KR20100072403A - Half tone mask and fabricating method - Google Patents

Abstract

PURPOSE: A half tone mask and a fabricating method are provided to increase the accuracy of a half-tone mask by laminating at least one semi-transmitting layer to control light transmittance thereof. CONSTITUTION: A halftone mask includes a plurality of semi-transmitting areas(A,B) having at least one semi-transmitting layer(120,130) which are laminated thereon. The plural semi-transmitting areas have the light transmittance difference of 4-75% between adjacent semi-transmitting areas. The semi-transmitting area is a laminated structure of same material and controls the light transmittance. The semi-transmitting area is also a laminated structure of different material and controls the light transmittance.

Description

Halftone mask and its manufacturing method {HALF TONE MASK AND FABRICATING METHOD}

The present invention relates to a halftone mask having a light shielding area, a transflective area, and a transmission area on a transparent substrate, and a method of manufacturing the same.

Many configurations used in the manufacture of liquid crystal displays and the like require multiple mask processes. As a result, the manufacturing process is complicated, which increases the manufacturing cost of the liquid crystal display. To solve this problem, it is currently developing toward reducing the number of mask processes.

A general photomask used for patterning by a photolithography process, as shown in FIG. 1, is formed on the transparent substrate 11 and the transparent substrate 11 and transmits light completely to transmit light 13. ) And a light blocking portion 15 that completely blocks the light. Since the conventional mask as described above can not only implement a pattern of one layer, it can be used only for a photolithography process of one cycle consisting of exposure → development → etching.

In detail, the thin film transistor (TFT) and color filter (CF) of the liquid crystal display have many layers deposited and coated, and each of the deposited and coated layers is patterned by a photolithography process. However, if one cycle can reduce the photolithography process, a large economic effect can be obtained. Since a conventional mask has a structure in which only one layer of pattern can be realized, a plurality of photomasks implementing separate patterns can be manufactured. There is an unnecessary economic economy.

In order to solve the above disadvantages, a slit mask, a gray tone mask, a halftone mask, and the like have been developed.

The slit mask uses scattering of light, and when light passes through a slit thinner than a slit that guarantees the linearity of an applied wavelength, scattering occurs to an adjacent part, and the entire light energy is dispersed. However, in the case of such a slit mask, since the light energy scattered in the fine slit is uneven and the exposure energy for each position is different, there is a point that the residual film thickness by location forms irregularities and thus it is difficult to obtain a uniform thickness of the residual film.

Gray tone mask (Gray Tone Mask) is a structure having a transmission portion through which light is completely transmitted, a light shielding layer through which light is completely blocked, and a slit pattern that reduces and transmits the amount of irradiated light. However, since the gray tone mask adjusts the amount of light transmitted using the diffraction phenomenon of light passing through the fine pattern, there is a limit on the amount of light transmittable that can be adjusted due to the limitation of the slit pattern implementation. There is a drawback to not being able to implement one patterning.

A halftone mask is a mask formed of a light transmitting portion formed on a transparent substrate, a light blocking portion completely blocking light, and a semi-transmissive portion adjusting a transmittance to transmit a part of light. Can be.

However, in the case of such a halftone mask, the light passing through the transflective portion uniformly passes through each position to form a uniform residual film thickness for each position, but it requires an additional process of manufacturing a mask, thereby increasing the manufacturing process and cost. It has the disadvantage of increasing. Therefore, the problem of reducing the plurality of mask processes still exists in the halftone mask.

The present invention has been made to solve the above-described problems, an object of the present invention is to provide a halftone mask that can control the light transmittance by stacking a semi-transmissive film, a database based on the actual process rather than the theoretical behavior characteristics The present invention provides a halftone mask having transmittance in a wide range of regions, rather than a specific transmittance, by implementing a light transmittance.

In addition, when fabricating a multitone mask having a halftone mask and a plurality of transflective areas, the transflective material is laminated on the transflective material to realize the necessary light transmittance, thereby shortening the manufacturing process and forming the halftone mask. The purpose of the present invention is to provide a manufacturing process that can increase the precision of the manufactured halftone mask by limiting the variation in light transmittance between adjacent semi-transmissive regions to be in the range of 4 to 75%. have.

The present invention provides a halftone mask comprising a plurality of (N) semi-transmissive regions having at least one semi-transmissive layer laminated with at least one transflective layer and having a separate light transmittance. do.

