Method for heteroepitaxial growth of yttrium-stabilized zirconia film

Abstract

The invention relates to a method for heteroepitaxial growth of a yttrium-stabilized zirconia film, which comprises the following steps of: sequentially depositing an initial layer and a yttrium-stabilized zirconia layer on a silicon substrate of phi 200mm to realize heteroepitaxial growth of the yttrium-stabilized zirconia film on the silicon substrate; and the initial layer is a thin film layer which can be subjected to reduction reaction with a natural oxide layer on the surface of the silicon substrate. According to the method, the initial layer and the yttrium-stabilized zirconia layer are sequentially deposited on the silicon substrate with the diameter phi of 200mm, so that heteroepitaxial growth of yttrium-stabilized zirconia is realized; the technological process is simple, the silicon substrate serves as a thin film growth substrate, existing semiconductor process equipment can be compatible, cost is low, the technology is mature, meanwhile, thin film epitaxial deposition on a large-size wafer is achieved, and large-scale industrial mass production is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of magnetron sputtering, and in particular to a method for heteroepitaxially growing a yttrium-stabilized zirconium oxide film. Background Art

[0002] Yttrium-stabilized zirconia (YSZ) is a ceramic material that plays a vital role in various high-tech industries due to its excellent thermal stability, ionic conductivity and mechanical properties. Due to its characteristics, YSZ thin films can also be used in the preparation of solid oxide fuel cell electrodes, functional layers of oxygen sensors, thermal barrier coatings, etc. At the same time, YSZ thin films can also be grown heteroepitaxially on silicon wafers, and thus used as a buffer layer of thin film materials to reduce the lattice mismatch of certain specific materials during the heteroepitaxial process and achieve heteroepitaxial growth.

[0003] At present, the preparation methods of YSZ thin films mainly include sputtering, hydrothermal synthesis, pulsed laser deposition, atomic layer deposition, etc., or use Smart-Cut to cut and transfer to a wafer to prepare YSZ thin films. For example, CN101319387A discloses a preparation method for a high-temperature superconductor nanostructure array, which includes the following steps: growing a CeO2 or YSZ buffer layer ultra-thin film on a single crystal substrate using a pulsed laser deposition method or other methods; the obtained CeO2 or YSZ thin film sample is a "grown" thin film sample; the "grown" thin film sample is made into a substrate with a CeO2 or YSZ nanostructure buffer layer; and growing a high-temperature superconducting thin film on a substrate with a CeO2 or YSZ nanostructure buffer layer using a pulsed laser deposition method or other methods. However, this method has the problems of long-term annealing and cumbersome process, which is not conducive to industrial-scale mass production. In addition, the small-scale laboratory-level results obtained by most preparation methods are not practical for mass production.

[0004] Compared with other preparation methods, the sputtering deposition method is more suitable for mass production, but the existing technical research still has the following problems: most of them use specially treated substrates such as silicon oxide, which does not have a price advantage; the target material is mostly reported to use Y-Zr alloy target material, and water vapor is introduced for reactive sputtering instead of conventional process gas. For example, CN101117704A discloses a method for growing a cubic textured yttrium-stabilized zirconium dioxide film layer, comprising: (1) cleaning a metal substrate with a cubic texture, or a metal substrate with a cubic textured oxide isolation layer, or a single crystal substrate with a cubic structure or a pseudo-cubic structure; (2) The cleaned substrate is placed in a magnetron sputtering deposition chamber and evacuated; the substrate is heated and then filled with argon; Zr-Y metal is used as a sputtering target and a DC magnetron sputtering deposition method is used to start pre-sputtering; (3) After 20 minutes of pre-sputtering, water vapor is introduced and the pressure in the deposition chamber is controlled to start formal sputtering deposition. After deposition, a yttrium-stabilized zirconium dioxide film is obtained; Some methods have more complicated manufacturing processes and require additional process conditions such as pretreatment, cleaning or annealing; in addition, the silicon substrate process currently does not have a deposition solution for large-sized substrates such as Φ200mm, which has limitations in mass production.

