TW202434988A - Method of manufacturing photo masks - Google Patents

Abstract

In a method of manufacturing an attenuated phase shift mask, a photo resist pattern is formed over a mask blank. The mask blank includes a transparent substrate, an etch stop layer on the transparent substrate, a phase shift material layer on the etch stop layer, a hard mask layer on the phase shift material layer and an intermediate layer on the hard mask layer. The intermediate layer is patterned by using the photo resist pattern as an etching mask, the hard mask layer is patterned by using the patterned intermediate layer as an etching mask, and the phase shift material layer is patterned by using the patterned hard mask layer as an etching mask. The intermediate layer includes at least one of a transition metal, a transition metal alloy, or a silicon containing material, and the hard mask layer is made of a different material than the intermediate layer.

Description

Method for manufacturing photomask

without

The semiconductor industry has experienced exponential growth. Technological advances in materials and design have produced generations of integrated circuits (ICs), each with smaller and more complex circuits than the previous generation. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased, while geometric size (i.e., the smallest component or wire that can be produced using a manufacturing process) has shrunk. This scaling down process generally provides benefits by increasing production efficiency and reducing associated costs.

without

The following disclosure provides many different embodiments, or examples, for implementing the different features of the present disclosure. Specific examples of components and configurations are described below to simplify the present disclosure. Of course, these are only examples and are not intended to be limiting. For example, in the following description, the formation of a first feature above or on a second feature may include an embodiment in which the first feature and the second feature are directly in contact, and may also include an embodiment in which an additional feature may be formed between the first feature and the second feature so that the first feature and the second feature may not be in direct contact. In addition, the present disclosure may repeatedly refer to numbers and/or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not itself specify the relationship between the various embodiments and/or configurations discussed.

Additionally, for ease of description, spatially relative terminology such as "below," "beneath," "lower," "above," "upper," and the like may be used herein to describe the relationship of one element or feature to another element or feature illustrated in the figures. Spatially relative terminology is intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be similarly interpreted accordingly.

In the manufacture of integrated circuits (ICs), the patterns representing the different layers of the IC are produced using a series of reusable photomasks (also referred to herein as photolithography masks or reticles). In the semiconductor device manufacturing process, photomasks are used to transfer the design of each layer of the IC onto a semiconductor substrate.

As IC sizes shrink, various types of lithography techniques (e.g., immersion lithography using a wavelength of about 193 nm from ArF lasers or extreme ultraviolet (EUV) lithography at a wavelength of 13.5 nm) are used in lithography processes such as transferring very small patterns (e.g., nanoscale patterns) from a mask to a semiconductor wafer.

The continuing demand for integrated devices with denser packaging has led to changes in lithography processes to form smaller individual feature sizes. The minimum feature size or "critical dimension" (CD) achievable by a process is approximately determined by the formula CD = _k1 * λ/NA, where _k1 is a process-specific factor, λ is the wavelength of the applied light/energy, and NA is the numerical aperture of the optical lens as seen through the substrate or wafer.

For the fabrication of densely packed features with a given value of _k1 , the ability to project a usable image of small features onto the wafer is limited by the wavelength λ and the ability of the projection optics to capture sufficient diffraction orders from the illumination mask. When densely packed features or isolated features are made from a mask or reticle of a particular size and/or shape, the transition between light and dark at the edge of the projected image may not be sharply defined enough to properly form the target photoresist pattern. This can result in, among other things, reduced contrast in the aerial image and the quality of the resulting photoresist profile. Therefore, features with sizes of 150nm or less may require the use of phase shifting mask (PSM) techniques to enhance the image quality at the wafer, for example, to sharpen the edges of the features to improve the resist profile.

Phase shifting typically involves selectively changing the phase of a portion of the energy that passes through the mask/reticle so that the phase-shifted energy is added to or subtracted from the unphase-shifted energy at the surface of the material on the wafer to be exposed and patterned. By carefully controlling the shape, position, and phase-shift angle of the mask features, the resulting photoresist pattern can have more precisely defined edges. As feature size decreases, the imbalance in transmitted intensity between the 0° and 180° phase portions and the phase shift that varies from 180° can result in significant critical dimension (CD) variations and placement errors in the photoresist pattern.

Phase shifting can be achieved in a variety of ways. For example, a process called attenuated phase shifting mask (APSM) includes a layer of light-transmitting material that causes a phase change in light passing through the light-transmitting material compared to the light passing through the transparent portion of the mask. Additionally, a non-opaque material can modulate the amount (intensity/amplitude) of light passing through the non-opaque material compared to the amount of light passing through the transparent portion of the mask.

Phase shift material is a material that affects the phase of light passing through the phase shift material so that the phase of light passing through the phase shift material is shifted relative to the phase of light that has not passed through the phase shift material (for example, light that has only passed through the transparent mask substrate material but not through the phase shift material). The phase shift material can also reduce the amount of light that passes through the phase shift material relative to the amount of incident light that passes through the portion of the mask that is not covered by the phase shift material.

During the formation of the patterned phase-shift material, a photoresist pattern is formed over a hard mask layer formed over the phase-shift material layer. As the pattern size decreases, it becomes more important to suppress the collapse of the resist pattern and round the corners of the hard mask pattern while obtaining APSM to produce the desired phase shift.

In embodiments of the present disclosure, a multi-layer resist system is disclosed with or without a combination of multiple hard mask layers in a patterning operation.

FIG. 1A is a cross-sectional view of a mask 100 (e.g., an APSM) according to an embodiment of the present disclosure. Referring to FIG. 1A , the APSM 100 includes a substrate 10 and a phase shift material layer 15 located above a front surface of the substrate 10. Between the phase shift material layer 15 and the substrate 10 is an etch stop layer 12. In the embodiment shown in FIG. 1A , a portion of the phase shift material layer 15 and the etch stop layer 12 are removed to provide an opening from which the upper surface of the substrate 10 is exposed. In the embodiment shown in FIG. 1A , the transparency to light (e.g., ArF laser or KrF laser light) is less than 100% and is in the range of about 95% to 99.5%. The ASPM 100 includes an image boundary feature 20B surrounding the periphery of an image area (circuit pattern area) 20C of the ASPM 100. In some embodiments, the phase-shift material layer 15 and the etch-stop layer 12 are etched so that a portion of the phase-shift material layer 15 and the etch-stop layer 12 located below the image boundary feature 20B is separated from the remaining portion of the phase-shift material layer 15 and the etch-stop layer 12. In such embodiments, a portion of the phase-shift material layer 15 and the etch-stop layer 12 located below the image boundary feature 20B is separated from the remaining portion of the phase-shift material layer 15 and the etch-stop layer 12 by a trench (not shown).

FIG. 1B is a cross-sectional view of an APSM 100A according to another embodiment of the present disclosure. Referring to FIG. 1B , in the APSM 100A, the portion of the substrate 100 exposed in the opening is etched or recessed. The recess amount is adjusted so that the phase difference between the light passing through the phase shift material layer 15 and the etch stop layer 12 and the light not passing through has a desired phase shift amount.

