JPH02139913A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate dead time of data retrieval by transferring exposure data of a basic unit section to a part of a buffer memory, by transmitting exposure data divided into blocks which become a non-repeatable section to the remaining renewable part and by forming a pattern through combination of both exposure data. CONSTITUTION:An electron beam exposure device 31 includes an A/B buffer 32, a pattern generating section 7 to divide pattern data into each shot of beam and a switch 8 to switch the A/B buffer 32 during data accession from a mass storage magnetic disc 5 and data transfer to the pattern generation section 7 of an after-stage. The A/B buffer 32 is provided with an A buffer renewable section 32-a, a B buffer renewable section 32-b, and an A, B buffer repetition data holding section 32-c. The A/B buffer 32 is provided with a holding section to hold data of a basic cell to be used for repetition exposure treatment among exposure data. Data of the basic cell stored in the holding section is held until exposure of the entire chips is finished.

Description

[Detailed Description of the Invention] C) A. Existing Industrial Application Fields Prior Art (Figures 2 to 6) Problems to be Solved by the Invention Examples of Means and Actions for Solving Problems to be Solved by the Invention One implementation of the present invention Example (First Title of the Invention [Summary]) Regarding a method for manufacturing a semiconductor device, it is possible to access exposure data in a mass storage device in a forward and continuous manner, eliminate wasted time in data retrieval, and The purpose of the present invention is to provide a method for manufacturing a semiconductor device that can save memory by making it possible to divide and transfer data, and to provide a method for manufacturing a semiconductor device, which includes a storage device that stores exposure data, and a predetermined exposure pattern based on the exposure data. A method for manufacturing a semiconductor device comprising: a pattern generation section for generating a pattern; and a buffer memory provided between the storage device and the pattern generation section for transferring and holding the exposure data, the method comprising: Of the exposure data, the exposure data of the basic unit section which becomes the repetitive exposure processing section is transferred to a part of the buffer memory, and the exposure data of the basic unit section is held until the end of exposure of the entire chip. The exposure data that is the non-repeating portion of the exposure data is divided into predetermined blocks and transferred to the remaining updatable portions, and the exposure data of the basic unit portion and the exposure data of the non-repeating portion are combined to form a pattern of the predetermined block. do,
Thereafter, the above steps are repeated to expose the entire chip.

[Industrial application field]

The present invention relates to a method for manufacturing a semiconductor device, and more particularly to an improvement in a pattern exposure method of an exposure apparatus.

Currently, phototransfer technology using ultraviolet light is often used to form semiconductor device patterns on wafers, and masks and reticles are used as original plates.

When a pattern is formed on a mask or reticle or directly on a wafer, a charged particle exposure device such as an electron beam is currently the mainstream pattern generating device.

The above exposure apparatus performs storage and control using data obtained by dividing the original pattern of a semiconductor device into basic unit figures such as rectangles or trapezoids.

This exposure data is generally stored and retained on a large-capacity magnetic disk within the device control computer. There is a part called a pattern generation part within the apparatus, which divides each basic unit figure into, for example, one shot of a finer electron beam.

While data access to a magnetic disk takes several milliseconds to several tens of seconds, processing in the pattern generation section is a high-speed processing on the order of several microseconds. Therefore, in order to fill the gap in processing speed between the two, it is common practice to place a buffer memory composed of semiconductor memory between the magnetic disk and the pattern generation section. Transfer and store all necessary exposure data,
Subsequent data transfer to the pattern generation section is performed from the buffer memory at high speed.

[Conventional technology]

In recent years, large-scale integration of memories such as 16 Mbit DRAMs has been progressing more and more, and the amount of exposure data that exposure apparatuses have to handle has also become enormous. For example, in the case of 16Mbit DRAM, it is a collection of hundreds of millions (hundreds of megabytes) of basic figures, but among memory products such as DRAM and SRAM, the memory cell part is made up of the same figure (several bits of memory). It's repetitive.

Taking advantage of this property, a "layered data structure" is created in which data is divided into a cell part and other peripheral circuit parts, and the cell part is further divided into several bits of data and its repetition information (starting point, number, pitch). Recently, data compression methods using .

