TWI575304B - Half tone mask and fabricating method - Google Patents

Description

Halftone mask and method of manufacturing same

The present invention relates to a halftone mask in which a light interruption region, a translucent region, and a transmissive region are formed on a transparent substrate, and a method of manufacturing the same.

Multiple configurations for fabricating liquid crystal displays require multiple masking methods. As a result, the manufacturing method becomes complicated, causing a problem that the manufacturing cost of the liquid crystal display device increases. As one of the methods for solving the above problem, the current trend is to reduce the number of mask processing.

As illustrated in FIG. 1 , the conventional photomask for patterning includes a transparent substrate 11 , a light penetrating unit 13 formed on the transparent substrate 11 and allowing light to completely penetrate, and a light lithography process. And a shading unit 15 that completely blocks light. Conventional masks can only be used in a cycle of photolithography processes formed by exposure-development-etching, since conventional masks can only implement one patterned layer.

More specifically, a thin film transistor (TFT) and a color filter (CF) are deposited/coated by a plurality of film layers, and each layer is deposited/coated by a film layer. The photolithography process is patterned. At the same time, even if only one photolithography process cycle is reduced, there is still a great economic effect. However, the conventional mask has a structure in which only one pattern layer can be implemented, so that there is an unnecessary non-economical efficiency due to the manufacture of a plurality of photomasks that implement different patterns.

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

A slit mask is a scattering property that utilizes the entire optical energy, where light scatters to adjacent portions as it passes through a thin slit rather than a slit that ensures linear properties of wavelength.

However, in the case of a slit mask, the distribution of light scattering in the fine slit is not uniform and the exposure energy at each position is different, so that in the thickness of the residual film, each position Concaveness and convexity are formed, and it is difficult to obtain a residual film having a uniform thickness.

The gray tone mask has a structure having a penetration portion through which light can pass completely, a light shielding portion that completely blocks light, and a slit pattern that allows light to pass in a manner that reduces the amount of light.

However, the disadvantage of the gray tone mask is that there is a limitation in implementing the slit pattern to limit the amount of light that can be adjusted due to the fact that the amount of light transmitted is adjusted by the diffraction phenomenon of the fine pattern. Therefore, in the case where the gray mask has a size larger than a predetermined range, the uniform patterning process cannot be performed.

The halftone mask is a mask having a transparent portion formed on a transparent substrate and allowing light to pass completely, a light shielding portion capable of completely blocking light, and an adjustable transmittance to allow light portion The translucent portion that passes through.

The halftone mask facilitates the uniform passage of light that has passed through the translucent portion from each location, thereby forming a residual film of uniform thickness at each location. However, halftone masks suffer from a disadvantage in that the halftone mask requires an additional process during the manufacture of the mask, thereby increasing the manufacturing cost and the number of manufacturing processes. At the same time, in the case of halftone masks, the problem of reducing multiple mask processes still exists.

The present invention has been disclosed herein to solve the aforementioned problems, and an object of the present invention is to provide a halftone mask capable of adjusting optical transmittance by stacking a translucent material, wherein optical transmittance can be established Implemented in a database that is based on actual manufacturing processes and is not based on theoretical behavioral characteristics, thereby providing a wide range of penetration rates rather than half the penetration rate in a particular area. Tone mask.

Another object is to provide a method for fabricating a halftone mask capable of increasing the precision of a manufactured halftone mask by performing an optical transmittance which is a half transparent region and a translucent material. Stacking to reduce the number of manufacturing processes; and in fabricating a multi-tone mask formed with a halftone mask and a plurality of translucent regions, by limiting optical wear between adjacent translucent regions The fluctuation range of the transmittance is in the range of 4% to 75% to implement a translucent region in which a halftone mask to be formed is formed.

In an exemplary embodiment, the halftone mask is formed with a plurality (N) of translucent portions each having a different optical transmittance by stacking at least one or more translucent materials.

In an exemplary embodiment, these (N) translucent portions should be optically transmissive to adjacent translucent portions, taking into account the fine adjustments made to the adjustment of the maximum penetration rate in the actual process. The difference is in the range of 4% to 75%.

In certain exemplary embodiments, the adjustment of the transmittance can form the translucent portions, wherein the transmittance is adjusted by a stacking structure of translucent materials each having the same material, or by having different materials each. The stack of translucent materials is adjusted or adjusted by a stack of translucent materials each having the same or a different combination of materials.

