Method for forming MPB in thin film material, MIM structure and preparation method and application of MIM structure

Abstract

The invention discloses a method for forming MPB in a thin film material, an MIM structure and a preparation method and application of the MIM structure, and relates to the technical field of thin film material manufacturing. According to the method, an electrode patterning mode with good compatibility is utilized, so that a local stress field is introduced into a film interface during subsequent annealing heat treatment, the randomness of spontaneous growth of a conventional crystal phase in a stress uniform field is broken, and the distribution of the crystal phase tends to be controllable from disorder; on the premise of not changing the intrinsic composition of the material, the spatial transformation and ordered arrangement of the polycrystal phase in a submicron-to-nanoscale specific region are realized, MPB is successfully induced to be formed in the thin film material, and the performance of the thin film material is improved. The problems that in an existing thin film material, the crystal phase structure is difficult to accurately regulate and control, the performance is unstable, and the process compatibility is poor are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thin film material manufacturing, and more particularly to: 1. a method for forming MPB in a thin film material; 2. a preparation method of MIM (Metal-Insulator-Metal) structure with MPB, a preparation method thereof and an application. BACKGROUND

[0002] With the development of new electronic devices, memories and advanced logic circuits towards high integration, low power consumption and high speed operation, higher requirements are put forward for the performance of thin film materials. Among them, the electrical, thermal, ferroelectric, dielectric and mechanical properties of thin film materials are decisively affected by the crystal phase of the material. For example, the dielectric constant, polarization strength, hysteresis characteristics, breakdown field strength and other key indicators of ferroelectric thin films are closely related to the type and distribution state of the crystal phase formed in the material. That is, different crystal phases (such as orthorhombic phase, monoclinic phase, tetragonal phase, cubic phase, etc.) determine the final performance of the thin film material and ultimately affect the application of the prepared device.

[0003] Among many thin film materials today, hafnium-zirconium oxide (HZO) has become a hot research and application material due to its excellent dielectric properties, stable ferroelectric response, good thermal stability and high compatibility with advanced micro-nano processes. However, as mentioned above, multiple crystal phases may coexist in HZO thin films, such as non-ferroelectric monoclinic phase, ferroelectric orthorhombic phase, and anti-ferroelectric tetragonal phase. The proportion and distribution of these crystal phases directly affect the dielectric and ferroelectric properties of HZO thin films. Existing research shows that stress regulation, doping process and annealing process can induce HZO to form favorable crystal phases to some extent. However, achieving spatial control of crystal phase distribution within the device scale, especially constructing MPB (Morphotropic Phase Boundary), still faces significant challenges.

[0004] MPB refers to the formation of a mixed crystal phase between two phases with similar lattice parameters but different symmetries. This structure can produce unique polarization behavior and excellent dielectric / ferroelectric properties, exhibiting higher dielectric constant and greater polarization strength, thus having great potential in performance improvement. Although some studies have attempted to induce similar structures through multilayer stacking, growth parameter regulation or doping strategies, these methods often have uncontrollable crystal phase induction regions, narrow process windows, poor reproducibility and insufficient compatibility with CMOS processes, making it difficult to achieve stable and reliable crystal phase regulation in actual micro-nano devices. In particular, in high-integration device structures, how to accurately control the crystal phase distribution of thin film materials in a small scale range and how to induce the formation of MPB to improve performance are still key technical problems that need to be solved. Summary of the Invention

[0005] Based on this, it is necessary to provide a method for forming MPB in thin film materials, MIM structure and its preparation method and application in order to address the problems of difficult to precisely control the crystal phase structure, unstable performance and poor process compatibility in current thin film materials.

[0006] The present invention is achieved by adopting the following technical solutions:

[0007] In a first aspect, the present invention discloses a first method for forming an MPB in a thin film material, comprising:

[0008] Patterning and growing a bottom electrode layer on the substrate;

[0009] Depositing and growing an insulating layer of thin film material on the bottom electrode layer to form a device to be processed;

[0010] The device to be processed is annealed in a protective gas atmosphere to generate MPB in the insulating layer.

