Nitride laminate and method for manufacturing nitride laminate

Abstract

To provide a nitride laminate that prevents a nitride layer from being contaminated and has improved crystallinity.SOLUTION: A nitride laminate comprises a polymer substrate, and a nitride layer formed on at least one surface of the polymer substrate, where the nitride layer has a Wurtzite-type crystal structure; the atomic weight of oxygen atoms present in the nitride layer is at most 2.5 atm%, and the atomic weight of hydrogen atoms is at most 2.0 atm%; and the full width half maximum of the X-ray rocking curve is at most 8°.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a nitride laminate and a method for manufacturing the nitride laminate. [Background technology]

[0002] Insulating nitrides such as aluminum nitride (AlN) are used in high-frequency noise filters, piezoelectric devices, ultrasonic devices, etc. Semiconductor nitrides such as gallium nitride (GaN) are used in optical semiconductor devices such as LEDs and lasers.

[0003] Nitride thin films can be formed by reactive sputtering, which has better material utilization efficiency and lower deposition temperatures than chemical vapor deposition. Inert gas ions are bombarded at high speed against a metal target, such as aluminum or metallic gallium, and the metal ions react with nitrogen gas to deposit sputter molecules that become the film material on the opposing substrate surface. A direct current (DC) power supply, radio frequency (RF) power supply, or other power source is used as the power source connected between the metal target and the substrate. Regardless of which power supply is used, placing a magnetron on the target electrode to accelerate charged particles promotes ionization of the inert gas and improves deposition speed.

[0004] Known techniques include forming an AlN layer on a silicon (Si) wafer by high-power RF sputtering (see, for example, Patent Document 1), and forming a wurtzite-type crystal piezoelectric layer on a polymer thin film by RF magnetron sputtering (see, for example, Patent Document 2).

[0005] An AlN thin film can also be formed on a Si substrate by DC magnetron sputtering. Prior to DC magnetron sputtering, a method has been proposed in which the chamber is heated and evacuated with a Si wafer placed on a substrate holder in the sputtering chamber, and then left for approximately two hours to remove water adhering to the inner walls of the chamber (see, for example, Patent Document 3).

[0006] It has been reported that high power impulse magnetron sputtering (HiPIMS) reduces the half-width of the X-ray rocking curve of an AlN film formed on a Si substrate (see, for example, Non-Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 03-104308 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-211095 [Patent Document 3] Japanese Patent Application Publication No. 07-316809 [Non-patent literature]

[0008] [Non-Patent Document 1] KA Aissa et al., "AlN films deposited by dc magnetron sputtering and high power impulse magnetron sputtering for SAW application", Journal of Physics D applied Physics 48(14):145307, March 2015 Summary of the Invention [Problem to be solved by the invention]

[0009] When forming a nitride thin film on a polymer substrate, the film formation temperature is limited compared to when forming a nitride thin film on an inorganic substrate such as a silicon wafer. Furthermore, even if heating and evacuation are performed using the method of Patent Document 3, moisture cannot be completely removed, and hydrogen (H) atoms and oxygen (O) atoms derived from moisture in the sputtering atmosphere may be incorporated into the film. In high-power RF sputtering, argon (Ar) atoms from the inert gas are incorporated into the film.

[0010] An object of the present invention is to provide a nitride laminate in which contamination of the nitride layer is suppressed and crystallinity is improved. [Means for solving the problem]

[0011] The inventors conducted repeated experiments based on the prediction that oxygen atoms, hydrogen atoms, etc. incorporated into nitrides act as impurities and affect the crystallinity and orientation of nitride thin films. By suppressing moisture contamination in the nitride layer laminated on the polymer substrate, they were able to realize a nitride laminate with good crystal quality.