[0005] Therefore, in view of the shortcomings of the existing technology, there is an urgent need to provide a method for epitaxial deposition of yttrium-stabilized zirconia thin films on large-size substrates with low cost and simple process. Summary of the invention

[0006] The purpose of the present invention is to provide a method for heteroepitaxially growing a yttrium-stabilized zirconia film, which realizes heteroepitaxially growing a yttrium-stabilized zirconia film on a Φ200mm silicon substrate, and has the characteristics of low cost and simple process.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, the method comprising the following steps:

[0009] The initial layer and the yttrium-stabilized zirconia layer are sequentially deposited on a Φ200 mm silicon substrate to achieve heteroepitaxial growth of a yttrium-stabilized zirconia film on the silicon substrate;

[0010] The initial layer is a thin film layer that can undergo a reduction reaction with a natural oxide layer on the surface of the silicon substrate.

[0011] The method for heteroepitaxial growth of a yttrium-stabilized zirconia film provided by the present invention only requires sequentially depositing an initial layer and a yttrium-stabilized zirconia layer on a Φ200mm silicon substrate, wherein the initial layer utilizes a natural oxide layer on the silicon surface to undergo a reduction reaction to generate a metal oxide, thereby realizing heteroepitaxial growth of the yttrium-stabilized zirconia; the silicon substrate does not need to be pretreated, and the produced film does not need subsequent annealing and other treatments, and the process flow is relatively simple. The silicon substrate is used as a thin film growth substrate and is compatible with existing semiconductor process equipment, with low cost and mature technology, and at the same time, thin film epitaxial deposition on large-size wafers is realized, which is conducive to large-scale industrial mass production.

[0012] Preferably, before depositing the initial layer, the vacuum degree of the sputtering chamber is controlled to be ≤4×10 -4 Pa, for example, can be 4×10 -4 Pa, 2×10 -4 Pa or 1×10 -4 Pa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0013] Preferably, the step of depositing the initial layer specifically includes: subjecting the silicon substrate to a first preheating treatment, then introducing a process gas, turning on a pulsed DC power supply, exciting plasma to perform magnetron sputtering, and completing the deposition of the initial layer.

[0014] Preferably, the target material used for depositing the initial layer includes any one of zirconium, yttrium or yttrium-zirconium alloy.

[0015] Preferably, the temperature of the first preheat treatment is 300-500°C, for example, 300°C, 350°C, 400°C, 450°C or 500°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] Preferably, the time of the first preheating treatment is 5-10 min, for example, 5 min, 6 min, 8 min, 9 min or 10 min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0017] Preferably, the flow rate of the process gas is 40-100 sccm, for example, 40 sccm, 50 sccm, 60 sccm, 80 sccm or 100 sccm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] Preferably, the process gas comprises argon.

[0019] Preferably, the power of the pulse DC power supply is 100-500W, for example, 100W, 200W, 300W, 400W or 500W, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] Preferably, the deposition thickness of the initial layer is 2 nm.

[0021] Preferably, before depositing the yttrium-stabilized zirconia layer, the vacuum degree of the sputtering chamber is controlled to be ≤4×10 -4 Pa, for example, can be 4×10 -4 Pa, 2×10 -4 Pa or 1×10 -4 Pa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, the step of depositing the yttrium-stabilized zirconia layer specifically includes: subjecting the silicon substrate on which the initial layer is deposited to a second preheating treatment, then introducing a process gas, turning on a radio frequency power supply, exciting the gas into a plasma for magnetron sputtering, and completing the deposition of the yttrium-stabilized zirconia layer.

[0023] Preferably, the target material used for depositing the yttrium-stabilized zirconia layer comprises a yttrium-stabilized zirconia ceramic target material.

[0024] Preferably, the temperature of the second preheat treatment is 600-800°C, for example, 600°C, 650°C, 700°C, 750°C or 800°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the time of the second preheating treatment is 5-20 min, for example, 5 min, 8 min, 10 min, 15 min or 20 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, the process gas comprises argon.