[0011] The present invention discloses a first method for preparing a MIM structure with MPB, which comprises:

[0012] The first method of forming MPB in the thin film material is first used for preparation;

[0013] A top electrode is then deposited and grown on the insulating layer to form a MIM structure comprising metal, an insulating layer containing MPB, and metal from top to bottom.

[0014] The invention discloses a first MIM structure with MPB, which is prepared by a method for preparing a first device structure with MPB.

[0015] The present invention discloses an application of a first MIM structure with an MPB in a target device. The application comprises replacing an original MIM structure in the target device with the first MIM structure with an MPB. The target device is any one of a DRAM capacitor, a CMOS logic device, a non-volatile memory, and a power device.

[0016] The above-mentioned first method for forming an MPB in a thin film material, the first method for preparing a MIM structure with an MPB, the first MIM structure with an MPB and the application thereof realize methods or processes according to embodiments of the present disclosure.

[0017] In a second aspect, the present invention discloses a second method for forming an MPB in a thin film material, comprising:

[0018] Depositing and growing an insulating layer of thin film material on the bottom electrode layer;

[0019] Graphically growing a top electrode layer on the insulating layer to form a device to be processed;

[0020] The device to be processed is annealed in a protective gas atmosphere to generate MPB in the insulating layer.

[0021] The present invention discloses a second method for preparing a MIM structure with MPB, which comprises:

[0022] The second method of forming MPB in a thin film material is adopted for preparation, that is, a MIM structure is formed which is metal, an insulating layer containing MPB, and metal in order from top to bottom.

[0023] The present invention discloses a second MIM structure with MPB, which is prepared by the second disclosed method for preparing a device structure with MPB.

[0024] The present invention discloses an application of a second MIM structure with an MPB in a target device. The application comprises replacing an original MIM structure in the target device with the second MIM structure with an MPB. The target device is any one of a DRAM capacitor, a CMOS logic device, a non-volatile memory, and a power device.

[0025] The above-mentioned second method of forming MPB in a thin film material, the second method of preparing a MIM structure with MPB, the second MIM structure with MPB and the application thereof realize the method or process according to the embodiment of the present disclosure.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention utilizes a highly compatible electrode patterning method to introduce a local stress field at the film interface during subsequent annealing heat treatment, thereby breaking the randomness of spontaneous growth of conventional crystalline phases in a uniform stress field, making the crystalline phase distribution from disordered to controllable, and achieving spatial transformation and ordered arrangement of polycrystalline phases in specific submicron to nanometer scale regions without changing the intrinsic composition of the material, successfully inducing the formation of MPB in the thin film material and improving the performance of the thin film material.

[0028] 2. The method of the present invention is simple and can achieve stress control by simply patterning the electrode and changing the structural design without introducing additional materials or complex processes. It has the advantages of simple process, strong repeatability, and low thermal budget, and can be seamlessly integrated into existing CMOS or BEOL process flows.

[0029] 3. The electrode patterning method adopted in the present invention can achieve spatial definition from submicron to nanometer scale, so that the crystal phase transformation area is accurately matched with the target device structure, which helps to improve the device integration density and structural consistency, solves the key bottleneck of the current "uncontrollable and non-repeatable" crystal phase induction, and improves the spatial resolution and repeatability of crystal phase regulation.