[0012] In one embodiment of the disclosure, a nitride laminate comprising a polymer substrate and a nitride layer formed on at least one surface of the polymer substrate, the nitride layer is a nitride layer having a wurtzite crystal structure, the atomic weight of oxygen atoms present in the nitride layer is 2.5 atm.% or less, and the atomic weight of hydrogen atoms present is 2.0 atm.% or less; The full width at half maximum of the X-ray rocking curve is less than 8°. [Effects of the Invention]

[0013] The above-described configuration makes it possible to obtain a nitride laminate in which contamination of the nitride layer is suppressed and crystallinity is improved. [Brief explanation of the drawings]

[0014] [Figure 1A] 1 is a schematic diagram of a nitride laminate according to an embodiment. [Figure 1B] 1 is a schematic diagram of a nitride laminate according to an embodiment. [Figure 1C] 1 is a schematic diagram of a nitride laminate according to an embodiment. [Figure 1D] 1 is a schematic diagram of a nitride laminate according to an embodiment. [Figure 2]FIG. 1 shows the full width at half maximum of the (002) plane X-ray rocking curves of nitride layers formed on polymer substrates by different methods. [Figure 3] FIG. 1 shows the composition of nitride layers formed on polymer substrates by different techniques. [Figure 4] 1A-1C show analytical results of nitride layers formed on glass and polymer substrates by different techniques. DETAILED DESCRIPTION OF THE INVENTION

[0015] In this embodiment, high-power impulse magnetron sputtering (hereinafter referred to as "HiPIMS") is used to activate nitrogen atoms, a reactive gas, and suppress moisture contamination that could not be completely removed, thereby improving the crystalline orientation of the nitride layer formed on the polymer substrate.

[0016] 1A to 1D are schematic diagrams of nitride laminates according to embodiments. In Fig. 1A, nitride laminate 10A includes polymer substrate 11 and nitride layer 13 formed on at least one main surface of polymer substrate 11. Nitride layer 13 is a layer having a wurtzite crystal structure and is deposited by the HiPIMS method.

[0017] In the HiPIMS method, a large amount of power, ranging from several tens of kilowatts to megawatts, is instantaneously applied, and over 99% of that time is in an OFF state. The instantaneous application of large amounts of power generates a higher density plasma than conventional magnetron sputtering, improving the ionization rate of the raw material particles and reactive gas. The raw material ions and reactive gas ions are easily transported and adhere to the surface of the polymer substrate 11, improving the chemical bonding state of the nitride. As a result, a smooth film with good crystallinity and density is formed on the main surface of the polymer substrate 11 at low temperatures.

[0018] The atomic weight of oxygen atoms present in the nitride layer 13 is 2.5 atm.% or less, and the atomic weight of hydrogen atoms present in the nitride layer 13 is 2.0 atm.% or less. The reason for this will be described later.

[0019] The nitride layer 13 is selected from AlN, GaN, InN, or a compound thereof. These materials have a wurtzite crystal structure and have polarization in the c-axis direction. Wurtzite crystals have a crystal structure that is stable in air. The band gap of InN is narrow, about 0.7 eV, while the band gap of AlN is wide, at 6.2 eV. The band gap of GaN is 3.4 eV. By using the nitride layer 13, light-emitting devices with a wide wavelength range, from near-infrared to ultraviolet, can be fabricated. Furthermore, the polarization in the c-axis direction can be utilized for piezoelectric devices.

[0020] The full width at half maximum of the X-ray rocking curve of the (002) plane of the nitride layer 13 is preferably 8° or less, and more preferably 7° or less. The reason for this will also be explained later.

[0021] The polymer substrate 11 is selected from polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic resin, cycloolefin polymer, polyimide (PI), etc. Use of the polymer substrate 11 makes it possible to apply it to flexible light-emitting devices, piezoelectric elements, frequency filters, and roll-to-roll processes.

[0022] Among the materials mentioned above, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), acrylic resins, and cycloolefin polymers are colorless and transparent materials, which are advantageous when nitride laminate 10A is applied to devices that require optical transparency, such as light-emitting elements. When nitride laminate 10A is used for applications that do not require optical transparency, such as healthcare products such as pulse monitors and heart rate monitors, or in-vehicle pressure detection seats, translucent or opaque plastic materials such as PI may be used.

[0023] The nitride layer 13 can have a desired thickness by controlling the film formation conditions, and can be, for example, 10 nm or more and 10 μm or less depending on the application. When the nitride layer 13 is used as an upper orientation control layer, the thickness may be 10 nm to 50 nm. When the nitride layer 13 is used as a piezoelectric layer or a sensor layer, the thickness may be 200 nm to 1 μm or more. An electrode layer may be provided on at least one surface of the nitride layer 13.