[0027] Preferably, the power of the RF power source is 1500-3000 W, for example, 1500 W, 1800 W, 2000 W, 2500 W or 3000 W, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0028] Preferably, the deposition thickness of the yttrium-stabilized zirconia layer is 20-200 nm, for example, 20 nm, 30 nm, 50 nm, 100 nm or 200 nm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] As a preferred technical solution of the method of the present invention, the method comprises the following steps:

[0030] Control the vacuum degree of the sputtering chamber ≤4×10 -4 Pa, a Φ200mm silicon substrate is subjected to a first preheating treatment at 300-500°C for 5-10min, and then a process gas with a flow rate of 40-100sccm is introduced, a pulsed DC power supply is turned on, and a power of 100-500W is used to excite plasma for magnetron sputtering to complete the deposition of a 2nm initial layer; the initial layer is a thin film layer that can undergo a reduction reaction with a natural oxide layer on the surface of the silicon substrate; the target material used for depositing the initial layer includes any one of zirconium, yttrium or yttrium-zirconium alloy;

[0031] Control the vacuum degree of the sputtering chamber ≤4×10 -4 Pa, the silicon substrate on which the initial layer is deposited is subjected to a second preheat treatment at 600-800°C for 5-20 minutes, and then a process gas is introduced, and an RF power supply is turned on with a power of 1500-3000W, and the gas is excited into a plasma for magnetron sputtering to deposit a yttrium-stabilized zirconia layer with a thickness of 20-200nm, thereby realizing heteroepitaxial growth of a yttrium-stabilized zirconia film on the silicon substrate; the target material used for depositing the yttrium-stabilized zirconia layer includes a yttrium-stabilized zirconia ceramic target material.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The method for heteroepitaxial growth of a yttrium-stabilized zirconia film provided by the present invention only requires sequentially depositing an initial layer and a yttrium-stabilized zirconia layer on a Φ200mm silicon substrate, wherein the initial layer utilizes a natural oxide layer on the silicon surface to undergo a reduction reaction to generate a metal oxide, thereby realizing heteroepitaxial growth of the yttrium-stabilized zirconia; the silicon substrate does not need to be pretreated, and the produced film does not need subsequent annealing and other treatments, and the process flow is relatively simple. The silicon substrate is used as a thin film growth substrate and is compatible with existing semiconductor process equipment, with low cost and mature technology, and at the same time, thin film epitaxial deposition on large-size wafers is realized, which is conducive to large-scale industrial mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is an optical image of a yttrium-stabilized zirconia film heteroepitaxially grown on a silicon substrate provided in Example 1 of the present invention;

[0035] Figure 2 is a 9-point XRD spectrum of the yttrium-stabilized zirconia thin film grown heteroepitaxially on a silicon substrate provided in Example 1 of the present invention;

[0036] Figure 3 It is a Phi scan spectrum of the in-plane (0,0) point of the yttrium-stabilized zirconia thin film heteroepitaxially grown on the silicon substrate provided in Example 1 of the present invention;

[0037] Figure 4 It is a Phi scan spectrum of the in-plane (0,45) point of the heteroepitaxially grown yttrium-stabilized zirconia thin film on the silicon substrate provided in Example 1 of the present invention;

[0038] Figure 5 It is a Phi scan spectrum of the in-plane (0, -45) point of the yttrium-stabilized zirconia thin film heteroepitaxially grown on the silicon substrate provided in Example 1 of the present invention;

[0039] Figure 6 It is a Phi scan spectrum of the in-plane (0,90) point of the heteroepitaxially grown yttrium-stabilized zirconia thin film on the silicon substrate provided in Example 1 of the present invention;

[0040] Figure 7 It is a Phi scan spectrum of the in-plane (0, -90) point of the heteroepitaxially grown yttrium-stabilized zirconia thin film on the silicon substrate provided in Example 1 of the present invention;

[0041] Figure 8 is the XRD spectrum of the (0,0) center point of a yttrium-stabilized zirconia film heteroepitaxially grown on a silicon substrate with a thickness of 30 nm provided in Example 2 of the present invention;

[0042] Fig. 9 It is a Phi scan spectrum of the (0,0) center point of a yttrium-stabilized zirconia film heteroepitaxially grown on a silicon substrate with a thickness of 30 nm provided in Example 2 of the present invention;

[0043] Fig.10 is the XRD spectrum of the (0,0) center point of a yttrium-stabilized zirconia film heteroepitaxially grown on a silicon substrate with a thickness of 100 nm provided in Example 3 of the present invention;

[0044] Fig.11 It is a Phi scan spectrum of the (0,0) center point of a yttrium-stabilized zirconia film with a thickness of 100 nm grown heteroepitaxially on a silicon substrate provided in Example 3 of the present invention;

