TWI615668B - Method of forming phase shift mask - Google Patents

Abstract

A method of forming a phase shift mask. A phase shift layer, a shielding layer, a promotion layer, and a mask layer are sequentially formed on the light-transmitting substrate. The mask layer is patterned to form a patterned mask layer. The promotion layer and the shielding layer are etched by using the patterned mask layer as a mask to form a patterning promoting layer and a first patterned shielding layer. The patterned mask layer and the patterning promoting layer are simultaneously removed. The phase shifting layer is etched with the first patterned masking layer as a mask to form a patterned phase shifting layer. The first patterned masking layer is selectively removed to form a second patterned masking layer.

Description

Method for forming phase shift mask

Embodiments of the present invention relate to a method of forming a reticle.

With the development of semiconductor technology, the size of semiconductor components is getting smaller and smaller, making their critical dimensions closer to the optical physical limit of the exposure machine. However, in order to improve the resolution of the reticle, a more advanced exposure machine is often required, or by adding multiple steps in the process of the reticle, resulting in an increase in equipment cost or a complicated process.

Embodiments of the present invention provide a method of forming a phase shift mask. A phase shift layer, a shielding layer, a promotion layer, and a mask layer are sequentially formed on the light-transmitting substrate. The mask layer is patterned to form a patterned mask layer. The promotion layer and the shielding layer are patterned by using the patterned mask layer as a mask to form a patterning promoting layer and a first patterned shielding layer. The patterning promoting layer is removed, wherein the patterned mask layer is simultaneously removed when the patterning promoting layer is removed. The phase shifting layer is etched with the first patterned masking layer as a mask to form a patterned phase shifting layer. The first patterned masking layer is selectively removed to form a second patterned masking layer.

Embodiments of the present invention provide a method of forming a phase shift mask. A phase shifting layer, a shielding layer and a double polymer layer are sequentially formed on the light transmissive substrate, wherein the double polymer layer comprises a mask layer and a promoting layer between the shielding layer and the mask layer. The mask layer is patterned to form a patterned mask layer. The promotion layer and the shielding layer are patterned by using the patterned mask layer as a mask to form a patterning promoting layer and a first patterned shielding layer. The patterning promoting layer is removed, wherein the patterned mask layer is simultaneously removed when the patterning promoting layer is removed. The phase shifting layer is etched with the first patterned masking layer as a mask to form a patterned phase shifting layer. A portion of the first patterned shielding layer is removed to form a second patterned shielding layer.

Embodiments of the present invention provide a method of forming a phase shift mask. A phase shift layer, a shielding layer, and a promoting layer are sequentially formed on the light-transmitting substrate. The promotion layer and the shielding layer are simultaneously etched with the same etching gas source to form a patterning promoting layer and a first patterned shielding layer. The patterning promoting layer is removed. The phase shifting layer is etched with the first patterned masking layer as a mask to form a patterned phase shifting layer. The first patterned masking layer is selectively removed to form a second patterned masking layer.

The above described features and advantages of the embodiments of the present invention will become more apparent and understood.

The following summary provides many different embodiments or examples for implementing different features of the subject matter provided. Specific examples of the components and configurations described below are for the purpose of conveying the present invention in a simplified manner. Of course, these are merely examples and not intended to be limiting. For example, in the following description, forming the second feature over the first feature or on the first feature may include an embodiment in which the second feature is formed in direct contact with the first feature, and may also include a second feature and Embodiments may be formed with a feature such that the second feature may not be in direct contact with the first feature. In addition, the present invention may have the same component symbols and/or letters in the various examples to refer to the same or similar components. The repeated use of the component symbols is for simplicity and clarity and does not represent a relationship between the various embodiments and/or configurations themselves to be discussed.

In addition, in order to facilitate the description of the relationship between one component or feature illustrated in the drawings and another component or feature, for example, "under", "below", "lower", Spatial relative terms for "on", "above", "upper" and similar terms. In addition to the orientation depicted in the figures, the spatially relative terms are intended to encompass different orientations of the elements in use or operation. The device can be otherwise oriented (rotated 90 degrees or at other orientations), while the spatially relative terms used herein are interpreted accordingly.