However, even if this data compression method is used, the data is still 16MbitD.
Even RAM must handle tens of millions of pieces of data (several tens of megabytes). If one piece of data is made up of several bytes, the number of semiconductor memories required for the buffer memory is on the order of several tens even if the current mainstream I Mbit DRAM is used, which increases the cost of the device and reduces reliability. The problem becomes even more serious when the memory density is 16M or more.

Examples of basic configurations of conventional methods for manufacturing semiconductor devices of this type include those shown in FIGS. 2 to 6, for example. Second
The figure is a diagram of the equipment configuration when using two buffers, Figure 3 is a diagram for explaining compression of memory data using a hierarchical data structure, Figure 4 is a diagram for explaining data storage in a magnetic disk, FIG. 5 is a diagram showing a chip pattern consisting of three exposure fields, and FIG. 6 is a diagram showing the data arrangement of the graphic data section in the magnetic disk in the case of FIG.

In FIG. 2, 1 is an electron beam exposure device equipped with two buffer memories to speed up data access.
The electron beam exposure apparatus 1 includes an apparatus control computer 2, a data bus 3, an interface 4, and an A/B buffer 6 consisting of a large capacity magnetic disk (storage device) 5.2 buffers (A/B) for temporarily storing pattern data. , a pattern generator 7 that divides the pattern data into each shot of the beam.
The structure includes a switch 8 for switching the A/B buffer 6 when receiving data from the large-capacity magnetic disk 5 and transferring data to the pattern generating section 7 at the subsequent stage. Shows the equipment inside.

Here, a large-capacity magnetic disk 5 is used as a large-capacity storage device for storing pattern data, and although the large-capacity magnetic disk 5 is fast in the forward direction and access processing between consecutive parts is fast, random access processing is slow. It has the characteristic of being unsuitable. In addition, the A/B buffer 6 is connected to each buffer A.
and B are independent and cannot be used like A+B.

A+B corresponds to the case of 1 buffer. Various variations other than the system configuration shown in FIG. 2 are possible.

For example, a buffer may be directly connected to a large computer for data processing without using the magnetic disk 5 of the device control computer 2, or a single buffer may be used but partitions may be managed using software to store multiple data. There are examples of receiving and forwarding. In any case, a combination of a large-capacity storage device that is fast in forward and continuous access but not good at random access processing, and buffers each having a limited capacity is sufficient. Incidentally, the advantage of two-bandwidth is that by alternately exchanging the roles of transfer/exposure, one's own data transfer time can be offset by the other party's exposure time.

FIG. 3 shows a tree diagram when the hierarchical data structure is applied to a memory IC. In Figure 3, the chip data is
They are classified horizontally into repeating parts C, such as memory cells, and non-repetitive parts D, such as other peripheral circuits, and each of these consists of a graphic data part expressing actual exposure data, and placement information specifying the arrangement within the chip. It is divided into part a. The arrangement information for the non-repeating portion d is simple, and it is sufficient to specify the individual arrangement coordinates of the graphic data group from the common origin of the graphic data portion, which is usually centered on the chip.

In the case of memory cells, a cell block in which basic cells consisting of only a few bits are arranged, for example, 128 bits, is further divided into one cell block.
A method of arranging 6 Mbits is adopted. Therefore, in this conventional example, the placement information is ``basic cell placement information within a cell block'' and ``cell block placement information within a chip.''
An example is shown in which the data is divided into two layers. However, if the layout information is controlled separately by software or logic circuits and only the figure data part is transferred to the buffer memory, it is sufficient to describe the transfer of the figure data part to the buffer; Whether something is a thing or not is not essential.

FIG. 4 shows an example of data storage order within a volume when a magnetic disk is employed as the mass storage device, as an example of data storage within the mass storage device.

As shown in FIG. 4, the layout information section and the graphic data section 4 are separated, and the graphic data section is stored following the layout information section. This is because although placement information and actual graphic data are associated using labels, they are independent in the sense that they are in different hierarchies. What is important in this case is that the data format that is the most advanced in data compression is that only one repeating unit of each type, such as all basic cells, is collected at the beginning of the graphic data, followed by a non-repeating section (today). This is realized within the large storage device.