In particular, in consideration of the control range of the maximum transmittance that can be finely adjusted in the actual manufacturing process, the plurality of transflective areas in the present invention, the difference in light transmittance between adjacent transflective areas is within 4% to 75% It is characterized by.

Adjusting the transmittance in the present invention described above to form the transflective region, the transmittance is controlled by the laminated structure of the semi-permeable membrane made of the same material, or the transmittance is controlled by the laminated structure of the semi-permeable membrane made of different materials In addition, the transmittance may be controlled by a combination of semi-permeable membranes made of the same material or different materials.

In addition, the plurality of the semi-permeable membrane constituting the semi-transmissive region of the present invention described above, the material constituting the semi-permeable membrane is Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf Or any one of V, Nd, Ge, spinel (MgO-Al ₂ O ₃ ), sialon (Si ₃ N ₄ ) as a main element, or a composite material in which at least two or more of the main elements are mixed; At least one of CO _x , O _x , N _x , C _x , F _x , B _x is added to the main element or the composite material.

In the present invention, of course, it is possible to perform the manufacturing process for manufacturing the above-described halftone mask.

Specifically, in the method of manufacturing a halftone mask having at least one semitransmissive region, each semitransmissive region is manufactured by manufacturing a halftone mask, wherein the light transmittance is controlled by stacking a plurality of semitransmissive layers. To provide a way.

Adjusting the light transmittance through the lamination of the semi-transmissive film in the above-described manufacturing process is characterized in that it comprises a sequential removal step of removing the unnecessary pattern after the semi-transmissive film is sequentially laminated. That is, by sequentially stacking semi-transparent materials required for transmittance control and sequentially removing the semi-transmissive materials, the semi-transmissive region having a plurality of light transmittances can be formed in a very simple process by controlling the light transmittance by leaving the necessary semi-transmissive film. can do.

In addition, in the above-described manufacturing process, controlling the light transmittance through lamination of the semi-transmissive film includes a sequential removal step of removing an unnecessary pattern after sequentially laminating the transflective film at a specific location of the halftone mask and specific transflectiveness. A semi-transmissive region having different light transmittances may be formed, including an independent forming process of separately forming layers.

In addition, adjusting the light transmittance through the lamination of the semi-transmissive layer may be performed by separately performing the sequential removal process or the independent formation process at least at one or more locations of the halftone mask to form a semi-transmissive region.

As described in the case of the halftone mask described above, in the present manufacturing process, a plurality of the semi-transmissive regions are formed, but the difference in the light transmittance between adjacent semi-transmissive regions is preferably formed to be 4 to 75%.

Photolithography may be used to remove a specific laminated semipermeable layer in the overall process.

According to the present invention, by providing a halftone mask that can control the light transmittance by laminating a semi-transmissive film, it is possible to implement a light transmittance that is established through a database based on the actual process rather than the theoretical behavior characteristics, not a specific transmittance There is an effect that it is possible to provide a halftone mask having a transmittance in a wide range.

In addition, when manufacturing a halftone mask and a multitone mask having a plurality of transflective areas, the transflective material is laminated on the transflective areas to realize the necessary light transmittance, thereby reducing the manufacturing process. There is also.

In particular, it is possible to implement the transflective region by limiting the fluctuation range of the light transmittance between adjacent transflective regions to 4 to 75% range, thereby improving the precision of the manufactured halftone mask.

In addition, due to precise transmittance control, the distinction between adjacent semi-transmissive areas is made clear so that it is easy to control the transferred pattern (the pattern of the product formed by using the mask), so that multiple layers can be formed with one mask to form a transfer pattern. It can be used easily.

Hereinafter, with reference to the drawings will be described in detail the configuration and manufacturing process according to the present invention.

SUMMARY OF THE INVENTION In the present invention, it is an object of the present invention to provide a halftone mask having a plurality of semitransmissive regions on one halftone mask by laminating at least one semitransparent film and adjusting light transmittance.

FIG. 2 is a diagram for explaining the behavior of light transmittance in a stacked structure of a halftone mask.

Semi-transmissive areas (A, B) to control the light transmittance by controlling the light transmittance (C) and the light-transmitting region (C) and the semi-transmissive layer (120, 130) on which the light shielding layer 110 is formed on the substrate 100 A halftone mask composed of) is described as an example. The region D corresponds to the complete light transmitting portion.