FIG. 1C is a cross-sectional view of an APSM 100B according to another embodiment of the present disclosure. In the APSM 100B shown in FIG. 1C , the etch stop layer 12 at the bottom of the opening is not etched.

FIG. 1D is a cross-sectional view of an APSM 100C according to another embodiment of the present disclosure. In the APSM 100C shown in FIG. 1D , the etch stop layer 12 at the bottom of the opening is partially removed.

Figures 2A to 2I show cross-sectional views of operations at various stages of manufacturing an APSM sequence according to some embodiments of the present disclosure. In some embodiments, additional operations are performed before, during and/or after the process of Figures 2A to 2I, or some of the operations described are replaced and/or eliminated. In some embodiments, some of the features described below are replaced or deleted. A person of ordinary skill in the art will understand that although some embodiments are discussed in terms of operations performed in a particular order, these operations may be performed in another logical order.

2A, according to some embodiments, an etch stop layer 12, a phase shift material layer 15, and a hard mask layer 20 are disposed on a substrate 10 as a blank mask (no circuit pattern is formed yet). In some embodiments, a multi-layer resist system including an intermediate layer 30 and a photoresist layer 40 is formed on the hard mask layer 20, as shown in FIG. 2A.

In some embodiments, substrate 10 is made of glass, silicon, quartz, or other low thermal expansion materials. Low thermal expansion materials help minimize image distortion caused by heating of the mask during use of the mask. In some embodiments, substrate 10 includes fused silica, fused quartz, calcium fluoride, silicon carbide, black diamond, or titanium oxide doped silicon oxide (SiO2/TiO2). In some embodiments, the thickness of substrate 10 ranges from about 1 mm to about 7 mm. If the thickness of substrate 10 is too small, the risk of mask damage or warping is sometimes increased. On the other hand, if the thickness of substrate 10 is too large, the weight and cost of the mask may be unnecessarily increased in some cases.

In some embodiments, the etch stop layer 12 is in direct contact with the front surface of the substrate 10. In some embodiments, the etch stop layer 12 is transmissive or semi-transmissive to light energy used in the lithography process. For example, in some embodiments, the etch stop layer is transmissive or semi-transmissive to deep ultraviolet or near ultraviolet light energy used in immersion lithography. In some embodiments, the exposure radiation is light from an ArF excimer laser having a wavelength of about 193nm or a KrF excimer laser having a wavelength of about 254nm. Semi-transmissive to light or radiation means that the material transmits less than 70% of the light incident on the surface of the material, and transmissive means that the transmittance is 95% or more (for example, Al or Ru or their compounds).

Examples of materials that can be used as the etch stop layer 12 include materials that are resistant to the materials used to etch the phase-shift material layer 15 described below. In an embodiment in which the phase-shift material layer 15 is formed of a MoSi compound, a fluorine-containing etchant is used to etch the phase-shift material layer 15. According to an embodiment of the present disclosure, the etch stop layer 12 is resistant to the fluorine-containing etchant. Examples of fluorine-containing etchants that can be used to remove a portion of the phase-shift material layer 15 include fluorine-containing gases such as CF ₄ , CHF ₃ , C ₂ F ₆ , CH ₂ F ₂ , SF ₆ or a combination thereof. Materials that are resistant to fluorine-containing etchants and can be used as the etch stop layer 12 include CrON, Al and Al alloys, Ru and Ru composites, such as Ru-Nb, Ru-Zr, Ru-Ti, Ru-Y, Ru-B, Ru-P, etc. In _{other embodiments, the etch stop layer 12 is light-transmissive (e.g., greater than about 95%) and is selected from materials having a chemical formula of AlxSiyOz ,} where x+y+ _z =1. Embodiments according to the present disclosure are not limited to etch stop layers of these specific materials. According to the embodiments described herein, other materials that are semi-transmissive to incident light and resistant to the above-mentioned fluorine-containing etchants can be used as the etch stop layer. In other embodiments, a material that is semi-transmissive to incident light and resistant to etchants other than the fluorine-containing etchant that can be used to etch the phase-shift material layer 15 may be used.

In some embodiments, the etch stop layer 12 can be etched with a chlorine-containing etchant. One advantage of using an etch stop layer 12 that can be etched with a chlorine-containing etchant is that the material used as the substrate 10 (e.g., quartz) is not etched by the chlorine-containing etchant. Examples of chlorine-containing etchants include chlorine-containing gases (e.g., Cl ₂ , SiCl ₄ , HCl, CCl ₄ , CHCl ₃ , other chlorine-containing gases, or combinations thereof) and oxygen-containing gases (e.g., O ₂ , other oxygen-containing gases, or combinations thereof).

In some embodiments, the etch stop layer 12 has a thickness between about 1 and 20 nm. In other embodiments, the etch stop layer 12 has a thickness between about 1 and 10 nm. Embodiments according to the present disclosure are not limited to etch stop layers having a thickness between 1 and 20 nm or between 1 and 10 nm. For example, in some embodiments, the etch stop layer 12 may be thinner than 1 nm or may be thicker than 20 nm.

The etch stop layer 12 may be formed by various methods, including a physical vapor deposition (PVD) process (e.g., evaporation and DC magnetron sputtering), an electroplating process (e.g., chemical plating or electroplating), a chemical vapor deposition (CVD) process (e.g., atmospheric pressure CVD, low pressure CVD, plasma enhanced CVD or high density plasma CVD), ion beam deposition, spin coating, metal-organic decomposition (MOD), other suitable methods or combinations thereof.

In some embodiments, the phase-shift material layer 15 is in direct contact with the front surface of the etch stop layer 12 on the substrate 10. The phase-shift material layer 15 generates a phase shift in light incident on and transmitted through the phase-shift material layer 15. According to an embodiment of the present disclosure, the degree of phase shift generated in light entering the phase-shift material layer 15 and passing through the phase-shift material layer 15 and the patterned etch stop layer 12, compared to the phase of the incident light that has not passed through the phase-shift material layer 15 or the etch stop layer 12, can be adjusted by changing the refractive index and thickness of the phase-shift material layer 15 and/or the refractive index and thickness of the etch stop layer 12. In some embodiments, the refractive index and thickness of the phase shift material layer 15 and the etch stop layer 12 are selected so that the phase shift produced in the light entering the phase shift material layer 15 and passing through the phase shift material layer 15 and the patterned etch stop layer 12 is approximately 180 degrees. Embodiments according to the present disclosure are not limited to producing a 180° phase shift. For example, in other embodiments, the desired phase shift may be greater or less than 180°.

In some embodiments, the transmission of incident light that enters the phase-shift material layer 15 and passes through the phase-shift material layer 15 and the patterned etch stop layer 12 can be adjusted by changing the absorption coefficient of the phase-shift material layer 15 and/or the etch stop layer 12, compared to the transmission of incident light that does not pass through the phase-shift material layer 15 or the etch stop layer 12.

The refractive index and thickness of the phase-shift material layer 15 can be adjusted alone or in combination with the refractive index and thickness of the etch stop layer 12 to provide a desired phase shift. The refractive index of the phase-shift material layer 15 can be adjusted by changing the material composition of the phase-shift material layer 15. For example, the ratio of Mo to Si in the MoSi compound can be changed to adjust the refractive index of the phase-shift material layer 15. The refractive index of the phase-shift material layer 15 can be adjusted by doping the phase-shift material layer 15 with elements such as B, C, O, N, Al, etc.