Normally, when designing with CAD, the original data of a cell is one piece, and a method is adopted in which placement information is given to it and expanded. Therefore, during data processing to create data compatible with an exposure apparatus, the above request can be automatically achieved by processing the cell portion first. In other words, it is sufficient to simply store the output as it is in the mass storage device. In this case, instead of collecting the basic cell data at the beginning of the figure data as described above, it is also possible to distribute the cell data to appropriate parts.If it is possible to do this, the solution described below The reciprocation of the head within the magnetic disk, as pointed out in the problem, is eliminated. However, in this case, in addition to the difficulty of data processing, there is a disadvantage that the data compression rate decreases.

FIG. 5 is a diagram showing an example of a pattern of a chip', and considers a case where an electron beam exposure device that moves a stage in a step-and-repeat manner is used as an exposure device. In FIG. 5, 10 is a chip pattern, and the pattern 1O consists of three exposure fields 11-13. A pattern is formed in the field by deflecting the electron beam with an electromagnetic/electrostatic deflector installed in the column of the apparatus, and after each field is exposed, the stage is moved to the next field position. Here, it is assumed that although the data of each field cannot be stored in the A/B buffer 6 at the same time, each field can be stored in both buffers.

The field 11 includes a cell block 15, which is an expanded basic cell (basic unit unit) 14 shown by hatching in the figure, and a peripheral circuit (
The field 12 is composed of a non-repetitive part) 21 and 22, and the field 12 is composed of only the peripheral circuit 23 and the field 13
is composed of a cell block 15 and peripheral circuits 24 and 25, respectively. Note that for the repetition expansion, the repetition start point coordinates (xo, yo), the number of placements (N, , Ny), and the placement pitch (P, , P,) are used as placement information.

As shown in FIG. 6, the arrangement of the graphic data in the graphic data section when this data is stored on the magnetic disk 5, only the non-repeated portion of each field is stored after the common basic cell data.

In the above configuration, the transfer/exposure movements of both buffers when the conventional transfer method is applied to the two-buffer electron beam exposure apparatus 1 are shown in Attached Table 1.

As shown in Attachment 1, first, the data of the part necessary for field 11 is transferred to the A buffer and then exposed.

At the end of the exposure, the next field 12 is stored in the B buffer during the exposure.
Transfer the necessary data to Then field 1
After exposure of field 1 is completed, the next field 13 of buffer A is exposed during the exposure of field 12 of B buffer.
Transfer the necessary data to

At that time, as shown in item 3 of the same table, the data of cells <',',+',') was transferred again in the same way as in item 1.

[Problem to be solved by the invention]

However, in such a conventional semiconductor device manufacturing method, data of cells having the same contents is transferred again as described above, and therefore, there are the following problems.

In other words, since the cell data is being transferred again, the disk head, which was logically waiting at field 12 within the magnetic disk, returns to the beginning of the cell once again to transfer the data, and then It becomes necessary to search the beginning of field 12 again, which is nothing but a request for random access to the mass storage device. In the case of magnetic disks, data retrieval time is only a few hundred microseconds when accessing in the forward direction and continuously, but when random access is performed as described above, it takes several tens of seconds just to retrieve the data. There is also. In this case, the exposure will not be completed within a realistic processing time, and the advantage of the apparatus using two buffers will not be realized.

Therefore, the present invention enables exposure data in a large-capacity storage device to be accessed in a forward and continuous manner, eliminates the wasted time of searching for the data, and saves memory by making it possible to transfer data in parts. It is an object of the present invention to provide a method for manufacturing a semiconductor device that can be performed.