[0045] Fig.12 is the XRD spectrum of the (0,0) center point of a yttrium-stabilized zirconia film heteroepitaxially grown on a silicon substrate with a thickness of 20 nm provided in Example 4 of the present invention;

[0046] Fig.13 It is a Phi scan spectrum of the center point (0,0) of a yttrium-stabilized zirconia film with a thickness of 20 nm grown heteroepitaxially on a silicon substrate provided in Example 4 of the present invention;

[0047] Fig.14 is the XRD spectrum of the (0,0) center point of a yttrium-stabilized zirconia film heteroepitaxially grown on a silicon substrate with a thickness of 200 nm provided in Example 5 of the present invention;

[0048] Fig.15 It is a Phi scan spectrum of the (0,0) center point of a yttrium-stabilized zirconia film with a thickness of 200 nm grown heteroepitaxially on a silicon substrate provided in Example 5 of the present invention;

[0049] Fig.16 The XRD spectrum of the (0,0) center point of a yttrium-stabilized zirconia film with a thickness of 50 nm heteroepitaxially grown on a silicon substrate with a second preheating treatment time of 15 min, 20 min, and 30 min provided in Examples 6-8 of the present invention;

[0050] Fig.17 The XRD spectrum of the (0,0) center point of a yttrium-stabilized zirconia film with a thickness of 50 nm heteroepitaxially grown on a silicon substrate with an initial layer thickness of 1.5 nm, 3 nm, and 5 nm provided in Examples 9-11 of the present invention;

[0051] Fig.18 It is the XRD spectrum of the (0,0) center point of a yttrium-stabilized zirconia film with a thickness of 50 nm heteroepitaxially grown on a silicon substrate with a second preheat treatment temperature of 500° C. provided in Example 12 of the present invention;

[0052] Fig.19 It is the XRD spectrum of the (0,0) center point of a yttrium-stabilized zirconia film with a thickness of 50 nm grown heteroepitaxially on a silicon substrate with an oxygen partial pressure of 22% in the mixed gas provided in Example 13 of the present invention;

[0053] Fig. 20 This is the XRD spectrum of the (0,0) center point of the directly deposited yttrium-stabilized zirconia layer provided in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0054] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0055] Example 1

[0056] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, the method comprising the following steps:

[0057] The vacuum degree of the sputtering chamber is controlled to be 2×10 -4 Pa, a Φ200 mm silicon substrate was first preheated at 400°C for 5 min, then argon gas with a flow rate of 60 sccm was introduced, a pulsed DC power supply was turned on with a power of 300 W, plasma was excited for magnetron sputtering, and the target material used was a zirconium target material, and the deposition of a 2 nm initial layer was completed;

[0058] The vacuum degree of the sputtering chamber is controlled to be 2×10-4 Pa, the silicon substrate on which the initial layer was deposited was subjected to a second preheat treatment at 700°C for 15 minutes, and then argon gas was introduced, and the RF power supply was turned on with a power of 2000 W. The gas was excited into plasma for magnetron sputtering to deposit a yttrium-stabilized zirconia layer with a thickness of 50 nm. The target material used was a yttrium-stabilized zirconia ceramic target, and the heteroepitaxial growth of a yttrium-stabilized zirconia film on the silicon substrate was achieved.

[0059] Optical images of heteroepitaxially grown yttrium-stabilized zirconia thin films on silicon substrates Figure 1 As shown; a coordinate system is established with the center of the wafer as the (0,0) point, and the position of the wafer notch is defined as (0,-100). Taking this as the reference standard, the center point (0,0) is selected, and 4 points are selected on a 45mm circumference from the center point as (0,45), (-45,0), (0,-45), (45,0). 4 points are selected on a 90mm circumference as (0,90), (-90,0), (0,-90), (90,0). 2cm×2cm samples are cut from 9 locations for X-ray diffraction analysis, and the resulting spectrum is shown below. Figure 2 As shown in the figure, it can be seen that all samples have measured diffraction peaks of wafer-level yttrium-stabilized zirconia that can characterize the C-axis orientation, confirming that wafer-level yttrium-stabilized zirconia films have been prepared on a Φ200mm silicon substrate scale.