According to an embodiment of the present disclosure, the transmission of incident light by the phase-shift material layer 15 can be adjusted by adjusting the incident light absorption coefficient of the phase-shift material layer 15. For example, increasing the UV or DUV absorption coefficient of the phase-shift material layer 15 will reduce the transmission of incident light through the phase-shift material layer 15. Reducing the absorption coefficient of the phase-shift material layer 15 will increase the transmission of incident light through the phase-shift material layer 15. The absorption coefficient of the phase-shift material layer 15 can be adjusted by changing the composition of the material of the phase-shift material layer 15. For example, the ratio of Mo to Si in the MoSi compound can be changed to adjust the absorption coefficient of the phase-shift material layer 15. Doping the phase-shift material layer 15 with elements such as B, C, O, N, Al, Ge, Sn, Ta, etc. can adjust the absorption coefficient of the phase-shift material layer 15.

According to some embodiments, the thickness of the phase-shift material layer 15 can be varied based on the desired degree of phase shift. For example, making the phase-shift material layer thicker can increase or decrease the phase shift. In other examples, making the phase-shift material layer thinner can increase or decrease the phase shift. In some embodiments, the phase-shift material layer 15 has a thickness between about 30 and 100 nanometers. It should be understood that embodiments according to the present disclosure are not limited to a phase-shift material layer 15 having a thickness between about 30 and 100 nm. In other embodiments, the phase-shift material layer 15 has a thickness less than 30 nm or greater than 100 nm.

Materials that can be used as the phase shift material layer 15 include MoSi compounds and the like. For example, the phase shift material layer 15 includes MoSi compounds, such as MoSi, MoSiCON, MoSiON, MoSiCN, MoSiCO, MoSiO, MoSiC, and MoSiN. The embodiments according to the present disclosure are not limited to the phase shift material layer using the aforementioned MoSi compounds. In other embodiments, the phase shift material layer 15 includes a compound other than the MoSi compound, which is capable of shifting the phase of light incident on the phase shift layer by, for example, 180 degrees.

The phase-shift material layer 15 can be formed by various methods, including physical vapor deposition (PVD) processes (e.g., evaporation and DC magnetron sputtering), plating processes (e.g., chemical plating or electroplating), chemical vapor deposition (CVD) processes (e.g., atmospheric pressure CVD, low pressure CVD, plasma enhanced CVD or high density plasma CVD), ion beam deposition, spin coating, metal organic decomposition (MOD), other suitable methods or combinations thereof.

The hard mask layer 20 will be patterned, and the pattern of the hard mask layer 20 will be transferred to the phase-shift material layer 15. In some embodiments, the hard mask layer 20 includes a material that protects the phase-shift material layer 15. In some embodiments, the hard mask layer 20 includes a chromium-containing material, such as Cr, CrN, CrO, CrC, CrON, CrCN, CrOC, CrOCN, other chromium-containing materials, or combinations thereof. In some alternative embodiments, the hard mask layer 20 includes a tantalum-containing material that can be etched with a fluorine-containing etchant, such as Ta, TaN, TaNH, TaHF, TaHfN, TaBSi, TaB, SiN, TaB, TaBN, TaSi, TaSiN, TaGe, TaGeN, TaZr, TaZrN, other tantalum-containing materials, or combinations thereof.

In some embodiments, the hard mask layer 20 has a thickness of about 3 nm to about 400 nm. In other embodiments, the thickness of the hard mask layer 20 is in a range of about 5 nm to about 100 nm. The hard mask layer 20 can be formed by various methods, including physical vapor deposition (PVD) processes (e.g., evaporation and DC magnetron sputtering), plating processes (e.g., chemical plating or electroplating), chemical vapor deposition (CVD) processes (e.g., atmospheric pressure CVD, low pressure CVD, plasma enhanced CVD, or high density plasma CVD), ion beam deposition, spin coating, metal organic decomposition (MOD), other suitable methods, or combinations thereof.

The intermediate layer 30 of the multi-layer resist system includes a material that can absorb ultraviolet light and has sufficient etching selectivity for the hard mask layer 20 and the phase-shift material layer 15 (made of different materials). In some embodiments, the intermediate layer 30 includes a transition metal or an alloy or compound of a transition metal. Examples of transition metals include Mo, Ta, Pd, Ir, Ni, Sn, Ru, or Au. The Mo compound, Ta compound, or Ru compound described above with respect to the etch stop layer 12, the phase-shift material layer 15, and the hard mask layer 20 can be used as the intermediate layer 30. In some embodiments, the intermediate layer 30 includes an organic/polymer-based Si-containing material or an inorganic Si-based material. Inorganic silicon-based materials include silicon nitride, silicon oxide, silicon oxynitride, SiOC, SiOCN, SiCN, SiC, SiBN, SiBC or SiBCN. In some embodiments, the intermediate layer 30 includes amorphous or polycrystalline Si, SiGe or SiC. In some embodiments, the intermediate layer 30 includes a silicon-containing polymer, such as polysiloxane. In some embodiments, the silicon content of polysiloxane is about 40wt% to about 70wt%. In some embodiments, the polymer substrate intermediate layer 30 further includes metal particles of Si or Mo, Ta, Pd, Ir, Ni, Sn, Ru or Au. In some embodiments, the diameter of the particles is in the range of 1nm to 20nm, or about 2nm to about 10nm. In some embodiments, the intermediate layer 30 is an organic polymer containing silicon particles and/or metal particles as described above.

In some embodiments, the minimum thickness of the intermediate layer 30 is about 2 nm, about 5 nm, or about 10 nm, and the maximum thickness of the intermediate layer 30 is about 30 nm, about 50 nm, about 100 nm, about 150 nm, or about 200 nm, or any range therebetween. The intermediate layer 30 is formed by CVD, PVD, ALD, or any other suitable film forming process.

As described in more detail below, the photoresist layer 40 is patterned and the patterned photoresist is used as a mask to pattern the intermediate layer 30 below. In some embodiments, the pattern of the photoresist layer 40 is transferred to the phase shift material layer 15 in a subsequent process. In some embodiments, the photoresist layer 40 can be a chemically enhanced resist catalyzed by acid. For example, the photoresist of the photoresist layer 40 can be prepared by dissolving an acid-sensitive polymer in a casting solution. In some embodiments, the photoresist of the photoresist layer 40 can be a positive photoresist, which will cause the subsequently formed pattern to have the same profile as the pattern on the mask (not shown). In some alternative embodiments, the photoresist of the photoresist layer 40 may be a negative photoresist, which will cause the subsequently formed pattern to have openings (not shown) corresponding to the pattern on the mask. The photoresist layer 40 may be formed by spin coating or other similar techniques.