[0024] The desired film thickness can be achieved by controlling the HiPIMS deposition time, pulse width, pulse application frequency, source gas flow rate, bias voltage, etc. Since a nitride layer is formed on the polymer substrate 11, it is desirable to deposit the film at a substrate temperature of 150°C or less, more preferably 100°C or less. The pulse width is set to 1 μs to 300 μs. If it is longer than 300 μs, the thermal impact on the polymer substrate 11 becomes significant. If it is shorter than 1 μs, it becomes difficult to ionize the source particles and gas.

[0025] 1B is a schematic diagram of a nitride stack 10B. The nitride stack 10B has a metal layer 12 between a polymer base material 11 and a nitride layer 13. The metal layer 12 functions as at least one of an electrode layer for applying a voltage to the nitride layer 13 and an underlayer for improving the crystal quality of the nitride layer 13.

[0026] The metal layer 12 is a metal with a body-centered cubic structure, such as molybdenum (Mo), tungsten (W), lithium (Li), tantalum (Ta), niobium (Nb), or a laminate of these metals. Alternatively, a metal with a hexagonal close-packed structure, such as titanium (Ti), hafnium (Hf), ruthenium (Ru), zirconium (Zr), cobalt (Co), or a laminate of these metals, may be used as the metal layer 12.

[0027] When a layer of these metals is disposed as an underlayer for the nitride layer 13, the crystal orientation of the nitride layer 13 is improved, as will be described later. When the metal layer 12 is used as an underlayer metal for the nitride layer 13, the thickness of the metal layer 12 is 10 nm to 200 nm, more preferably 30 nm to 150 nm. When the metal layer 12 is used as an electrode, the thickness is 50 nm to 400 nm, more preferably 100 nm to 300 nm, from the viewpoints of miniaturizing the device and stabilizing the electrical characteristics.

[0028] The metal layer 12 is formed by sputtering, which allows film formation at room temperature or at a slight heating temperature of 100° C. or less.

[0029] 1C is a schematic diagram of a nitride stack 10C. The nitride stack 10B has a metal layer 12 on the surface of a nitride layer 13 formed on a polymer substrate 11. The metal layer 12 is made of the same metal material as in FIG. 1B.

[0030] The nitride laminate 10C can be used as a device by forming an electrode layer on the back surface of the polymer-based material 11. Alternatively, a second nitride layer and a second metal layer can be laminated on the metal layer 12 to be used as a device.

[0031] 1D is a schematic diagram of a nitride laminate 10D. The nitride laminate 10D has a metal layer 12 and a metal layer 14 on both sides of a nitride layer 13. The nitride laminate 10D has a sandwich structure of the metal layer 12, the nitride layer 13, and the metal layer 14, and is applied to piezoelectric elements, high-frequency filters, sensors, and the like. The nitride laminate 10D uses a thin, easily deformed polymer substrate 11, so when used as a piezoelectric element, it can generate electric charge by polarization even with a weak force.

[0032] 2 shows the full width at half maximum of the X-ray rocking curves of the AlN (002) plane formed by various sputtering methods on the polymer substrate 11. A polyimide (PI) film with a thickness of 50 μm was used as the polymer substrate 11.

[0033] The full width at half maximum of the X-ray rocking curve is used as an index of crystal orientation. The smaller the full width at half maximum, the more uniform the crystal orientation. The integrated value of the rocking curve (peak area) indicates the crystallinity. The larger the peak area, the larger the crystal size.

[0034] As a sputtering method, in addition to HiPIMS used in the embodiment, an AlN layer is formed by DC magnetron sputtering (DCMS) and RF sputtering as a reference example. In both sputtering methods, the power is 500 W, the pressure is 0.67 Pa, the distance between the target and the substrate is 65 mm, the nitrogen (N2) gas share is 17%, and the back pressure is 3 × 10 -5 The pressure was set to 0.5 Pa. Furthermore, all samples were heated and evacuated to a vacuum prior to sputtering. Two types of samples were fabricated using each sputtering method, with AlN layer thicknesses of 0.5 μm and 1.0 μm.

