Pvd film layer of photomask and preparation method thereof

Abstract

This invention relates to a PVD film layer for a photomask and its fabrication method. The fabrication method includes the following steps: pre-treating the photomask substrate; depositing a transition layer on the pre-treated substrate and activating the transition layer; low-temperature depositing a main functional layer on the activated transition layer to obtain the PVD film layer; and performing post-treatment to release the internal stress of the PVD film layer. This invention significantly improves the interfacial bonding force between the PVD functional film layer and the photomask substrate, increases the critical load to above 35N, ensures the reliability of the film layer under harsh conditions, effectively reduces and controls the intrinsic stress of the film layer, lowering the stress value to below -200 MPa, thereby minimizing substrate deformation and pattern distortion caused by stress.

Description

Technical Field

[0001] This invention relates to the field of semiconductor and display panel manufacturing technology, and to a PVD film layer for a photomask and its preparation method, particularly to a PVD film layer for improving the adhesion of a photomask PVD film layer and its preparation method. Background Technology

[0002] As a core component in semiconductor lithography and display panel manufacturing, the photomask is a crucial carrier for realizing micro- and nano-pattern transfer. Its fabrication quality directly determines the linewidth accuracy, pattern fidelity, and device yield of the lithography process. Photomask substrates are primarily made of quartz or synthetic quartz glass, and functional films such as chromium (Cr) and molybdenum silicon (MoSi) are prepared on their surfaces using physical vapor deposition (PVD) to achieve core functions such as light blocking, reflection, and phase shifting. Currently, the industry generally faces the following technical defects when preparing PVD functional films on photomask substrates: 1) Insufficient film-substrate adhesion: Due to the significant differences in physicochemical properties and thermal expansion coefficients between the quartz substrate and the metal film, the interfacial bonding strength is low. 1) The critical load (Lc) for film-substrate adhesion in traditional processes is usually below 25N, which can easily lead to edge peeling or flaking of the film during subsequent cleaning, inspection, or use; 2) Excessive internal stress in the film: In order to pursue high deposition rate and density, conventional PVD processes often use high power or substrate temperature, resulting in high intrinsic stress in the film (usually compressive stress above -400 MPa). This stress is transferred to the brittle quartz substrate, causing micro-warping of the substrate (Bow / Warp), which directly leads to distortion of the photolithography pattern and affects linewidth uniformity (CD Uniformity); 3) Interface contamination and substrate damage: Incomplete pretreatment will leave interface contaminants, which become weak points in the bonding; while using plasma cleaning with excessively high energy (such as >150W) can clean the surface, it may bombard and damage the quartz lattice structure or cause surface charge accumulation, introducing new defects. Summary of the Invention

[0003] This invention aims to overcome the aforementioned deficiencies by providing a PVD film layer for photomasks and its preparation method. Specifically, it provides a PVD film layer and its preparation method that improve the adhesion between the PVD film layer and the photomask substrate. This invention significantly enhances the interfacial adhesion between the PVD functional film layer and the photomask substrate, raising the critical load (Lc) to over 35N, ensuring the reliability of the film layer under stringent processes, and effectively reducing and controlling the intrinsic stress of the film layer, lowering the stress value to below -200 MPa, thereby minimizing substrate deformation and pattern distortion caused by stress. This invention also achieves ultra-clean, low-physical-damage substrate interface pretreatment, activating the substrate surface while ensuring the integrity of its microstructure. It provides a method with low temperature throughout the process (critical deposition steps ≤100℃), completely avoiding the risk of thermal damage to the dimensional stability of the photomask substrate and existing patterns caused by high temperatures.

[0004] The first aspect of this invention provides a method for preparing a PVD film layer of a photomask, comprising the following steps: Pre-process the photomask substrate; A transition layer is deposited on the pretreated substrate, and the transition layer is activated after the transition layer is deposited and before the main functional layer is deposited. The main functional layer is deposited at low temperature on the activated transition layer; and Post-processing is performed to release the internal stress of the transition layer and the main functional layer to obtain the PVD film.

[0005] Furthermore, the substrate is a quartz substrate or synthetic quartz glass.

[0006] Furthermore, the pretreatment involves a combined cleaning of the substrate, including ultraviolet ozone (UV-O3) cleaning, wherein the ultraviolet wavelength is 185nm / 254nm and the irradiation time is 10~20 min.

[0007] Furthermore, the pretreatment also includes low-power plasma cleaning, in which the plasma is an inert gas (Ar), with a power ≤50W (low power), a pressure of 0.3~0.5Pa, and a cleaning time of 100~150s.

