A chromium nitride film, a method for preparing the same and applications thereof

Abstract

The application provides a chromium nitride film and a preparation method and application thereof, and belongs to the technical field of mask plate preparation for extreme ultraviolet lithography. The application provides a preparation method of a chromium nitride film, which comprises the following steps: using a mixed gas of argon and nitrogen as a working gas, using a chromium target material as a sputtering target material to perform magnetron sputtering, generating chromium nitride particles from nitrogen and chromium and sputtering the chromium nitride particles to a substrate surface to form a chromium nitride film; the volume concentration of the nitrogen is 5-50%. The chromium nitride film prepared by the application has small roughness and good adhesion, can be used for manufacturing a mask plate for extreme ultraviolet lithography, and has a significant promoting effect on the extreme ultraviolet lithography industry. Chromium nitride (CrN) has the characteristics of high melting point and high hardness, has excellent chemical stability and wear resistance, and can maintain its mechanical properties at high temperatures, and can well maintain the stability of the extreme ultraviolet mask plate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mask plate preparation for extreme ultraviolet lithography, and particularly relates to a chromium nitride film and a preparation method and application thereof. BACKGROUND

[0002] In the development of nanometer processing technology, lithography has always been a core driving force, determining the feature size of integrated circuit elements. The development of lithography technology has experienced equal-multiple lithography to microprojection lithography, and the wavelength has gradually become shorter. The lithography resolution has become an important indicator affecting the development of lithography technology. Among them, extreme ultraviolet projection lithography has attracted widespread attention due to its high resolution and high production efficiency, and is considered as an important node of 7nm or even shorter wavelength lithography technology.

[0003] There are many factors affecting the commercialization of extreme ultraviolet lithography, and the mask plate for extreme ultraviolet lithography is one of the keys. Since all materials have strong absorption in the extreme ultraviolet (11-14nm) band, a reflective optical system is required, which also puts higher requirements on the structure and uniformity of the mask.

[0004] The CrN film prepared in the prior art mostly has problems of large roughness (about 2nm) and poor adhesion, and cannot be used for the manufacture of mask plates for extreme ultraviolet lithography. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a chromium nitride film and a preparation method and application thereof. The chromium nitride film provided by the present application has small roughness and good adhesion, and can be used for the preparation of extreme ultraviolet lithography mask plates.

[0006] In order to achieve the above purpose, the present application provides the following scheme:

[0007] The present application provides a preparation method of a chromium nitride film, comprising the following steps:

[0008] A mixture gas of argon and nitrogen is used as a working gas, and a chromium target material is used as a sputtering target material for magnetron sputtering. Nitrogen and chromium generate chromium nitride particles and are sputtered onto the surface of a substrate to form a chromium nitride film.

[0009] The volume concentration of the nitrogen is 13-50%.

[0010] Preferably, the base vacuum degree of the magnetron sputtering is ≤1x10 -4 Pa, and the power is 1000-1500W.

[0011] Preferably, the gas flow of the argon is 40-150sccm, and the charging pressure of the argon is 0.06-1.0Pa.

[0012] Preferably, the substrate comprises fused quartz, ultra-low expansion glass or high borosilicate glass.

[0013] The application provides the chromium nitride film prepared by the preparation method.

[0014] Preferably, the thickness of the chromium nitride film is 5-40 nm.

[0015] Preferably, the crystal orientation of the chromium nitride film is <111>, <220> and <311>, and the corresponding XRD characteristic peak intensity is <220>≥<111>><311>; the roughness of the chromium nitride film is 1.4-1.5 nm.

[0016] The application provides the application of the chromium nitride film in an extreme ultraviolet lithography mask plate.

[0017] Preferably, the extreme ultraviolet wave band applied by the extreme ultraviolet lithography mask plate is 11-14 nm.

[0018] Preferably, the chromium nitride film is used as one or more of a conductive layer, a buffer layer and a hard mask layer of the extreme ultraviolet lithography mask plate.

[0019] The application provides a preparation method of a chromium nitride film, which comprises the following steps: using a mixed gas of argon and nitrogen as a working gas, using a chromium target as a sputtering target to perform magnetron sputtering, generating chromium nitride particles from the nitrogen and the chromium and sputtering the chromium nitride particles to a substrate surface to form a chromium nitride film; the volume concentration of the nitrogen is 5-50%. Compared with ion beam sputtering and evaporation deposition, the chromium nitride film prepared by the magnetron sputtering has small roughness and good adhesion, can be used for manufacturing an extreme ultraviolet lithography mask plate, and has a significant promoting effect on the extreme ultraviolet lithography industry.