1 through 7 are cross-sectional views showing various stages of a process for fabricating a phase shift mask in accordance with some embodiments of the present invention. 8 is a flow chart of a process for fabricating a phase shift mask in accordance with some embodiments of the present invention.

Referring to FIG. 1 and FIG. 8, step 800, a transparent substrate 100 is provided. The material of the transparent substrate 100 includes quartz, molten cerium oxide, calcium fluoride, glass or other suitable light transmissive material.

Next, in step 810, the phase shift layer 200 is formed on the light-transmitting substrate 100. The phase shift layer 200 can generate a phase shift of about 180 degrees for light penetrating the light-transmitting substrate 100, and the light transmittance of the phase shift layer 200 is, for example, between 4% and 20%. In some embodiments, the phase shift layer 200 has a light transmittance of 6%; in other embodiments, the phase shift layer 200 has a light transmittance of 9%; in still other embodiments, the phase shift layer 200 is transparent. The light rate is 19%. The material of the phase shifting layer 200 includes Mo _x Si _y , MoSi _x N _y , MoSi _x O _y N _z , SiN or other suitable materials, wherein the ranges of X, Y, and Z are respectively feasible stoichiometry well known in the art. range. The phase shift layer 200 can be formed by an electron beam (EB) vapor deposition method, a laser deposition method, an atomic layer film formation (ALD) method, an ion assisted sputtering method, or the like. The thickness of the phase shifting layer 200 is, for example, between about 60 nanometers (nm) and about 80 nanometers.

Thereafter, in step 810, after the phase shift layer 200 is formed on the light-transmitting substrate 100, the shielding layer 300 is formed on the phase shift layer 200. The material of the shielding layer 300 includes Cr, CrO _x N _y , CrN _x , Cr ₂ O ₃ , SiN, SiO _x N _y , SiC, SiO _x C _y , TiN, TiSi _x N _y , Mo _x Si _y , TaN, TaBN. Or other suitable opaque materials, the ranges of X, Y, Z are respectively possible stoichiometric ranges well known in the art. The phase shift layer 200 may be formed by chemical vapor deposition (CVD) or physical vapor deposition (PVD) or the like, and has a thickness of, for example, between about 40 nm and about 60 nm.

Referring to FIG. 1 and FIG. 8 , in step 810 , after the shielding layer 300 is formed on the phase shift layer 200 , the promoting layer 400 is formed on the shielding layer 300 . In some embodiments, the material of the promotion layer 400 includes an organic material. The promotion layer 400 is, for example, comprising a copolymer material. In some exemplary embodiments, the facilitating layer 400 is comprised of a copolymeric material. The copolymer material used to form the promoting layer 400 is a non-photosensitive material, and the promoting layer 400 does not contain a photoacid generator (PAG). A part of the monomer of the copolymer material used to form the promoting layer 400 includes a monomer having a hydrophobic group, and the monomer having a hydrophobic group includes methyl methacrylate, diphenyl ketone, glycidyl methacrylate or the like. . In some embodiments, the molecular weight of the copolymer material used to form the promoting layer 400 is greater than or equal to 10,000. The method of forming the promotion layer 400 is, for example, dissolving a copolymer material formed of selected monomers in an organic solvent; uniformly coating a solution having a copolymer material on the shielding layer 300 by spin coating. A solution having a copolymer material coated on the masking layer 300 is baked to form the promoting layer 400. The thickness of the promoting layer 400 is, for example, between about 10 nanometers and about 20 nanometers.

