a cell formation window), and in addition to this, the product name and user number are added.

In the ROM pattern generation process of job step 60, the truth value data file 59 is read, the cell placement information conversion file 52 and the bulk exposure data file 55 registered in the library are read, and the truth value data file 59 and the cell placement are read. The information file 52 is matched with the address in the memory, and the ROM pattern exposure data is generated in consideration of the presence / absence of the cell formation window for each cell pattern. At the same time, a pattern for displaying the type name and the user number is added to the bulk exposure data, and then the exposure data file 61 for exposing the entire main pattern 11 by the electron beam exposure apparatus is generated by merging with the exposure data of the ROM pattern. To do.

In the mask ROM of the type already developed, only the input data processing 58 and the ROM pattern generation processing shown in FIG. 1C are executed according to the user's order.

When all the processes shown in FIGS. 1A, 1B and 1C are executed, the same processing time as the conventional one is required, but a relatively long time is required for the mask ROM of the type already developed. Since it is not necessary to execute the job steps 51 and 54, the time for executing the job in FIG.
It is shortened to 5 to 1/10.

〔The invention's effect〕

As described above, according to the exposure data creation method of the mask ROM integrated circuit of the present invention, the processing time required to create the exposure data is significantly shortened as compared with the conventional method, and the short delivery time of the product can be realized. It is extremely useful in practice.

[Brief description of drawings]

FIG. 1 is a system flowchart of one embodiment of the method of the present invention, FIG. 2 is a system configuration diagram for realizing the method of the present invention, FIG. 3 is a diagram for explaining a mask ROM integrated circuit, and FIG. FIG. 5 is a diagram for explaining a multi-layered mask, FIG. 5 is a diagram for explaining a ROM cell, FIG. 6 is a system flowchart of a conventional method, and FIG. 7 is a diagram for explaining a part of the processing of FIG. Is. In the figure, 50 is cell arrangement information, 51 is cell arrangement information translation processing, 52 is cell arrangement information conversion file, 53 is bulk information file, 54 is bulk exposure data creation processing, 55 is bulk exposure data file, and 56 is write data. A file, 58 is an input data process, 59 is a truth value data file, and 60 is a ROM pattern generation process.

Claims (1)

[Claims] 1. A ROM section pattern (13) of a single product type.
Only the exposure data for manufacturing the mask ROM integrated circuit (10) in which the pattern (14, 15) of the peripheral circuit part other than the pattern (13) of the ROM part is the same in the exposure apparatus. In a method of creating exposure data of a mask ROM integrated circuit to be created, cell arrangement information (50) of a plurality of ROM cells forming the ROM section is processed in advance to a form used in the exposure apparatus regardless of the value of write data, Location information conversion file (5
(2) is registered as (2), and bulk exposure data used for exposing the patterns (14, 15) of the peripheral circuit section in the exposure apparatus is generated in advance from the arrangement information of the pattern of the peripheral circuit section, and a bulk exposure data file is generated. It is registered as (55) (54), and when the data to be written is given, the ROM section in the exposure apparatus is read from the truth value for each bit of the data to be written and the cell information conversion file (52). Exposure data of the entire mask ROM integrated circuit (10) is obtained by combining it with the bulk exposure data from the bulk exposure data file (55) (60). ) A method of creating exposure data for a mask ROM integrated circuit, characterized in that