[0020] The chromium nitride (CrN) has the characteristics of high melting point and high hardness, has excellent chemical stability and wear resistance, and can maintain its mechanical properties at high temperatures, and can well maintain the stability of the extreme ultraviolet mask plate; at the same time, the CrN film can serve as a conductive layer on the back of the extreme ultraviolet lithography mask plate, a buffer layer on the front and a hard mask layer on the top. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0022] Figure 1 XRR curve (a) and XRD graph (b) of the chromium nitride film of Example 1.

[0023] Figure 2 The actual picture of the results of the mesh test of the chromium nitride film of Example 1;

[0024] Figure 3 The XRR curve (left) and the XRD graph (right) of the chromium nitride film of Example 2;

[0025] Figure 4 The XRR curve (left) and the XRD graph (right) of the chromium nitride film of Comparative Example 1. DETAILED DESCRIPTION

[0026] The present application provides a preparation method of a chromium nitride film, comprising the following steps:

[0027] The chromium target material is used as the sputtering target material for the magnetron sputtering with the mixed gas of argon and nitrogen as the working gas, and the chromium nitride particles are generated from the nitrogen and the chromium and sputtered to the surface of the substrate to form the chromium nitride film.

[0028] Unless otherwise specified, the materials and devices used in the present application are commercially available.

[0029] In the present application, the volume concentration of the nitrogen is 13-50%, and in the embodiments of the present application, it can be specifically 13%, 18%, 20%, 25%, 30%, 33%, 35%, 40%, 45% or 50%. In the present application, the gas flow of the argon is preferably 40-150sccm, and in the embodiments of the present application, it can be specifically 40sccm, 50sccm, 60sccm, 70sccm, 80sccm, 90sccm, 100sccm, 120sccm or 140sccm. In the present application, the filling pressure of the argon is preferably 0.06-1.0Pa, and in the embodiments of the present application, it can be specifically 0.06Pa, 0.10Pa, 0.12Pa, 0.15Pa, 0.18Pa or 1.0Pa. The volume concentration of the nitrogen is controlled by controlling the gas flow of the nitrogen and the argon in the present application. The chromium nitride film obtained by controlling the volume concentration of the nitrogen has <111>, <220> and <311> three crystal orientations, and the corresponding XRD characteristic peak intensity is <220>≥<111>><311> in the present application.

[0030] In the present application, the purity of the chromium target material is preferably 99.99%. In the present application, the base vacuum degree of the magnetron sputtering is preferably ≤1×10 -4The accompanying plate is preferably an ultra-smooth single crystal silicon wafer. In the present application, the power of the magnetron sputtering is preferably 1000-1500 W, and in the embodiments of the present application, it can be specifically 1000 W, 1100 W, 1200 W, 1300 W, 1400 W or 1500 W. The present application does not have special requirements for the time of the magnetron sputtering, and it can reach the target thickness of the chromium nitride film. In the present application, the substrate preferably includes fused quartz, ultra-low expansion glass (ULE glass) or high borosilicate glass. In the present application, the fused quartz, ultra-low expansion glass (ULE glass) and high borosilicate glass are all ultra-smooth low thermal expansion materials.

[0031] The present application provides a chromium nitride film prepared by the preparation method described in the above scheme.

[0032] In the present application, the thickness of the chromium nitride film is preferably 5-40 nm, and in the embodiments of the present application, it can be specifically 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm or 40 nm. In the present application, the crystal direction of the chromium nitride film is preferably <111>, <220> and <311>, and the corresponding XRD characteristic peak intensity is preferably <220>≥<111>><311>; the roughness of the chromium nitride film is preferably 1.4-1.5 nm.

[0033] The present application provides the application of the chromium nitride film described in the above scheme in an extreme ultraviolet lithography mask plate.

[0034] In the present application, the extreme ultraviolet wave band applied to the extreme ultraviolet lithography mask plate is preferably 11-14 nm. In the present application, the chromium nitride film is preferably used as one or more of the conductive layer, the buffer layer and the hard mask layer of the extreme ultraviolet lithography mask plate.

[0035] The present application preferably directly sputters the chromium nitride film to the target position according to the preparation method described in the above scheme when preparing the extreme ultraviolet lithography mask plate, to form the conductive layer, the buffer layer or the hard mask layer of the extreme ultraviolet lithography mask plate.

[0036] The chromium nitride film provided by the present application has small roughness and good adhesion, and can be used in the manufacture of the extreme ultraviolet lithography mask plate, which has a significant promoting effect on the extreme ultraviolet lithography industry.