[0035] When an AlN layer is formed on a PI film by DCMS, the full width at half maximum of the X-ray rocking curve is as wide as 27° to 28° regardless of the film thickness, and the orientation is insufficient.

[0036] When an AlN layer is formed on a PI film by RF sputtering, the full width at half maximum of the X-ray rocking curve is 24.4° at a thickness of 0.5 μm, indicating insufficient orientation. When the film is grown to a thickness of 1.0 μm, the full width at half maximum improves to 23.2°, but the crystal orientation is still insufficient.

[0037] When an AlN layer is formed on a PI film by HiPIMS, the full width at half maximum of the X-ray rocking curve is 6.5° at a film thickness of 0.5 μm and 6.0° at a film thickness of 1.0 μm. By using HiPIMS, a full width at half maximum of 7.0° or less can be obtained regardless of the thickness of the AlN layer. Based on this finding, in this embodiment, a nitride layer 13 is formed on a polymer substrate 11 by the HiPIMS method.

[0038] Figure 3 shows the composition of AlN layers formed by various sputtering methods. The aluminum (Al), nitrogen (N), oxygen (O), and argon (Ar) contents in the film were measured by Rutherford backscattering spectroscopy, and the hydrogen (H) content was measured by hydrogen forward scattering spectroscopy.

[0039] In the case of DC sputtering, the AlN layer contains 4.2 atm.% H and 2.9 atm.% O, but the Ar content is so low that it cannot be detected.

[0040] In the case of RF sputtering, no O was observed in the AlN layer, but 0.6 atm.% H and 0.1 atm.% Ar were detected. This is thought to be because the application of high power causes H and the inert gas Ar to be incorporated into the AlN layer during sputtering.

[0041] In contrast, with the HiPIMS method, no Ar or O was observed in the AlN layer, and the H content was low at 0.4 atm.%. This shows that both water contamination in the AlN layer and the incorporation of Ar are suppressed, resulting in a nitride layer with good crystal quality.

[0042] 4 shows the characteristics and film composition of nitride layers in the examples, together with a reference example. In Examples 1 to 4 and Reference Example 1, an AlN layer was formed on a PI substrate by HiPIMS, and the film composition and full width at half maximum of the X-ray rocking curve were measured. In Example 5, a GaN layer was formed on a PI substrate by HiPIMS, and the film composition and full width at half maximum of the X-ray rocking curve were measured. Of these, in Examples 1 to 5, a degassing treatment was performed prior to film formation by HiPIMS, but in Reference Example 1, a degassing treatment was not performed.

[0043] In Reference Example 2, an AlN layer was formed on a PI substrate by RF magnetron sputtering, and the film composition and full width at half maximum of the X-ray rocking curve were measured. In Reference Example 3, an AlN layer was formed on a PI substrate by DC magnetron sputtering, and the film composition and full width at half maximum of the X-ray rocking curve were measured. In Reference Example 4, a GaN layer was formed on a PI substrate by DC magnetron sputtering, and the film composition and full width at half maximum of the X-ray rocking curve were measured. In all of Reference Examples 2 to 4, degassing treatment was not performed.

[0044] Throughout Examples 1 to 5 and Reference Examples 1 to 4, the film thicknesses of the nitride layers (AlN layers or GaN layers) and the metal layers used were measured by observing the cross section with a FIB-TEM (Focused Ion Beam Transmission Electron Microscope). X-ray rocking curves were measured using a powder X-ray diffractometer (Rigaku Corporation's "RINT-2000") under the following measurement conditions. The full width at half maximum (FWHM) was then determined.

