KR100707014B1 - Exposure mask using space division manner - Google Patents

Abstract

The present invention relates to an exposure mask using a spatial division method to reduce the manufacturing cost and to increase the applicability of the pattern mask by allowing the exposure to a plurality of layers with only one mask, for transferring a specific pattern A pattern mask configured to divide the exposure mask into squares of a predetermined area by n and to spatially classify pattern information of n layers at respective positions, and information of a desired layer among the pattern information of n layers of the pattern mask It is configured to selectively project a bay, and is composed of a spatial filtering mask in which a transparent pattern having a square shape is arranged at regular intervals on an overall opaque mask, and the spatial filtering mask and the pattern mask are arranged at regular intervals and formed on the pattern mask. Patterns in multiple layers included in In order to classify the information, the spatial filtering mask is moved by a predetermined length and exposed.

Description

Exposure mask using space division manner}

1A to 1C are schematic diagrams of basic spatial filtering masks and pattern masks

2A to 2C are schematic diagrams of an exposure mask comprising four layers in a spatial division method;

3A to 3B are diagrams illustrating the extraction of pattern information of a pattern mask for each layer as a spatial filtering mask;

Explanation of symbols on the main parts of the drawings

21: Layer 1 22: Layer 2

23: layer 3 24: layer 4

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure mask, and more particularly, to an exposure mask using a spatial division method that enables exposure to a plurality of layers with only one mask, thereby reducing manufacturing costs and increasing applicability of a pattern mask.

In the current lithography technique, a method of projecting and exposing a mask pattern onto an LSI substrate through a reduction optical system is mainly used. However, when a high-pressure mercury lamp is used as a light source, a minimum line width is 0.5 μm.

While the development of direct drawing techniques using X-ray diffraction lasers or electron beams and X-ray equalization exposure techniques for pattern dimensions of 0.5 µm or less, expectations for optical lithography are increasing due to mass production and processor versatility. .

Various light sources such as g-rays, i-rays, excimer lasers, and X-rays are considered as light sources, and development of new resists and new resist treatments such as REL have been considered for resists, and the SREP and CEL image reverse methods. Research is also underway.

Although the mask fabrication technique has not been sufficiently examined, a phase shift mask has been attracting attention in 1982 by IBM's Levenson et al.

Photolithography is a technique used to form fine patterns that are difficult to implement by hand or by machine. The photolithography process irradiates light that passes through a mask in which a desired pattern is formed on a material whose properties are changed by a specific light. After implanting a pattern on the material, the exposed area between the photosensitive material is etched.

Such a photolithography process has an advantage of precisely realizing fine patterns, and thus, is used in the manufacturing of electronic components including semiconductors and display devices such as LCDs and PDPs.

 However, the above-mentioned exposure mask and exposure system of the prior art have the following problems.

In order to secure the precision, the manufacturing cost of expensive exposure equipment and exposure mask is required.

In particular, in the case of the exposure mask, the manufacturing cost is very expensive and there is a problem in that an additional cost is required when modifying the pattern. As the number of patterns is increased, the number of exposure masks is not only required, but also the cost is increased because several masks must be newly produced when the pattern is modified.

The present invention is to solve the problem of the exposure method and the exposure mask of the prior art, by implementing a pattern of a plurality of layers in one mask so that only one mask is additionally produced when changing the design of the pattern to a plurality of layers It is an object of the present invention to provide an exposure mask using a space division method that enables exposure using only one mask, thereby reducing manufacturing cost and increasing applicability of a pattern mask.

In the exposure mask using the spatial division method according to the present invention for achieving the above object, in the exposure mask for transferring a specific pattern, by dividing the square of a certain area by n equal parts n pattern information of n layers at each position A pattern mask configured to be classified and arranged spatially, and selectively project only information of a desired layer among the pattern information of n layers in the pattern mask, and a transparent transparent pattern having a square shape is formed on the mask that is opaque as a whole. The spatial filtering mask is disposed at regular intervals, and the spatial filtering mask and the pattern mask are arranged at regular intervals, and the spatial filtering mask has a predetermined length to classify the pattern information of a plurality of layers included on the pattern mask. Move by exposure The.

Hereinafter, an exposure mask using a space division method according to the present invention will be described in detail with reference to the accompanying drawings.

1A to 1C are structural diagrams of a basic spatial filtering mask and a pattern mask, and FIGS. 2A to 2C are structural diagrams of an exposure mask including four layers in a spatial division method.

3A to 3B are structural diagrams in which pattern information of a pattern mask is extracted for each layer using a spatial filtering mask.

The present invention is a method of implementing a plurality of patterns in one mask, each pattern is divided into unit areas of a predetermined size and then spatially divides the information of the unit areas of different layers into one mask (pattern mask) to recombine will be.

During exposure, the spatial filtering mask is used to reclassify the pattern information of multiple layers on the pattern mask. In this case, light is irradiated to only half or a quarter of the photosensitive material as compared with other exposure methods, and a desired pattern is obtained by supplementing it using the principle of half-tone masking.