[0060] Select five points in the vertical direction (0,0), (0,45), (0,-45), (0,90), (0,-90) again for φ scanning, and the resulting spectra are as follows Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 As shown, Figure (a) is the sample diffraction peak, and Figure (b) is the substrate peak of the reference surface. It can be seen from the figure that the peak values ​​measured for all samples correspond one to one with the substrate peak values ​​of the reference surface, proving that the yttrium-stabilized zirconia film has epitaxial properties and epitaxial growth is achieved on a Φ200mm silicon substrate.

[0061] Example 2

[0062] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, the method comprising the following steps:

[0063] The vacuum degree of the sputtering chamber is controlled to be 2×10 -4 Pa, a Φ200 mm silicon substrate was first preheated at 400°C for 5 min, then argon gas with a flow rate of 60 sccm was introduced, a pulsed DC power supply was turned on with a power of 300 W, plasma was excited for magnetron sputtering, and the target material used was a zirconium target material, and the deposition of a 2 nm initial layer was completed;

[0064] The vacuum degree of the sputtering chamber is controlled to be 4×10 -4 Pa, the silicon substrate on which the initial layer was deposited was subjected to a second preheat treatment at 700°C for 10 minutes, and then argon gas was introduced, and the RF power supply was turned on with a power of 1500 W. The gas was excited into plasma for magnetron sputtering to deposit a yttrium-stabilized zirconia layer with a thickness of 30 nm. The target material used was a yttrium-stabilized zirconia ceramic target, and the heteroepitaxial growth of a yttrium-stabilized zirconia film on the silicon substrate was achieved.

[0065] The heteroepitaxially grown yttrium-stabilized zirconia film on the silicon substrate obtained in this embodiment was subjected to X-ray diffraction analysis. The XRD spectrum of the (0,0) center point of the 30 nm thick yttrium-stabilized zirconia film is as follows: Figure 8 As shown, it is possible to prepare pure C-axis oriented films of different thicknesses on a Φ200mm silicon substrate. Fig. 9 The Phi scan results, the left picture is the sample diffraction peak, and the right picture is the substrate peak of the reference surface, indicating that a 30nm thick yttrium-stabilized zirconia film has achieved epitaxial growth on a Φ200mm silicon substrate.

[0066] Example 3

[0067] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, the method comprising the following steps:

[0068] The vacuum degree of the sputtering chamber is controlled to be 2×10 -4 Pa, a Φ200 mm silicon substrate was first preheated at 400°C for 5 min, then argon gas with a flow rate of 60 sccm was introduced, a pulsed DC power supply was turned on with a power of 300 W, plasma was excited for magnetron sputtering, and the target material used was a zirconium target material, and the deposition of a 2 nm initial layer was completed;

[0069] The vacuum degree of the sputtering chamber is controlled to be 1×10 -4 Pa, the silicon substrate on which the initial layer was deposited was subjected to a second preheat treatment at 800°C for 15 minutes, and then argon gas was introduced, and the RF power supply was turned on with a power of 1500 W. The gas was excited into plasma for magnetron sputtering to deposit a yttrium-stabilized zirconia layer with a thickness of 100 nm. The target material used was a yttrium-stabilized zirconia ceramic target, and the heteroepitaxial growth of a yttrium-stabilized zirconia film on the silicon substrate was achieved.

[0070] The heteroepitaxially grown yttrium-stabilized zirconia film on the silicon substrate obtained in this embodiment was subjected to X-ray diffraction analysis. The XRD spectrum of the (0,0) center point of the 100 nm thick yttrium-stabilized zirconia film is as follows: Fig.10 As shown, it is possible to prepare pure C-axis oriented films of different thicknesses on a Φ200mm silicon substrate. Fig.11Phi scan results. The left picture shows the sample diffraction peak, and the right picture shows the substrate peak of the reference surface. A 100nm thick yttrium-stabilized zirconia film is epitaxially grown on a Φ200mm silicon substrate.

[0071] Example 4

[0072] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film. The difference from Embodiment 1 is that the deposition thickness of the yttrium-stabilized zirconia layer is adjusted to 20 nm, and the rest is the same as Embodiment 1.