[Means to solve the problem]

In order to achieve the above object, the method for manufacturing a semiconductor device according to the present invention includes a storage device that stores exposure data, a pattern generation section that generates a predetermined exposure pattern based on the exposure data, the storage device, and the pattern generation section. a buffer memory provided between the part and the part for transferring and holding the exposure data;
A method for manufacturing a semiconductor device, comprising: first transferring exposure data of a basic unit section to be a repetitive exposure processing section out of the exposure data to a part of the buffer memory; is held until the exposure of the entire chip is completed, and the exposure data that is the non-repeated portion of the exposure data is divided into predetermined blocks and transferred to the remaining updateable portions of the buffer memory, and the exposure data and A method of manufacturing a semiconductor device is provided, characterized in that a pattern of a predetermined block is formed by combining exposure data of non-repeated portions, and thereafter, the above steps are repeated to expose the entire chip.

[Effect]

In the present invention, among the exposure data, the exposure data of the basic unit that becomes the repeated exposure processing section is transferred to a part of the buffer memory and is held until the end of the entire exposure, and becomes the non-repetitive section of the exposure data. The exposure data is divided and transferred to the remaining updatable portions of the buffer memory in predetermined blocks. Then, the exposure data of the basic unit part and the exposure data of the non-repeating part are combined and the exposure of the corresponding part is sequentially repeated.

Therefore, data access within the mass storage device is performed in the forward direction and only between consecutive parts, eliminating wasted time searching for data within the mass storage device without degrading data compression. Ru.

〔Example〕

Hereinafter, the present invention will be explained based on the drawings.

FIG. 1 is a diagram showing an embodiment of the method for manufacturing a semiconductor device according to the present invention, and the same components as those in the conventional example shown in FIG. 2 are given the same numbers and their explanations will be omitted. In Figure 1,
This is an electron beam exposure apparatus equipped with two buffer memories, and the electron beam exposure apparatus 31 includes an apparatus control computer 2, a data bus 3, an interface 4, and a large-capacity N magnetic disk 5.2 buffers for temporarily storing pattern data ( A
/B) A/B buffer (buffer memory) 32 consisting of
, for receiving data from the pattern generating section 7 that divides pattern data into each shot of the beam and from the large-capacity magnetic disk 5, and for switching the A/B buffer 32 when transferring data to the pattern generating section 7 at the subsequent stage. The A/B buffer 32 includes a switch 8, and an A buffer updatable section 2-a, a B buffer updatable section 2-b, and an A and B buffer repeated data holding section 32-C.

Therefore, only the configuration of the A/B buffer 32 differs from that of the conventional example shown in FIG. A/B buffer 32
is provided with a holding section for holding basic cell data used in repeated exposure processing among the exposure data, and the basic cell data stored in the holding section is held until the exposure of the entire chip is completed. Ru. Further, it is assumed that examples of compression of memory data, examples of data storage in the large-capacity magnetic disk 5, examples of patterns, and arrangement of graphic data in the large-capacity magnetic disk 5 are the same as those in the conventional example shown in FIGS. 3 to 6.

Next, the effect will be explained.

Attached Table 2 shows both buffers (A/B) of the electron beam exposure device 31.
This is to explain the transfer/output movement of the buffer 32), where * indicates transfer, 0 indicates a holding section, and indicates a remaining updatable section.

As shown in Appendix 2, first, cell data is transferred and held in both buffers A and B. When storing from the beginning of the A/B buffer 32, assuming that the cell parts of 48 figures are stored in a buffer that corresponds to 2048 figures in total, the remaining 2000 cells can be used for the non-repeating part. . Therefore, if the total of the peripheral circuits 21 and 22, the total of the peripheral circuits 23, 24, and 25 are each 2000 or less, exposure is possible. The usable area of the buffer will be slightly reduced due to the holding section that stores cell data, but since the basic cell section only requires a few dozen figures, even if modifications are made to compensate for this, the overall capacity will be reduced. You only need to increase it a little. Needless to say, the actual buffer capacity is determined by
The decision should be made according to careful predictions of data density.

Next, the peripheral circuit 2 is added to the remaining updatable portion of the A buffer.
1. Transfer only 22. Exposure of the field 11 is performed by combining the cell data stored in the holding section and the data of the peripheral circuits 21 and 22 transferred this time to the remaining updatable section. During this time, data from the peripheral circuit 23 is transferred to the B buffer. During B buffer exposure, only the data of the peripheral circuits 24 and 25 is transferred to the A buffer.