[0030] 4. The present invention has good versatility, a wide range of applications, and is highly scalable and has mass production potential. It is applicable to different generations of technology nodes and device structures, has good large-scale adaptability, and is suitable for high-density integration and mass production needs, providing a feasible process solution foundation for the manufacture of high-performance electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 Schematic diagram of MPB improving the free energy of thin film materials;

[0033] Figure 2 Schematic diagram of MPB improving the polarization strength of thin film materials;

[0034] Figure 3 A schematic diagram of a first method for forming an MPB in a thin film material provided in Example 1 of the present invention;

[0035] Figure 4 Schematic diagram of the preparation method of the first MIM structure with MPB provided in Example 1 of the present invention;

[0036] Figure 5 A schematic diagram of a second method for forming an MPB in a thin film material provided in Example 2 of the present invention;

[0037] Figure 6 This is a flow chart of the experimental sample processing provided in Example 3 of the present invention;

[0038] Figure 7 This is a diagram of experimental results provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component. When a component is considered to be "fixed to" another component, it may be directly fixed to the other component or there may be a central component.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] As mentioned in the background art, MPB is a mixed crystal phase formed by two phases with similar lattice parameters but different symmetries. Taking the ferroelectric (FE) crystal phase and the antiferroelectric (AFE) crystal phase as an example, MPB is the coupling of the FE crystal phase and the AFE crystal phase. Figure 1 , which shows the free energy change of MPB coupled by FE crystal phase and AFE crystal phase. Figure 1 It can be seen that the free energy curve of MPB is smoother than that of FE crystal phase and AFE crystal phase (the second-order derivative is close to 0), which makes the dielectric parameters larger; see Figure 2 , which shows the change of the polarization curve of MPB coupled by FE crystal phase and AFE crystal phase. Figure 2 It can be seen that the polarization curve of MPB shows a unique trend compared with the FE crystal phase and AFE crystal phase, indicating that it has a greater polarization intensity.

[0043] The present invention aims to realize the formation of MPB in thin film materials, provides two specific methods for forming MPB in thin film materials, and further provides a MIM structure preparation method designed based on the method for forming MPB in thin film materials.

[0044] Example 1

[0045] See Figure 3 , which is the first method for forming an MPB in a thin film material provided in this embodiment 1, comprising:

[0046] S101, patterning and growing a bottom electrode layer on a substrate.

[0047] Graphical growth is already a very mature processing technology (which can adopt micro-nano manufacturing technologies such as nanoimprinting, electron beam exposure, laser interference patterning, and dry etching), which can achieve high-precision customization of the bottom electrode layer pattern (up to submicron to nanometer scale) - the bottom electrode layer pattern is not limited to linear, grid, and island structures, but can also adopt a variety of two-dimensional or three-dimensional morphologies such as dot matrix, ring, fish scale, and irregular distribution, which can be flexibly adjusted according to actual processing needs; the line width, spacing, thickness and other dimensional parameters of the bottom electrode layer pattern can be flexibly adjusted according to actual processing needs.

[0048] Then, after the S101 process is completed, when observing along the direction perpendicular to the bottom electrode layer, the solid portion of the bottom electrode layer pattern will cover the substrate, while the non-solid portion will expose the substrate.

[0049] S102 , depositing and growing an insulating layer of thin film material on the bottom electrode layer to form a device to be processed.

[0050] Deposition growth is also a very mature processing technology (which can adopt ALD process, PEALD process, PVD process, MOCVD process, ebeam process, PECVD process, sputter process, etc.), which can accurately control the thickness of the deposition to achieve sub-nanometer to several nanometer level precision, and ensure its continuity and density.

[0051] As mentioned in the background art, there are many types of thin film materials, and the present invention is applicable to functional thin film materials with a polycrystalline phase competition relationship, such as oxides (such as HZO, HfO2, ZrO2, HfZrAlO x 、HfZrSiO x , BaTiO3, SrTiO3, PZT, ZnO, In2O3, etc.), nitrides (such as AlN, SiN, AlScN, etc.).

[0052] Then, after the S102 process is completed, when observing in a direction perpendicular to the insulating layer, there are regions in the insulating layer that are in direct contact with the bottom electrode layer, and there are also regions in direct contact with the substrate.

[0053] S103 , performing annealing treatment on the device to be processed in a protective gas atmosphere to generate MPB in the insulating layer.