Referring to FIG. 2B , an intermediate structure after patterning the photoresist layer 40 is shown. The photoresist layer 40 is patterned by performing an exposure process on the photoresist layer 40. The exposure process may include a lithography technique with a mask (e.g., a lithography process) or a lithography technique without a mask (e.g., an electron beam (e-beam) exposure process or an ion beam exposure process). After the exposure process, a post-baking process may be performed to harden at least a portion of the photoresist layer 40. Depending on the material or type of the photoresist layer 40, the polymer of the photoresist layer may react differently (snapping or cross-linking of the polymer) when the light beam is irradiated and baked. Thereafter, a developing process is performed to remove at least a portion of the photoresist layer 40. In some embodiments, the portion of the positive resist material exposed to the light beam may undergo a chain breaking reaction, making the exposed portion easier to remove by the developer than other portions not exposed to the light beam. On the other hand, the portion of the negative resist material exposed to the light beam may undergo a cross-linking reaction, making the exposed portion more difficult to remove by the developer than other portions not exposed to the light beam. In some embodiments, after the development of the photoresist layer 40, a portion of the underlying intermediate layer 30 is exposed.

Then, as shown in FIG. 2C , after the development of the photoresist layer 40 is completed, the intermediate layer 30 is etched through the openings in the developed photoresist layer 40. The intermediate layer 30 is patterned by etching the exposed portions of the intermediate layer 30 through the openings in the developed photoresist layer 40. The etching process may include a dry etching process, a wet etching process, or a combination thereof. The dry and wet etching processes have adjustable etching parameters, such as the etchant used, etching temperature, etching solution concentration, etching pressure, source power, RF bias, RF bias power, etchant flow rate, and other suitable parameters, so that the intermediate layer 30 is selective to other materials that will be exposed to the etchant during etching of the intermediate layer 30. In some embodiments, a fluorine-containing etchant is used to remove portions of the intermediate layer 30 made of, for example, oxide or silicon-based materials. Examples of fluorine-containing etchants include fluorine-containing gases, such as _CF4 , CHF3 _{, C2F6} , _{CH2F2 , CH3F ,} or combinations thereof. In some embodiments, a chlorine-containing etchant is used to remove a portion of the intermediate layer 30 made of, for example, a nitride-based material. Examples of chlorine-containing etchants include chlorine-containing gases, such as Cl ₂ , BCl ₃ , or a combination thereof. In some embodiments, one or more additional gases, such as O ₂ , Ar, N ₂ , or H ₂ , are added to the etching gas. After etching the intermediate layer 30 , the photoresist layer 40 is removed, as shown in FIG. 2C .

Next, as shown in FIG. 2D , the hard mask layer 20 is etched through the openings in the patterned intermediate layer 30. The hard mask layer 20 is patterned by etching the exposed portions of the hard mask layer 20 through the openings in the patterned intermediate layer 30. The etching process may include a dry etching process, a wet etching process, or a combination thereof. The dry and wet etching processes have adjustable etching parameters, such as the etchant used, etching temperature, etching solution concentration, etching pressure, source power, RF bias, RF bias power, etchant flow rate, and other suitable parameters, so that the material of the hard mask layer 20 is selective to other materials that may contact the etchant during etching of the hard mask layer _20. In some embodiments, a fluorine-containing etchant is used to remove portions of the hard mask layer 20 made of, for example, oxide or silicon-based materials. Examples of fluorine-containing etchants include fluorine-containing gases, such as _CF4 , _CHF3 , _{C2F6 , CH2F2} , _CH3F , or combinations thereof. In some embodiments, a chlorine-containing etchant is used to remove a portion of the hard mask layer 20 made of, for example, a Cr-based material. Examples of chlorine-containing etchants include chlorine-containing gases, such as Cl ₂ , CCl ₄ , BCl ₃ , or combinations thereof. In some embodiments, one or more additional gases, such as O ₂ , Ar, N ₂ , or H ₂ , are added to the etching gas. After etching the hard mask layer 20 , the intermediate layer 30 is removed by one or more dry and/or wet etching operations and/or chemical mechanical polishing (CMP) operations, as shown in FIG. 2D .

Then, the pattern of the hard mask layer 20 is transferred to the phase-shift material layer 15 by etching the phase-shift material layer 15 through the openings in the patterned hard mask layer 20, as shown in FIG. 2E. The patterning of the phase-shift material layer 15 is to expose a portion of the etch stop layer 12 through the openings in the phase-shift material layer 15. The etching of the phase-shift material layer 15 is achieved by exposing the portion of the phase-shift material layer 204 exposed through the openings in the patterned hard mask layer 20 to an etchant that is selective to the material of the phase-shift material layer 15 relative to the material of the hard mask layer 20 and the material of the etch stop layer 12. The etching process may include a dry etching process, a wet etching process, or a combination thereof. The dry and wet etching processes have adjustable etching parameters, such as the etchant used, etching temperature, etching solution concentration, etching pressure, source power, RF bias, RF bias power, etchant flow rate, and other suitable parameters, so as to be selective to the material of the phase-shift material layer 15 relative to other materials that will be exposed to the etchant during etching of the phase-shift material layer 15, such as the patterned hard mask layer 20 and the etch stop layer 12. In some embodiments, a fluorine-containing etchant is used to remove portions of the phase-shift material layer 15. Examples of fluorine-containing etchants include fluorine-containing gases, such as CF ₄ , CHF ₃ , C ₂ F ₆ , CH ₂ F ₂ , SF _{6 ,} or combinations thereof. In some embodiments, chlorine-containing etchants are used to remove portions of the phase-shift material layer 15 . Examples of chlorine-containing etchants include chlorine-containing gases, such as Cl ₂ , CCl ₄ , BCl ₃ , or combinations thereof. In some embodiments, one or more additional gases, such as O ₂ , Ar, N ₂ , or H ₂ , are added to the etching gas. After the pattern of the hard mask layer 20 is transferred to the phase-shift material layer 15 , the patterned hard mask layer 20 is removed to obtain a mask structure consistent with FIG. 1C .

In some embodiments, the patterns of the hard mask layer 20 and the phase shift material layer 15 are transferred to the etch stop layer 12 as shown in FIG2F without removing the hard mask layer 20. In some embodiments, etching the etch stop layer is performed when the transmittance of the etch stop layer 12 is less than about 95%.

The pattern transfer of the hard mask layer 20 and the phase-shift material layer 15 is achieved by etching the etch stop layer 12 through the openings in the hard mask layer 20 and the phase-shift material layer 15. In some embodiments, the etch stop layer 12 is etched using a chlorine-containing gas (e.g., _Cl2 , _SiCl4 , HCl, _CCl4 , _CHCl3 , other chlorine-containing gases, or combinations thereof) and an oxygen-containing gas (e.g., _O2 , other oxygen-containing gases, or combinations thereof). In other embodiments, the etch stop layer 12 can be etched using an etchant other than a chlorine-containing gas and an oxygen-containing gas. For example, the etch stop layer 12 may be etched using an etchant that is selective to the material of the etch stop layer 12 relative to the material of the hard mask layer 20 and the phase-shift material layer 15 and is selective to the material of the etch stop layer 12 relative to the material of the substrate 10. According to some embodiments, when the hard mask layer 20 and the etch stop layer 12 have similar selectivity with respect to the etchant, the patterned hard mask layer 20 may be removed in the same step as the patterning of the etch stop layer 12. For example, when the etch stop layer 12 is patterned using a chlorine-containing etchant, the patterned hard mask layer 20 may be removed by exposure to the chlorine-containing etchant.