The above operation corresponds to the arrangement of graphic data shown in FIG. Therefore, it can be seen that data retrieval requires only a series of operations at the highest speed (on the order of several hundred microseconds), which is access between consecutive parts of the magnetic disk in the forward direction.

In this way, in this embodiment, all the basic unit parts are transferred and held in a predetermined part in the buffer memory 32 in advance, and then the non-repetitive part is transferred to the remaining updatable part of the buffer.
For example, the image is divided into appropriate blocks, such as fields 11 to 13, and transferred, and these blocks are combined to expose a predetermined portion, which is sequentially repeated. Therefore, by performing disk access within the mass storage device only in the forward direction and between consecutive parts, it is possible to eliminate wasted time in data retrieval within the mass storage device, and the time required for data retrieval is reduced to the normal number of times. It will not take more than 100 microseconds.Also, if the buffer capacity is not divided and transferred, even after data compression, a 16Mbit DRAM that needed to support several hundred Mbytes (several tens of megabytes of graphics) can now be used. By making divisional transfer possible, a buffer memory that can handle at most tens of bytes (several kilograms of graphics) can be used.

Although this embodiment is an example in which the present invention is applied to an electron beam exposure apparatus using two buffers, it is of course not limited to this, and one buffer may be divided into a fixed part and an update block, or three buffers may be used. Needless to say, it can be applied to a case where one buffer is used for a fixed block and the other one is used for two buffer operations in an update section.

〔Effect of the invention〕

According to the present invention, the following effects can be obtained.

(1) By having only one type of repeating part, data compression is the best and it is easy to correspond to the design method.

(II) Since the mass storage device normally used for data storage is accessed in the forward direction and between consecutive parts, the search time can be as fast as several hundred microseconds.

(III) By making divisional transfer practical, even for large-capacity memories, the buffer capacity can be saved to, for example, only a few dozen exposure data storage frames, thereby avoiding increased costs and decreased reliability. be able to.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing one embodiment of the method for manufacturing a semiconductor device according to the present invention, FIGS. 2 to 6 are diagrams showing a conventional method for manufacturing a semiconductor device, and FIG. 3 is a diagram for explaining the compression of memory data using the layered data structure; FIG. 4 is a diagram for explaining disk storage in the magnetic disk; FIG. 5 is a diagram showing the pattern of the chip consisting of three exposure fields, and FIG. 6 is a diagram showing the data arrangement of the graphic data section in the magnetic disk in the case of FIG. 2...Device control computer, 3...Data bus, 4...Interface, 5...Large capacity magnetic disk (storage device), 7.
...Pattern generation part, 8...Switch, 11-13...Field, 14...Basic cell (basic unit part), 15...
... Cell block, 21-25 ... Peripheral circuit (non-repetitive part), 3
1... Electron beam exposure device (semiconductor device), 3
2...A, /B buffer (ba sofa memory)
, 32-a...A buffer updatable section, 32-
b...B Bafufu Prefecture New Possibility Department, 32-C...
...A, B buffer repetition data holding section. Appendix, O

Claims (1)

[Scope of Claims] A storage device that stores exposure data, a pattern generation section that generates a predetermined exposure pattern based on the exposure data, and a pattern generation section that is provided between the storage device and the pattern generation section, and that A method for manufacturing a semiconductor device, comprising: a buffer memory for transferring and holding exposure data; first, exposure data of a basic unit section serving as a repetitive exposure processing section out of the exposure data is stored in a part of the buffer memory; In addition to transferring the
retaining the exposure data of the basic unit part until the end of exposure of the entire chip; dividing and transferring the exposure data that is a non-repeating part of the exposure data into predetermined blocks to the remaining updatable parts of the buffer memory; A method for manufacturing a semiconductor device, characterized in that a pattern of a predetermined block is formed by combining exposure data of a basic unit part and exposure data of a non-repeating part, and the above steps are repeated to expose the entire chip. .