[0045] <Measurement conditions> Light source: Cu-Kα line (wavelength: 0.15418nm) Measurement mode: θ scan 2θ position: The 2θ angle at which the AlN (200) plane peak appears is set for each sample by X-ray diffraction measurement. Measurement range: 0° to 2θ position setting angle Measurement interval: 0.1° Divergence slit: 1.00 mm Divergence vertical limit slit: 10 mm Exposure time: 3 seconds. [Example]

[0046] A 50 μm thick PI substrate ("200EN" manufactured by Toray DuPont Co., Ltd.) was placed in a vacuum sputtering device, and the ultimate vacuum was 3 × 10 -5The chamber was evacuated sufficiently to a pressure of 0.6 Pa and degassed. Then, under a vacuum atmosphere (below 0.6 Pa), Ar and N2 were introduced at a flow ratio of Ar:N2 = 83:17, and an Al target was used to form an AlN layer with a thickness of 0.5 μm by HiPIMS. The HiPIMS average power was 0.5 kW, the peak power was 52 kW, the frequency was 1000 Hz, and the pulse time was 20 microseconds. No underlying metal layer was used below the AlN layer.

[0047] The full width at half maximum of the X-ray rocking curve of Example 1 was narrow at 6.5°, indicating good crystal orientation. The Al composition of the AlN layer was 50.8 atm.%, and the nitrogen composition was 48.8 atm.%, which is close to the stoichiometric composition. The H content was low at 0.4 atm.%. O and Ar were not observed. The number "0.01" in parentheses for the Ar composition is listed as a reference value, as it is near the lower limit of detection by the instrument. [Example]

[0048] Before forming an AlN layer on the PI substrate, a 100 nm thick Mo layer was formed by DC magnetron sputtering (DC power: 0.4 kW) using a Mo target in a vacuum atmosphere (0.2 Pa) containing Ar. Other conditions were the same as in Example 1, and a 0.5 μm thick AlN layer was formed on the Mo layer on the PI substrate by HiPIMS.

[0049] The full width at half maximum of the X-ray rocking curve of Example 2 was narrow at 7.0°, indicating good crystal orientation. The Al composition of the AlN layer was 49.5 atm.% and the nitrogen composition was 50.2 atm.%, which is close to the stoichiometric composition. The H content was low at 0.3 atm.%. O and Ar were not observed. [Example]

[0050] Before forming an AlN layer on the PI substrate, a 100 nm thick Ti layer was formed by DC magnetron sputtering (DC power: 0.4 kW) using a Ti target in a vacuum atmosphere (0.2 Pa) containing Ar. Other conditions were the same as in Example 1, and a 0.5 μm thick AlN layer was formed on the Ti layer on the PI substrate by HiPIMS.

[0051] The full width at half maximum of the X-ray rocking curve of Example 3 was narrow at 4.0°, indicating good crystal orientation. The Al composition of the AlN layer was 49.1 atm.%, and the nitrogen composition was 50.6 atm.%, which is close to the stoichiometric composition. The H content was low at 0.3 atm.%, similar to Example 2 in which a Mo layer was inserted. No O or Ar was observed. [Example]

[0052] Except for the fact that the thickness of the AlN layer was 1 μm, an Al layer was formed on a PI substrate under the same conditions as in Example 1. No underlying metal layer was inserted below the AlN layer.

[0053] The full width at half maximum of the X-ray rocking curve of Example 4 is 6.0°. By making the AlN layer thicker than in Example 1, the crystal orientation is improved compared to Example 1. The Al composition of the AlN layer is 50.1 atm.%, and the nitrogen composition is 49.5 atm.%, which is close to the stoichiometric composition. The H content is 0.4 atm.%, the same as in Example 1. O and Ar were not observed. [Example]

[0054] Without introducing Ar, only N2 was introduced at a flow ratio of Ar:N2 = 0:100, and a GaN layer was formed by HiPIMS using a GaN target. The HiPIMS average power was 0.2 kW, the peak power was 88 kW, the frequency was 200 Hz, and the pulse width was 30 microseconds. A GaN layer was formed on a PI substrate under the same conditions as in Example 1. No underlying metal layer was inserted below the GaN layer.

[0055] The full width at half maximum of the X-ray rocking curve of Example 5 was narrow at 7.6°, indicating good crystal orientation. The GaN layer had a Ga composition of 49.9 atm.% and a nitrogen composition of 49.6 atm.%, which is close to a chemically biphasic composition. The H content was 0.5 atm.%. No O was observed, and Ar was not observed because it was not used.