As shown in FIG. 2F , an opening is formed in the etch stop layer 12, through which a portion of the substrate 10 is exposed. According to an embodiment of the present disclosure, etching of the substrate 10 does not occur during the etching of the etch stop layer 12. After etching the etch stop layer 12, the hard mask layer 20 is removed, as shown in FIG. 2G . As described above, the hard mask layer 20 is completely removed when the etch stop layer is patterned, or is removed separately from the etching of the etch stop layer 12.

In some embodiments, as shown in FIG. 2H , after the etch stop layer is etched, the substrate 10 is etched without etching or removing a portion of the patterned etch stop layer 12 or the patterned phase shift material layer 15. According to such an embodiment, as shown in FIG. 2H , etching of the substrate 10 removes a portion of the substrate 10 where a trench or a recess is formed. The substrate 10 is etched using an etchant that does not remove the etch stop layer 12 or the phase shift material layer 15.

In some embodiments, as shown in FIG. 2I , only a portion of the etch stop layer 12 is removed. In some embodiments, the remaining thickness of the portion of the etch stop layer 12 is about 30% to about 80% of the unetched portion of the etch stop layer.

According to some embodiments, the mask is cleaned to remove any contaminants therein after etching the etch stop layer 12 or etching the substrate 10. In some embodiments, the mask is cleaned by immersing the mask in an ammonium hydroxide ( _NH4OH ) solution.

In some embodiments, the hard mask layer 20 is removed from the circuit area but not from the border area, thereby leaving it as image border features 20B (see FIGS. 1A to 1D ).

FIGS. 3A through 3F show cross-sectional views of various stages of operations in a sequence for making an APSM according to various embodiments of the present disclosure. It should be understood that additional operations may be performed before, during, and/or after the processes of FIGS. 3A through 3F, and that some of the operations described below may be replaced or removed for additional embodiments of the method. The order of operations/processes may be interchangeable. The materials, processes, configurations, and/or dimensions described above may be applied to the following embodiments, and detailed explanations may be omitted.

In some embodiments, as shown in FIG. 3A , the blank mask does not include an etch stop layer between the substrate 10 and the phase-shift material layer 15. As shown in FIG. 3A , a multi-layer resist system including an intermediate layer 30 and a photoresist layer 40 is formed over the hard mask layer 20. As shown in FIG. 3B , the photoresist layer 40 is patterned, for example, using electron beam lithography. Then, as shown in FIG. 3C , the intermediate layer 30 is patterned using the photoresist pattern as an etch mask, and the photoresist layer 40 is removed. Furthermore, the hard mask layer 20 is patterned by using the patterned intermediate layer 30 as an etch mask, and the intermediate layer 30 is removed, as shown in FIG. 3D . Next, the patterned hard mask layer 20 is used as an etching mask to pattern the phase shift material layer 15, as shown in FIG. 3E. In some embodiments, the etching substantially stops at the surface of the substrate 10. Then, a portion or all of the hard mask layer 20 is removed, as shown in FIG. 3F.

FIGS. 4A to 4E illustrate a method of manufacturing an APSM sequence according to various embodiments of the present disclosure. It should be understood that additional operations may be performed before, during, and/or after the processes of FIGS. 4A to 4E, and that some of the operations described below may be replaced or removed for additional embodiments of the method. The order of operations/processes may be interchangeable. The materials, processes, configurations, and/or dimensions described above may be applied to the following embodiments, and detailed explanations may be omitted.

In some embodiments, as shown in FIG. 4A, the multi-layer resist system includes an intermediate layer 30 disposed above the first hard mask layer 20, a second hard mask layer 22, and a photoresist layer 40. The materials and configurations of the first hard mask layer and the second hard mask layer of FIG. 4A are the same as the hard mask layer 20 described with respect to FIGS. 1A to 1D, FIGS. 2A to 2H, and FIGS. 3A to 3F. In some embodiments, at least one material or configuration (e.g., thickness) of the second hard mask layer 22 is different from the material or configuration of the first hard mask layer 20. In some embodiments, the materials and structures of the first hard mask layer and the second hard mask layer are the same.

As shown in FIG. 4B, for example, the photoresist layer 40 is patterned using electron beam lithography and the second hard mask layer 22 is patterned. Then, the middle layer 30 is patterned using the patterned second hard mask layer 22 as an etching mask, as shown in FIG. 4C. After removing the second hard mask layer 22, the first hard mask layer 20 is patterned using the patterned middle layer 30 as an etching mask, as shown in FIG. 4D. After removing the middle layer 30, the phase shift material layer 15 is patterned using the patterned hard mask layer 20 as an etching mask, as shown in FIG. 4E. Then, the operations described with respect to FIGS. 2E to 2I are performed. In some embodiments, similar to the embodiments of FIGS. 3A to 3F that do not include the etch stop layer 12, after patterning the phase-shift material layer 15, a structure consistent with FIG. 3E is obtained.

FIGS. 5A to 5F illustrate a method of manufacturing an APSM sequence according to various embodiments of the present disclosure. It should be understood that additional operations may be performed before, during, and/or after the processes of FIGS. 5A to 5F, and that some of the operations described below may be replaced or removed for additional embodiments of the method. The order of operations/processes may be interchangeable. The materials, processes, configurations, and/or dimensions described above may be applied to the following embodiments, and detailed explanations may be omitted.

In some embodiments, as shown in FIG. 5A , the multi-layer anti-etching agent system includes four layers disposed above the first hard mask layer 20, namely, the first intermediate layer 30, the second hard mask layer 22, the second intermediate layer 32, and the photoresist layer 40. The materials and configurations of the first hard mask layer and the second hard mask layer of FIG. 5A are the same as those of the hard mask layer 20 described with respect to FIGS. 1A to 1D, FIGS. 2A to 2H, and FIGS. 3A to 3F, and the materials and configurations of the first intermediate layer and the second intermediate layer of FIG. 5A are the same as those of the intermediate layer 30 described with respect to FIGS. 1A to 1D, FIGS. 2A to 2H, and FIGS. 3A to 3F. In some embodiments, at least one material or configuration (e.g., thickness) of the second hard mask layer 22 is different from the material or configuration of the first hard mask layer 20. In some embodiments, the material and configuration of the first hard mask layer and the second hard mask layer are the same. In some embodiments, at least one material or configuration (e.g., thickness) of the second intermediate layer 32 is different from the material or configuration of the first intermediate layer 30. In some embodiments, the material and configuration of the first intermediate layer and the second intermediate layer are the same.