In certain exemplary embodiments, the material forming the translucent material is a material having one of the following main elements: Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf, V, Nd, Ge, MgO-Al ₂ O ₃ or Si ₃ N ₄ , or may be a combination material of at least two or more elements, or may be added with Co _x , O _x , N _x , C _x , At least one of F _x or B _x to a single primary element material or a material of these combination materials.

Obviously, the present invention can perform a manufacturing method for manufacturing the above-described halftone mask.

More specifically, in a method of fabricating a halftone mask having at least one or more translucent portions, each translucent portion is stacked with a plurality of translucent materials to adjust an optical transmittance.

In certain exemplary embodiments, the step of adjusting the optical transmittance by stacking the translucent materials may include a subsequent removal step to remove unnecessary patterns after sequentially stacking the translucent materials.

In certain exemplary embodiments, the step of adjusting the optical transmittance by stacking the translucent materials may include sequentially stacking the translucent materials to remove unnecessary patterns while being specific on the halftone mask. These translucent portions are formed at a number of positions (subsequent removal steps).

That is, sequentially stacking and then sequentially removing the translucent material to adjust the required transmittance, thereby adjusting the optical transmittance by leaving the necessary translucent material, thereby utilizing a very simple process To form a translucent portion having multiple optical transmittances.

In certain exemplary embodiments, the step of adjusting the optical transmittance by stacking the translucent materials may include sequentially stacking the translucent materials to remove unnecessary patterns while on the halftone mask. A translucent portion is formed at a specific number of locations; and a specific translucent layer is formed independently, whereby translucent portions each having a different optical transmittance can be formed.

Additionally, it will be apparent that the step of adjusting the optical transmittance by stacking the translucent materials may comprise the step of independently performing the subsequent removal step, or at least one or more locations of the halftone mask, independently A separate forming step is performed to form a translucent portion.

As explained above, in the halftone mask, these translucent portions are formed, and the difference in optical transmittance between adjacent translucent portions is preferably in the range of 4% to 75%.

In certain exemplary embodiments, the step of removing a particular stack of translucent material throughout the process may use a photolithography method.

An advantage of the present invention is that a halftone mask capable of adjusting optical transmittance can be provided by stacking a translucent material, wherein the optical can be implemented via a database based on actual processes rather than theoretical behavioral characteristics. The transmittance, whereby a halftone mask having a transmittance in a wide range, rather than a transmittance in a specific region, can be provided.

Another advantage of the present invention is that in the process of fabricating a multi-tone mask formed with a halftone mask and a plurality of translucent regions, the necessary optical penetration can be performed by stacking translucent materials in the translucent portions. Rate to thereby reduce the manufacturing process.

Another advantage of the present invention is that the optical transmittance between adjacent translucent regions is limited to a range of 4% to 75% to increase the accuracy of the manufactured halftone mask.

Yet another advantage of the present invention is that adjacent translucent portions can be significantly different due to precise limits of penetration, such that control of the transferred pattern (pattern of the product formed using the mask) is facilitated, The use of a mask to form a plurality of film layers is achieved and the formation of a simplified transfer pattern is facilitated.

The structure and manufacturing method of the present invention will be described in detail in conjunction with the accompanying drawings.

The gist of the present invention is to provide a halftone mask having a plurality of translucent portions formed thereon, and the halftone mask can adjust the optical transmittance by stacking at least one or more translucent materials.

2 is a schematic view for explaining behavior characteristics of a stacking structure of transmittance in a halftone mask.

Now, an example of a halftone mask includes: a light shielding portion (C) having an optical shielding layer (110) formed on a substrate (100), and optical transparency is adjusted by stacking a translucent layer (120, 130). The translucent portion (A, B) of the rate, and a fully transparent portion (D) of the light, wherein the portion D is the portion through which the light is completely penetrated.

That is, the light-shielding portion (C) has zero optical transmittance (0%), the light-completed portion (D) has 100% optical transmittance, and the translucent layer (120) has 70% optical wear. The transmittance, while the translucent layer (130) has an optical transmittance of 35%.