Referring to FIG. 1 and FIG. 8 , step 810 is performed to form the mask layer 500 on the promoting layer 400 after the promoting layer 400 is formed on the shielding layer 300 . In some embodiments, the composition of the mask layer 500 is different from the composition of the facilitating layer 400. In some exemplary embodiments, mask layer 500 can be a photoresist layer. The mask layer 500 is, for example, a positive photoresist layer or a negative photoresist layer. The material of the photoresist layer is, for example, a photosensitive polymer material and a crosslinking agent. And photoacid generators. The method of forming the mask layer 500 is, for example, dissolving a selected photoresist material in an organic solvent; uniformly coating a solution having a photoresist material on the promotion layer 400 by spin coating; and baking coating on the promotion layer 400. A solution of photoresist material is formed to form mask layer 500. The thickness of the mask layer 500 is, for example, between about 800 angstroms and about 2000 angstroms.

In some embodiments of the present invention, the adhesion layer 400 and the mask layer 500 have good adhesion, and the adhesion between the promotion layer 400 and the shielding layer 300 is good. Furthermore, the promotion layer 400 is not miscible with the mask layer 500, and therefore, the promotion layer 400 is not dissolved during the formation of the mask layer 500. The promotion layer 400 and the mask layer 500 have different compositions such that the promotion layer 400 and the mask layer 500 have different chemical and physical properties. In some exemplary embodiments, the mask layer 500 includes a photosensitive polymer material, a crosslinking agent, and a photoacid generator; the promotion layer 400 includes a non-photosensitive polymer, but does not include a crosslinking agent and a photoacid generator. .

In another aspect, in some embodiments, the promotion layer 400 and the mask layer 500 each comprise a polymer layer and, therefore, can be considered together as a dual polymer layer 450. However, both the polymer layer as the mask layer 500 and the polymer layer as the promotion layer 400 have different chemical and physical properties. More specifically, the polymer layer as the mask layer 500 is a photosensitive polymer which can be reacted (for example, crosslinked or cracked) by exposure in a subsequent exposure process for patterning; The polymer layer of the promoting layer 400 is a non-photosensitive polymer that does not undergo a reaction (for example, crosslinking or cracking) due to exposure in a subsequent exposure process. Furthermore, the polymer layer as the mask layer 500 is exposed after exposure/non-exposure. The development process for patterning can be developed; and the polymer layer used as the promotion layer 400 is not developed in the subsequent development process, whether or not exposed or unexposed. A common developer is, for example, an organic alkali developer. The organic alkali developer is, for example, tetramethylammonium hydroxide (TMAH).

In some embodiments of the invention, the facilitating layer 400 is interposed between the masking layer 300 and the masking layer 500 and adheres to both. The promotion layer 400 and the mask layer 500 can be formed using the same method, for example, spin coating, so that the process can be simplified. Since an additional hard mask layer is not required between the masking layer 300 and the mask layer 500 as a mask for the subsequent step of patterning the masking layer 300. Therefore, an additional chemical vapor deposition process may not be required to form the hard mask layer.

Referring to FIG. 2 and FIG. 8, step 820 is performed to pattern the mask layer 500 to form a patterned mask layer 500a. The method of patterning the mask layer 500 is, for example, exposing a specific area of the mask layer 500, and then removing the exposed (or unexposed) mask layer 500 with a developer. The light source used to expose the mask layer 500 is, for example, a KrF light source (248 nm), an ArF light source (193 nm), or other light source of suitable wavelength. The developer is, for example, an organic alkali developer. The organic alkali developer is, for example, tetramethylammonium hydroxide (TMAH).

Since a relatively thin mask layer 500 (having a thickness of, for example, between about 800 angstroms and about 2000 angstroms) can be used in the present invention, sufficient depth of focus (DOF) can be achieved by exposure using an existing exposure machine. Further, when a portion of the mask layer 500 is removed with the developer, the promotion layer 400 positioned under the mask layer 500 is not developed. The liquid is removed or damaged by the developer, and can be left behind, and is used as a mask in conjunction with the patterned mask layer in the subsequent process of patterning the masking layer 300.