FIG. 1A illustrates a configuration of a spatial filtering mask, and FIG. 1B illustrates a configuration of a pattern mask.

FIG. 1C is an enlarged view of the pattern mask of FIG. 1B and shows one unit region including four divided regions.

The spatial filtering mask is arranged in a transparent area of a certain size in the mask which is entirely opaque, that is, the filtering windows are disposed over the entire effective area of the mask for exposure at regular intervals, the size of which is divided region, that is, the unit area shown in FIG. Is equal to 1/4 of.

The principle of spatial division of the four layers is as follows.

FIG. 2A shows that four layers are actually implemented and includes an enlarged view of a specific portion.

2B shows pattern information of the corresponding enlarged area for each layer.

The structure in which four layers are spatially divided and reconstructed into one mask is as shown in FIG. 2C.

As shown in FIG. 2B, the hook that divides the enlarged pattern for space division into a predetermined size is reduced to 1/4 to correspond to the corresponding position of FIG. 2C.

The pattern information of 21, 22, 23, and 24 of layers 1, 2, 3, and 4 of FIG. 2B is reduced to 1/4 in 25, 26, 27, and 28 of FIG. 2C, respectively.

The principle of extracting the pattern information of the pattern mask for each layer using the spatial filtering mask is as follows.

FIG. 3A illustrates four unit regions each composed of four divided regions with a completed pattern mask as in FIG. 2C.

3B shows that the pattern information of each layer is displayed through the filtering window of the spatial filtering mask as the spatial filtering mask is moved.

That is, the positional movement of the spatial filtering mask for displaying the pattern information of each layer is shown. The dotted line indicates the position of the initial spatial filtering mask and the arrow indicates the moving direction of the spatial filtering mask with respect to the initial position.

Thus, the exposure mask of this invention consists of a spatial filtering mask and a pattern mask.

The spatial filtering mask selectively projects only information of a desired layer among the pattern information of a plurality of layers in the pattern mask, and square transparent patterns are arranged at regular intervals on the opaque mask as a whole.

In addition, the pattern mask is configured to divide the square of a predetermined area into four and to spatially classify the pattern information of four layers at each position.

In addition, the pattern of the pattern mask includes pattern information of four layers in each unit area, and information of four different layers is recorded separately in a divided area of one unit area divided into quarters.

For example, the pattern information of one quadrant of each layer, for example, layers 1, 3, and 4 have patterns in one quadrant, and layer 2 has no patterns in one quadrant. Thus, in FIG. 2C, patterns exist at 25, 27, 28 of layers 1, 3, and 4.

In order to perform exposure using the pattern information of each layer included in the pattern mask, the spatial filtering mask and the pattern mask are overlapped with a small gap, and then the window of the spatial filtering mask is placed in the partition area containing the pattern information of the desired layer. Irradiate light with alignment to match.

The pattern information of each layer may be decomposed while changing the position of the spatial filtering mask to expose the pattern of each layer.

When the exposure is performed in the above manner, the pattern portion receives no light at all, and the portion without the pattern receives about 1/4 of the light amount as compared with other masks.

To compensate for this, by adjusting the focus and the amount of light, a pattern as close as possible to the desired pattern can be obtained. This method is already proven through the halftone masking technique.

Such an exposure mask using the spatial division method according to the present invention is not limited to including four layers in one mask, it is natural that two or three layers can be applied in a similar manner.

Of course, if the technology of light quantity and focus is secured, the same technique can be applied to 5 to 6 layers. If there are 7 or more layers, two pattern masks including 4 layer informations can be mounted and used together. Can be.

Such an exposure mask using the spatial division method according to the present invention has the following effects.                     

The exposure method using the spatial filtering mask and the pattern mask can reduce the initial manufacturing cost because only one mask is manufactured for several layers instead of each mask for several layers.

This means that additional manufacturing costs incurred in design changes can also be reduced.

In addition, the spatial filtering mask can be used commonly for pattern masks in various products with different designs by manufacturing a spatial filtering mask having filtering holes of appropriate size and spacing when the minimum line width required by the product is determined. It is advantageous economically.

Claims (3)

In the exposure mask for transferring a specific pattern, A pattern mask configured to divide the square of a certain area into n equally and to classify and arrange the pattern information of n layers at each position; By selectively projecting only information of a desired layer among the pattern information of n layers in the pattern mask, and using a spatial filtering mask in which a transparent pattern having a square shape is arranged at regular intervals on an overall opaque mask, The spatial filtering mask is disposed at regular intervals, and the spatial filtering mask is moved by a predetermined length to expose the pattern information of a plurality of layers included on the pattern mask. Exposure mask using the. 2. The exposure mask according to claim 1, wherein the spatial filtering mask has a transparent pattern having a predetermined size disposed over all effective areas of the mask for exposure at regular intervals. delete

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