[0054] Annealing is also a very mature processing technology (which can be rapid thermal annealing, laser annealing, furnace annealing, etc.), which actually provides stress field generation conditions for the device to be processed. The protective gas (which can be nitrogen or ammonia) atmosphere is to avoid oxidation reaction of the device to be processed and affect the formation of MPB. Then, when S103 is performed, the stress generated in the area where the insulating layer is in direct contact with the bottom electrode layer and the area where the insulating layer is in direct contact with the substrate are different, which will affect the crystal growth path or energy barrier, thereby generating two phases with similar lattice parameters but different symmetries in the insulating layer - that is, MPB is formed.

[0055] It should be noted that since the graphical growth in S101 is customizable, the regulation of MPB production can be achieved in S103.

[0056] See Figure 4 , which is the preparation method of the first MIM structure with MPB provided in Example 1, comprising:

[0057] The first method of forming MPB in the thin film material is first used for preparation;

[0058] A top electrode layer is then deposited and grown on the insulating layer to form an MIM structure consisting of metal, an insulating layer containing MPB, and metal from top to bottom - that is, the part excluding the substrate.

[0059] It should be noted that the following step can be added: the substrate is removed to obtain an independent MIM structure with MPB.

[0060] This embodiment 1 simultaneously provides a first MIM structure with MPB, which is prepared using the preparation method of the first MIM structure with MPB.

[0061] As is well known, in the field of microelectronics (e.g., DRAM capacitors, CMOS logic devices, non-volatile memory, power devices, etc.), many devices have MIM structures. Therefore, this embodiment 1 simultaneously discloses the application of the first MIM structure with MPB, which specifically involves replacing the original MIM structure in the target device with the first MIM structure with MPB. The target device is a DRAM capacitor, a CMOS logic device, a non-volatile memory, a power device, etc. After adopting this application, the target device can obtain significant performance enhancement.

[0062] Example 2

[0063] See Figure 5 , which is a second method for forming an MPB in a thin film material provided in Example 2, comprising:

[0064] S201, depositing and growing an insulating layer of thin film material on the bottom electrode layer.

[0065] It should be noted that the existing electrode can be used as the bottom electrode layer; the bottom electrode layer can also be obtained by deposition and growth on the substrate: first clean the silicon wafer substrate, and then deposit and grow an electrode layer on the silicon wafer substrate as the bottom electrode layer.

[0066] Deposition growth is a very mature processing technology (which can adopt ALD process, PEALD process, PVD process, MOCVD process, ebeam process, PECVD process, sputter process, etc.), which can accurately control the thickness of the deposition to achieve sub-nanometer to several nanometer level accuracy and ensure its continuity and density.

[0067] As mentioned in the background art, there are many types of thin film materials, and the present invention is applicable to functional thin film materials with a polycrystalline phase competition relationship, such as oxides (such as HZO, HfO2, ZrO2, HfZrAlO x 、HfZrSiO x , BaTiO3, SrTiO3, PZT, ZnO, In2O3, etc.), nitrides (such as AlN, SiN, AlScN, etc.).

[0068] Then, after the S201 process is completed, when observing perpendicularly to the insulating layer, the insulating layer completely covers the substrate.

[0069] S202 , patterning and growing a top electrode layer on the insulating layer to form a device to be processed.

[0070] Graphical growth is also a very mature processing technology (which can adopt micro-nano manufacturing technologies such as nanoimprinting, electron beam exposure, laser interference patterning, and dry etching), which can achieve high-precision customization of the top electrode layer pattern (up to submicron to nanometer scale) - the top electrode layer pattern is not limited to linear, grid, and island structures, but can also adopt a variety of two-dimensional or three-dimensional morphologies such as dot matrix, ring, fish scale, and irregular distribution, which can be flexibly adjusted according to actual processing needs; the line width, spacing, thickness and other dimensional parameters of the top electrode layer can be flexibly adjusted according to actual processing needs.