[0008] Furthermore, the deposition of the transition layer or the low-temperature deposition of the main functional layer is carried out using magnetron sputtering.

[0009] Furthermore, the transition layer comprises chromium nitride (CrN). x ), chromium oxide (CrO) x ), Chromium oxynitride (CrON) x ), chromium carbide (CrC) x ), molybdenum nitride (MoN) x Silicon nitride (SiN)x ), molybdenum silicon nitride (MoSiN) x The transition layer comprises at least one of titanium nitride, titanium nitride, aluminum oxide, silicon dioxide, or nickel-chromium alloy; the chemical composition of the transition layer is between that of the quartz substrate and the main functional layer, i.e., the transition layer can be selected from metal-based nitride / oxide, multi-element alloy compound, amorphous ceramic thin film, etc., depending on the material of the main functional layer (Cr, MoSi, etc.) and the application scenario of the photomask (semiconductor lithography / display panel manufacturing). The core principle is that the chemical composition, mechanical properties, and lattice structure of the transition layer are between those of the quartz substrate and the main functional layer, so as to achieve the three core functions of chemical bonding enhancement, thermal expansion coefficient buffering, and interface stress relaxation. Among them, chromium nitride, chromium oxide, chromium oxynitride, and chromium carbide are suitable for Cr main functional layers (semiconductor binary mask light-shielding layer); molybdenum nitride, silicon nitride, and molybdenum silicon nitride are suitable for MoSi-based main functional layers (AttPSM phase shift mask / EUV reflection mask); and / or The main functional layer includes at least one of a Cr main functional layer or a MoSi main functional layer.

[0010] Furthermore, the deposition conditions (gas type, flow rate ratio, power, pressure, time) for different transition layers need to be specifically adjusted according to the target material type and reactant gases. See the table below: More preferably, the transition layer is CrN. x Transition layer; deposited CrN on the pretreated substrate. x The transition layer includes the following steps: N2 and Ar are introduced into the PVD cavity at a flow rate ratio of 30:70 sccm, and the cavity pressure is 0.25 Pa; and A Cr target was sputtered at 1.5 kW for 45 seconds to form a CrN layer with a thickness of approximately 6.5 nm on the substrate surface. x Transition layer.

[0011] Furthermore, the transition layer is a nanoscale ultrathin film layer (3-10 nm).

[0012] Further, the activation process includes: An Ar / N2 mixed gas is introduced into the PVD chamber, with an Ar / N2 volume ratio of (6~7):(3~4), and the chamber pressure is 0.5~0.8 Pa; and The transition layer surface is treated with 60-80W radio frequency power for 20-40 seconds to achieve micro-shaping and reactivation of the transition layer surface.

[0013] Furthermore, the low-temperature deposition of the main functional layer on the activated transition layer includes the following steps: Under an Ar atmosphere and a pressure of 0.2~0.4 Pa, a Cr target or a molybdenum-silicon target is sputtered at a power of 2.0~5.0 kW, with the substrate temperature controlled at ≤100℃ and the deposition rate at 0.8~1.0 nm / s, to deposit a Cr main functional layer or a MoSi main functional layer on the surface of the transition layer.

[0014] Furthermore, the thickness of the Cr main functional layer is 80~100 nm; the thickness of the MoSi main functional layer is determined according to the design wavelength and phase shift requirements of the photomask. For example, when used for an attenuation-type phase shift mask for a 193nm ArF light source, the typical thickness range of the MoSi layer is 60~80 nm to achieve a phase shift of about 180° and a preset transmittance.

[0015] Further, the post-processing includes: The PVD film was subjected to low-temperature annealing under vacuum; wherein the vacuum degree was ≤1×10⁻⁶. -3 Pa, in the low-temperature annealing treatment, the annealing temperature is 170~180℃ and the annealing time is 25~40 min.

[0016] A second aspect of the present invention provides a PVD film layer, characterized in that it comprises: The substrate is a quartz substrate or a synthetic quartz glass substrate; A main functional layer, which serves as a carrier for photomasks to perform photolithography, is disposed on the substrate; and A transition layer is disposed between the substrate and the main functional layer and is configured to eliminate performance abrupt changes between the substrate and the main functional layer.