As shown in FIG. 5B , for example, the photoresist layer 40 is patterned using electron beam lithography and the second intermediate layer 32 is patterned. After removing the photoresist layer 40, the second hard mask layer 22 is patterned using the patterned second intermediate layer 32 as an etching mask, as shown in FIG. 5C . After removing the second intermediate layer 32, the first intermediate layer 30 is patterned using the patterned second hard mask layer 22 as an etching mask, as shown in FIG. 5D . After removing the second hard mask layer 22, the first hard mask layer 20 is patterned using the patterned first intermediate layer 30 as an etching mask, as shown in FIG. 5E . After removing the first intermediate layer 30, the patterned hard mask layer 20 is used as an etching mask to pattern the phase-shift material layer 15, as shown in FIG. 5F. Then, the operations described with respect to FIG. 2E to FIG. 2I are performed. In some embodiments, similar to the embodiment of FIG. 3A to FIG. 3F that does not include an etching stop layer 12, after patterning the phase-shift material layer 15, a structure consistent with FIG. 3E is obtained.

In some embodiments, the multi-layer resist system includes three or more intermediate layers disposed below the photoresist layer and two or more hard mask layers. In some embodiments, the bottom hard mask layer directly in contact with the phase shift material layer 15 is considered to be part of the multi-layer resist system.

In some embodiments, as shown in FIGS. 6A and 6B, the multi-layer resist system includes N pairs of hard mask layers and intermediate layers on the hard mask layers, including first intermediate layers 30-1 to Nth intermediate layers 30-N and first hard mask layers 20-1 to Nth hard mask layers 20-N, alternately stacked above the phase-shift material layer 15. In some embodiments, N is 2, 3, 4, or 5. In some embodiments, the uppermost one of the intermediate layers 30-N is not used, and a photoresist layer 40 is disposed above the Nth hard mask layer 20-N. In FIG. 6A, an etch stop layer 12 is used, and in FIG. 6B, an etch stop layer is not used.

In some embodiments, at least one of the materials or configurations (e.g., thickness) of at least one of the first to Nth hard mask layers 22 is different from the materials or configurations of at least one of the remaining hard mask layers. In some embodiments, the materials and configurations of the first to Nth hard mask layers are the same. In some embodiments, at least one of the materials or configurations (e.g., thickness) of the first to Nth intermediate layers is different from the materials or configurations of at least one of the remaining intermediate layers. In some embodiments, the materials and structures of the first to Nth intermediate layers are the same.

Similar to the previous embodiment, each of the intermediate layer and the hard mask layer is patterned step by step.

In some embodiments, as shown in FIG. 6C , one or more intermediate layers include two or more sublayers made of materials different from each other. In some embodiments, the bottom of the intermediate layer includes a lower layer 30A and an upper layer 30B made of a material different from the lower layer 30A, and the upper layer of the intermediate layer includes a lower layer 32A and an upper layer 32B made of a material different from the lower layer 32A. In some embodiments, the lower layer 30A is made of the same material as the lower layer 32A, and in other embodiments, the lower layer 30A is made of a material different from the lower layer 32A. Similarly, in some embodiments, the material of the upper layer 30B is the same as the material of the upper layer 32B, and in other embodiments, the material of the upper layer 30B is different from the material of the upper layer 32B. Similar to the aforementioned embodiment, each of the intermediate layer and the hard mask layer is patterned stepwise. In other embodiments, a patterned hard mask layer or a photoresist pattern is used as an etching mask to simultaneously etch or pattern multiple intermediate layers.

In some embodiments, as shown in FIG. 6D , the etching support layer 18 is disposed between the phase-shift material layer 15 and the hard mask layer 20. In some embodiments, the etching support layer 18 is patterned and used as an etching mask for the patterned phase-shift material layer 15. In some embodiments, the etching support layer 18 is made of a material different from that of the hard mask layer 20 and the phase-shift material layer 15, including metal, metal oxide or other suitable materials. In some embodiments, the etching support layer 18 includes a tantalum-containing material (e.g., Ta, TaN, TaNH, TaHF, TaHfN, TaBSi, TaBSiN, TaB, TaBN, TaSi, TaSiN, TaGe, TaGeN, TaZr, TaZrN, other tantalum-containing materials, or combinations thereof), a chromium-containing material (e.g., Cr, CrN, CrO, CrC, CrON, CrCN, CrOC, CrOCN, other chromium-containing materials, or combinations thereof), a titanium-containing material (e.g., Ti, TiN, other titanium-containing materials, or combinations thereof), other suitable materials, or combinations thereof. In some embodiments, the etching support layer 18 is made of an opaque material. Similar to the previous embodiments, the hard mask layer 20 is used as an etch mask to pattern the etch support layer 18, and (after removing the hard mask layer 20) the patterned etch support layer 18 is used to pattern the phase shift material layer 15. In some embodiments, the circuit area above the etch support layer 18 is removed, and a portion of the etch support layer remains as a boundary feature 20B.

FIG. 7A shows a flow chart of manufacturing a semiconductor device, and FIG. 7B, FIG. 7C, FIG. 7D and FIG. 7E show the operations of each stage of the sequence of manufacturing a semiconductor device according to multiple embodiments of the present disclosure.

A semiconductor substrate or other suitable substrate is provided to form an integrated circuit thereon. In some embodiments, the semiconductor substrate comprises silicon. Alternatively or additionally, the semiconductor substrate comprises germanium, silicon germanium or other suitable semiconductor materials, such as III-V semiconductor materials. In S101 of FIG. 7A , a target layer to be patterned is formed above the semiconductor substrate. In some embodiments, the target layer is a semiconductor substrate. In some embodiments, the target layer comprises a conductive layer (e.g., a metal layer or a polysilicon layer), a dielectric layer (e.g., silicon oxide, silicon nitride, SiON, SiOC, SiOCN, SiCN, bismuth oxide or aluminum oxide) or a semiconductor layer (e.g., an epitaxially formed semiconductor layer). In some embodiments, the target layer is formed on top of an underlying structure, such as an isolation structure, a transistor, or a wiring. In S102 of FIG. 7A , a photoresist layer is formed over the target layer, as shown in FIG. 7B . In a subsequent lithography exposure process, the photoresist layer is sensitive to radiation from an exposure source. In the present embodiment, the photoresist layer is sensitive to UV or DUV light used in the lithography exposure process. The photoresist layer may be formed over the target layer by spin coating or other suitable techniques. The coated photoresist layer may be further baked to drive off solvents in the photoresist layer. In S103 of FIG. 7A , the photoresist layer is patterned using one of the above-mentioned masks, as shown in FIG. 7C . Patterning of the photoresist layer includes performing a lithography exposure process by a DUV or UV exposure system (scanner or stepper). During the exposure process, the integrated circuit (IC) design pattern defined on the mask is imaged onto the photoresist layer to form a latent pattern thereon. Patterning the photoresist layer also includes developing the exposed photoresist layer to form a patterned photoresist layer having one or more openings. In an embodiment in which the photoresist layer is a positive photoresist layer, the exposed portion of the photoresist layer is removed during the development process. Patterning of the photoresist layer may also include other process steps, such as various baking steps at different stages. For example, a post-exposure baking (PEB) process may be performed after the lithography exposure process and before the development process.

In S104 of FIG. 7A , the target layer is patterned using the patterned photoresist layer as an etching mask, as shown in FIG. 7D . In some embodiments, patterning the target layer includes applying an etching process to the target layer using the patterned photoresist layer as an etching mask. The portion of the target layer exposed within the opening of the patterned photoresist layer is etched, while the remaining portion is protected from etching. Further, the patterned photoresist layer can be removed by wet stripping or plasma ashing, as shown in FIG. 7E .

The disclosed embodiment can improve the pattern fidelity of the patterned phase-shift material layer by forming a multi-layer photoresist system on a hard mask layer on the phase-shift material layer, and in particular, can suppress the rounded corners of the pattern of the phase-shift material layer.

It should be understood that other embodiments may have other advantages over the known art, that not all advantages are discussed in this disclosure, and that no particular advantage may be applicable to all embodiments.

According to one aspect of the present disclosure, in a method for manufacturing an attenuated phase-shift mask, a photoresist pattern is formed above a blank photomask. The blank photomask includes a transparent substrate, an etch stop layer located on the transparent substrate, a phase-shift material layer located on the etch stop layer, a hard mask layer located on the phase-shift material layer, and an intermediate layer located on the hard mask layer. The intermediate layer is patterned using the photoresist pattern as an etch mask. The hard mask layer is patterned using the patterned intermediate layer as an etch mask. The phase-shift material layer is patterned using the patterned hard mask layer as an etch mask. The intermediate layer includes at least one selected from the group consisting of a transition metal, a transition metal alloy, and a silicon-containing material. The hard mask layer is made of a material different from that of the intermediate layer. In one or more of the foregoing and following embodiments, the intermediate layer comprises at least one selected from the group consisting of Mo, Ta, Pd, Ir, Ni, Sn, Ru and Au. In one or more of the foregoing and following embodiments, the intermediate layer comprises an alloy selected from the group consisting of Mo, Ta, Pd, Ir, Ni, Sn, Ru and Au. In one or more of the foregoing and following embodiments, the intermediate layer comprises at least one selected from the group consisting of silicon nitride, silicon oxide, silicon oxynitride, SiOC, SiOCN, SiCN, SiC, SiBN, SiBC and SiBCN. In one or more of the foregoing and following embodiments, the intermediate layer comprises polysiloxane or an organic polymer containing silicon or metal particles. In one or more of the foregoing and following embodiments, the hard mask layer comprises at least one selected from the group consisting of Cr, CrN, CrO, CrC, CrON, CrCN, CrOC, and CrOCN. In one or more of the foregoing and following embodiments, the etch stop layer comprises at least one selected from the group consisting of Al, Ru, Ru-Nb, Ru-Zr, Ru-Ti, Ru-Y, Ru-B, and Ru-P. In one or more of the foregoing and following embodiments, the deep ultraviolet light transmittance of the etch stop layer is 95% or more. In one or more of the foregoing and following embodiments, the thickness of the intermediate layer is in the range of 2 nm to 200 nm. In one or more of the foregoing and following embodiments, the phase-shift material layer includes at least one selected from the group consisting of MoSi, MoSiCON, MoSiON, MoSiCN, MoSiCO, MoSiO, MoSiC, and MoSiN.

According to another aspect of the present disclosure, in a method of manufacturing an attenuated phase-shift mask, a photoresist pattern is formed above a blank photomask. The blank photomask includes a transparent substrate, an etch stop layer on the transparent substrate, a phase-shift material layer on the etch stop layer, a first hard mask layer on the phase-shift material layer, a first intermediate layer on the first hard mask layer, a second hard mask layer on the first intermediate layer, and a second intermediate layer on the second hard mask layer. The second intermediate layer is patterned by using the photoresist pattern as an etch mask. The second hard mask layer is patterned by patterning the second intermediate layer as an etch mask. The first intermediate layer is patterned by patterning the second hard mask layer as an etch mask. The first hard mask layer is patterned by patterning the first intermediate layer as an etching mask. The phase-shift material layer is patterned by patterning the first hard mask layer as an etching mask. The first intermediate layer and the second intermediate layer respectively include at least one selected from the group consisting of transition metals, transition metal alloys, and silicon-containing materials. The first hard mask layer and the second hard mask are made of a material different from the first intermediate layer and the second intermediate layer. In one or more of the foregoing and following embodiments, the first hard mask layer and the second hard mask layer respectively include at least one selected from the group consisting of Cr, CrN, CrO, CrC, CrON, CrCN, CrOC, and CrOCN. In one or more of the foregoing and following embodiments, the first intermediate layer and the second intermediate layer respectively include at least one selected from the group consisting of Mo, Ta, Pd, Ir, Ni, Sn, Ru and Au, and alloys thereof. In one or more of the foregoing and following embodiments, the first intermediate layer and the second intermediate layer respectively include at least one selected from the group consisting of silicon nitride, silicon oxide, silicon oxynitride, SiOC, SiOCN, SiCN, SiC, SiBN, SiBC and SiBCN. In one or more of the foregoing and following embodiments, the first intermediate layer and the second intermediate layer respectively include polysiloxane or an organic polymer containing silicon or metal particles. In one or more of the foregoing and following embodiments, the etch stop layer includes at least one selected from the group consisting of Al, Ru and alloys thereof. In one or more of the foregoing and following embodiments, the phase-shift material layer includes at least one selected from the group consisting of MoSi, MoSiCON, MoSiON, MoSiCN, MoSiCO, MoSiO, MoSiC, and MoSiN.

According to another aspect of the present disclosure, in a method for manufacturing an attenuated phase-shift mask, a photoresist pattern is formed above a blank mask. The blank mask includes a transparent substrate, an etch stop layer located on the transparent substrate, a phase-shift material layer located on the etch stop layer, and a multi-layer structure. The multi-layer structure includes N pairs of hard mask layers and an intermediate layer located in the hard mask layer. By gradually patterning each of the N pairs of the multi-layer structure, a patterned hard mask layer is formed from the bottommost hard mask layer in the multi-layer structure. The phase-shift material layer is patterned by using the patterned hard mask layer as an etch mask. N is a natural number within 5. The intermediate layer includes at least one selected from the group consisting of a transition metal, a transition metal alloy, and a silicon-containing material. The hard mask layer is made of a different material than the intermediate layer. In one or more of the foregoing and following embodiments, in one or more of the foregoing and following embodiments, N is 3, 4 or 5. In one or more of the foregoing and following embodiments, the etch stop layer is further patterned.

The foregoing summarizes the features of several embodiments so that those skilled in the art can better understand the aspects of the present disclosure. Those skilled in the art should understand that they can easily use the present disclosure as a basis for designing or modifying other processes and structures for implementing the same purpose and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also recognize that such equivalent structures do not deviate from the spirit and scope of the present disclosure, and such equivalent structures can be variously changed, substituted, and replaced herein without departing from the spirit and scope of the present disclosure.

