CN116997245A - AlScN ferroelectric film with high Sc component and preparation method and application thereof - Google Patents
AlScN ferroelectric film with high Sc component and preparation method and application thereof Download PDFInfo
- Publication number
- CN116997245A CN116997245A CN202310768552.6A CN202310768552A CN116997245A CN 116997245 A CN116997245 A CN 116997245A CN 202310768552 A CN202310768552 A CN 202310768552A CN 116997245 A CN116997245 A CN 116997245A
- Authority
- CN
- China
- Prior art keywords
- alscn
- film
- ferroelectric
- layer
- ferroelectric film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- 229910052984 zinc sulfide Inorganic materials 0.000 claims abstract description 16
- 150000004767 nitrides Chemical class 0.000 claims abstract description 10
- 238000005516 engineering process Methods 0.000 claims abstract description 9
- 239000010408 film Substances 0.000 claims description 116
- 238000000034 method Methods 0.000 claims description 29
- 239000000463 material Substances 0.000 claims description 24
- 230000015654 memory Effects 0.000 claims description 21
- 239000000758 substrate Substances 0.000 claims description 19
- 238000002955 isolation Methods 0.000 claims description 18
- 239000010409 thin film Substances 0.000 claims description 17
- 229910052757 nitrogen Inorganic materials 0.000 claims description 15
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 13
- 239000013078 crystal Substances 0.000 claims description 13
- 239000012298 atmosphere Substances 0.000 claims description 11
- 239000013077 target material Substances 0.000 claims description 10
- 230000008569 process Effects 0.000 claims description 9
- 239000000919 ceramic Substances 0.000 claims description 8
- 238000000151 deposition Methods 0.000 claims description 8
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- 239000003990 capacitor Substances 0.000 claims description 5
- 229910052697 platinum Inorganic materials 0.000 claims description 4
- 239000004065 semiconductor Substances 0.000 claims description 4
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 4
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 claims description 3
- 239000011521 glass Substances 0.000 claims description 3
- 229910052594 sapphire Inorganic materials 0.000 claims description 3
- 239000010980 sapphire Substances 0.000 claims description 3
- 239000000956 alloy Substances 0.000 claims description 2
- 229910045601 alloy Inorganic materials 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims description 2
- 229910052782 aluminium Inorganic materials 0.000 claims 1
- 230000003647 oxidation Effects 0.000 claims 1
- 238000007254 oxidation reaction Methods 0.000 claims 1
- 230000008021 deposition Effects 0.000 abstract description 3
- 230000005621 ferroelectricity Effects 0.000 description 15
- 238000011065 in-situ storage Methods 0.000 description 14
- 238000000137 annealing Methods 0.000 description 11
- 238000010438 heat treatment Methods 0.000 description 8
- 238000001755 magnetron sputter deposition Methods 0.000 description 6
- 230000010287 polarization Effects 0.000 description 6
- 230000005684 electric field Effects 0.000 description 5
- 238000002347 injection Methods 0.000 description 5
- 239000007924 injection Substances 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical group [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 3
- 230000010354 integration Effects 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- VZPPHXVFMVZRTE-UHFFFAOYSA-N [Kr]F Chemical compound [Kr]F VZPPHXVFMVZRTE-UHFFFAOYSA-N 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000007872 degassing Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000010849 ion bombardment Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000001451 molecular beam epitaxy Methods 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 230000004888 barrier function Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000002860 competitive effect Effects 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
- H01L28/40—Capacitors
- H01L28/55—Capacitors with a dielectric comprising a perovskite structure material
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
- C23C14/0641—Nitrides
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
- C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
- C23C14/24—Vacuum evaporation
- C23C14/28—Vacuum evaporation by wave energy or particle radiation
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10B—ELECTRONIC MEMORY DEVICES
- H10B53/00—Ferroelectric RAM [FeRAM] devices comprising ferroelectric memory capacitors
- H10B53/30—Ferroelectric RAM [FeRAM] devices comprising ferroelectric memory capacitors characterised by the memory core region
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Power Engineering (AREA)
- Mechanical Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Computer Hardware Design (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
The application provides an AlScN ferroelectric film with high Sc component, a preparation method and application thereof, wherein PLD technology is adopted in the whole preparation process of the AlScN ferroelectric film, and the AlScN ferroelectric film grows on the surface of the AlScN ferroelectric film based on an atomic-level III-nitride film serving as a buffer layer; the group III nitride has a (002) crystalline phase orientation; the AlScN ferroelectric film has a wurtzite structure. According to the technical scheme, the Pulse Laser Deposition (PLD) technology is adopted to grow the AlN film with (002) orientation and atom level flatness at high temperature (more than or equal to 700 ℃), and on the basis, the growth of the high Sc doped AlScN film can be performed, so that good matching can be formed, wherein the Sc content is more than 30%, and the surface of the obtained AlScN film can reach atom level flatness.