Referring to FIG. 3 and FIG. 8, step 830 is performed to pattern the mask layer 500a as a mask, and the promotion layer 400 and the shielding layer 300 are patterned to form a patterning promoting layer 400a and a first patterned shielding layer 300a. . The method of patterning the promotion layer 400 and the shielding layer 300 is, for example, transferring the pattern of the patterned mask layer 500a onto the promotion layer 400 and the shielding layer 300 by plasma etching. When the promotion layer 400 and the shielding layer 300 are etched by the aforementioned plasma etching method, a gas which can be used is, for example, chlorine (Cl ₂ ), oxygen (O ₂ ), or a combination thereof. In some embodiments, the promotion layer 400 and the masking layer 300 can be patterned using a single etching step. In other words, the same gas, even the same parameters, can be used when etching the promotion layer 400 and the shielding layer 300. On the other hand, after the promotion layer 400 is etched to form the patterning promoting layer 400a, it is not necessary to remove the patterned mask layer 500a first, and the etching layer under the patterning promoting layer 400a can be directly etched. 300. If the patterned mask layer 500a is etched and etched during the etching of the mask layer 300, the patterning promoting layer 400a may also serve as a mask (or hard mask) to continue the etching process of the mask layer 300.

Since the present invention uses a single layer of patterned mask layer 500a as a mask to pattern the promotion layer 400 and the mask layer 300, and etching the promotion layer 400, the etching gas used for etching the mask layer 300 can be used without In addition, an additional hard mask layer is formed as a mask or otherwise a different masking gas is used to etch the hard mask, and an additional removal step may be eliminated to remove the patterned mask prior to patterning the masking layer 300. The curtain layer, therefore, can reduce the steps of fabricating the phase shift mask, simplify the process of the phase shift mask, and reduce the processing time. In some embodiments, the phase shift mask manufacturing time can be reduced by about 20%.

Referring to FIG. 4 and FIG. 8, step 840, the patterned mask layer 500a and the patterning promoting layer 400a are removed, leaving the first patterned masking layer 300a. The patterned mask layer 500a and the patterning promoting layer 400a can be removed in the same manner, even with the same liquid. In some embodiments, the method of removing the patterned mask layer 500a and the patterning promoting layer 400a is to physically pattern the mask layer 500a and the patterning promoting layer 400a from a physical manner instead of a chemical reaction. A patterned masking layer 300a is removed. In some exemplary embodiments, the method of removing the patterned mask layer 500a and the patterning promoting layer 400a is to use a non-chemical solvent. The non-chemical solvent refers to a solvent that does not chemically react with the patterned mask layer 500a and the patterning promoting layer 400a, and may be a non-organic solvent such as water or other suitable liquid.

Referring to FIG. 5 and FIG. 8, step 850 is performed to pattern the phase shift layer 200 with the first patterned shielding layer 300a as a mask to form a patterned phase shift layer 200a. The method of patterning the phase shift layer 200 transfers the pattern of the first patterned masking layer 300a to the phase shift layer 200, for example, by plasma etching. When the phase shift layer 200 is etched by the aforementioned plasma etching method, a gas which can be used is, for example, a fluorine-containing gas, and the fluorine-containing gas includes a perfluoro-substituted gas and a partial fluorine-substituted gas. The perfluoro-substituted gas includes SF ₆ , CF ₄ or a combination thereof.

Referring to FIG. 6 to FIG. 8, step 860, a portion of the first patterned shielding layer 300a is selectively removed to form a second patterned shielding layer 300b. Referring first to FIG. 6, first, a patterned mask layer 600 is formed on the first patterned shielding layer 300a. The patterned mask layer 600 is, for example, a patterned photoresist layer. The patterned photoresist layer can be a positive photoresist or a negative photoresist. The first patterned shielding layer 300a is etched by using the patterned mask layer 600 as a mask to form a second patterned shielding layer 300b. A method of etching the first patterned shielding layer 300a to form the second patterned shielding layer 300b is, for example, a plasma etching method. When the first patterned shielding layer 300a is etched by the aforementioned plasma etching method, a gas which can be used is, for example, chlorine (Cl ₂ ), oxygen (O ₂ ), or a combination thereof. Thereafter, as shown in FIG. 7, the patterned mask layer 600 is removed. In some embodiments, the method of removing the patterned mask layer 600 is, for example, water or other suitable liquid. After the patterned mask layer 600 is removed, fabrication of the phase shift mask 700 is completed.

Referring to FIG. 7, the phase shift mask 700 formed by the present invention has an opaque area A, a light transmitting area B, and a partial light transmitting area C. The opaque area A has a patterned phase shift layer 200a and a second patterned masking layer 300b to completely shield the exposure light source. The patterned phase shifting layer 200a and the second patterned shielding layer 300b are absent on the transparent region B, and the surface of the opaque substrate 100 is exposed, so that the exposure light source can be completely penetrated to expose the photoresist on the wafer. The partially transparent region C has a patterned phase shifting layer 200a for allowing partial exposure light source to penetrate, but the intensity of the partially penetrated exposure light source is insufficient to expose the photoresist on the wafer, and the light can be generated by about 180 degrees. Phase shift. Since the exposure light source penetrating part of the light transmitting area C and the exposure light source penetrating the light transmitting area B have a phase difference of 180 degrees, the exposure light source penetrating part of the light transmitting area C and the exposure light source penetrating the light transmitting area B are generated. Destructive interference increases the contrast of the edges of the image to be exposed.

In some embodiments of the present invention, referring to FIG. 1, an additional hard mask layer is not required between the shielding layer 300 and the mask layer 500 as a mask for the subsequent step of patterning the masking layer 300. The invention simplifies the process of the phase shift mask. At the same time, since the present invention has a promoting layer 400 under the mask layer 500, a thin mask layer 500 can be used to enhance the resolution of the photoresist pattern. In some embodiments, the resolution can be increased by more than 20%.

In order to illustrate the advantages of the present invention, the experimental examples are enumerated below to more specifically describe the present invention.

<Experimental example>

Example 1 is a sub-resolution assist feature (SRAF) or a scattering bar (SB) which forms various aspect ratios according to the method of the present invention corresponding to FIGS. 1 to 7. The thickness of the promotion layer is 10 nm. The thickness of the photoresist layer on the promotion layer is 100 nm.

Comparative Example 1 is to replace the promotion layer with a ruthenium oxynitride hard mask layer to form various width-to-width ratio scattering strips. The thickness of the ruthenium oxynitride hard mask layer is 10 nm, and the photoresist on the hard coat layer of the ruthenium oxynitride layer. The thickness of the layer is 100 nm.

Comparative Example 2 is similar to Example 1, except that no other layer (promotion layer) is provided between the photoresist layer and the shielding layer.

In Example 1, Comparative Example 1, and Comparative Example 2, the pattern ratio of the photomask was four times that of the pattern to be transferred.

Table 1         <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> </td><td> DIA (minimum resolution) </td>< /tr><tr><td> Aspect Ratio</td><td> Example 1 </td><td> Comparative Example 1 </td><td> Comparative Example 2 </td></tr>< Tr><td> 1:1 </td><td> 44nm </td><td> 78nm </td><td> 92nm </td></tr><tr><td> 2:1 < /td><td> 32nm </td><td> 70nm </td><td> 80nm </td></tr><tr><td> 3:1 </td><td> 28nm </ Td><td> 62nm </td><td> 72nm </td></tr><tr><td> 4:1 </td><td> 24nm </td><td> 52nm </td ><td> 64nm </td></tr><tr><td> 5:1 </td><td> 20nm </td><td> 40nm </td><td> 48nm </td> </tr></TBODY></TABLE>

As shown in Table 1, in Example 1, after the photoresist layer was exposed and developed, the results of the post-development inspection (ADI) showed that the aspect ratio of the sub-analytical auxiliary features were 1:1, 2:1, respectively. At 3:1, 4:1, and 5:1, the critical dimensions (CD) of the phase shift mask can reach 44 nm, 32 nm, 28 nm, 24 nm, and 20 nm, respectively. The patterned promoting layer can firmly adhere the patterned photoresist layer without being easily collapsed.

In Comparative Example 1, after the photoresist layer was exposed and developed, the results of the post-development inspection (ADI) showed that the aspect ratio of the sub-analytical auxiliary features were 1:1, 2:1, 3:1, respectively. At 4:1 and 5:1, the critical dimensions of the phase shift mask can reach 78 nm, 70 nm, 62 nm, 52 nm, and 40 nm, respectively. In Comparative Example 2, after the photoresist layer was exposed and developed, the results of the post-development inspection (ADI) showed that the aspect ratio of the sub-analytical auxiliary features were 1:1, 2:1, 3:1, respectively. At 4:1 and 5:1, the critical dimensions of the phase shift mask can reach 92 nm, 80 nm, 72 nm, 64 nm, and 48 nm, respectively.

It can be seen from Table 1 that when the promotion layer is added in the phase shift mask process, the resolution of the formed phase shift mask can be improved. In particular, under the aspect ratio of the same secondary analytical auxiliary feature, the process method with the phase shift mask of the facilitating layer can increase the secondary analysis auxiliary feature window (SRAF window) by more than 50%. For example, when the aspect ratio of the secondary resolution auxiliary feature is 1:1, the critical dimension of the photoresist layer after development can be improved from 78 nm to 44 nm.

In summary, the embodiment of the present invention can form a patterning promoting layer and a patterned shielding layer by using a single layer of patterned mask layer (for example, a photoresist layer), without using a hard mask layer as a mask. To pattern the masking layer, and to remove the patterned mask layer and the patterning promoting layer at the same time by a single removal step, so that the process can be simplified, the cost is low, and the process window (margin) is large. Degree of phase shift mask.

Since the promoting layer used in the embodiment of the present invention is formed of a specific polymer monomer, it has a property of being not dissolved by the developing solution, and can be used as an etching hard mask together with the patterned photoresist layer after being patterned. Therefore, a thinner photoresist layer can be used, which improves the resolution of the pattern and is compatible with the current phase shift mask process.

Embodiments of the present invention provide a method of forming a phase shift mask. A phase shift layer, a shielding layer, a promotion layer, and a mask layer are sequentially formed on the light-transmitting substrate. The mask layer is patterned to form a patterned mask layer. The promotion layer and the shielding layer are patterned by using the patterned mask layer as a mask to form a patterning promoting layer and a first patterned shielding layer. The patterning promoting layer is removed, wherein the patterned mask layer is simultaneously removed when the patterning promoting layer is removed. The phase shifting layer is etched with the first patterned masking layer as a mask to form a patterned phase shifting layer. The first patterned masking layer is selectively removed to form a second patterned masking layer.

According to some embodiments of the invention, wherein the promoting layer comprises a non-photosensitive copolymer and is not dissolved by the developer.

According to some embodiments of the invention, wherein the promoting layer comprises a copolymer formed from a monomer having a hydrophobic group.

According to some embodiments of the invention, the promoting layer is a co-polymer formed from a group consisting of methyl methacrylate, diphenyl ketone, and glycidyl methacrylate.

In accordance with some examples of the present invention, a method of patterning the promotion layer and the masking layer comprises plasma etching with the same source of etching gas.

According to some examples of the present invention, the method of patterning the promotion layer and the masking layer comprises plasma etching with a same source of etching gas, wherein the same source of etching gas comprises chlorine (Cl ₂ ), Oxygen (O ₂ ) or a combination thereof.

According to some examples of the invention, wherein the patterning promoting layer is removed in a physical manner.

In accordance with some examples of the present invention, a method of removing the patterned promotion layer includes using water.

According to some examples of the invention, the material of the promoting layer comprises an organic material.

According to some examples of the invention, the composition of the promotion layer is different from the composition of the mask layer.

According to some examples of the invention, wherein the material of the promoting layer comprises a first polymer; the material of the mask layer comprises a second polymer, wherein the material of the first polymer and the material of the second polymer are different.

According to some examples of the invention, the material of the promoting layer comprises a non-photosensitive polymer; the material sensitivity of the mask layer comprises a polymer.

Embodiments of the present invention provide a method of forming a phase shift mask. A phase shifting layer, a shielding layer and a double polymer layer are sequentially formed on the light transmissive substrate, wherein the double polymer layer comprises a mask layer and a promoting layer between the shielding layer and the mask layer. The mask layer is patterned to form a patterned mask layer. The promotion layer and the shielding layer are patterned by using the patterned mask layer as a mask to form a patterning promoting layer and a first patterned shielding layer. The patterning promoting layer is removed, wherein the patterned mask layer is simultaneously removed when the patterning promoting layer is removed. The phase shifting layer is etched with the first patterned masking layer as a mask to form a patterned phase shifting layer. A portion of the first patterned shielding layer is removed to form a second patterned shielding layer.

According to some embodiments of the invention, wherein the promoting layer comprises a non-photosensitive copolymer and is not dissolved by the developer.

According to some embodiments of the invention, wherein the promoting layer comprises a copolymer formed from a monomer having a hydrophobic group.

According to some embodiments of the invention, the promoting layer is a co-polymer formed from a group consisting of methyl methacrylate, diphenyl ketone, and glycidyl methacrylate.

In accordance with some examples of the present invention, a method of patterning the promotion layer and the masking layer comprises plasma etching with the same source of etching gas.

According to some examples of the present invention, the method of patterning the promotion layer and the masking layer comprises plasma etching with a same source of etching gas, wherein the same source of etching gas comprises chlorine (Cl ₂ ), Oxygen (O ₂ ) or a combination thereof.

According to some examples of the invention, wherein the patterning promoting layer is removed in a physical manner.

In accordance with some examples of the present invention, a method of removing the patterned promotion layer includes using water.

According to some examples of the invention, the material of the promoting layer comprises an organic material.

According to some examples of the invention, the composition of the promotion layer is different from the composition of the mask layer.

According to some examples of the invention, wherein the material of the promoting layer comprises a first polymer; the material of the mask layer comprises a second polymer, wherein the material of the first polymer and the material of the second polymer are different.

According to some examples of the invention, the material of the promoting layer comprises a non-photosensitive polymer; the material sensitivity of the mask layer comprises a polymer.

Embodiments of the present invention provide a method of forming a phase shift mask. A phase shift layer, a shielding layer, and a promoting layer are sequentially formed on the light-transmitting substrate. The promotion layer and the shielding layer are simultaneously etched with the same etching gas source to form a patterning promoting layer and a first patterned shielding layer. The patterning promoting layer is removed. The phase shifting layer is etched with the first patterned masking layer as a mask to form a patterned phase shifting layer. The first patterned masking layer is selectively removed to form a second patterned masking layer.

According to some embodiments of the invention, wherein the promoting layer comprises a non-photosensitive copolymer and is not dissolved by the developer.

According to some embodiments of the invention, wherein the promoting layer comprises a copolymer formed from a monomer having a hydrophobic group.

According to some embodiments of the invention, the promoting layer is a co-polymer formed from a group consisting of methyl methacrylate, diphenyl ketone, and glycidyl methacrylate.

According to some examples of the invention, wherein the patterning promoting layer is removed in a physical manner.

In accordance with some examples of the present invention, a method of removing the patterned promotion layer includes using water.

According to some examples of the invention, the material of the promoting layer comprises an organic material.

According to some embodiments of the invention, the material of the promoting layer comprises a first polymer.

According to some examples of the invention, the material of the promoting layer comprises a non-photosensitive polymer.

The present invention has been characterized in several embodiments as described above, and various aspects of the present invention will become more apparent to those of ordinary skill in the art. Those skilled in the art will appreciate that other processes and structures can be readily constructed or modified in accordance with the present invention to achieve the same objectives and/or advantages of the embodiments described herein. It will be understood by those skilled in the art that various equivalents can be made without departing from the spirit and scope of the invention, and those skilled in the art without departing from the spirit and scope of the invention Various modifications, changes, substitutions, and alterations are made to this document.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.

100‧‧‧Transparent substrate

200‧‧‧ phase shift layer

200a‧‧‧ patterned phase shift layer

300‧‧‧shading layer

300a‧‧‧First patterned masking layer

300b‧‧‧Second patterned masking layer

400‧‧‧Promotional layer

400a‧‧‧patterned promotion layer

450‧‧‧Double polymer layer

500‧‧‧ mask layer

500a‧‧‧ patterned mask layer

600‧‧‧ patterned mask layer

700‧‧‧ phase shift mask

800~860‧‧‧Steps

A‧‧‧Opacity zone

B‧‧‧Light transmission area

C‧‧‧Partial light transmission area

1 through 7 are cross-sectional views showing various stages of a process for fabricating a phase shift mask in accordance with some embodiments of the present invention. 8 is a flow chart of a process for fabricating a phase shift mask in accordance with some embodiments of the present invention.

100‧‧‧Transparent substrate

200‧‧‧ phase shift layer

300a‧‧‧First patterned masking layer

400a‧‧‧patterned promotion layer

500a‧‧‧ patterned mask layer

Claims (10)

A method for forming a phase shift mask includes: sequentially forming a phase shift layer, a shielding layer, a promoting layer, and a mask layer on the transparent substrate; patterning the mask layer to form a patterned mask layer; The patterned mask layer is a mask, the promotion layer and the shielding layer are patterned to form a patterning promoting layer and a first patterned shielding layer; and the patterning promoting layer is removed, wherein Removing the patterned mask layer while removing the patterning promoting layer; after removing the patterning promoting layer, using the first patterned masking layer as a mask, performing the phase shifting layer Etching to form a patterned phase shifting layer; and selectively removing the first patterned shielding layer to form a second patterned shielding layer. A method for forming a phase shift mask includes: sequentially forming a phase shift layer, a shielding layer, and a double polymer layer on the light transmissive substrate, wherein the double polymer layer comprises a mask layer and the shielding layer and the a promoting layer between the mask layers; patterning the mask layer to form a patterned mask layer; patterning the promoting layer and the shielding layer with the patterned mask layer as a mask Forming a patterning promoting layer and a first patterned shielding layer; removing the patterning promoting layer, wherein the patterned mask layer is simultaneously removed when the patterning promoting layer is removed; Using the first patterned shielding layer as a mask, etching the phase shifting layer to form a patterned phase shifting layer; and removing a portion of the first patterned shielding layer to form a second patterned masking layer Floor. The method of forming a phase shift mask according to claim 1 or 2, wherein the method of patterning the promoting layer and the shielding layer comprises plasma etching with the same etching gas source. The method of forming a phase shift mask according to claim 3, wherein the same source of etching gas comprises chlorine (Cl ₂ ), oxygen (O ₂ ), or a combination thereof. A method for forming a phase shift mask includes: sequentially forming a phase shift layer, a shielding layer, and a promoting layer on the transparent substrate; etching the promoting layer and the shielding layer with the same etching gas source to Forming a patterning promoting layer and a first patterned shielding layer; removing the patterning promoting layer; etching the phase shifting layer with the first patterned shielding layer as a mask to form a patterned phase shift a layer; and selectively removing the first patterned masking layer to form a second patterned masking layer. The method of forming a phase shift mask according to claim 1, wherein the acceleration layer comprises a non-photosensitive copolymer and is not dissolved by the developer. The method of forming a phase shift mask according to claim 1, wherein the promoting layer comprises a copolymer formed of a monomer having a hydrophobic group. The method of forming a phase shift mask according to any one of claims 1 to 2, wherein the promoting layer is selected from the group consisting of methyl methacrylate, diphenyl ketone, and methacrylic acid. a copolymer formed by a group of glycerides. The method of forming a phase shift mask according to claim 1, wherein the second patterned masking layer exposes a portion of the patterned phase shifting layer and a portion of the light transmissive substrate. The method of forming a phase shift mask as described in claim 1, 2 or 5, wherein the method of removing the patterning promoting layer comprises using water.