10: substrate 12: etching stop layer 15: phase shift material layer 18: etching support layer 20: hard mask layer 20-1: hard mask layer 20-N: hard mask layer 20B: image boundary feature 20C: image area 22: hard mask layer 30: intermediate layer 30-1: intermediate layer 30-N: intermediate layer 30A: lower layer 30B: upper layer 32: intermediate layer 32A: lower layer 32B: upper layer 40: photoresist layer 100: photomask 100A: photomask 100B: photomask 100C: photomask S101: Operation S102: Operation S103: Operation S104: Operation

The aspects of the present disclosure are best understood from the following detailed description when read in conjunction with the accompanying drawings. It should be noted that various features are not drawn to scale in accordance with standard practices in the industry. In fact, the sizes of various features may be arbitrarily increased or decreased for clarity of discussion. Figures 1A, 1B, 1C, and 1D show cross-sectional views of masks according to various embodiments of the present disclosure. Figures 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, and 2I show cross-sectional views of various stages of the manufacturing sequence of masks according to various embodiments of the present disclosure. Figures 3A, 3B, 3C, 3D, 3E and 3F show cross-sectional views of various stages of the manufacturing process of the photomask according to various embodiments of the present disclosure. Figures 4A, 4B, 4C, 4D and 4E show cross-sectional views of various stages of the manufacturing process of the photomask according to various embodiments of the present disclosure. Figures 5A, 5B, 5C, 5D, 5E and 5F show cross-sectional views of various stages of the manufacturing process of the photomask according to various embodiments of the present disclosure. Figures 6A, 6B, 6C and 6D show cross-sectional views of blank photomasks according to various embodiments of the present disclosure. FIG. 7A shows a flow chart of manufacturing a semiconductor device, and FIG. 7B, FIG. 7C, FIG. 7D and FIG. 7E show the operations of each stage of the manufacturing sequence of a semiconductor device according to multiple embodiments of the present disclosure.

Domestic storage information (please note in the order of storage institution, date, and number) None Foreign storage information (please note in the order of storage country, institution, date, and number) None

S101: Operation

S102: Operation

S103: Operation

S104: Operation

Claims (20)

A method for manufacturing an attenuated phase-shift mask, comprising: forming a photoresist pattern on a blank mask, the blank mask comprising a transparent substrate, an etch stop layer on the transparent substrate, a phase-shift material layer on the etch stop layer, a hard mask layer on the phase-shift material layer, and an intermediate layer on the hard mask layer; patterning the intermediate layer using the photoresist pattern as an etch mask; patterning the hard mask layer using the patterned intermediate layer as an etch mask; and patterning the phase-shift material layer using the patterned hard mask layer as an etch mask, wherein: The intermediate layer includes at least one selected from the group consisting of a transition metal, a transition metal alloy, and a silicon-containing material, and the hard mask layer is made of a material different from that of the intermediate layer. The method of claim 1, wherein the intermediate layer comprises at least one selected from the group consisting of Mo, Ta, Pd, Ir, Ni, Sn, Ru and Au. The method of claim 1, wherein the intermediate layer comprises an alloy selected from at least one of the group consisting of Mo, Ta, Pd, Ir, Ni, Sn, Ru and Au. The method as described in claim 1, wherein the intermediate layer comprises at least one selected from the group consisting of silicon nitride, silicon oxide, silicon oxynitride, SiOC, SiOCN, SiCN, SiC, SiBN, SiBC and SiBCN. The method of claim 1, wherein the intermediate layer comprises a polysiloxane or an organic polymer containing silicon or metal particles. The method of claim 1, wherein the hard mask layer comprises at least one selected from the group consisting of Cr, CrN, CrO, CrC, CrON, CrCN, CrOC, and CrOCN. The method of claim 1, wherein the etch stop layer comprises at least one selected from the group consisting of Al, Ru, Ru-Nb, Ru-Zr, Ru-Ti, Ru-Y, Ru-B and Ru-P. The method of claim 1, wherein the etch stop layer has a deep ultraviolet light transmittance of 95% or more. The method as described in claim 1, wherein a thickness of the intermediate layer is in the range of 2nm to 200nm. The method of claim 1, wherein the phase-shift material layer comprises at least one selected from the group consisting of MoSi, MoSiCON, MoSiON, MoSiCN, MoSiCO, MoSiO, MoSiC and MoSiN. A method for manufacturing an attenuated phase-shift mask, comprising: forming a photoresist pattern on a blank mask, the blank mask comprising a transparent substrate, an etch stop layer on the transparent substrate, a phase-shift material layer on the etch stop layer, a first hard mask layer on the phase-shift material layer, a first intermediate layer on the first hard mask layer, a second hard mask layer on the first intermediate layer, and a second intermediate layer on the second hard mask layer; patterning the second intermediate layer by using the photoresist pattern as an etch mask; patterning the second hard mask layer by using the patterned second intermediate layer as an etch mask; The first intermediate layer is patterned by the patterned second hard mask layer being an etching mask; The first hard mask layer is patterned by the patterned first intermediate layer being an etching mask; and The phase-shift material layer is patterned by the patterned first hard mask layer being an etching mask, wherein: The first intermediate layer and the second intermediate layer respectively include at least one selected from the group consisting of a transition metal, a transition metal alloy, and a silicon-containing material, and The first hard mask layer and the second hard mask are made of a material different from the first intermediate layer and the second intermediate layer. The method as described in claim 11, wherein the first hard mask layer and the second hard mask layer respectively include at least one selected from the group consisting of Cr, CrN, CrO, CrC, CrON, CrCN, CrOC and CrOCN. The method as described in claim 12, wherein the first intermediate layer and the second intermediate layer respectively comprise at least one selected from the group consisting of Mo, Ta, Pd, Ir, Ni, Sn, Ru and Au, and alloys thereof. The method as described in claim 12, wherein the first intermediate layer and the second intermediate layer respectively include at least one selected from the group consisting of silicon nitride, silicon oxide, silicon oxynitride, SiOC, SiOCN, SiCN, SiC, SiBN, SiBC and SiBCN. The method as described in claim 12, wherein the first intermediate layer and the second intermediate layer respectively comprise a polysiloxane or an organic polymer containing silicon or metal particles. The method of claim 12, wherein the etch stop layer comprises at least one selected from the group consisting of Al, Ru and alloys thereof. The method of claim 12, wherein the phase-shift material layer comprises at least one selected from the group consisting of MoSi, MoSiCON, MoSiON, MoSiCN, MoSiCO, MoSiO, MoSiC, and MoSiN. A method for manufacturing an attenuated phase-shift mask, comprising: forming a photoresist pattern on a blank mask, the blank mask comprising a transparent substrate, an etch stop layer on the transparent substrate, a phase-shift material layer on the etch stop layer, and a multi-layer structure, the multi-layer structure comprising N pairs of a hard mask layer and an intermediate layer on the hard mask layer; forming a patterned hard mask layer from a bottom hard mask layer in the multi-layer structure by gradually patterning each of the N pairs of the multi-layer structure; and patterning the phase-shift material layer by using the patterned hard mask layer as an etch mask, wherein: N is a natural number within 5, The intermediate layer includes at least one selected from the group consisting of a transition metal, a transition metal alloy, and a silicon-containing material, and the hard mask layer is made of a material different from that of the intermediate layer. The method as described in claim 18, wherein N is 3, 4 or 5. The method of claim 18, further comprising patterning the etch stop layer.