Description
Technical Field
The application relates to the technical field of semiconductors, in particular to an AlScN ferroelectric film with high Sc component, a preparation method and application thereof.
Background
The ferroelectric memory is a nonvolatile memory which uses spontaneous polarization of ferroelectric film material as logic unit to store data in two different orientations (N-polarization and M-polarization) in electric field, and has the advantages of high-speed read-write, high density integration and radiation resistance. The most critical part of the memory is the memory unit, and the memory unit determines the integration level and the read-write performance of the memory. For ferroelectric memories, the memory cells are typically ferroelectric capacitor structures. Therefore, whether a high-quality ferroelectric thin film can be grown to make a ferroelectric capacitor is a key to improving the performance of a ferroelectric memory. The ferroelectric film mainly comprises PZT and HfO 2 And the like, the ferroelectric films have the problems of poor stability, incompatibility with a CMOS process and the like, so that the finding of a novel ferroelectric film is urgent.
In 2019, akiyama et al demonstrated that AlScN has ferroelectricity, which opens up a new way for the development of ferroelectric memories. AlScN is obtained by doping AlN with a wurtzite structure, and the AlN has excellent physical properties of high resistivity, high heat conductivity, high stability, high sound wave transmission rate and the like, and is a piezoelectric material with wide application. It is considered that when the applied electric field strength of AlN is smaller than the breakdown electric field strength of the AlN thin film medium, it is impossible to reverse polarization, and thus AlN cannot exhibit ferroelectricity. Whereas doping of Sc lowers the energy barrier between the two polarization states N-polarization and M-polarization of AlN, so that its polarization switching electric field strength is lowered, below the breakdown electric field strength, alScN exhibits ferroelectricity. This finding makes it possible to apply the AlScN ferroelectric thin film as a ferroelectric capacitor structure to ferroelectric memories. The AlScN-based ferroelectric film has high remnant polarization intensity and coercive field which are difficult to achieve by other ferroelectric materials, and the preparation process of the AlScN is compatible with the CMOS process, has higher temperature stability and meets various requirements of a novel ferroelectric memory.
The ferroelectricity of the AlScN ferroelectric film is highly correlated with the crystal quality of the film, so that the preparation of a high-quality ferroelectric film is the basis for preparing a ferroelectric memory. The main methods for preparing AlScN film include magnetron sputtering, molecular Beam Epitaxy (MBE) and chemical vapor depositionMOCVD), and the like. In the prior art, the AlScN film grows to 5nm and the ferroelectricity is detected, but the remnant polarization is only 23 mu C/cm 2 The requirements of ferroelectric memories are far from being met. Generally, the higher the Sc element doping ratio is, the stronger the ferroelectricity of the film is, so the ferroelectric property of the ferroelectric film can be improved by a method of improving Sc doping concentration. However, in the prior art, when the Sc doping ratio exceeds 30%, a rock salt structure starts to appear to destroy the crystallization quality of a wurtzite structure, thereby affecting ferroelectricity; when the proportion of Sc element reaches 46%, the whole film is converted into a rock salt structure film, and the rock salt structure film does not have ferroelectricity. Also, as a result, the preparation of AlScN-based ferroelectric memories remains in the laboratory stage, and the Sc doping ratio of the AlScN ferroelectric films actually used in the prior art is generally not more than 30%.
On the other hand, in the prior art, the growth of the AlScN ferroelectric film is generally performed by a magnetron sputtering method, for example, chinese patent No. CN113174574A provides a preparation method of a high-quality scandium-doped aluminum nitride film template, which comprises the following steps: 1. preparing a substrate; 2. depositing an AlN transition layer on the substrate by adopting a coating technology; 3. carrying out high-temperature heat treatment on the AlN film transition layer by adopting a high-temperature face-to-face heat treatment technology under a pure nitrogen atmosphere to form a high-quality buffer layer; 4. and depositing an AlScN film on the buffer layer by adopting a reactive magnetron sputtering deposition method. In the patent, an AlN buffer layer is directly grown on a substrate, magnetron sputtering cannot be used for high-temperature growth, a polycrystalline structure can be caused, the quality of the AlN buffer layer can be influenced, the quality of an AlScN film is influenced, although the Sc atomic concentration (Sc/(Al+Sc)) reaches 40%, the AlScN film is in a polycrystalline structure state, the ferroelectricity performance is greatly influenced, and the crystal phase structure of the AlScN film is not evaluated in the patent; on the other hand, the magnetron sputtering method is adopted to grow the film, the uniformity of the film is poor, the surface cannot reach the level of atoms, and the atomic level ultrathin film cannot be prepared; in particular, after the AlN buffer layer is grown, high-temperature heat treatment is carried out, and the thin film is polluted in the transfer between different devices, so that the growth quality of the thin film is affected.