Theoretically, the final optical transmittance of the light passing through the translucent portion must be about 25% because the optical transparency of the translucent layer (120) is 70%, while the optical transparency of the translucent layer (130) The penetration rate is 35%. However, the theoretical penetration rate is difficult to apply in the actual manufacturing process, and the behavioral characteristics of the actual transmittance have a 25% difference in transmittance in Part A, so that it is difficult to calculate an accurate transmittance. That is to say, in the actual process, it is difficult to adjust the transmittance by stacking translucent materials.

The present invention implements subtle errors in optical transmittance ranging from 4% to 75% in a stacked structure of translucent material to form a plurality of translucent portions in a single halftone mask. This may have a fatal problem: when the penetration between adjacent translucent portions is within a range of less than 4%, it is impossible to distinguish adjacent semi-transparent portions. That is to say, when the fluctuation range of the transmittance is less than 4% between adjacent translucent portions, there is no difference in each translucent portion. Thus, the pattern transferred in each of the translucent portions becomes blurred, and after the transfer, defects are generated between the patterns. Therefore, in the formation of the translucent portion according to the present invention, the transmittance is adjusted by a structure in which at least one or more translucent materials capable of adjusting the transmittance are stacked.

The material forming the translucent material may be one having one of the following main elements: Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf, V, Nd, Ge, MgO-Al. ₂ O ₃ or Si ₃ N ₄ , or may be a combination material of at least two or more elements, or may be added with at least one of Co _x , O _x , N _x , C _x , F _x or B _x to A single primary element material or a material of these combination materials. The translucent material forming each stacked structure is a stacked structure in which the same material is selected, or a stacked structure in which materials are different from each other, or a composite stacked structure of the two structures, in which the suffixes x, y, and z are natural numbers.

The most striking feature of the present invention is that the translucent portion is formed into a plurality of structures, and each of the structures has mutually different optical transmittances. Another feature is that the adjustment of optical transmittance is controlled by a stacked structure comprising one or more translucent materials.

Of course, the formation of individual stacked translucent portions, the optical transmittance of the translucent material can be adjusted by varying the composition or thickness of the translucent material. That is, the properties of the composition forming the translucent material can change the optical transmittance, and the difference in thickness of the same composition can adjust the optical transmittance.

As described above, the material containing the translucent material may have Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf, V, Nd, Ge, MgO-Al ₂ O ₃ Or a material of one of Si ₃ N ₄ as a main element, which has been described in detail.

Alternatively, the materials may be a combination material in which at least two or more elements are mixed, or at least one of Co _x , O _x , N _x , C _x , F _x or B _x may be added to a single main element material. Or the material of these composite materials.

It is worth noting that the composition of the stacked translucent portions can be applied variably as long as a portion of the illuminating light can pass through the composition. For example, the translucent portion of the stack may be 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 Formed by any one or combination of Al _x CO _y N _z , Ti _x O _y , Ti _x O _y N _{z ,} and Ti _x CO _y , wherein the suffixes x, y, and z are natural numbers and define each chemical element number.

[invention mode]

3 is a schematic view illustrating a translucent portion of an exemplary embodiment of the present invention. In other words, the translucent portion is formed of three types of translucent materials stacked on a substrate. Obviously, the structure of the translucent portion can be formed on a single halftone mask in a single form or in multiple forms, as desired. It is also apparent that these translucent materials can be laid on a light shielding film to form a light shielding portion.

When the transmittance of a first translucent material (H1) is x%, the transmittance of a second translucent material (H2) is y%, and the transmittance of a third translucent material (H3) is At z%, the portions formed by the three different transmittances may be the A portion, the B portion, and the C portion.

In detail, basically, z% of the light will pass through the C part, (z × y)% of the light will pass through the B part, and {(z × y) × x}% of the light will pass through the A part. Preferably, the range of change in optical transmittance in each of the portions A, B, and C is adjusted to a range of 4% to 75% according to the penetration characteristics.

Based on the above adjustment, it is possible to avoid forming a structure using only a specific transmittance to precisely adjust the transmittance of the stacked halftone material in the translucent portion formed on the halftone mask. Implement a translucent part.

4 is a schematic view showing another exemplary embodiment of a half transparent portion of FIG. 3, the translucent portion being composed of a first translucent material (H1, transmittance x%), and a second translucent material (H2) , the penetration rate is y%) and a third translucent material (H3, penetration rate z%) is stacked.