That is, in the above-mentioned light shielding area C, the light transmittance is 0%, the perfect transmission area D is 100%, but the transflective layer 120 has 70% light transmittance, and the transflective layer 100 has a light transmittance. This is 35%. In theory, the final transmittance of the light transmitted through the transflective region described above is 70% of the transmissive layer 130 once transmitted through the transflective layer 120 (70% transmittance). 35%), the transmittance should be about 25%. In practice, however, these theoretical transmittances are rarely applied in the manufacturing process, and the behavior of the actual transmittance differs from 25% in the region A, but it is very difficult to calculate precise transmittance. That is, it is very difficult to control the transmittance by laminating the semi-permeable membrane in the actual process.

In the present invention, the micro-error of the light transmittance in the laminated structure of the semi-transmissive film is implemented in the range of 4 to 75%, so that a plurality of semi-transmissive regions can be provided in one halftone mask. This is a fatal problem that can not be distinguished between the neighboring semi-transmissive region when the variation in transmittance between neighboring semi-transmissive region is formed in the range less than 4%. That is, when the variation in transmittance between adjacent transflective areas according to the present invention is less than 4%, the transflective area is not distinguished between the transflective areas. As a result, the transfer pattern in each transflective area becomes ambiguous, so that the defects between the patterns after the transfer are blurred. Will occur.

Therefore, in the present invention, in forming the transflective region, the transmittance may be controlled by stacking at least one semi-permeable membrane made of a plurality of materials to adjust the transmittance.

The semi-transmissive film is Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf (hafnium), V (vanadium), Nd (niobium), Ge, spinel (MgO-Al ₂ O ₃ ), any one containing sialon (Si ₃ N ₄ ) as a main element, a composite material in which at least two or more of the main elements are mixed, or CO _x , O _x , N in the main element or composite material At least one of _x , C _x , F _x , and B _x may be used, and any one selected from materials may be used, and the semi-transmissive layer forming each laminate may be a laminate of the same material selected or a laminate of different materials. It is possible to form a composite laminated structure of both. (In the formula, the subscripts x, y, z are natural numbers.)

The biggest feature of the present invention is that the transflective areas are provided in multiple, and the transflective areas provided in multiples have different light transmittances. In particular, the control of the light transmittance is characterized by controlling the laminated structure of one or more semi-transmissive film.

Of course, the light transmittance of the semi-permeable membrane constituting the individual stacked semi-transmissive region can be adjusted by varying the composition of the semi-transmissive layer to be laminated or by varying the thickness. That is, the light transmittance can be different from each other according to the properties of the composition of the semi-transmissive film, and even when the same composition is used, the light transmittance can be adjusted by changing the thickness.

As described above, the material capable of forming the semi-transmissive film of the present invention is Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf (hafnium), V (vanadium), Nd ( Niobium), Ge, spinel (MgO-Al ₂ O ₃ ), sialon (Si ₃ N ₄ ) It can be any one of the main element has been described above.

In addition, at least two or more of the main elements are mixed materials, or at least one of CO _x , O _x , N _x , C _x , F _x , B _x is added to the main element or composite material Any one selected may be applied, and a material applied thereto may be variously formed as long as the composition of the laminated semi-transmissive region can pass only a part of light of a predetermined wavelength band to be irradiated. For example, Cr _x O _y , Cr _x CO _y , Cr _x O _y N _z , Si _x O _y , Si _x O _y N _z , Si _x CO _y , Si _x CO _y N _z , Mo _x Si _y , Mo _x O _y , Mo _x O _y N _z , Mo _x CO _y , Mo _x O _y N _z , Mo _x Si _y O _z , Mo _x Si _y O _z N Mo _x Si _y CO _z N, Mo _x Si _y CO _z , Ta _x O _y , Ta _x O _y N _z , Ta _x CO _y , Ta _x O _y N _z , Al _x O _y , Al _x CO _y , Al _x O _y N _z , Al _x CO _y N _z , Ti The laminated transflective part may be formed by any one or a combination of _x O _y , Ti _x O _y N _z , and Ti _x CO _y . The subscripts x, y and z are natural numbers and represent the number of each chemical element.

Figure 3 shows an embodiment of a semi-transmissive region of such a laminated structure.

Three semi-transmissive layers stacked on the substrate are formed to provide semi-transmissive regions, and one or more of these structures may be formed on one half-tone mask as necessary. Of course, the semi-transmissive film may be disposed on the light shielding film to form a light shielding part.