Clearly, the prior art has not been able to achieve a method for improving the ferroelectric properties of AlScN films by high Sc doping techniques.
In view of this, the application can improve the ferroelectricity of AlScN film by improving the technical scheme of Sc doping concentration, and improve the ferroelectricity of AlScN film by improving the Sc doping proportion under the condition of not changing wurtzite structure by optimizing the technical scheme. The patent proposes a method for preparing an AlScN ferroelectric film by PLD, which can lead the Sc doping proportion to exceed 30 percent and has excellent ferroelectricity. The method can remarkably improve the ferroelectricity of the AlScN film, has important significance and application value for the development of the AlScN-based ferroelectric memory, and provides a pushing effect for the performance and further popularization of the ferroelectric memory.
Disclosure of Invention
In view of the above, the application provides an AlScN film with high Sc component, a preparation method and application thereof, the Sc doping content is more than 30%, the growth of the AlScN film with high Sc doping is realized, good matching can be formed, the wurtzite structure is not damaged, and the application prospect of the AlScN film in the field of ferroelectric memories is greatly improved.
In order to achieve the above object, the present application provides a method for preparing an AlScN film with high Sc component, comprising: growing an AlScN ferroelectric film on the surface of the group III nitride film with atomic level by adopting PLD technology; the group III nitride buffer layer has a (002) crystalline phase orientation; the AlScN ferroelectric film has a wurtzite structure.
Preferably, in the AlScN ferroelectric film, the doping proportion of Sc is 30-50%; more preferably, the doping ratio of Sc is 30-50%; most preferably, the doping proportion of Sc is 40%.
Preferably, the AlScN ferroelectric film has a thickness of 5-50 nm.
Preferably, the target material selected by the AlScN ferroelectric film comprises one or more of an AlScN ceramic target material, an AlSc alloy target material, al and Sc bimetallic target material.
Preferably, the AlScN ferroelectric filmThe growth temperature can be 200-500 ℃, N 2 Under the atmosphere, the pressure is 0.5-3 Pa, the laser frequency is 1-10 Hz, the laser energy is 200-500 mJ, and the target base distance is 50-70 mm.
Preferably, the group III nitride includes any one of AlN, gaN, alGaN, inN, inGaN.
As a preferable technical scheme, a covering layer can be further grown on the surface of the AlScN ferroelectric film, so that the AlScN ferroelectric film can be protected from being oxidized.
The cover layer may be a metal as an electrode; preferably, the material of the cover layer may comprise any one of Pt, mo, W, ni.
Based on the preparation technology of the AlScN ferroelectric film with high Sc doping concentration provided by the technical scheme, the application also provides a laminated structure body which at least comprises the buffer layer-AlScN ferroelectric film-covering layer provided by the technical scheme.
Further, the laminated structure includes a substrate-spacer-bottom electrode-buffer-AlScN ferroelectric thin film-top electrode-cover layer.
In some preferred embodiments, PLD-based systems can be directly grown at one time with a stacked structure comprising TiN-Pt-AlN-AlScN-TiN-Pt in order from bottom to top.
Further, the preparation method of the laminated structure adopts PLD method in the whole process and forms a film at one time, and the preparation method specifically comprises the following steps:
s1, providing a substrate;
s2, growing an isolation layer (or an adhesion layer) on the surface of the substrate;
s3, growing a bottom electrode film on the surface of the isolation layer;
s4, growing a buffer layer on the surface of the bottom electrode film;
s5, growing an AlScN ferroelectric film on the surface of the buffer layer;
s6, growing a top electrode on the surface of the AlScN ferroelectric film;
s7, growing a covering layer on the surface of the top electrode.
Wherein, the materials and the processes of the top electrode and the bottom electrode are the same or different; the materials and processes of the cover layer and the isolation layer are the same or different;
the buffer layer is the III-nitride film.
Preferably, the thickness of the III-nitride film is 2-20 nm.