[0073] The heteroepitaxially grown yttrium-stabilized zirconia film on the silicon substrate obtained in this embodiment was subjected to X-ray diffraction analysis. The XRD spectrum of the (0,0) center point of the 20 nm thick yttrium-stabilized zirconia film is as follows: Fig.12 As shown, it is possible to prepare pure C-axis oriented films of different thicknesses on a Φ200mm silicon substrate. Fig.13 Phi scan results. The left picture shows the sample diffraction peak, and the right picture shows the substrate peak of the reference surface. A 20nm thick yttrium-stabilized zirconia film is epitaxially grown on a Φ200mm silicon substrate.

[0074] Example 5

[0075] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film. The difference from Embodiment 1 is that the deposition thickness of the yttrium-stabilized zirconia layer is adjusted to 200 nm, and the rest is the same as Embodiment 1.

[0076] The heteroepitaxially grown yttrium-stabilized zirconia film on the silicon substrate obtained in this embodiment was subjected to X-ray diffraction analysis. The XRD spectrum of the (0,0) center point of the 200 nm thick yttrium-stabilized zirconia film is as follows: Fig.14 As shown, it is possible to prepare pure C-axis oriented films of different thicknesses on a Φ200mm silicon substrate. Fig.15 Phi scan results. The left picture shows the sample diffraction peak, and the right picture shows the substrate peak of the reference surface. A 200nm thick yttrium-stabilized zirconia film is epitaxially grown on a Φ200mm silicon substrate.

[0077] Example 6

[0078] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, which is different from Embodiment 1 in that, except for adjusting the time of the second preheating treatment to 15 minutes, the rest is the same as Embodiment 1.

[0079] In this embodiment, the XRD spectrum of the (0,0) center point of a 50 nm thick yttrium-stabilized zirconia film grown heteroepitaxially on a silicon substrate is as follows: Fig.16As shown, it is shown that a second heat treatment time of 15 minutes can also prepare a wafer-level yttrium-stabilized zirconia film on a Φ200mm silicon substrate scale, but the strength of the crystallization will be affected. The longer the second heat treatment time is, the weaker the crystallization strength will be.

[0080] Example 7

[0081] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, which is different from Embodiment 1 in that, except for adjusting the time of the second preheating treatment to 20 minutes, the rest is the same as Embodiment 1.

[0082] In this embodiment, the XRD spectrum of the (0,0) center point of a 50 nm thick yttrium-stabilized zirconia film grown heteroepitaxially on a silicon substrate is as follows: Fig.16 As shown, it is shown that a second heat treatment time of 20 minutes can also prepare a wafer-level yttrium-stabilized zirconia film on a Φ200mm silicon substrate scale, but the strength of the crystallization will be affected. The longer the second heat treatment time is, the weaker the crystallization strength will be.

[0083] Example 8

[0084] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, which is different from Embodiment 1 in that, except for adjusting the time of the second preheating treatment to 30 minutes, the rest is the same as Embodiment 1.

[0085] In this embodiment, the XRD spectrum of the (0,0) center point of a 50 nm thick yttrium-stabilized zirconia film grown heteroepitaxially on a silicon substrate is as follows: Fig.16 As shown, it is shown that a second heat treatment time of 30 minutes can also prepare a wafer-level yttrium-stabilized zirconia film on a Φ200mm silicon substrate scale, but the strength of the crystallization will be affected. If the second heat treatment time is too long, the crystallization strength will be significantly weakened.

[0086] Example 9

[0087] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, which is different from Embodiment 1 in that, except for adjusting the deposition thickness of the initial layer to 1.5 nm, the rest is the same as Embodiment 1.

[0088] Since the present invention uses the natural oxide layer on the silicon surface in the initial layer to perform a reduction reaction to generate metal oxide, thereby achieving heteroepitaxial growth of yttrium-stabilized zirconia, the thickness of the initial layer is too thin, and the natural oxide layer cannot be completely consumed, and the reaction is not thorough, which affects the growth of the yttrium-stabilized zirconia film and forms abnormal crystals, and the effect of epitaxial growth cannot be achieved. The XRD spectrum of the (0,0) center point of the yttrium-stabilized zirconia film with a thickness of 50nm heteroepitaxially grown on a silicon substrate is as follows Fig.17As shown, heteroepitaxial growth of yttrium-stabilized zirconia thin film cannot be achieved on the silicon substrate in this embodiment.