[0037] The chromium nitride (CrN) has the characteristics of high melting point and high hardness, has excellent chemical stability and wear resistance, and can maintain its mechanical properties at high temperature, and can well maintain the stability of the extreme ultraviolet mask plate; at the same time, the CrN film can serve as the conductive layer on the back of the extreme ultraviolet lithography mask plate, the buffer layer on the front and the hard mask layer on the top.

[0038] In order to further illustrate the present application, a chromium nitride film, a preparation method and application thereof provided by the present application are described in detail below in conjunction with the accompanying drawings and examples, but they should not be understood as limiting the protection scope of the present application.

[0039] Example 1

[0040] The super-smooth fused quartz was selected as the substrate, the super-smooth silicon wafer was selected as the accompanying plated piece, and after being fixed on the clamp, it was placed into the magnetron sputtering equipment. The equipment was vacuumed, and when the cavity pressure was less than 1x10 -4 Pa, the vacuuming was stopped, argon (Ar) was filled at a gas flow rate of 70 seem, the cavity pressure at this time was 0.12 Pa, the chromium (Cr) target was started at a power of 1000 W, nitrogen (N2) was filled at a gas flow rate of 30 seem (at this time, the volume concentration of nitrogen was 30 / (30+70)=30%), N2 and Cr were allowed to fully react, the required CrN particles were formed and sputtered onto the prepared substrate to grow uniformly. After 25 nm was expected to grow, the sputtering was stopped, the protective gas Ar was filled, the gas pressure reached 10 Pa, and then the gas valve was slowly opened to fill the atmosphere.

[0041] Example 2

[0042] The super-smooth fused quartz was selected as the substrate, the super-smooth silicon wafer was selected as the accompanying plated piece, and after being fixed on the clamp, it was placed into the magnetron sputtering equipment. The equipment was vacuumed, and when the cavity pressure was less than 1x10 -4 Pa, the vacuuming was stopped, argon (Ar) was filled at a gas flow rate of 70 seem, the cavity pressure at this time was 0.12 Pa, the chromium (Cr) target was started at a power of 1000 W, nitrogen (N2) was filled at a gas flow rate of 30 seem (at this time, the volume concentration of nitrogen was 30 / (30+70)=30%), N2 and Cr were allowed to fully react, the required CrN particles were formed and sputtered onto the prepared substrate to grow uniformly. After 25 nm was expected to grow, the sputtering was stopped, the protective gas Ar was filled, the gas pressure reached 10 Pa, and then the gas valve was slowly opened to fill the atmosphere.

[0043] Comparative Example 1

[0044] The super-smooth fused quartz was selected as the substrate, the super-smooth silicon wafer was selected as the accompanying plated piece, and after being fixed on the clamp, it was placed into the magnetron sputtering equipment. The equipment was vacuumed, and when the cavity pressure was less than 1x10 -4Pa, stop vacuumizing, fill in argon (Ar) with a gas flow of 70 sccm, at this time the gas pressure in the chamber is 0.12 Pa, start the chromium (Cr) target with a power of 1000 W, fill in nitrogen (N2) with a gas flow of 10 sccm, at this time the volume concentration of nitrogen is 12.5%. Let N2 and Cr fully react to form the required CrN particles and sputter onto the prepared substrate to grow uniformly. After 47 nm is expected to grow, stop sputtering, fill in the protective gas Ar to a pressure of 10 Pa, then slowly open the exhaust valve to fill in the atmosphere.

[0045] Application Example 1

[0046] Select super-smooth double-sided polished fused quartz as the substrate, the front side up is fixed on the clamp. Put it into the magnetron sputtering equipment and vacuumize, wait for the gas pressure in the chamber to be less than 1×10 -4 Pa, stop vacuumizing, fill in argon (Ar) with a gas flow of 70 sccm, at this time the gas pressure in the chamber is 0.12 Pa, start the chromium (Cr) target with a power of 1000 W, wait for the glow to stabilize, and then deposit a 10 nm Cr undercoat layer, and then turn off the power;

[0047] Keep the gas pressure unchanged, start the power of the molybdenum (Mo) target and the silicon (Si) target, the power is 1000 W and 1500 W respectively, wait for the glow to stabilize, and then deposit a Mo / Si multilayer film on the Cr undercoat layer, the period thickness is 6.96 nm, deposit 50 periods, and then turn off the power after the deposition is completed;

[0048] Keep the gas pressure unchanged, start the power of the ruthenium (Ru) target, the power is 1200 W, wait for the glow to stabilize, and then deposit 2 nm of Ru on the Mo / Si multilayer film, and then turn off the power after the deposition is completed, fill in the protective gas Ar to a gas pressure of 10 Pa, then slowly open the exhaust valve to fill in the atmosphere.