Preferably, the growth conditions of the III-nitride compound comprise a temperature of 650-800 ℃, N 2 Under the atmosphere, the pressure is 0-5 Pa, the laser frequency is 1-10 Hz, the laser energy can be 200-500 mJ, and the target base distance is 50-70 mm.
Preferably, the material of the substrate is any one of Si (100), si (111), sapphire, gallium nitride (GaN), silicon carbide (SiC) and glass, which can be used for depositing the semiconductor thin film.
Preferably, the material of the cover layer and/or the isolation layer comprises TiN or TaN.
Preferably, the thickness of the isolation layer is 1-20 nm.
Preferably, the growth temperature of the isolation layer is 650-800 ℃ and N 2 Under the atmosphere, the air pressure is 0.5-3 Pa, the laser frequency is 1-10 Hz, the laser energy is 200-500 mJ, and the target base distance is 50-70 mm.
Preferably, the materials of the bottom electrode and the top electrode are materials that can be used as electrodes, including any one of Pt, mo, W, ni.
Preferably, the thicknesses of the top electrode and the covering layer are 20-200 nm, the growth temperature is 20-400 ℃, the air pressure is 0.5-3 Pa under the N2 atmosphere, the laser frequency is 1-10 Hz, the laser energy is 200-500 mJ, and the target base distance is 50-70 mm.
Preferably, the bottom electrode film and the isolation layer have the same crystal orientation.
Preferably, the spacer layer is a (111) crystal phase, and the bottom electrode thin film grown on the surface of the spacer layer also has the same (111) crystal orientation.
The laminated structure provided by the technical scheme can be applied to an AlScN-based ferroelectric memory.
The beneficial technical effects obtained by the application are as follows:
1. according to the technical scheme, a Pulse Laser Deposition (PLD) technology is adopted to grow an AlN film with (002) orientation and with an atomic level flatness as a buffer layer at a high temperature (more than or equal to 700 ℃), and on the basis, the growth of a high Sc doped AlScN film can be performed, so that good matching can be formed, wherein the Sc content is more than 30%, the highest doping concentration can be obtained by 50%, and the surface of the obtained AlScN film can reach the atomic level flatness; in particular, the AlScN ferroelectric film has wurtzite structure which keeps good ferroelectric performance.
2. The laminated structure body prepared by adopting the technical scheme of the application comprises the AlScN ferroelectric film with high Sc doping concentration, wherein the AlScN has a wurtzite structure and can keep higher ferroelectricity, so that the ferroelectric property of the ferroelectric film is improved by a method for improving the Sc doping concentration, and the laminated structure body has more competitive power in the field of ferroelectric storage.
3. The technical scheme of the application realizes the whole film growth process based on PLD technology without exposing in the environment to realize one-time film formation, thereby reducing the pollution of the atmosphere environment and the like to the film.
4. The AlScN film prepared by adopting a Pulse Laser Deposition (PLD) system can be subjected to stoichiometric ratio transfer, is deposited with the same component, has good component retention, and can be used for preparing nitrides with any proportion; the film quality is higher than that of magnetron sputtering, and the surface is smoother; and film growth is faster and less costly than MBE.
Drawings
Fig. 1 is a flow chart of a process for preparing a high Sc doped AlScN ferroelectric thin film according to embodiment 1 of the present application.
Figure 2 XRD diffractogram of the AlScN ferroelectric thin film prepared in example 1 of the present application.
FIG. 3 is a schematic diagram of a PLD system of the application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application.
The application provides a preparation method of an AlScN ferroelectric film with high Sc component and a laminated structure body, which is prepared based on PLD method. The PLD method adopted by the application is based on a PLD system, and the PLD system mainly comprises a light source system and a vacuum growth system (shown in figure 3).
Specifically, referring to fig. 3, the light source system consists of a pulse excimer laser and a focusing light path system, and the vacuum growth system consists of a sample injection chamber and an epitaxial growth chamber; the laser is pulse energy of a ComPexPro201 series krypton fluoride (KrF) pulse excimer laser produced in Germany, and the focusing light path system consists of an optical reflector and a focusing lens, so that the energy focusing and the dynamic regulation and control of the incident direction of an incident laser beam can be realized.
The vacuum growth system comprises an epitaxial growth chamber and a sample injection chamber; the epitaxial growth chamber is provided with 4 target trays, so that samples can be subjected to in-situ treatment (such as heating, argon ion bombardment and the like) under ultrahigh vacuum (the vacuum degree after baking and degassing is better than 2 multiplied by 10) -8 pa) epitaxial growth of the film; four target trays of the epitaxial growth chamber are respectively provided with an Al0.6Sc0.4N ceramic target, an AlN ceramic target, a Pt metal target and a TiN target, so that the whole laminated structure can be grown in a vacuum environment at one time without being exposed in the atmosphere.