[0017] The synergistic working principle of the PVD film preparation method of the present invention is as follows: 1) Pretreatment is fundamental: UV ozone cleaning mainly decomposes and removes organic pollutants; subsequent low-power plasma cleaning removes atomic-level adsorption layers and pollutants through physical sputtering, and activates the quartz surface without damaging the substrate, increasing surface energy and providing an ideal "clean and active" interface for subsequent film adhesion. 2) The transition layer is a key bridge: Directly depositing the main functional layer (such as Cr) on quartz results in poor adhesion due to lattice mismatch and weak chemical bonding. The interfacial transition layer (such as CrN) deposited in this invention... x Its composition and structural design lie between the substrate and the main layer. Chemically, it can form stronger chemical bonds with O in quartz and Cr in the main layer; mechanically, its gradient structure can buffer the difference in thermal expansion coefficients and effectively relax interfacial stress. 3) Plasma activation enhances the interface: Interlayer plasma activation is not a regular cleaning process. Its specific low-energy parameters are designed to "micro-shape" and reactivate the surface of the newly deposited transition layer, further removing any weak adsorption layers that may exist, and increasing the dangling bonds and nucleation sites on the surface. This allows the subsequently arriving main layer atoms to achieve stronger chemical adsorption, thereby significantly improving the interfacial binding energy between the transition layer and the main layer. 4) Low-temperature deposition and post-treatment stress control: Low-temperature PVD coating of the main functional layer suppresses the thermal stress caused by high temperature from the source. The low-temperature annealing treatment after deposition provides a controllable atomic micro-diffusion energy, which helps the film atoms rearrange and release the intrinsic stress (such as growth stress) generated by the deposition process, making the film structure more stable.

[0018] This invention, through the synergistic effect of multiple steps, reduces stress while maintaining or even improving the overall performance of the film. The transition layer provides a well-bonded interface with quartz, providing a "lattice matching" basis for the growth of the upper Cr layer. Even at a low deposition temperature, the bonding force is significantly improved (Lc from 22N to 38.5N). The activation treatment increases the dangling bonds and nucleation sites on the surface of the transition layer, enabling subsequent Cr atoms to achieve "chemical adsorption" rather than simple physical adhesion, enhancing the interfacial bonding energy and compensating for the kinetic deficiencies of low-temperature deposition. Non-equilibrium magnetron sputtering generates high-density plasma, ensuring that even at low substrate temperatures, the ions reaching the substrate still have high energy, enabling dense growth. The film density is comparable to or even better than that of traditional high-temperature processes (LWR from 5.5nm to 3.8nm, with reduced roughness). Low-temperature annealing after deposition (170~180℃) provides limited atomic diffusion energy, helping to release intrinsic stress while optimizing the grain boundary structure. The film exhibits stable performance and withstands over 200 cleaning tests without peeling.

[0019] The PVD film preparation method of this invention is specifically applicable to: 1. Fabrication of chromium (Cr) masks and binary mask light-shielding layers for semiconductor photolithography; 2. Deposition of molybdenum-silicon (MoSi) multilayer reflective masks and attenuation-type phase-shift masks (AttPSM) for extreme ultraviolet (EUV) lithography; 3. Preparation of metal and dielectric film layers for large photomasks used in the manufacture of high-resolution liquid crystal display (LCD) and organic light-emitting diode (OLED) panels.

[0020] The present invention has at least the following beneficial effects: 1) The present invention constructs a composite interface structure of "substrate / gradient transition layer / main functional layer". This structure has a gradient transition in chemical composition and mechanical properties, avoiding abrupt performance changes. Moreover, the interface state is optimized at the atomic scale through plasma activation, forming a strong bonding interface dominated by chemical bonding; 2) The PVD film bonding force of the present invention is significantly enhanced: taking a chromium mask as an example, the critical load (Lc) of film-substrate bonding force can be increased from about 22.0 N in the traditional method to more than 38.5 N, an increase of more than 75%; 3) The film stress of the present invention is greatly reduced: the internal stress of the film can be reduced from about -520 MPa (high pressure stress) in the traditional method to about -180 MPa, a reduction of 65%, which greatly improves the pattern fidelity; 4) The pattern accuracy of the present invention is improved: the low stress makes the photolithography pattern more stable during the processing, and the line width roughness (LWR) can be improved by more than 30%; 5) The method of the present invention has excellent compatibility and reliability: the entire process is carried out at low temperature (≤100℃), which is fully compatible with the thermal sensitivity of the photomask substrate. The membrane exhibits excellent resistance to thermal cycling and chemical cleaning stability; 6) Through the synergistic effect of multiple steps, this invention reduces stress while maintaining or even improving the overall performance of the membrane. Attached Figure Description

[0021] To further illustrate the above and other advantages and features of the various embodiments of the present invention, a more specific description of the embodiments of the invention will be presented with reference to the accompanying drawings. It is to be understood that these drawings depict only typical embodiments of the invention and are therefore not intended to limit its scope. In the drawings, identical or corresponding parts will be indicated by identical or similar reference numerals for clarity.

[0022] Figure 1 A flowchart of a method for preparing a PVD film layer for a photomask in some embodiments of the present invention is shown. Detailed Implementation

[0023] It should be noted that the components in the accompanying drawings may be shown exaggerated for illustrative purposes and may not be to scale.

[0024] In this invention, the various embodiments are merely intended to illustrate the solutions of the invention and should not be construed as limiting.

[0025] In this invention, unless otherwise specified, the quantifiers “a” and “one” do not exclude scenarios involving multiple elements.

[0026] It should also be noted that, in the embodiments of the present invention, only a portion of the parts or components may be shown for clarity and simplicity. However, those skilled in the art will understand that, under the teachings of the present invention, the required parts or components can be added as needed for specific scenarios.

[0027] It should also be noted that within the scope of this invention, the terms "same", "equal", and "equal to" do not mean that the two values ​​are absolutely equal, but allow for a certain reasonable error. In other words, the terms also cover "substantially the same", "substantially equal", and "substantially equal to".

[0028] It should also be noted that in the description of this invention, the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not explicitly or implicitly suggest that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] Furthermore, the embodiments of the present invention describe the method steps in a specific order; however, this is only for the convenience of distinguishing each step, and is not intended to limit the order of the steps. In different embodiments of the present invention, the order of the steps can be adjusted according to the method.

[0030] The following embodiment describes a method for preparing a PVD film layer of a photomask. Figure 1 A flowchart of a PVD film preparation method is shown, including the following steps: Ultra-clean pretreatment of substrate: The photomask substrate (quartz substrate or synthetic quartz glass) is cleaned in combination, including ultraviolet ozone (UV-O3) cleaning and low-power plasma cleaning. In ultraviolet ozone cleaning, the ultraviolet wavelength is 185nm / 254nm and the irradiation time is 10~20 min. In low-power plasma cleaning, the plasma is an inert gas (Ar), the power is ≤50W (low power), the pressure is 0.3~0.5Pa, and the cleaning time is 100~150s. Interfacial transition layer deposition and interlayer plasma activation treatment: A compositionally controllable nanoscale transition layer is deposited on the pretreated substrate using magnetron sputtering. After the transition layer deposition and before the main functional layer deposition, a low-energy mixed gas (e.g., Ar / N2) plasma is used to perform a short-term activation treatment on the transition layer. The transition layer is a nanoscale ultrathin film layer (3-10 nm) and includes chromium nitride (CrN). x ), chromium oxide (CrO) x ), Chromium oxynitride (CrON) x ), chromium carbide (CrC) x ), molybdenum nitride (MoN) x Silicon nitride (SiN) x ), molybdenum silicon nitride (MoSiN)x The transition layer is selected from at least one of titanium nitride, titanium nitride, aluminum oxide, silicon dioxide, or nickel-chromium alloy; the chemical composition of the transition layer is between that of the quartz substrate and the main functional layer. That is, the transition layer can be selected from metal-based nitride / oxide, multi-element alloy compound, amorphous ceramic thin film, etc., depending on the material of the main functional layer (Cr, MoSi, etc.) and the photomask application scenario (semiconductor lithography / display panel manufacturing). The core principle is that the chemical composition, mechanical properties, and lattice structure of the transition layer are between those of the quartz substrate and the main functional layer, enabling it to achieve three core functions: enhanced chemical bonding, buffered thermal expansion coefficient, and interface stress relaxation. Specifically, chromium nitride, chromium oxide, chromium oxynitride, and chromium carbide are suitable for Cr main functional layers (semiconductor binary mask light-shielding layers); molybdenum nitride, silicon nitride, and molybdenum silicon nitride are suitable for MoSi-based main functional layers (AttPSM). Phase shift mask / EUV reflection mask); the activation process includes: introducing an Ar / N2 mixed gas into the PVD cavity, with an Ar / N2 volume ratio of (6~7):(3~4), and a cavity pressure of 0.5~0.8 Pa; and treating the transition layer surface with 60~80W radio frequency power for 20~40 s to achieve micro-shaping and reactivation of the transition layer surface; Low-temperature PVD deposition of the main functional layer: The main functional layer is deposited at low temperature on the activated transition layer using magnetron sputtering. This includes sputtering a Cr target or a molybdenum-silicon target at a power of 2.0–5.0 kW under an Ar atmosphere and a pressure of 0.2–0.4 Pa, controlling the substrate temperature to ≤100℃ and the deposition rate to 0.8–1.0 nm / s. A Cr or MoSi main functional layer is deposited on the surface of the transition layer to obtain a PVD film. The main functional layer includes at least one of a Cr main functional layer or a MoSi main functional layer, and the thickness of the Cr main functional layer is 80–100 nm. Post-stress relief treatment: Post-treatment is performed to release the internal stress of the PVD film. This post-treatment includes: low-temperature annealing of the PVD film under vacuum conditions; wherein the vacuum degree is ≤1×10⁻⁶. -3 Pa, in the low-temperature annealing treatment, the annealing temperature is 170~180℃ and the annealing time is 25~40 min.