When the transmittance of the first semi-permeable membrane H 1 is x%, the transmittance of the second semi-permeable membrane H 2 is y%, and the transmittance of the third semi-permeable membrane H 3 is z%. The regions having different transmittances formed by the three transflective layers may be formed as A, B, and C regions.

In particular, z% of the light transmitted through the C region will be finally transmitted, (z × y)% of the B region, and ((z × y) × x)% of the A region. Through such a transmission characteristic, it is preferable that the fluctuation range of the light transmittance in each of the A, B, and C regions is adjusted to 4 to 75%.

Through this, in forming the transflective region in the halftone mask, the transmissive region can be realized by precisely controlling the transmittance by stacking a halftone material, deviating from the structure capable of forming only a specific transmittance.

4 is a first semi-transmissive film (H1; transmittance is x%), a second semi-transmissive film (H2; transmittance is y%), and a third semi-transmissive film (H3; transmittance is z%) stacked in FIG. It shows another modified embodiment provided with.

That is, in any case, the gist of the present invention can control each transmittance by laminating a plurality of semi-permeable membranes on one halftone mask, and the width of the control of the transmittance can be adjusted to 4 to 75% between adjacent semi-transmissive regions. In this way, it is possible to form a plurality of semi-transmissive regions having different transmittances in one halftone mask without having to manufacture a separate mask, thereby improving efficiency of manufacturing cost.

This transmittance control method will be described with reference to Figure 5a.

The lamination structure of semi-permeable material to form the semi-permeable region is implemented based on the experimental data that is made by database.

First, the transmittance of each material is formed in the semi-permeable material database (DB ₁ ~ DB _n , n is a natural number), and the transmittance to be realized in a specific semi-transmissive region of the halftone mask is selected.

Then, the transmittance to be sputtered in the first semi-permeable membrane is selected, and the transmittance to be sputtered in the second semi-permeable membrane is selected. In addition, the transmittance of the first and second semi-permeable membranes is realized, and the transmittances of the layers in which the two membranes are combined are also realized. The implementation DB of such a transmittance is stored in the transmittance database 210 shown, and in particular, the calculation of each transmittance is implemented in the controller 220, thereby stacking 230 on the substrate. In this way, two or more transmittances can be realized in one mask, and the quantitative data stored in the database can be reproduced with the same identity.

Table 1 below illustrates the quantitative derivation of the result of calculating the transmittance of the laminated semi-transmissive region as a preferred embodiment of the present invention.

{Table 1}

An example of calculating the transmittance according to the stacking of the semi-transmissive region for the above {Table 1} will be described with reference to FIG. 5B.

'Reference T (%)' of Table 1 is the transmittance of the 'reference layer (R)' of FIG. 5B, and X (%) of FIG. 5B means the transmittance of the semi-transmissive layer stacked on the reference layer (R). . Therefore, the transmissivity Y of the semi-transmissive region finally laminated can be quantitatively calculated by the above equation. Of course, when the transmittance of the semi-transmissive region (Reference Layer; R) is changed, the above calculation formula may be changed.

Figure 6 shows an application example in which the various transflective areas are implemented according to the present invention. A manufacturing process of the semi-transmissive region of the halftone mask according to the present invention will be described with reference to the illustrated structure.

Since the manufacturing process of the halftone mask is formed by stacking a light shielding region, a light transmissive region, and a semi-transmissive region on a substrate and patterning it, it will be omitted.

However, in the present invention, a method of forming a plurality of semi-transmissive regions having different light transmittances by forming a plurality of semi-transmissive layers in one forming a halftone mask to control transmittance will be described. do.

6A is a conceptual diagram of a plurality of transflective regions according to a process of manufacturing a transflective region performed by a process similar to FIGS. 3 and 4.

In other words, the first semi-permeable membrane (H1), the second semi-permeable membrane (H2), and the third semi-permeable membrane (H3) are sequentially stacked and the unnecessary portions are removed in each region (sequential removal process). To be performed. That is, (a) the photoresist (PR) is raised on the stacked H3 in the H1, H2, H3 shown, and a portion of H3 is removed through exposure / development, (b) thereafter, the photoresist (PR) is raised and again When a part of H2 is sequentially removed, (c) finally a semi-transmissive area having A, B, and C areas is formed, and the fluctuation range of light transmittance between adjacent areas is adjusted to 4 to 75%. This is preferred. The region D corresponds to the complete light transmitting portion.