The sample injection chamber is provided with a sample warehouse and a sample heating table; the sample library can be loaded with 6 samples or targets, so that the influence of vacuum degree of the targets and the samples in the transmission process can be reduced; the heating temperature range of the sample heating table is adjustable within the range of room temperature to 800 ℃, so that the temperature-rising growth and in-situ annealing of the film sample can be realized; the differential high-energy electron diffractometer (RHEED) arranged on the PLD system can accurately control the growth of the epitaxial film of the atomic layer in situ in real time, and observe the surface structure of the sample.
The AlScN film and the laminated structure body are prepared by adopting the PLD system, so that the one-time growth can be realized, the transfer in different equipment is not needed, and the influence of the pollution of the atmosphere environment on the film quality is avoided.
Specifically, the AlScN ferroelectric film with high Sc component provided by the application is based on a III-nitride film with atomic level as a buffer layer, and the AlScN ferroelectric film is grown on the surface of the AlScN ferroelectric film; wherein the group III nitride has a (002) crystal phase orientation; the AlScN ferroelectric film has a wurtzite structure.
In some embodiments, the Sc doping ratio in the AlScN ferroelectric thin film is 30% to 50%. The Sc doping concentration or doping ratio referred to in the present application refers to the ratio or concentration of Sc/(al+sc), unless otherwise specified.
The technical scheme of the application is further described in detail through specific examples.
Example 1
The embodiment provides a PLD system, which mainly comprises a light source system and a vacuum growth system. Specifically, the light source system consists of a pulse excimer laser and a focusing light path system, and the vacuum growth system consists of a sample injection chamber and an epitaxial growth chamber; the laser is pulse energy of a ComPexPro201 series krypton fluoride (KrF) pulse excimer laser produced in Germany, and the focusing light path system consists of an optical reflector and a focusing lens, so that the energy focusing and the dynamic regulation and control of the incident direction of an incident laser beam can be realized.
The vacuum growth system comprises an epitaxial growth chamber and a sample injection chamber; the epitaxial growth chamber is provided with 4 target trays, so that samples can be subjected to in-situ treatment (such as heating, argon ion bombardment and the like) under ultrahigh vacuum (the vacuum degree after baking and degassing is better than 2 multiplied by 10) -8 Pa) epitaxial growth of thin films; four target trays of the epitaxial growth chamber are respectively loaded with Al 0.6 Sc 0.4 The N ceramic target, the AlN ceramic target, the Pt metal target and the TiN target ensure that the whole laminated structure can grow in a vacuum environment at one time without being exposed in an atmosphere.
The embodiment provides a laminated structure, referring to fig. 1, and the specific preparation method includes:
1. providing a substrate; the material of the substrate can be selected from any one of Si (100), si (111), sapphire, gallium nitride (GaN), silicon carbide (SiC) and glass for depositing the semiconductor film; as a preferred embodiment, siC is selected as the substrate material in this example.
2.2. Providing an isolation layer; firstly, growing a layer of TiN with the thickness of 20nm on the substrate as an isolation layer and an adhesion layer, wherein the growth temperature is 700 ℃, N 2 The air pressure is 2.5Pa, the pulse laser frequency is 2Hz, the laser energy is 350mJ, the target base distance is 57mm, the growth time is 120min, and the in-situ annealing is carried out for 60min after the growth is finished.
3. Providing a bottom electrode film layer; pt with the thickness of 20nm is grown on the surface of the substrate as a bottom electrode film, a target male rotating rod is rotated, a Pt metal target is aligned to a sample table, the growth temperature is 700 ℃, and N is the same as that of the sample table 2 The air pressure is 2.5Pa, the pulse laser frequency is 2Hz, the laser energy is 350mJ, the target base distance is 57mm, the growth time is 120min, the in-situ annealing is carried out for 60min after the growth is finished, and the metal film growing on the (111) crystalline phase is (111) oriented.
4. Providing a buffer layer; alN with the thickness of 2-3nm is grown on the surface of the bottom electrode film as a buffer layer, a target male rotating rod is rotated, an AlN ceramic target is aligned to a sample stage, the growth temperature is 650 ℃, and N is the same as that of the sample stage 2 The air pressure is 2.5Pa, the pulse laser frequency is 2Hz, the laser energy is 350mJ, the target base distance is 57mm, the growth time is 5min, and the in-situ annealing is carried out for 60min after the growth is finished.