[0071] Then, after the S202 process is completed, when observing along the vertical top electrode layer, the solid part of the top electrode layer pattern will cover the insulating layer, and the non-solid part will expose the insulating layer.

[0072] S203 , performing an annealing process on the device to be processed in a protective gas atmosphere to generate an MPB in the insulating layer.

[0073] Annealing is also a very mature processing technology (which can be rapid thermal annealing, laser annealing, furnace annealing, etc.), which actually provides stress field generation conditions for the device to be processed. The protective gas (which can be nitrogen or ammonia) atmosphere is to avoid oxidation reaction of the device to be processed and affect the formation of MPB. Then, when performing S203, the stress generated in the area where the insulating layer is in direct contact with the top electrode layer and the area where the insulating layer is directly exposed are different, which will affect the crystal growth path or energy barrier, thereby generating two phases with similar lattice parameters but different symmetries in the insulating layer - that is, MPB is formed.

[0074] It should be noted that, since the graphical growth in S202 is customizable, the regulation of MPB production can be achieved in S203.

[0075] See Figure 5 , which actually also shows the preparation method of the second MIM structure with MPB provided in this embodiment 2, which includes:

[0076] The second method of forming MPB in a thin film material is adopted for preparation, that is, a MIM structure is formed which is metal, an insulating layer containing MPB, and metal in order from top to bottom.

[0077] It should be noted that if the existing electrode is used as the bottom electrode layer in S201, then an independent MIM structure with MPB can be directly obtained by the second preparation method of the MIM structure with MPB; if the bottom electrode layer is obtained by deposition growth on the substrate in S201, then the following step can be added: the substrate is removed to obtain an independent MIM structure with MPB.

[0078] This embodiment 1 simultaneously provides a second MIM structure with MPB, which is prepared using the preparation method of the second MIM structure with MPB.

[0079] As is well known, in the field of microelectronics (e.g., DRAM capacitors, CMOS logic devices, non-volatile memory, power devices, etc.), many devices have MIM structures. Therefore, this embodiment 1 simultaneously discloses the application of a second MIM structure with MPB, which specifically involves replacing the original MIM structure in the target device with the second MIM structure with MPB. The target devices include DRAM capacitors, CMOS logic devices, non-volatile memory, power devices, etc. After adopting this application, the target device can obtain significant performance enhancement.

[0080] Example 3

[0081] Since Examples 1 and 2 are actually based on similar stress regulation principles, this Example 3 provides experimental verification to illustrate the effect of the present invention.

[0082] See Figure 6 , this Example 3 was prepared by referring to the method of Example 2, and the specific steps are as follows:

[0083] S1, depositing an electrode layer (made of TiN) on a substrate (not shown) as a bottom electrode layer;

[0084] S2, depositing an insulating layer of a growth thin film material (the material is HZO) on the bottom electrode layer;

[0085] S3, patterning and growing a top electrode layer (made of TiN) on the insulating layer to form structure three;

[0086] It should be noted that the top electrode layer is designed to have an area smaller than that of the insulating layer, so that the top electrode layer covers half of the insulating layer and the other half of the insulating layer is directly exposed.

[0087] S4, performing a rapid thermal annealing treatment (N2 atmosphere, annealing temperature of 500°C, annealing time of 1 minute) to obtain a MIM structure;

[0088] S5, longitudinally cutting the MIM structure to obtain Structure 1 and Structure 2. Structure 1 includes a portion of the top electrode layer, a corresponding portion of the insulating layer, and a portion of the bottom electrode layer. Structure 2 includes another portion of the insulating layer and a corresponding portion of the bottom electrode layer.

[0089] The dielectric constants of structure 1, structure 2 and structure 3 are compared, and the results are as follows: Figure 7 As shown in the figure, the dielectric constants of Structures 1 and 2 are both improved compared to Structure 3, and the dielectric constant of Structure 1 is significantly larger than that of Structure 2. This indicates that the FE crystal phase has formed in this part of the insulating layer in Structure 2, and the AFE crystal phase has formed in this part of the insulating layer in Structure 1. Therefore, for the entire insulating layer, there is coupling between the FE crystal phase and the AFE crystal phase to achieve MPB.

[0090] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for forming MPB in a thin film material, characterized in that: It includes: Patterning and growing a bottom electrode layer on the substrate; Depositing and growing an insulating layer of thin film material on the bottom electrode layer to form a device to be processed; The device to be processed is annealed in a protective gas atmosphere to generate MPB in the insulating layer.

2. The method for forming MPB in a thin film material according to claim 1, characterized in that: The bottom electrode layer has a pattern of any one or more of a line, a grid, an island, a dot matrix, a ring, a fish scale, and an irregular distribution; Or / and, the thin film material of the insulating layer is HZO, HfO2, ZrO2, HfZrAlO x 、HfZrSiO x , any one of BaTiO3, SrTiO3, PZT, ZnO, In2O3, AlN, SiN, AlScN; or / and, the insulating layer is deposited and grown by any one of an ALD process, a PEALD process, a PVD process, an MOCVD process, an ebeam process, a PECVD process, and a sputter process; or / and, the protective gas is nitrogen or ammonia; Or / and, the annealing treatment adopts any one of rapid thermal annealing, laser annealing, and furnace annealing.

3. A method for preparing a MIM structure with MPB, characterized in that: It includes: First, the method for forming MPB in a thin film material as described in claim 1 or 2 is used for preparation; A top electrode layer is then deposited and grown on the insulating layer to form a MIM structure comprising metal, an insulating layer containing MPB, and metal from top to bottom.

4. A MIM structure with MPB, characterized in that: The device is prepared by the method for preparing a device structure with MPB as claimed in claim 3.

5. Application of the MIM structure with MPB as claimed in claim 4 in a target device, comprising: Replacing the original MIM structure in the target device with the MIM structure with MPB; The target device is any one of DRAM capacitors, CMOS logic devices, non-volatile memory, and power devices.

6. A method for forming MPB in a thin film material, characterized in that: It includes: Depositing and growing an insulating layer of thin film material on the bottom electrode layer; Graphically growing a top electrode layer on the insulating layer to form a device to be processed; The device to be processed is annealed in a protective gas atmosphere to generate MPB in the insulating layer.

7. The method for forming MPB in a thin film material according to claim 6, wherein: The thin film material of the insulating layer is HZO, HfO2, ZrO2, HfZrAlO x 、HfZrSiO x , any one of BaTiO3, SrTiO3, PZT, ZnO, In2O3, AlN, SiN, AlScN; or / and, the insulating layer is deposited and grown by any one of an ALD process, a PEALD process, a PVD process, an MOCVD process, an ebeam process, a PECVD process, and a sputter process; or / and, the pattern of the top electrode layer is any one or more of a linear shape, a grid shape, an island shape, a lattice shape, a ring shape, a fish scale shape, and an irregular distribution shape; or / and, the protective gas is nitrogen or ammonia; Or / and, the annealing treatment adopts any one of rapid thermal annealing, laser annealing, and furnace annealing.

8. A method for preparing a MIM structure with MPB, characterized in that: It includes: The method for forming MPB in a thin film material as claimed in claim 6 or 7 is used for preparation, that is, a MIM structure is formed which comprises metal, an insulating layer containing MPB, and metal in order from top to bottom.

9. A MIM structure with MPB, characterized in that: It is prepared by the method for preparing a device structure with MPB as claimed in claim 8.

10. Application of the MIM structure with MPB according to claim 9 in a target device, comprising: Replacing the original MIM structure in the target device with the MIM structure with MPB; The target device is any one of DRAM capacitors, CMOS logic devices, non-volatile memory, and power devices.

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