[0056] [Reference example 1] The ultimate vacuum level of the degassing process before the deposition of the AlN layer was 5×10 -4 An AlN layer was formed on a PI substrate under the same conditions as in Example 1, except that the pressure was set to Pa. The ultimate vacuum level in the degassing treatment was one order of magnitude higher than that in Example 1.

[0057] The full width at half maximum of the X-ray rocking curve of Reference Example 1 is as wide as 29.0°, and satisfactory crystal orientation is not obtained in the AlN layer. The Al composition of the AlN layer is 48.5 atm.%, and the nitrogen composition is 49.3 atm.%, which is a large deviation from the stoichiometric composition compared to Examples 1 to 4. The H composition has increased to 2.2 atm.%. The increase in the H composition is thought to be due to moisture remaining in the chamber due to insufficient vacuum during the degassing process. On the other hand, O and Ar are not observed, as in Examples 1 to 4.

[0058] [Reference example 2] An AlN layer was formed on a PI substrate under the same conditions as in Example 1, except that the sputtering power supply was an RF power supply and RF magnetron sputtering (RF power 0.5 kW) was used.

[0059] The full width at half maximum of the X-ray rocking curve for Reference Example 2 is a wide 24.4°, indicating that satisfactory crystal orientation is not achieved in the AlN layer. The Al composition of the AlN layer is 50.2 atm.%, and the nitrogen composition is 49.1 atm.%, which is close to the stoichiometric composition. The H content has increased to 0.6 atm.%. No O was observed, and the AlN layer contains 0.1 atom.% Ar.

[0060] [Reference example 3] An AlN layer was formed on a PI substrate under the same conditions as in Example 1, except that the sputtering power supply was a DC power supply and DC magnetron sputtering (DC power 0.5 kW) was used.

[0061] The full width at half maximum of the X-ray rocking curve of Reference Example 3 is as wide as 27.8°, and satisfactory crystal orientation is not obtained in the AlN layer. The Al composition of the AlN layer is 47.4 atm.%, and the nitrogen composition is 45.5 atm.%, which is a large deviation from the stoichiometric composition compared to Examples 1 to 4. The H content is very high at 4.2 atm.%. Furthermore, O and Ar are also contained in the AlN layer.

[0062] The results of Examples 1 to 4 and Reference Examples 1 to 3 show that by forming a nitride layer on a polymer substrate by HiPIMS, the full width at half maximum of the X-ray rocking curve can be set to 8° or less, more preferably 7° or less, regardless of the film thickness. These results support the characteristics shown in Figure 2.

[0063] [Reference example 4] A GaN layer was formed on a PI substrate under the same conditions as in Example 5, except that the sputtering power supply was a DC power supply and DC magnetron sputtering (DC power 0.2 kW) was used.

[0064] The full width at half maximum of the X-ray rocking curve of Reference Example 4 was as wide as 29.8°, indicating that satisfactory crystal orientation was not obtained in the GaN layer. The GaN layer had a Ga composition of 47.7 atm.% and a nitrogen composition of 47.6 atm.%, which is close to the stoichiometric composition, but the H content was very high at 3.2 atm.%. Furthermore, the GaN layer contained O.

[0065] The results of Examples 1 to 5 and Reference Examples 1 to 4 show that by forming a nitride layer on a polymer substrate by the HiPIMS method, the full width at half maximum of the X-ray rocking curve can be set to 8° or less, more preferably 7° or less, regardless of the film thickness. These results support the characteristics shown in Figure 2.

[0066] The results of Examples 1 to 5 and Reference Examples 1 to 4 show that by forming a nitride layer on a polymer substrate by the HiPIMS method, a nitride layer with a composition close to the stoichiometric composition is formed, and contamination by impurity atoms such as H, O, and Ar is suppressed. These results support the film composition shown in Figure 3.

[0067] 2 and 3, the AlN layer formed by HiPIMS has a small amount of Ar in the film and a small full width at half maximum of the X-ray rocking curve. From this, it can be inferred that the small amount of Ar in the film improves the crystal orientation.

[0068] On the other hand, when we look at the film deposition results using DC magnetron sputtering and RF magnetron sputtering, the full width at half maximum of the X-ray rocking curve is smaller with RF magnetron sputtering than with DC sputtering, even though the Ar amount is slightly larger. Looking at this result, we can make the opposite assumption that the Ar amount in the film does not necessarily correlate with the crystal orientation.