[0031] The following embodiments also provide a PVD film layer, comprising: The substrate is a quartz substrate or a synthetic quartz glass substrate; The main functional layer, which serves as the carrier for photomasks to perform photolithography, is disposed on the substrate; and A transition layer is configured to eliminate the abrupt change in performance between the substrate and the main functional layer in order to achieve compatibility between the two. The transition layer is disposed between the substrate and the main functional layer.

[0032] Example 1 This embodiment provides a method for preparing a chromium mask for semiconductor ArF lithography, including the following steps: 1. Substrate pretreatment: The quartz substrate was irradiated with UV-O3 at wavelengths of 185nm / 254nm for 15 minutes; then it was cleaned in the PVD chamber with low-power Ar plasma at 50W power and 0.3 Pa pressure for 120 seconds.

[0033] 2. Deposition of CrN transition layer: N2 and Ar (flow ratio 30:70 sccm) were introduced at a pressure of 0.25 Pa, and Cr target was used for sputtering at a power of 1.5 kW for 45 seconds to form a CrN layer with a thickness of approximately 6.5 nm. x Transition layer.

[0034] 3. Interlayer plasma activation: Introduce an Ar / N2 (7:3) mixed gas at a pressure of 0.5 Pa and treat the transition layer surface with 60W radio frequency power for 30 seconds.

[0035] 4. Deposition of Cr main functional layer: Under pure Ar atmosphere and 0.2 Pa pressure, Cr target was sputtered at 2.0 kW power, the substrate temperature was strictly controlled at 100℃, and the deposition rate was about 0.8 nm / s to obtain a Cr film with a thickness of 80 nm.

[0036] 5. Post-stress relief treatment: The sample is placed under a vacuum of ≤1×10⁻⁶. -3 Anneal at 180°C for 30 minutes, then cool with the furnace.

[0037] Performance Verification: Testing revealed that the sample exhibited a film-substrate adhesion strength (Lc) of 38.5 N, a film stress of -180 MPa, and a linewidth roughness (LWR) of 3.8 nm. Compared to the traditional method without a transition layer and activation (Lc = 22.0 N, stress = -520 MPa, LWR = 5.5 nm), all performance characteristics showed significant and unexpected improvements. This was achieved through the synergistic effect of the transition layer, activation, bias modulation, and low-temperature annealing, resulting in a balance between low stress and high performance.

[0038] Example 2 This embodiment provides a method for fabricating a MoSi mask for 193nm ArF lithography, including the following steps: 1. Substrate pretreatment: The quartz substrate was irradiated with UV-O3 at wavelengths of 185nm / 254nm for 15 minutes; then it was cleaned in the PVD chamber with low-power Ar plasma at 50W power and 0.3 Pa pressure for 120 seconds.

[0039] 2. Deposition of a transition layer (can be selected as needed, or MoSi can be deposited directly): If a transition layer is used, SiN can be deposited.x or MoSiN x Transition layer. For example, deposited SiN. x N2 and Ar (N2:Ar = 20:80~40:60 sccm) are introduced at a pressure of 0.3 Pa, and SiN is sputtered at a power of 2.0 kW using a Si target (RF sputtering) to form a SiN layer with a thickness of approximately 3~5 nm. x Transition layer.

[0040] 3. Interlayer plasma activation: Introduce an Ar / N2 (7:3) mixed gas at a pressure of 0.5 Pa and treat the surface of the transition layer with 60W radio frequency power for 30 seconds (this step can be omitted or adjusted if no transition layer has been deposited).