[0049] After breaking the vacuum, take out the sample, fix the back side up on the clamp, select super-smooth silicon wafer as the accompanying deposition piece, put it into the magnetron sputtering equipment and vacuumize, wait for the gas pressure in the chamber to be less than 1×10 -4 Pa, stop vacuumizing, fill in argon (Ar) with a gas flow of 70 sccm, at this time the gas pressure in the chamber is 0.12 Pa, start the chromium (Cr) target with a power of 1000 W, fill in nitrogen (N2) with a gas flow of 10 sccm, at this time the volume concentration of nitrogen is 12.5%. Let N2 and Cr fully react to form the required CrN particles and sputter onto the prepared substrate to grow uniformly. After 47 nm is expected to grow, stop sputtering, fill in the protective gas Ar to a pressure of 10 Pa, then slowly open the exhaust valve to fill in the atmosphere.

[0050] Performance Test

[0051] After the samples were removed, XRR and XRD tests were performed on the fused silica substrate samples obtained in Examples 1-2 and Comparative Example 1.

[0052] Example 1: XRR and XRD images of chromium nitride thin film are shown below. Figure 1 As shown. From Figure 1 It can be seen that the XRR fitting thickness (a) is 25 nm and the roughness is 1.4 nm; from the XRD test curve (b), the CrN crystal orientations are as follows according to the intensity: <220> , <111> , <311> Furthermore, the position of the characteristic peaks matches well with the standard PDF card, proving that the structure of the CrN film is consistent with that of standard CrN, further demonstrating that the prepared CrN film meets the performance requirements of standard CrN.

[0053] like Figure 2 As shown, a cross-cut adhesion test was performed on the quartz substrate sample of Example 1, and the film layer did not peel off, further proving that the CrN film has high adhesion.

[0054] Example 2: XRR and XRD images of chromium nitride thin films are shown below. Figure 3 According to the XRR curve (left figure), the thickness of the deposited CrN is 32.3 nm and the roughness is 1.5 nm by numerical fitting. From the XRD test curve (right figure), its three characteristic peaks are in good agreement with the standard PDF card, indicating that a good CrN film can be prepared at this N2 concentration.

[0055] The above test results demonstrate that the chromium nitride thin film prepared by this invention can be used for the preparation of extreme ultraviolet lithography masks.

[0056] Comparative Example 1: XRR and XRD tests of chromium nitride thin film as follows Figure 4 Through numerical fitting (left figure), the thickness of the deposited CrN film can be obtained as 47 nm; from the XRD test curve (right figure), <111> The characteristic peak shifts to the right, and there is no <220> Characteristic peaks and <311> The characteristic peak indicates that the N2 flow rate is too low and needs to be increased.

[0057] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for producing a chromium nitride film, characterized by, The method comprises the following steps: A mixed gas of argon and nitrogen is used as a working gas, a chromium target is used as a sputtering target for magnetron sputtering, nitrogen and chromium generate chromium nitride particles and are sputtered to the surface of a substrate to form a chromium nitride film; The volume concentration of the nitrogen is 13-35%; the base vacuum degree of the magnetron sputtering is ≤1×10 -4 Pa, and the power is 1000-1500 W; the substrate comprises fused quartz, ultra-low expansion glass or high borosilicate glass; The thickness of the chromium nitride film is 5-40 nm, the crystal orientation of the chromium nitride film is <111>, <220> and <311>, and the corresponding XRD characteristic peak intensity is <220>≥<111> > <311>; the roughness of the chromium nitride film is 1.4-1.5 nm.

2. The production method according to claim 1, characterized by, The gas flow of the argon is 40-150 sccm, and the argon filling pressure is 0.06-1.0 Pa.

3. The chromium nitride film prepared by the preparation method of claim 1 or 2.

4. The application of the chromium nitride film of claim 3 in an extreme ultraviolet lithography mask plate.

5. Use according to claim 4, characterized in that, The extreme ultraviolet waveband applied by the extreme ultraviolet lithography mask plate is 11-14 nm.

6. Use according to claim 4, characterized in that, The chromium nitride film is used as one or more of a conductive layer, a buffer layer and a hard mask layer of an extreme ultraviolet lithography mask plate.

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