That is, the gist of the present invention is to stack a plurality of translucent materials on a single halftone mask to adjust each transmittance, whereby the transmittance adjustment between adjacent translucent materials is In the range of 4% to 75%, it is possible to pass through a translucent portion which forms a single halftone mask and each has a different transmittance, thereby eliminating the need to manufacture different masks, thereby increasing manufacturing cost effectiveness.

Now, a control method of adjusting the above-described transmittance will be described with reference to Fig. 5a.

A stack structure of translucent materials for forming a translucent portion is implemented based on library-based experimental data.

First, the penetration of each material is generated by a database of each translucent material (DB1~DBn, where n is a natural number) and is implemented in a specific translucent portion of the halftone mask. The penetration rate was chosen.

Thereafter, the transmittance of the first translucent material formed by sputtering is selected, and the transmittance of the second translucent material formed by sputtering is selected. In this way, the transmittance of the first translucent material and the second translucent material and the transmittance of the combined film layer of the two-layer film are realized.

The penetration rate database is stored in a transmittance database (210). In detail, a calculation of each transmittance is achieved by a controller (220) to form a film on a substrate. A layer (230) whereby two or more transmittances can be implemented in a single mask, and the quantitative data stored in the database can be reproduced once or in the same manner.

The following table is a calculation result illustrating the transmittance of the stacked translucent portion according to an exemplary embodiment of the present invention, and this calculation result is in a quantitative format.

Wherein, "reference T (%)" is the transmittance of the reference layer (R) of Fig. 5b, and X (%) of Fig. 5b is defined as the transmittance of the translucent layer stacked on the reference layer (R) .

Now, regarding Table 1, based on the stacked layers of the translucent portions, an example of calculation of the transmittance will be explained with reference to Fig. 5b.

With the above Table 1, the transmittance (Y) of the final stacked translucent portion can be quantitatively calculated. Of course, when the transmittance of the translucent portion (reference layer: R) is changed, the above calculated data may be changed.

Figure 6 illustrates an exemplary embodiment of various translucent portions of the present invention. The method of fabricating the translucent portion of the halftone mask will be described in the structure described later.

For the sake of convenience, a method of manufacturing a halftone mask which is a conventional technique in which a light shielding portion, a penetrating portion and a half transparent portion are stacked on a substrate is omitted.

However, according to the present invention, it will be described below that a plurality of translucent portions each having a different optical transmittance can be formed by stacking a plurality of translucent materials and adjusting transmittance during formation of a single halftone mask. Manufacturing method.

Figure 6a is a conceptual schematic diagram of a similar method of performing the plurality of translucent portions of Figures 3 and 4.

The first translucent material (H1), the second translucent material (H2), and the third translucent material (H3) may be sequentially stacked, and unnecessary segments at each portion are removed according to a subsequent removal process.

That is, in the step (b-1), a photoresist (PR) is formed on the third translucent material (H3), and a portion of the third translucent material (H3) is removed via exposure and development; In b-2), a photoresist (PR) is formed to remove a portion of the second translucent material (H2); in the step (b-3), a translucent portion formed with the A portion, the B portion, and the C portion is finally formed. In part, wherein the optical transmittance between adjacent portions is preferably in the range of 4% to 75%, and the portion D is a portion in which the light completely penetrates.

The structure of the translucent portion in Figures 7a and 7b may also be that each translucent material is sequentially stacked, and the subsequent removal process is performed by using a photoresist, wherein the fully penetrating portion (P) is followed by During the photoresist patterning process of the removal process, each stacked translucent material is completely removed to form.

Part A and Part B of Figure 7b can be formed by a simplified process and via the subsequent removal methods mentioned above, but the C portion can be implemented via a separate forming process that independently forms the H3 translucent material.

In the case of a translucent portion constructed in a different manner in FIG. 7c, the A portion can be formed by a subsequent removal process, and the B portion and the C portion can be formed by an independent formation process.

[Industrial Availability]

The present invention is applicable to a variety of industries that can provide a halftone mask capable of adjusting optical transmittance by stacking translucent materials, wherein a database is established based on actual processes rather than theoretical behavioral characteristics. Optical transmittance can be implemented, whereby a halftone mask having a transmittance over a wide range, rather than a transmittance in a specific region, can be provided.

Another application is that in fabricating a multi-tone mask having a halftone mask and a plurality of translucent regions, the necessary optical transmittance can be achieved by stacking translucent materials in the translucent portions, In order to reduce the manufacturing process.