[0089] Example 10

[0090] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, which is different from Embodiment 1 in that, except for adjusting the deposition thickness of the initial layer to 3 nm, the rest is the same as Embodiment 1.

[0091] In this embodiment, the thickness of the initial layer is too thick, which will cause the remaining Zr to form a metal layer, which will affect the growth of the yttrium-stabilized zirconia film and form abnormal crystals, and the effect of epitaxial growth cannot be achieved. The XRD spectrum of the (0,0) center point of the yttrium-stabilized zirconia film with a thickness of 50nm heteroepitaxially grown on a silicon substrate is as follows: Fig.17 As shown, heteroepitaxial growth of yttrium-stabilized zirconia thin film cannot be achieved on the silicon substrate in this embodiment.

[0092] Embodiment 11

[0093] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, which is different from Embodiment 1 in that, except for adjusting the deposition thickness of the initial layer to 5 nm, the rest is the same as Embodiment 1.

[0094] In this embodiment, the thickness of the initial layer is too thick, which will cause the remaining Zr to form a metal layer, which will affect the growth of the yttrium-stabilized zirconia film and form abnormal crystals, and the effect of epitaxial growth cannot be achieved. The XRD spectrum of the (0,0) center point of the yttrium-stabilized zirconia film with a thickness of 50nm heteroepitaxially grown on a silicon substrate is as follows: Fig.17 As shown, heteroepitaxial growth of yttrium-stabilized zirconia thin film cannot be achieved on the silicon substrate in this embodiment.

[0095] Example 12

[0096] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, which is different from Embodiment 1 in that, except for adjusting the temperature of the second preheat treatment to 500° C., the rest is the same as Embodiment 1.

[0097] Since the present invention utilizes the natural oxide layer on the silicon surface in the initial layer to perform a reduction reaction to generate metal oxide, the heteroepitaxial growth of yttrium-stabilized zirconia is achieved. If the sputtering temperature of yttrium-stabilized zirconia is too low, it will affect the growth of yttrium-stabilized zirconia film, forming abnormal crystals and failing to achieve the effect of epitaxial growth. The XRD spectrum of the (0,0) center point of a 50nm thick yttrium-stabilized zirconia film grown heteroepitaxially on a silicon substrate is shown in the figure. Fig.18 As shown, heteroepitaxial growth of yttrium-stabilized zirconia thin film cannot be achieved on the silicon substrate in this embodiment.

[0098] Embodiment 13

[0099] This embodiment provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film. The difference from Embodiment 1 is that a mixture of argon and oxygen is introduced after the second preheat treatment, and the partial pressure of oxygen in the mixture is 22%. The rest is the same as Embodiment 1.

[0100] Too high oxygen flow rate will affect the growth of yttrium-stabilized zirconia film, forming abnormal crystals and failing to achieve the effect of epitaxial growth. The XRD spectrum of the (0,0) center point of a 50nm thick yttrium-stabilized zirconia film grown heteroepitaxially on a silicon substrate is shown in the figure below: Fig.19 As shown, heteroepitaxial growth of yttrium-stabilized zirconia thin film cannot be achieved on the silicon substrate in this embodiment.

[0101] Comparative Example 1

[0102] This comparative example provides a method for heteroepitaxially growing a yttrium-stabilized zirconia film, which differs from Example 1 in that no initial layer is deposited before depositing the yttrium-stabilized zirconia layer, and the rest is the same as Example 1.

[0103] The XRD spectrum of the (0,0) center point of the yttrium-stabilized zirconia layer deposited directly on the silicon substrate without depositing the initial layer is as follows: Fig. 20 As shown, since the initial layer is not deposited before the yttrium-stabilized zirconia layer is deposited, the grown yttrium-stabilized zirconia film will be affected by the natural oxide layer on the silicon substrate and will show abnormal crystallization, and the epitaxial growth effect cannot be achieved.