The structure of the transflective regions shown in FIGS. 7A and 7B may also be performed in the case of sequentially layering each transflective layer and performing a sequential removal process using a photoresist, and the part of the completely transmissive region P is sequentially When the photoresist is patterned in the removal process, it may be performed by patterning the stacked semi-transmissive layers so as to remove all of them.

However, in FIG. 7B, the A and B regions may be simplified through the sequential removal process with the above-described structure. However, in the case of the C region, the A and B regions may be implemented through an independent forming process for forming an H3 semi-permeable film independently. .

In the case of various transflective regions having a structure as shown in FIG. 7C, the A region may be performed through the sequential removal process, and the B and C regions may be performed through the independent formation process.

In the foregoing detailed description of the present invention, specific examples have been described. However, various modifications are possible within the scope of the present invention. The technical idea of the present invention should not be limited to the embodiments of the present invention but should be determined by the equivalents of the claims and the claims.

1 is a conceptual diagram illustrating a conventional photomask.

2 is a view for explaining the behavior characteristic of the transmittance in the laminated structure of the halftone mask.

3 and 4 illustrate one embodiment of a transflective area according to the present invention.

5A and 5B are conceptual views illustrating a transmittance control of a semi-transmissive region and a lamination process according to the present invention.

6A and 6B are explanatory diagrams of a structure of a semi-transmissive region and a manufacturing process thereof according to another embodiment of the present invention.

7A to 7C are explanatory views of a structure of a semi-transmissive region and a manufacturing process thereof according to another embodiment of the present invention.

Claims (12)

A halftone mask, characterized in that at least one semi-transmissive film is laminated to have a plurality of (N) semi-transmissive regions having separate light transmittances. The method according to claim 1, wherein the plurality of transflective areas, A halftone mask, characterized in that the difference in light transmittance between adjacent transflective areas is within 4% to 75%. The method according to claim 1 or 2, The semi-transmissive region is a halftone mask, characterized in that to control the transmittance in a laminated structure of a semi-transmissive film made of the same material. The method according to claim 1 or 2, The semi-transmissive region is a halftone mask, characterized in that the transmittance is controlled by a laminated structure of a semi-transmissive film made of different materials. The method according to claim 1 or 2, The semi-transmissive region is a halftone mask, characterized in that the transmittance is controlled by a combination of semi-transmissive film made of the same material or different materials. The method according to claim 1 or 2, The material constituting the transflective film is Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf, V, Nd, Ge, Spinel (MgO-Al ₂ O ₃ ), sialon Any one of (Si ₃ N ₄ ) as a main element, or a composite material in which at least two or more of the main elements are mixed; Halftone mask, characterized in that the material is added to at least one of CO _x , O _x , N _x , C _x , F _x , B _{x to} the main element or composite material. (However, the subscripts x, y, and z are natural numbers and mean the number of chemical elements.) In the method of manufacturing a halftone mask having at least one semi-transmissive region, Each semi-transmissive region is a method of manufacturing a halftone mask, characterized in that the light transmittance is adjusted by stacking a plurality of semi-transmissive film. The method of claim 7, Laminating the semi-transmissive film to control the light transmittance, A method of manufacturing a halftone mask comprising the step of sequentially removing a semi-permeable film and then removing unnecessary patterns. The method of claim 7, By controlling the light transmittance by stacking the semi-transmissive film, forming a semi-transmissive region at a specific location of the halftone mask, Sequentially removing the semi-permeable membrane and then removing unnecessary patterns; and Independent formation process of forming a specific semi-permeable layer separately; Method for producing a halftone mask, characterized in that carried out including a. The method according to claim 7 or 8, Laminating the semi-transmissive film to control the light transmittance, And a semi-transmissive region is formed by separately performing the sequential removal process or the independent formation process at least one or more places of the halftone mask. The method according to any one of claims 7 to 9, A plurality of semi-transmissive areas are formed, the method of manufacturing a halftone mask, characterized in that the difference in light transmittance between adjacent semi-transmissive areas are formed to be 4 to 75%. The method according to any one of claims 7 to 9, The step of removing the laminated semi-transmissive film is a method for producing a halftone mask, characterized in that using photolithography.

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