Another application to the above-mentioned industries is that the optical transmittance between adjacent translucent regions is limited to a range of 4% to 75% to increase the precision of the manufactured halftone mask.

A further application to the above-mentioned industries is that adjacent translucent portions can be significantly different due to the accuracy of the transmittance, so that the control of the transfer pattern (the pattern of the product formed by using the mask) is changed. It is easy to achieve the formation of a plurality of film layers using one mask and to facilitate the formation of a simplified transfer pattern.

While the embodiments have been described with reference to the embodiments of the embodiments the embodiments More particularly, various variations and modifications are possible in the component parts and/or arrangements of the claimed combinations. Alternative uses will be apparent to those skilled in the art, in addition to variations and modifications in parts and/or configurations.

11. . . Transparent substrate

13. . . Light penetration unit

15. . . Shading unit

100. . . Substrate

120. . . Translucent layer

130. . . Translucent layer

210. . . Penetration database

220. . . Controller

A. . . Translucent part

B. . . Translucent part

C. . . Translucent part / shading part

D. . . Full penetration

DB1~DB4. . . database

H1. . . First half transparent material

H2. . . Second translucent material

H3. . . Third translucent material

P. . . Full penetration

PR. . . Photoresist

R. . . Reference layer

FIG. 1 is a conceptual diagram illustrating a conventional photomask.

2 is a schematic view for explaining behavior characteristics of a stacking structure of transmittance in a halftone mask.

3 and 4 are schematic views illustrating a translucent portion of an exemplary embodiment of the present invention.

5a and 5b are conceptual diagrams for explaining the transmittance adjustment of the translucent portion of the present invention and the stacking process thereof.

6a and 6b are schematic views illustrating the structure of a translucent portion and a method of fabricating the same according to another exemplary embodiment of the present invention.

7a, 7b, and 7c are schematic views illustrating a structure of a translucent portion and a method of fabricating the same according to still another exemplary embodiment of the present invention.

100. . . Substrate

A. . . Translucent part

B. . . Translucent part

C. . . Translucent part

H1. . . First half transparent material

H2. . . Second translucent material

H3. . . Third translucent material

Claims (9)

A halftone mask formed with a plurality of translucent portions, wherein at least half of the transparent material is stacked on a substrate such that each of the translucent portions has a different optical transmittance, wherein the translucent portions have The difference between the optical transmittance and the optical transmittance of an adjacent translucent portion is in the range of 4% to 75%, and the translucent portions have at least three regions having different optical transmittances, and at least two halves A transparent material is in contact with the substrate. The halftone mask of claim 1, wherein the at least half of the transparent material comprises the same material. The halftone mask of claim 1, wherein the at least half of the transparent material comprises a different material. The halftone mask of claim 1, wherein the at least half of the transparent material comprises the same material or a different material. The halftone mask of claim 1, wherein the at least half of the transparent material comprises a material having Cr, Si, Mo, Ta, Ti, Al, Zr, Sn, Zn, In, Mg, Hf, V, Nd, a main element of one of Ge, MgO-Al ₂ O ₃ and Si ₃ N ₄ , mixing a combination of at least two elements, or adding Co _x , O _x , N _x , C _x , F _x or B At least one of _x to the primary element or material of the composite material, wherein the suffixes x, y, and z are a natural number and mean the number of each chemical element. A method for fabricating a halftone mask, the method comprising: stacking at least half of a transparent material on a substrate to form a plurality of translucent portions; Adjusting the optical transmittance of the translucent portions, wherein the translucent portions have a difference in optical transmittance from an adjacent translucent portion in the range of 4% to 75%; The translucent portions have at least three regions each having a different optical transmittance; and at least two translucent materials are in contact with the substrate. The method of fabricating a halftone mask according to claim 6, wherein the adjusting of the optical transmittance comprises: removing unnecessary patterns after stacking at least half of the transparent material. The method of manufacturing a halftone mask according to claim 6, wherein the adjusting of the optical transmittance comprises: removing unnecessary patterns after stacking at least half of the transparent material; and forming at least one independent half of the translucent material Transparent layer. The method of manufacturing a halftone mask according to claim 6, wherein after stacking at least half of the transparent material, removing the unnecessary pattern is to use a photolithography method.