[0104] In summary, the method for heteroepitaxial growth of yttrium-stabilized zirconia thin film provided by the present invention only requires sequential deposition of an initial layer and a yttrium-stabilized zirconia layer on a Φ200mm silicon substrate, wherein the initial layer utilizes the natural oxide layer on the silicon surface to undergo a reduction reaction to generate a metal oxide, thereby realizing heteroepitaxial growth of yttrium-stabilized zirconia; the silicon substrate does not need to be pretreated, and the produced thin film does not need subsequent annealing or other treatments, and the process flow is relatively simple. The silicon substrate is used as a thin film growth substrate, which is compatible with existing semiconductor process equipment, has low cost and mature technology, and at the same time realizes thin film epitaxial deposition on large-size wafers, which is conducive to large-scale industrial mass production.

[0105] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for heteroepitaxially growing a yttrium-stabilized zirconia thin film, characterized in that: The method comprises the following steps: The initial layer and the yttrium-stabilized zirconia layer are sequentially deposited on a Φ200 mm silicon substrate to achieve heteroepitaxial growth of a yttrium-stabilized zirconia film on the silicon substrate; The initial layer is a thin film layer that can undergo a reduction reaction with a natural oxide layer on the surface of the silicon substrate.

2. The method according to claim 1, characterized in that Before depositing the initial layer, the vacuum degree of the sputtering chamber is controlled to be ≤4×10 -4 Pa.

3. The method according to claim 1 or 2, characterized in that: The step of depositing the initial layer specifically includes: performing a first preheating treatment on the silicon substrate, then introducing a process gas, turning on a pulsed DC power supply, exciting plasma to perform magnetron sputtering, and completing the deposition of the initial layer; Preferably, the target material used for depositing the initial layer includes any one of zirconium, yttrium or yttrium-zirconium alloy.

4. The method according to claim 3, characterized in that The temperature of the first preheating treatment is 300-500°C; Preferably, the first preheating treatment lasts for 5-10 minutes; Preferably, the flow rate of the process gas is 40-100 sccm; Preferably, the process gas comprises argon.

5. The method according to claim 3 or 4, characterized in that: The power of the pulse DC power supply is 100-500W; Preferably, the deposition thickness of the initial layer is 2 nm.

6. The method according to any one of claims 1 to 5, characterized in that: Before depositing the yttrium-stabilized zirconia layer, the vacuum degree of the sputtering chamber is controlled to be ≤4×10 -4 Pa.

7. The method according to any one of claims 1 to 6, characterized in that: The step of depositing the yttrium-stabilized zirconia layer specifically includes: subjecting the silicon substrate on which the initial layer is deposited to a second preheating treatment, then introducing a process gas, turning on a radio frequency power supply, exciting the gas into a plasma for magnetron sputtering, and completing the deposition of the yttrium-stabilized zirconia layer; Preferably, the target material used for depositing the yttrium-stabilized zirconia layer comprises a yttrium-stabilized zirconia ceramic target material.

8. The method according to claim 7, characterized in that The temperature of the second preheating treatment is 600-800°C; Preferably, the second preheating treatment time is 5-20min; Preferably, the process gas comprises argon.

9. The method according to claim 7 or 8, characterized in that: The power of the radio frequency power supply is 1500-3000W; Preferably, the deposition thickness of the yttrium-stabilized zirconia layer is 20-200 nm.

10. The method according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: Control the vacuum degree of the sputtering chamber ≤4×10 -4 Pa, a Φ200mm silicon substrate is subjected to a first preheating treatment at 300-500°C for 5-10min, and then a process gas with a flow rate of 40-100sccm is introduced, a pulsed DC power supply is turned on, and a power of 100-500W is used to excite plasma for magnetron sputtering to complete the deposition of a 2nm initial layer; the initial layer is a thin film layer that can undergo a reduction reaction with a natural oxide layer on the surface of the silicon substrate; the target material used for depositing the initial layer includes any one of zirconium, yttrium or yttrium-zirconium alloy; Control the vacuum degree of the sputtering chamber ≤4×10 -4 Pa, the silicon substrate on which the initial layer is deposited is subjected to a second preheat treatment at 600-800°C for 5-20 minutes, and then a process gas is introduced, and an RF power supply is turned on with a power of 1500-3000W, and the gas is excited into a plasma for magnetron sputtering to deposit a yttrium-stabilized zirconia layer with a thickness of 20-200nm, thereby realizing heteroepitaxial growth of a yttrium-stabilized zirconia film on the silicon substrate; the target material used for depositing the yttrium-stabilized zirconia layer includes a yttrium-stabilized zirconia ceramic target material.

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