5. Providing a ferroelectric thin film layer; growing 20nm AlScN ferroelectric film on the buffer layer surface, rotating the target male rod to make Al 0.6 5c 0.4 N target material is aligned with the sample stage, the growth temperature is 400 ℃, N 2 The air pressure is 1Pa, the pulse laser frequency is 2Hz, the laser energy is 350mJ, the target base distance is 57mm, and the in-situ annealing is performed for 60min after the growth is finished. The AlScN wurtzite structure grown on the (002) crystal phase is not easily damaged, so the doping concentration of Sc element can be increased.
5. Providing a covering layer and a top electrode, sequentially growing 20nm TiN and 20nm Pt on the surface of the AlScN ferroelectric film as the covering layer and the top electrode, wherein the growth temperature is room temperature, and N 2 The air pressure is 1Pa, the pulse laser frequency is 2Hz, the laser energy is 350mJ, the target base distance is 57mm, and the in-situ annealing is performed for 60min after the growth is finished.
By adopting the technical scheme, the storage device with the laminated structure can be directly grown at one time, and the laminated structure sequentially comprises TiN-Pt-AlN-AlScN-TiN-Pt (excluding the substrate) from bottom to top.
Referring to fig. 2, the XRD pattern of example 1 is shown. The XRD peak positions of AlScN and AlN are both about 36 DEG, and the peak positions of AlScN and AlN shown in the figure coincide (or the XRD peak of AlScN overlaps the XRD peak of A1N).
It can be seen from the XRD diffractogram that TiN grown under this condition is a (111) crystalline phase, while AlN layer grown on the TiN surface has a (002) crystalline phase; alScN grown on the (002) crystal phase of AlN exhibits the (002) orientation of wurtzite structure.
Example 2
The present embodiment provides a laminated structure in which
1. Providing a substrate; the substrate material is SiC.
2. Providing an isolation layer; firstly, growing a layer of TiN with the thickness of 20nm on the substrate as an isolation layer and an adhesion layer, wherein the growth temperature is 650 ℃, N 2 The air pressure is 2Pa, the pulse laser frequency is 2Hz, the laser energy is 350mJ, the target base distance is 57mm, the growth time is 120min, and the in-situ annealing is performed for 60min after the growth is finished.
3. Providing a bottom electrode film layer; pt with the thickness of 20nm is grown on the surface of the substrate as a bottom electrode film, a target male rotating rod is rotated, a Pt metal target is aligned to a sample table, the growth temperature is 700 ℃, and N is the same as that of the sample table 2 The air pressure is 2.5Pa, the pulse laser frequency is 2Hz, the laser energy is 350mJ, the target base distance is 57mm, the growth time is 120min, the in-situ annealing is carried out for 60min after the growth is finished, and the metal film growing on the (111) crystalline phase is (111) oriented.
4. Providing a buffer layer; alN with the thickness of 2-3nm is grown on the surface of the bottom electrode film as a buffer layer, a target male rotating rod is rotated, an AlN ceramic target is aligned to a sample stage, the growth temperature is 800 ℃, and N is the same as that of the sample stage 2 The air pressure is 5Pa, the pulse laser frequency is 8Hz, the laser energy is 500mJ, the target base distance is 60mm, the growth time is 5min, and the in-situ annealing is carried out for 60min after the growth is finished.
5. Providing a ferroelectric thin film layer; growing 20nm AlScN ferroelectric film on the buffer layer surface, rotating the target male rod to make Al 0.5 Sc 0.5 N target material is aligned with the sample stage, and the growth temperature is 400 DEG C，N 2 The air pressure is 1Pa, the pulse laser frequency is 2Hz, the laser energy is 350mJ, the target base distance is 57mm, and the in-situ annealing is performed for 60min after the growth is finished. The AlScN wurtzite structure grown on the (002) crystal phase is not easily damaged, so the doping concentration of Sc element can be increased.
5. Providing a cover layer and a top electrode; growing TiN with 20nm and Pt with 20nm on the surface of AlScN ferroelectric film as cover layer and top electrode, the growing temperature is room temperature, N 2 The air pressure is 1Pa, the pulse laser frequency is 2Hz, the laser energy is 350mJ, the target base distance is 57mm, and the in-situ annealing is performed for 60min after the growth is finished.
In this example, the same diffraction pattern as in example 1 was obtained by the detection of the XRD diffractogram, which revealed that the AlScN wurtzite structure grown on the (002) crystal phase was not easily damaged, and thus the doping concentration of Sc element could be increased.