[0041] 4. Deposition of MoSi main functional layer: A MoSi alloy target (Si content approximately 10%~20%, determined based on the target's optical constants) is used. Ar atmosphere was introduced at a pressure of 0.3 Pa; Sputtering power 3.0 kW; The substrate temperature should be controlled at ≤100℃; The deposition rate is approximately 0.6 nm / s; Through real-time optical monitoring, a thickness of approximately 70 nm was deposited (to achieve a 180° phase shift and approximately 6% transmittance at a wavelength of 193 nm).

[0042] 5. Post-stress relief treatment: The sample is placed under a vacuum of ≤1×10⁻⁶. -3 Annealed at 170°C for 30 minutes at 180°C, then cooled in the furnace.

[0043] Effect verification: The method of this invention is also applicable to the fabrication of MoSi-based phase-shifting masks. While maintaining the precision of optical performance, it achieves a significant improvement in adhesion and effective control of stress, solving the problems of "high-temperature damage" and "stress warping" in traditional MoSi coatings.

[0044] While some embodiments of the present invention have been described in this application, those skilled in the art will understand that these embodiments are merely illustrative. Numerous variations, alternatives, and improvements will arise in those skilled in the art under the teachings of this invention without departing from its scope. The appended claims are intended to define the scope of the invention and thereby cover methods and structures within the scope of the claims themselves and their equivalents.

Claims

1. A method for preparing a PVD film layer using a photomask, characterized in that, Includes the following steps: A transition layer is deposited on the substrate, and the transition layer is activated. The main functional layer is deposited at low temperature on the activated transition layer; and Post-processing is performed to release the internal stress of the transition layer and the main functional layer to obtain the PVD film.

2. The method for preparing a PVD film layer of a photomask according to claim 1, characterized in that, The substrate is a quartz substrate or synthetic quartz glass.

3. The method for preparing a PVD film layer of a photomask according to claim 1, characterized in that, Before depositing the transition layer, the photomask substrate is pretreated, including ultraviolet ozone cleaning, in which the ultraviolet wavelength is 185nm / 254nm and the irradiation time is 10~20 min.

4. The method for preparing a PVD film layer of a photomask according to claim 3, characterized in that, The pretreatment also includes low-power plasma cleaning, in which the plasma is an inert gas with a power ≤50W, a pressure of 0.3~0.5Pa, and a cleaning time of 100~150s.

5. The method for preparing a PVD film layer of a photomask according to claim 1, characterized in that, The transition layer or the main functional layer is deposited at low temperature using magnetron sputtering.

6. The method for preparing a PVD film layer of a photomask according to claim 1, characterized in that, The transition layer comprises at least one of chromium nitride, chromium oxide, chromium oxynitride, chromium carbide, molybdenum nitride, silicon nitride, molybdenum silicon nitride, titanium nitride, titanium nitride, aluminum oxide, silicon dioxide, or a nickel-chromium alloy; and / or The main functional layer includes at least one of a Cr main functional layer or a MoSi main functional layer.

7. The method for preparing a PVD film layer of a photomask according to claim 1, characterized in that, The activation process includes: An Ar / N2 mixed gas is introduced into the PVD chamber, with an Ar / N2 volume ratio of (6~7):(3~4), and the chamber pressure is 0.5~0.8 Pa; and The transition layer surface is treated with 60~80W RF power for 20~40 s.

8. The method for preparing a PVD film layer of a photomask according to claim 1, characterized in that, The low-temperature deposition of the main functional layer on the activated transition layer includes the following steps: Under an Ar atmosphere and a pressure of 0.2~0.4 Pa, a Cr target or a molybdenum-silicon target is sputtered at a power of 2.0~5.0 kW, with the substrate temperature controlled at ≤100℃ and the deposition rate at 0.8~1.0 nm / s, to deposit a Cr main functional layer or a MoSi main functional layer on the surface of the transition layer.

9. The method for preparing a PVD film layer of a photomask according to claim 1, characterized in that, The post-processing includes: The PVD film was subjected to low-temperature annealing under vacuum; wherein the vacuum degree was ≤1×10⁻⁶. -3 Pa, in the low-temperature annealing treatment, the annealing temperature is 170~180℃ and the annealing time is 25~40 min.

10. A PVD film layer, characterized in that, include: The substrate is a quartz substrate or a synthetic quartz glass substrate; The main functional layer serves as a carrier for photomasks to perform photolithography, and the main functional layer is disposed on the substrate; as well as A transition layer is disposed between the substrate and the main functional layer and is configured to eliminate performance abrupt changes between the substrate and the main functional layer.

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