[0069] In DC magnetron sputtering, the amount of Ar in the film is small, but the X-ray rocking curve is broad. This is thought to be because the degree of vacuum in the film deposition chamber is insufficient, causing the crystal orientation to become distorted due to the influence of residual gas. Possible causes include Ar, H, and O reacting with the nitride film, or H, O, and Ar being trapped within the wurtzite crystal, causing the crystal to become distorted.

[0070] From Figures 2 and 3, no correlation can be drawn between the amount of Ar in the film and the crystal orientation, but it can be concluded that reducing the amounts of at least H and O by HiPIMS improves the crystal orientation.

[0071] 3 and 4, in the wurtzite nitride layer formed on the polymer substrate by HiPIMS, the atomic weight of oxygen atoms is 2.5 atm.% or less, the atomic weight of hydrogen atoms is 2.0 atm.% or less, and the full width at half maximum of the X-ray rocking curve is 8° or less.

[0072] A metal layer may be disposed on at least one surface of the nitride layer. When the metal layer is inserted below the nitride layer in the stacking direction, the full width at half maximum of the X-ray rocking curve is reduced, and the crystal orientation is improved.

[0073] Before forming a nitride layer on a polymer substrate by the HiPIMS method, degassing in a vacuum chamber improves the crystal orientation.

[0074] The nitride laminate of the embodiment can be applied to piezoelectric elements, high frequency noise filters, concentration sensors, ultraviolet sensors, ultrasonic sensors, light emitting devices, and the like. [Explanation of symbols]

[0075] 10A-10D Nitride laminates 11 Polymer base material 12 metal layer 13 nitride layer 14 Metal layer

Claims

1. A nitride laminate comprising a polymer substrate and a nitride layer formed on at least one surface of the polymer substrate, the nitride layer is a nitride layer having a wurtzite crystal structure, the nitride layer has a thickness of 0.5 μm to 1 μm; the atomic weight of oxygen atoms present in the nitride layer is 2.5 atm.% or less, and the atomic weight of hydrogen atoms present is 0.5 atm.% or less; The full width at half maximum of the X-ray rocking curve is 6.5° or less. Nitride stack.

2. 2. The nitride stack of claim 1, wherein the nitride layer is selected from aluminum nitride, gallium nitride, indium nitride, or a combination thereof.

3. The nitride layer is mainly composed of aluminum nitride. The nitride laminate according to claim 1 or 2.

4. the polymer substrate is formed of a material selected from polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), an acrylic resin, a cycloolefin polymer, and polyimide (PI); The nitride laminate according to any one of claims 1 to 3.

5. a metal layer provided on at least one surface of the nitride layer; The nitride laminate according to any one of claims 1 to 4, further comprising:

6. The metal layer is a body-centered cubic metal including molybdenum (Mo), tungsten (W), lithium (Li), tantalum (Ta), niobium (Nb), or a lamination thereof, or a hexagonal close-packed metal including titanium (Ti), hafnium (Hf), ruthenium (Ru), zirconium (Zr), cobalt (Co), or a lamination thereof. The nitride stack according to claim 5 .

7. A nitride layer is formed on a polymer substrate by high-power impulse magnetron sputtering at a substrate temperature of 150°C or less; the nitride layer is a nitride layer having a wurtzite crystal structure, the nitride layer has a thickness of 0.5 μm to 1 μm; the atomic weight of oxygen atoms present in the nitride layer is 2.5 atm.% or less, and the atomic weight of hydrogen atoms present is 0.5 atm.% or less; The full width at half maximum of the X-ray rocking curve is 6.5° or less. A method for manufacturing a nitride laminate.

8. Prior to forming the nitride layer, a degassing treatment is performed on the vacuum chamber. The method for producing the nitride laminate according to claim 7 .

9. A method for manufacturing a nitride laminate described in claim 7 or 8, wherein the high-power impulse magnetron sputtering method has an average power of 0.2 kW or more, a peak power of 52 kW or more, a frequency of 200 Hz or more, and a pulse time of 30 microseconds or less.

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