According to the technical scheme, the ferroelectric film prepared on the surface of the (002) crystal phase orientation III nitride film by using the PLD method is not easy to damage, so that the ferroelectric film with high doping concentration of Sc element can be obtained, and excellent ferroelectric performance can be maintained, even when the doping concentration (Sc/(Sc+Al)) reaches 50%, the AlScN wurtzite structure of the ferroelectric film can be maintained, and therefore, the support is provided for the capacitor and the ferroelectric memory to maintain good ferroelectric performance.
In particular, the laminated structure body prepared by adopting the technical scheme of the application comprises the AlScN ferroelectric film with high Sc doping concentration, wherein the AlScN has a wurtzite structure and can keep higher ferroelectricity, and the ferroelectric property of the ferroelectric film is improved by a method for improving the Sc doping concentration, so that the laminated structure body has higher competitiveness in the field of ferroelectric storage.
The above is only a preferred embodiment of the present application, which is not to be construed as limiting the scope of the present application, and various modifications and variations of the present application will be apparent to those skilled in the art. Variations, modifications, substitutions, integration and parameter changes may be made to these embodiments by conventional means or may be made to achieve the same functionality within the spirit and principles of the present application without departing from such principles and spirit of the application.
Claims (10)
1. A preparation method of an AlScN ferroelectric film with high Sc component comprises the following steps: growing an AlScN ferroelectric film on the surface of the group III nitride film with atomic level by adopting PLD technology; wherein the group III nitride has a (002) crystalline phase orientation; the AlScN ferroelectric film has a wurtzite structure.
2. The method for preparing an AlScN ferroelectric film with high Sc content according to claim 1, wherein the doping ratio of Sc in the AlScN ferroelectric film is 30-50%;
and/or the thickness of the AlScN ferroelectric film is 5-50 nm;
and/or the target material selected by the AlScN ferroelectric film comprises one or more of an AlScN ceramic target material, an AlSc alloy target material, an Al and Sc bimetallic target material;
and/or the AlScN ferroelectric film can be grown at 200-500 ℃ and N 2 Under the atmosphere, the pressure is 0.5-3 Pa, the laser frequency is 1-10 Hz, the laser energy is 200-500 mJ, and the target base distance is 50-70 mm;
and/or the group III nitride includes any of AlN, gaN, alGaN, inN, inGaN.
3. The method for preparing high Sc component AlScN ferroelectric film according to claim 1 or 2, characterized in that a covering layer is grown on the surface of the AlScN ferroelectric film, which can protect the AlScN ferroelectric film from oxidation;
and/or the material of the covering layer comprises TiN or TaN.
4. An A1ScN ferroelectric film prepared by the preparation method as claimed in any one of claims 1 to 3.
5. A laminated structure comprising at least the AlScN ferroelectric thin film according to claim 4.
6. The laminated structure according to claim 5, comprising a substrate-spacer-bottom electrode-buffer-AlScN ferroelectric thin film-capping layer-top electrode;
and/or, the buffer layer is a III-nitride film;
and/or the material of the covering layer comprises TiN or TaN.
7. A method for producing the laminated structure according to claim 5 or 6, wherein the PLD method is adopted for the whole process and the laminated structure is formed at one time, and the method comprises the steps of:
s1, providing a substrate;
s2, growing an isolation layer (or an adhesion layer) on the surface of the substrate;
s3, growing a bottom electrode film on the surface of the isolation layer;
s4, growing a buffer layer on the surface of the bottom electrode film;
s5, growing an AlScN ferroelectric film on the surface of the buffer layer;
s6, growing a top electrode on the surface of the AlScN ferroelectric film;
s7, growing a covering layer on the surface of the top electrode;
wherein the materials and processes of the top electrode and the bottom electrode are the same or different; the materials and processes of the cover layer and the isolation layer are the same or different;
and/or, the buffer layer is a III-nitride film.
8. The method of producing a laminated structure according to claim 7, wherein the growth conditions of the buffer layer include a temperature of 650 to 800 ℃, N 2 Under the atmosphere, the pressure is 0-5 Pa, the laser frequency is 1-10 Hz, the laser energy can be 200-500 mJ, and the target base distance is 50-70 mm;
and/or the material of the substrate can be selected from thin film materials used for depositing semiconductors, and specifically comprises any one of Si (100), si (111), sapphire, gallium nitride (GaN), silicon carbide (SiC) and glass;
and/or the material of the covering layer and/or the isolating layer comprises TiN or TaN;
and/or the thickness of the isolation layer is 1-20 nm;
and/or the growth temperature of the isolation layer is 650-800 ℃ and N 2 Under the atmosphere, the air pressure is 0.5-3 Pa, the laser frequency is 1-10 Hz, the laser energy is 200-500 mJ, and the target base distance is 50-70 mm;
and/or the materials of the bottom electrode and the top electrode are materials that can be used as electrodes, including any one of Pt, mo, W, ni;
and/or the thickness of the top electrode and the cover layer is 20-200 nm, the growth temperature is 20-400 ℃, and N 2 Under the atmosphere, the air pressure is 0.5-3 Pa, the laser frequency is 1-10 Hz, the laser energy is 200-500 mJ, and the target base distance is 50-70 mm;
and/or the isolation layer is in a (111) crystal phase, and the bottom electrode films grown on the surface of the isolation layer have the same (111) crystal orientation;
and/or the material of the top electrode and/or the bottom electrode including TiN or TaN may be a metal as an electrode;
and/or the material of the cover layer may be any one of Pt, mo, W, ni.
9. A ferroelectric memory comprising at least the AlScN ferroelectric thin film according to claim 4 or the stacked structure according to claim 5 or 6.
10. A ferroelectric capacitor comprising at least the AlScN ferroelectric thin film as claimed in claim 4 or the stacked structure as claimed in claim 5 or 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310768552.6A CN116997245A (en) | 2023-06-27 | 2023-06-27 | AlScN ferroelectric film with high Sc component and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310768552.6A CN116997245A (en) | 2023-06-27 | 2023-06-27 | AlScN ferroelectric film with high Sc component and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116997245A true CN116997245A (en) | 2023-11-03 |
Family
ID=88522176
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310768552.6A Pending CN116997245A (en) | 2023-06-27 | 2023-06-27 | AlScN ferroelectric film with high Sc component and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116997245A (en) |
-
2023
- 2023-06-27 CN CN202310768552.6A patent/CN116997245A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6143072A (en) | Generic process for preparing a crystalline oxide upon a group IV semiconductor substrate | |
| US5830270A (en) | CaTiO3 Interfacial template structure on semiconductor-based material and the growth of electroceramic thin-films in the perovskite class | |
| US20160240375A1 (en) | STRESS MITIGATING AMORPHOUS SiO2 INTERLAYER | |
| CN101064258B (en) | Method of forming highly orientated silicon film, method of manufacturing three-dimensional semiconductor device, and three-dimensional semiconductor device | |
| JP2019524982A (en) | IIIA nitride growth system and method | |
| CN112831768B (en) | Preparation method and application of hafnium nitride film with high crystallization quality | |
| KR100611108B1 (en) | Method of manufacturing a thin film layer | |
| US6821338B2 (en) | Particle beam biaxial orientation of a substrate for epitaxial crystal growth | |
| CN103996718A (en) | Silicon-based ferroelectric grid thin film transistor and preparation method thereof | |
| CN1851039A (en) | Method for preparing lead zirconate titanate ferroelectric film material | |
| KR19990006318A (en) | Deposition of Ferroelectric Films and Ferroelectric Capacitor Devices | |
| JP3608459B2 (en) | Thin film laminate, ferroelectric thin film element, and manufacturing method thereof | |
| CN116997245A (en) | AlScN ferroelectric film with high Sc component and preparation method and application thereof | |
| Kawakubo et al. | Novel ferroelectric epitaxial (Ba, Sr) TiO/sub 3/capacitor for deep sub-micron memory applications | |
| CN108269912B (en) | Titanium lead magnesio-niobate ferroelectric thin film gallium nitride-based epitaxial is integrated and preparation method thereof | |
| US20220320417A1 (en) | Method of manufacturing aluminum nitride films | |
| KR101041659B1 (en) | A Method Of Manfacturing GaN Epitaxial Layer Using ZnO Buffer Layer | |
| JP3929964B2 (en) | Method for manufacturing thin film laminated structure | |
| CN114068444A (en) | Protection structure for gallium nitride high-temperature annealing and application thereof | |
| JPH04252018A (en) | Formation of polycrystalline silicon film | |
| JP2004091253A (en) | SUPER-FLAT P-TYPE OXIDE SEMICONDUCTOR NiO SINGLE CRYSTAL THIN FILM | |
| CN109898138B (en) | Method for epitaxial growth of single-crystal barium titanate film on germanium substrate | |
| JPH10275896A (en) | Memory element | |
| Miu et al. | Pulsed laser deposition of SrZrO~ 3 as a buffer layer for ferroelectric thin films | |
| JPH0657411A (en) | Method and device for producing dielectric thin film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |