WO2023108611A1 - Annealing apparatus and annealing method - Google Patents

Abstract

Disclosed in embodiments of the present application are an annealing apparatus and an annealing method. The annealing apparatus comprises a heating component and an electric field providing component. The heating component can be used for annealing a sample to be annealed comprising a ferroelectric film layer to crystallize the ferroelectric film layer, and an amorphous and non-ferroelectric crystal phase is crystallized into a ferroelectric crystal phase after heat treatment inside the ferroelectric film layer, such that the ferroelectric film layer has ferroelectricity. In the process of performing thermal annealing on said sample, the electric field providing component can provide an auxiliary electric field for the ferroelectric film layer, and the included angle between the direction of the auxiliary electric field and the surface of the ferroelectric film layer is a preset included angle, such that the orientations of crystal grains in the ferroelectric film layer tend to be consistent under the action of the auxiliary electric field, the ferroelectricity of the ferroelectric film layer is improved, the performance of a device based on the ferroelectric film layer is improved, and more application scenarios are met.

Description

Annealing device and annealing method technical field

The present application relates to the field of semiconductor technology, in particular to an annealing device and an annealing method.

Background technique

The continuous development of Moore's Law has led to the continuous shrinking of the transistor size. At present, the continuous reduction of the characteristic size of the transistor has reached the physical limit. Because the continuation of Moore's Law has encountered a technical bottleneck, the industry urgently needs to find a high storage capacity, scalable, and low energy consumption. And a high-performance general-purpose memory with enough times to replace the traditional dynamic random access memory (DRAM), so as to improve the computing power of the chip, save the chip area, and further reduce the chip cost.

Ferroelectric random access memory (FERAM) is a new type of non-volatile memory, which has the advantages of low power consumption, high density, high speed, radiation resistance and non-volatility, so it has great application potential. The core of FERAM is the ferroelectric film layer. As the storage medium layer, the ferroelectric film layer has ferroelectric domains that can be reversed (or called "reversal"), that is, it has ferroelectricity. FERAM uses ferroelectric domains in the electric field. Different polarization orientations are used as logic information to store data, which can also be called ferroelectric memory.

The orientation of the grains in the ferroelectric film layer affects the ferroelectricity of the ferroelectric film layer, which in turn affects the performance of devices based on the ferroelectric film layer. At present, the orientation of the grains in the ferroelectric film layer is disorderly and irregular, resulting in The ferroelectricity of the electric film layer is limited.

Contents of the invention

In view of this, the embodiment of the present application provides an annealing device and an annealing method, which can control the orientation of the crystal grains in the ferroelectric film layer to tend to be consistent, improve the ferroelectricity of the ferroelectric film layer, and improve the ferroelectric film layer. performance of the device.

According to the first aspect of the embodiments of the present application, an annealing device is provided. The annealing device includes a heating component and an electric field supplying component. The heating component can anneal a sample to be annealed including a ferroelectric film layer to crystallize the ferroelectric film layer. The interior of the film layer is composed of amorphous and non-ferroelectric crystal phases and then crystallized into ferroelectric crystal phases after heat treatment, so that the ferroelectric film layer has ferroelectricity. The electric film layer provides an auxiliary electric field, and the angle between the direction of the auxiliary electric field and the surface of the ferroelectric film layer is a preset angle, so that the orientation of the crystal grains in the ferroelectric film layer tends to be consistent under the action of the auxiliary electric field, improving The ferroelectric film layer is ferroelectric, so as to improve the performance of devices based on the ferroelectric film layer and meet more application scenarios.

In a possible implementation manner, the electric field providing component includes a first electrode plate and a second electrode plate that are oppositely arranged, and the first electrode plate and the second electrode plate are used to treat the sample to be annealed. Different voltages are applied during annealing to generate an auxiliary electric field.

In the embodiment of the present application, the electric field providing part may include a first electrode plate and a second electrode plate, so as to form a stable auxiliary electric field between the first electrode plate and the second electrode plate to induce the ferroelectric film in the sample to be annealed The orientation of the crystal grains inside the layer tends to be in the same direction as the electric field.

In a possible implementation manner, at least one of the first electrode plate and the second electrode plate is designed to be movable or rotatable, so that the electric field direction of the auxiliary electric field can be adjusted.

In the embodiment of the present application, at least one of the first electrode plate and the second electrode plate can be moved or rotated, so that electric fields in different directions can be applied to the sample to be annealed, and the degree of freedom for inducing the crystallization direction of the ferroelectric film layer is improved, thereby The annealing device provided by the embodiment of the present application can be applied to various scenarios, and a set of annealing device can meet the needs of different users, save costs, and improve user experience.

In a possible implementation manner, the heating component includes at least one of a halogen lamp, a resistance wire, a flash lamp, and a laser.

In the embodiment of the present application, various methods can be used for heating, so that the annealing device can be applied to various scenarios, and a set of annealing device can meet the needs of different users, saving costs and improving user experience.

In a possible implementation manner, the heating device further includes: a sample fixing device, configured to fix at least one of the samples to be annealed.

In the embodiment of the present application, a sample fixing device may be provided to fix the sample to be annealed, so that the sample to be annealed is located in the auxiliary electric field.

In a possible implementation manner, the sample fixing device is designed to be movable or rotatable, so that the direction of the surface normal of the ferroelectric film layer relative to the direction of the auxiliary electric field can be adjusted.

In the embodiment of the present application, the sample fixing device is designed to be movable or rotatable, which improves the degree of freedom in inducing the crystallization direction of the ferroelectric film layer, so that the annealing device provided in the embodiment of the present application can be applied to various scenarios. The annealing device meets the needs of different users, saves costs, and improves user experience.

In a possible implementation manner, the heating component is a hot plate tray, and the heating component is also used to fix the sample to be annealed thereon; the electric field providing component includes the hot plate tray and a third electrode The plate, the hot plate tray and the third electrode plate are arranged opposite to each other, and are used to apply different voltages to generate an auxiliary electric field when annealing the sample to be annealed.

In the embodiment of the present application, the heating tray can form an electrode pair with the third electrode plate, so that the heating plate tray is a device that integrates fixing, heating, and applying an electric field, which saves costs.

In a possible implementation manner, the third electrode plate is designed to be movable or rotatable, so that the electric field direction of the auxiliary electric field can be adjusted.

In the embodiment of the present application, the third electrode plate is designed to be movable or rotatable, so that electric fields in different directions can be applied to the sample to be annealed, which improves the degree of freedom for inducing the crystallization direction of the ferroelectric film layer, so that the embodiment of the present application provides The advanced annealing device can be applied to a variety of scenarios. A set of annealing device can meet the needs of different users, save costs and improve the user experience.

In a possible implementation manner, the preset included angle is greater than or equal to 45° and less than or equal to 90°.

In the embodiment of the present application, the preset included angle may be between 45° and 90°, which improves the effective ferroelectric polarization of the ferroelectric film layer in some scenarios.

In a possible implementation manner, the device further includes: a cavity for placing the sample to be annealed; the cavity has a gas outlet and an air inlet, and the gas inlet is used to The gas is passed through the body, and the gas outlet is used to lead out the gas in the cavity.

In the embodiment of the present application, the sample to be annealed can be placed in the cavity, and the gas in the cavity can have the function of heat conduction, so that the temperature of the sample to be annealed can be raised or lowered to cool down, and at the same time, the sample to be annealed can be protected.

In a possible implementation manner, the electric field providing component is disposed in the cavity; the heating component is disposed in or outside the cavity.

In the embodiment of the present application, the electric field providing component is arranged in the cavity, which can reduce energy consumption, and when the material of the cavity is metal, it can prevent the metal cavity from shielding the electric field. The heating component is arranged in the cavity, which avoids the loss of heat, can save energy, and is conducive to improving the annealing efficiency. The heating component is arranged outside the cavity, which is beneficial to reduce the volume of the cavity.

In a possible implementation manner, the material of the ferroelectric film layer is a perovskite type ferroelectric material, an organic type ferroelectric material or an HfO2-based ferroelectric storage material.

In the embodiment of the present application, the ferroelectric film layer can be configured in various ways, so that the annealing device in the embodiment of the present application can perform thermal annealing operation on the ferroelectric film layer of various materials, and has a wide range of applications.

In a possible implementation manner, the auxiliary electric field is a direct current electric field, an alternating current electric field, or a mixed electric field of direct current and alternating current.

In the embodiment of the present application, the auxiliary electric field can have various forms, so that various forms of electric fields can be used to induce the direction of the crystal grains of the ferroelectric film layer to tend to be consistent, and the application range is wide.

The second aspect of the embodiment of the present application provides an annealing method, which is applied to the annealing device described in the first aspect of the embodiment of the present application, including: using a heating component to anneal the sample to be annealed, the sample to be annealed includes a ferroelectric film layer, during the thermal annealing process of the sample to be annealed, the electric field providing component can provide an auxiliary electric field for the ferroelectric film layer, and the angle between the direction of the auxiliary electric field and the surface of the ferroelectric film layer is a preset angle.

In a possible implementation manner, the electric field providing component includes a first electrode plate and a second electrode plate oppositely arranged, and when the sample to be annealed is annealed, the electric field providing component is used to provide the ferroelectric The film layer providing an auxiliary electric field includes: when annealing the sample to be annealed, applying different voltages to the first electrode plate and the second electrode plate to generate an auxiliary electric field.

In a possible implementation manner, the method further includes: moving or rotating at least one of the first electrode plate and the second electrode plate, and/or moving or rotating the handle used to fix the sample to be annealed A sample fixing device, so that the angle between the surface of the ferroelectric film layer and the auxiliary electric field is a preset angle.

In a possible implementation manner, the heating component is a hot plate tray, the heating component is also used to fix the sample to be annealed thereon, the electric field providing component includes a third electrode plate, and the heating plate The tray is arranged opposite to the third electrode plate; when annealing the sample to be annealed, using an electric field providing component to provide an auxiliary electric field for the ferroelectric film layer includes: annealing the sample to be annealed When , different voltages are applied to the hot plate tray and the third electrode plate to generate an auxiliary electric field.

In a possible implementation manner, the method further includes: moving or rotating the third electrode plate, so that an included angle between the surface of the ferroelectric film layer and the auxiliary electric field is a preset included angle.

In a possible implementation manner, the preset included angle is greater than or equal to 45° and less than or equal to 90°.

In a possible implementation manner, the annealing process for the sample to be annealed includes a heating process, a temperature constant process and a cooling process, and an electric field providing component is used to provide an auxiliary electric field for the ferroelectric film layer, and during the heating process, Performed in at least one of the temperature constant process and the cooling process.

In a possible implementation manner, the generating time of the auxiliary electric field is earlier than the starting time of the heating process, and the canceling time of the auxiliary electric field is later than the ending time of the cooling process.

In a possible implementation manner, the annealing device further includes a chamber, the chamber has a gas outlet and an air inlet, and the method further includes: using the air inlet to feed gas into the chamber , using the gas outlet to lead out the gas in the cavity.

In a possible implementation manner, the auxiliary electric field is a direct current electric field, an alternating current electric field, or a mixed electric field of direct current and alternating current.

It can be seen from the above technical solutions that the embodiments of the present application have the following advantages:

Embodiments of the present application provide an annealing device and an annealing method. The annealing device includes a heating component and an electric field supplying component. The heating component can anneal a sample to be annealed including a ferroelectric film layer to crystallize the ferroelectric film layer. Inside the ferroelectric film layer The amorphous and non-ferroelectric crystal phases are crystallized into ferroelectric crystal phases after heat treatment, so that the ferroelectric film layer has ferroelectricity. In the process of thermal annealing of the sample to be annealed, the electric field supply component can be a ferroelectric film layer Provide an auxiliary electric field, the angle between the direction of the auxiliary electric field and the surface of the ferroelectric film layer is a preset angle, so that the direction of the crystal grains in the ferroelectric film layer tends to be consistent under the action of the auxiliary electric field, and the ferroelectric film layer is improved. Layer ferroelectricity to improve the performance of devices based on ferroelectric layers to meet more application scenarios.

Description of drawings

In order to clearly understand the specific implementation manners of the present application, the accompanying drawings used in describing the specific implementation manners of the present application will be briefly described below. Apparently, these drawings are only some embodiments of the present application.

Fig. 1 is the crystal phase schematic diagram of present a kind of ferroelectric film layer;

FIG. 2 is a schematic diagram of an annealing device provided in an embodiment of the present application;

Figure 3 is a schematic diagram of another annealing device provided in the embodiment of the present application;

Fig. 4 is a schematic diagram of the relationship between the crystal orientation of a ferroelectric film layer and the direction of the auxiliary electric field provided by the embodiment of the present application;

5 is a schematic diagram of the relationship between the crystal orientation and the direction of the auxiliary electric field of another ferroelectric film layer provided by the embodiment of the present application;

6 is a schematic diagram of the direction of an electric dipole in a ferroelectric film layer provided by an embodiment of the present application;

FIG. 7 is a schematic diagram of another annealing device provided in the embodiment of the present application;

Fig. 8 is a schematic diagram of another annealing device provided in the embodiment of the present application;

Fig. 9 is a schematic diagram of another annealing device provided in the embodiment of the present application;

Fig. 10 is a schematic diagram of another annealing device provided in the embodiment of the present application;

Fig. 11 is a schematic diagram of another annealing device provided in the embodiment of the present application;

Fig. 12 is a schematic diagram of the structure of a quartz boat in different placement directions in the embodiment of the present application;

Fig. 13 is a schematic diagram of an electric field control provided by an embodiment of the present application.

Detailed ways

The embodiment of the present application provides an annealing device and an annealing method, which can control the direction of the crystal grains in the ferroelectric film layer to tend to be consistent, so as to improve the ferroelectricity of the ferroelectric film layer, so as to improve the devices based on the ferroelectric film layer performance.

The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of this application and the above drawings are used to distinguish similar objects, and not necessarily Used to describe a specific sequence or sequence. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

The present application is described in detail in combination with schematic diagrams. When describing the embodiments of the present application in detail, for the convenience of explanation, the cross-sectional view showing the device structure will not be partially enlarged according to the general scale, and the schematic diagram is only an example, which should not limit the present application. scope of protection. In addition, the three-dimensional space dimensions of length, width and depth should be included in actual production.

The core of FERAM is the ferroelectric film layer. As the storage medium layer, the ferroelectric film layer has ferroelectric domains that can be reversed (or called "reversal"), that is, it has ferroelectricity. FERAM uses ferroelectric domains in the electric field. Different polarization orientations are used as logic information to store data, which can also be called ferroelectric memory. The orientation of crystal grains in the ferroelectric film layer directly affects the ferroelectricity of the ferroelectric film layer, and further affects the performance of devices based on the ferroelectric film layer.

In actual operation, when the ferroelectric film layer is just grown, its interior is amorphous and non-ferroelectric crystal phase, and it needs subsequent heat treatment to crystallize into a ferroelectric crystal phase, thus possessing ferroelectricity. However, the crystallization process of the crystal is a random process as a whole, as shown in Figure 1, which is a schematic diagram of the crystal orientation of a ferroelectric film layer at present, taking the material of the ferroelectric film layer as HfO ₂ as an example, as shown in Figure 1A , is a schematic diagram of the molecular structure of HfO ₂ in the ferroelectric film layer _after heat treatment. HfO ₂ molecules include Hf ⁴⁺ and O ^2- . consistency. Referring to Fig. 1B, it is a schematic diagram of the orientation of crystal grains in the ferroelectric film layer after heat treatment, and the direction of the arrow indicates the orientation of the crystal grains in the ferroelectric film layer. It can be seen that polycrystals are formed inside the ferroelectric film layer after heat treatment, The orientation of the HfO ₂ molecules inside each grain is consistent, but the orientation between different grains is not consistent, that is, the orientation of the grains in the ferroelectric film layer is in all directions.

The grains in the ferroelectric film layer have different crystal phases, which can be divided into ferroelectric crystal phases and non-ferroelectric crystal phases. The grains of the ferroelectric crystal phase have reversible ferroelectric domains, which can be flipped by an external electric field. The flipping of ferroelectric domains is essentially the change of the direction of the electric dipole in the ferroelectric film layer. The electric dipole in the film layer comes from the separation of the positive and negative charge centers inside the ferroelectric film lattice, so the orientation of the crystal grains in the ferroelectric film layer determines the orientation of its internal electric dipole, and the orientation of the electric dipole It directly affects the ferroelectricity of the ferroelectric film layer, so the orientation of the grains in the ferroelectric film layer affects the ferroelectricity of the ferroelectric film layer.

For example, two electrodes are arranged on both sides of the ferroelectric film layer. When the electrodes are applied with different voltages, the ferroelectric film layer is placed in an electric field. The direction of the electric field is perpendicular to the surface of the ferroelectric film layer and also perpendicular to the surface of the electrodes. The direction of is the normal direction of the electrode. When a large number of electric dipoles in the ferroelectric film layer actually contribute to the normal direction of the electrode as the effective ferroelectric polarization, the initial direction of the electric dipole directly affects the effective ferroelectric film layer. For the ferroelectric polarization, if the direction of the ferroelectric crystal grains is chaotic and random, the direction of the electric dipole will be chaotic and random, which will lead to the limitation of the ferroelectric polarization of the ferroelectric film layer. In addition, when the size of the ferroelectric device is small, for example, when the size of the ferroelectric device is reduced to the order of 10nm, there are often only a few or dozens of crystal grains inside a unit device. At this time, the randomness of the grain orientation will seriously It affects the consistency of ferroelectric performance between different unit devices. Therefore, it is necessary to control the crystallization process of the ferroelectric film layer so that the orientation of each ferroelectric grain is as consistent as possible, so as to enhance the effective ferroelectric polarization and improve the inter-device uniformity effect.

At present, the ferroelectric film layer can be sandwiched by the electrode layer. Specifically, the ferroelectric film layer can be arranged on a substrate (substrate, SUB), the electrode layer is arranged on the ferroelectric film layer and is in contact with the ferroelectric film layer, and the ferroelectric film layer The film layer is, for example, a hafnium zirconium oxide (HZO) layer, and the material of the electrode layer can be TiN. Under the joint action of thermal annealing and electrode layer stress induction, the HZO layer is crystallized into a ferroelectric layer with a noncentrosymmetric structure. crystalline phase, resulting in ferroelectricity.

However, in this crystallization method, the electrode layer needs to have a specific crystal orientation to induce better ferroelectric properties of the ferroelectric film layer. When the HZO layer is set on the SUB, the TiN electrode layer is set on the HZO layer, and the TiN electrode layer When the crystal orientation is (002), after thermal annealing, the capacitance per unit area of the HZO layer is always small, that is, the ferroelectric polarization under different electric field strengths is small, that is, the ferroelectricity of the HZO layer is still weak; When the HZO layer is set on the SUB, the TiN electrode layer is set on the HZO layer, and the crystal orientation of the TiN electrode layer is (111), after thermal annealing, the capacitance per unit area of the HZO layer can reach a large level, that is, the HZO layer The ferroelectric polarization of the HZO layer is stronger, and the ferroelectricity of the HZO layer is stronger.

That is to say, in the scheme of using the electrode layer to clamp the ferroelectric film layer so that the ferroelectric film layer can realize the uniform crystal orientation under the stress induction of the electrode layer, the requirements for electrode preparation are relatively high, and it is difficult to guarantee On the wafer, for example, on a 12-inch wafer, all TiN layers with (111) crystal orientation can be uniformly deposited, so it is difficult to ensure the uniform polarization of the ferroelectric layer on larger-sized wafers sex.

Common annealing devices include furnace tubes for annealing and rapid thermal annealing furnaces. By increasing the cooling rate, the ferroelectric film layer can stabilize the ferroelectric crystal phase and improve the ferroelectric properties. Therefore, compared with rapid thermal annealing, which has a faster cooling rate, the annealing time required for furnace tube annealing is longer, and the cooling rate Slower, making the grain growth process in the ferroelectric film layer more random, will further lead to deterioration of the ferroelectricity and uniformity of the device. However, neither furnace tube annealing nor rapid thermal annealing can regulate the grain orientation inside the ferroelectric film layer.

Based on the above technical problems, embodiments of the present application provide an annealing device and an annealing method. The annealing device includes a heating component and an electric field supplying component. The heating component can anneal a sample to be annealed including a ferroelectric film layer to crystallize the ferroelectric film layer. The interior of the ferroelectric film layer is composed of amorphous and non-ferroelectric crystal phases and then crystallized into ferroelectric crystal phases after heat treatment, so that the ferroelectric film layer has ferroelectricity. During the thermal annealing process of the sample to be annealed, the electric field supply components can Provide an auxiliary electric field for the ferroelectric film layer, the angle between the direction of the auxiliary electric field and the surface of the ferroelectric film layer is a preset angle, so that the direction of the crystal grains in the ferroelectric film layer tends to be consistent under the action of the auxiliary electric field , improve the ferroelectricity of the ferroelectric film layer, so as to improve the performance of devices based on the ferroelectric film layer, and meet more application scenarios.

In order to better understand the technical solutions and technical effects of the present application, specific embodiments will be described in detail below in conjunction with the accompanying drawings.

In the embodiment of the present application, the annealing device can be used to anneal the sample 22 to be annealed. Referring to FIG. 2 and FIG. 3, it is a schematic structural diagram of the annealing device provided in the embodiment of the present application, wherein the sample 22 to be annealed includes a ferroelectric film layer , which can promote the crystallization of the ferroelectric film layer into a ferroelectric crystal phase to have ferroelectricity, so that the sample 22 to be annealed has storage properties or other functional properties based on the ferroelectricity of the ferroelectric film layer.

Specifically, the material of the ferroelectric film layer may be a perovskite type ferroelectric material, may also be an organic type ferroelectric material, or may be a ferroelectric storage material such as HfO2 base. The sample 22 to be annealed can include storage devices based on ferroelectric film layers such as FERAM, ferroelectric field effect transistor (ferroelectric field effect transistor, FFET) or ferroelectric tunneling junction (ferroelectric tunneling junction, FTJ), and can also be other using ferroelectric Materials for novel device structures. The sample 22 to be annealed can be applied to products such as embedded storage, DRAM-like storage, and in-storage computing.

Among them, the storage unit of FERAM can include a transistor and a ferroelectric capacitor. A transistor and a ferroelectric capacitor are connected to form a storage unit. - Ferroelectric-metal structure capacitors (metal-ferroelectric-metal, MFM), used to store charge capacitance, use the polarization reversal of the electric dipole in the ferroelectric film layer to realize data writing and reading. At this time, the ferroelectric The change of the polarization reversal of the electric dipole in the electric film layer will cause the charge and discharge of the capacitor, which can be recognized by the external circuit to realize the storage state of "0" and "1". In the two storage states of the ferroelectric film layer, The internal electric dipole points to two opposite directions as a whole, and the change in the direction of the electric dipole as a whole is called polarization reversal. The difference in capacitance density in different storage states depends on the angle between the electric dipole and the normal mass of the electrode in the two states. In some scenarios, the difference in capacitance density in different storage states depends on the electric dipole in the two states. The dipole is parallel to the size of the total amount of the electrode normal, and in other scenarios, the difference in capacitance density in different storage states depends on the size of the total amount of the electric dipole perpendicular to the electrode direction in the two states, so the ferroelectric The orientation of the ferroelectric grains in the film determines how much of its internal electric dipole can actually contribute to the MFM capacitance.

FEFET uses a ferroelectric film layer to replace the gate dielectric layer of a conventional metal-oxide-semiconductor field-effect transistor (MOSFET) to form an MFIS structure, which can include sequentially stacked metal layers, ferroelectric layers , an insulator layer and a semiconductor layer, the conductance of the surface of the semiconductor layer can be modulated by using the ferroelectric layer.

In the embodiment of the present application, the annealing device may include: a heating component 21 and an electric field providing component 24 . In the embodiment of the present application, the heating unit 21 is used to anneal the sample 22 to be annealed, so that the ferroelectric film layer is crystallized into a ferroelectric crystal phase and has ferroelectricity. Wherein, the annealing process may include a heating process, a temperature constant process and a cooling process, and the heating unit 21 may heat the sample 22 to be annealed so that the temperature of the sample 22 to be annealed is raised and kept constant, and the heating of the sample 22 to be annealed can be stopped to make the sample 22 to be annealed heated. The temperature of the annealed sample 22 was decreased.

The heating component 21 can heat the sample 22 to be annealed by heat radiation, heat conduction and the like. Specifically, the heating part 21 can be a hot plate tray, and the hot plate tray is used to fix the sample to be annealed 22 on it, and the hot plate tray can be in contact with the sample to be annealed 22 on it, and then the sample to be annealed can be heated by heat conduction 22. The annealing device can be a hot plate annealing furnace, as shown in FIG. 3; the heating component 21 can include at least one of a radiation filament, a halogen lamp, a resistance wire, a flash lamp, and a laser, so that heat radiation can be used to heat the sample 22 to be annealed. Heating, as shown in Figure 2. In actual operation, the device that uses laser for thermal annealing is a laser annealing furnace, and the common one is a laser spike annealing furnace; a rapid thermal annealing (rapid temperature processing) furnace can be a tungsten-halogen filament for radiation heating Device; flash lamp annealing (flash lamp annealing) device can use a xenon flash lamp for heating.

In the embodiment of the present application, the heating member 21 may include one or multiple heating members 21 may be arranged on different sides of the sample to be annealed 22, or may be arranged on the same side of the sample to be annealed 22, so that The heating and annealing of the sample 22 to be annealed is carried out from multiple directions, so that the sample 22 to be annealed is heated evenly, and the crystallization quality of the ferroelectric film layer is improved. The extending direction of the heating member 21 may be parallel to the extending direction of the sample to be annealed 22, so that the ferroelectric film layer can be evenly heated. Referring to FIG. 2 , the sample to be annealed 22 is placed horizontally, and the two heating components 21 are located on the upper side and the lower side of the sample to be annealed 22 respectively, and extend along the horizontal direction. Referring to FIG. 3 , the sample to be annealed 22 is placed horizontally, and the hot plate tray is used as the heating part 21 , located on the lower side of the sample to be annealed 22 and extends along the horizontal direction.

In the conventional annealing process, since the crystallization process is a random process as a whole, the ferroelectric crystal phase of the ferroelectric film layer after annealing is often crystallized into random polycrystalline, and the grains in the ferroelectric film layer are oriented toward In all directions, the direction of crystal grains in the ferroelectric film layer is chaotic and random, which will lead to the direction of electric dipoles in the ferroelectric film layer to be chaotic and random, which in turn leads to the limitation of the ferroelectric performance of the ferroelectric film layer.

In the embodiment of the present application, the electric field providing part 24 can be used to provide an auxiliary electric field for the ferroelectric film layer 23 when the sample 22 to be annealed is annealed, so that the orientation of the crystal grains in the ferroelectric film layer is along the direction of the electric field, so that the ferroelectric film layer The angle between the crystal grains in the film and the surface of the ferroelectric film is a preset angle, which can improve the ferroelectricity of the ferroelectric film, so as to improve the performance of devices based on the ferroelectric film and meet more requirements. Application scenarios. The auxiliary electric field may exist in at least one of the heating process, temperature constant process and cooling process of the annealing process. For example, the auxiliary electric field may exist in the entire annealing process to effectively improve the orientation consistency of the grains in the ferroelectric film layer. The auxiliary electric field can be a DC electric field, an AC electric field or a mixed electric field of DC and AC, etc., wherein the DC electric field can be a positive electric field or a negative electric field, and the AC electric field can have a certain intensity and a certain frequency.

Wherein, the electric field providing part 24 may include a plurality of electrode plates, for example, may include a first electrode plate 241 and a second electrode plate 242, as shown in FIG. When different voltages are applied to the first electrode plate 241 and the second electrode plate 242, an auxiliary electric field is formed between the two, and the annealed sample 22 is placed between the first electrode plate 241 and the second electrode plate 242, and the annealed sample 22 is placed between In the auxiliary electric field; referring to Fig. 3, when the heating part 21 is a hot plate tray, the electric field providing part 24 can include a heating tray and at least one electrode plate, for example, include a heating tray and a third electrode plate 243, the third electrode plate 243 and the hot plate tray are set opposite to each other to achieve stable control of the auxiliary electric field. When the third electrode plate 243 and the hot plate tray are applied with different voltages, an auxiliary electric field is formed between the two, and the sample 22 to be annealed is placed on the third electrode. Between the plate 243 and the hot plate tray, the sample 22 to be annealed is placed in the auxiliary electric field.

Under the action of the auxiliary electric field, the orientation of the crystal grains tends to be consistent with the direction of the electric field, so the orientation of the crystal grains in the ferroelectric film layer tends to be consistent. Referring to Figure 4 and Figure 5, it is a schematic diagram of the relationship between the crystal orientation of the ferroelectric film layer and the direction of the auxiliary electric field in the embodiment of the present application. Referring to Figure 4A and Figure 4B, when the surface normal direction parallel to the ferroelectric film layer is applied, During the auxiliary electric field, the direction of the auxiliary electric field is perpendicular to the surface of the ferroelectric film layer 23, and the crystal grain obtained has the polarization direction (direction of P) parallel to the normal direction of the ferroelectric film layer 23 surface, and the obtained crystallization state refers to As shown in FIG. 4C, the orientations of the grains are basically the same, and the overall polarization direction of the ferroelectric film layer 23 is parallel to the normal direction of the surface of the ferroelectric film layer 23, as shown in FIG. 4D; with reference to FIG. 5A, in When applying an auxiliary electric field inclined relative to the surface normal of the ferroelectric film layer 23, the direction of the auxiliary electric field intersects and is not perpendicular to the surface of the ferroelectric film layer 23, and the crystal grains obtained have a surface normal direction relative to the ferroelectric film layer 23. Slanted polarization direction (direction of P), the obtained crystallization state is shown in Fig. 5B with reference to, and each crystal grain faces substantially the same, and the overall polarization direction of the ferroelectric film layer 23 that reflects is the same as that of the ferroelectric film layer 23. The surface normal has a certain inclination angle, as shown in FIG. 5C .

In the embodiment of the present application, the ferroelectric device is generally formed by stacking the ferroelectric film layer 23 and the electrode layers on both sides. The thickness of each layer in the ferroelectric film layer 23 and the electrode layer can be on the order of 10nm. The electrode layer is generally a metal layer. When the ferroelectric device is working, the electrode layers on both sides of the ferroelectric film layer 23 are used as the operating electrodes of the ferroelectric device to provide an operating voltage for the ferroelectric film layer 23. The direction of the operating voltage is perpendicular to the ferroelectric film. On the surface of the layer 23, the operating voltage can act on the electric dipole in the ferroelectric film layer 23, causing the electric dipole to reverse, driving the ferroelectric film layer 23 to change the polarization direction of the electric dipole, and then making the iron The electrical film layer 23 exhibits different storage states. In different scenarios, the direction of the operating voltage and the electric dipole can be set at different angles, so that the device has different performance characteristics. Since the direction of the operating voltage is perpendicular to the surface of the ferroelectric film layer 23, the direction of the electric dipole ( That is, the orientation of the crystal grains) is affected by the auxiliary electric field and the crystallization process. In different scenarios, the electric dipoles in the ferroelectric film layer 23 can have different angles by setting the ferroelectric film layer 23 and the auxiliary electric field. Direction, so that the angle between the operating voltage and the electric dipole is set differently to meet more diverse needs. For example, the electric dipole direction regulated by the auxiliary electric field can be perpendicular to the surface of the ferroelectric film layer 23, or not perpendicular to the surface of the ferroelectric film layer 23, and the angle of the auxiliary electric field can be adjusted according to actual needs, so that the ferroelectric film layer 23 The angle between the surface and the auxiliary electric field is a preset angle, and the preset angle is greater than or equal to 0° and less than or equal to 90°.

Referring to FIG. 6, it is a schematic diagram of the direction of an electric dipole in a ferroelectric film layer provided by an embodiment of the present application, wherein the sample 22 to be annealed includes a ferroelectric film layer 23, and the ferroelectric film layer 23 is respectively On both sides of the first electrode layer 251 and the second electrode layer 252, the horizontal direction of the electrodes represents the direction of extension of the parallel ferroelectric film layer 23, which can be referred to as the X direction, and the normal direction of the electrodes represents the direction of extension of the vertical ferroelectric film layer 23 The direction of the electric dipole can be recorded as the Y direction. The direction of the electric dipole can be represented by a gray solid line with an arrow. The direction after the electric dipole is flipped is represented by a black solid line with an arrow. α, the preset included angle is the included angle between the auxiliary electric field and the surface of the ferroelectric film layer 23 , that is, the included angle between the electric dipole and the X direction, and the sum of the preset included angle and the included angle α is 90°.

Concretely, the more components of the electric dipole on the electrode normal direction (Y direction), the higher the effective ferroelectric polarization of the ferroelectric film layer 23, then the electric dipole and the electrode normal direction (Y direction) can be set. The included angle α is small, that is, a larger preset included angle can be set, and the preset included angle can be set to be greater than or equal to 45° and less than or equal to 90°, corresponding to 0°<α<45°, refer to Figure 6A As shown, the electric dipole in the ferroelectric film layer 23 has more components on the electrode normal direction (Y direction), so that the effective ferroelectric polarization of the ferroelectric film layer 23 is larger, and the electric dipole reversal needs The electric field of the ferroelectric device is low, thereby greatly reducing the operating voltage of the ferroelectric device and improving the circuit integration of the ferroelectric device. Conversely, when the preset included angle can be set to be less than 45° and greater than or equal to 0°, corresponding to 45°<α≤90°, as shown in Figure 6B, the electric dipole is in the normal direction of the electrode (Y direction) The component of is less, so that the effective ferroelectric polarization of the ferroelectric film layer 23 is smaller, and requires a higher operating voltage.

In the embodiment of the present application, when the electric field providing part 24 includes the first electrode plate 241 and the second electrode plate 242, the electric field direction of the auxiliary electric field can be adjusted, which can be realized by movable or rotatable electrode plates. Specifically, at least one of the first electrode plate 241 and the second electrode plate 242 is designed to be movable or rotatable, so that the electric field direction of the auxiliary electric field can be adjusted, so that electric fields in different directions can be applied to the sample 22 to be annealed, and the In order to induce the degree of freedom of the crystallization direction of the ferroelectric film layer 23, the annealing device provided by the embodiment of the present application can be applied to various scenarios, and a set of annealing device can meet the needs of different users, saving costs and improving the use of users experience.

For example, the first electrode plate 241 and the second electrode plate 242 can be rotated and set at a certain angle with the surface of the sample 22 to be annealed, so that the auxiliary electric field provided by the first electrode plate 241 and the second electrode plate 242 is consistent with the iron The surface of the electric film layer 23 intersects, so that the direction of the internal crystal grains and electric dipoles of the ferroelectric film layer 23 forms a certain angle with the normal direction of the ferroelectric film layer 23 . Referring to FIG. 7 , which is a structural schematic diagram of another annealing device in the embodiment of the present application, the first electrode plate 241 can be rotated to be located at the position of the dotted line frame, so as to be set at a certain angle with the surface of the sample 22 to be annealed.

In the embodiment of the present application, when the electric field providing component 24 includes the first electrode plate 241 and the second electrode plate 242, the electric field direction of the auxiliary electric field can be adjusted, which can be realized by a plurality of fixed electrode plates. Specifically, there are multiple first electrode plates 241 and/or second electrode plates 242, these first electrode plates 241 and second electrode plates 242 can have different orientations, and can also be located at different positions. An electrode plate 241 and a pair of electrodes in the second electrode plate 242 provide, and also can be provided by many pairs of electrodes in the first electrode plate 241 and the second electrode plate 242, thereby promoted the ability of inducing the crystallization direction of the ferroelectric film layer 23 The degree of freedom can unify the direction of the crystal grains in the ferroelectric film layer 23 to more directions, so as to reflect different device performances and improve user experience.

For example, referring to FIG. 8 , which is a schematic structural diagram of another annealing device in the embodiment of the present application, the first electrode plate 241 may include a first sub-electrode plate 2411 located on the upper left of the sample to be annealed 22, and a first sub-electrode plate 2411 on the upper right. The second sub-electrode plate 2412 and the third sub-electrode plate 2413 directly above, that is, three first electrode plates 241 are simultaneously set in the annealing device provided in the embodiment of the present application. The first sub-electrode plate 2411 and the second electrode plate 242 on the upper left provide an auxiliary electric field toward the upper left or lower right. The electrode plate 242 provides an auxiliary electric field facing directly above or directly below. When it is necessary to direct the grain to the upper right, the second sub-electrode plate 2412 and the second electrode plate 242 on the upper right can be used to provide an auxiliary electric field directed to the upper right or lower left. electric field.

In the embodiment of the present application, referring to FIG. 9, when the electric field providing component 24 includes a hot plate tray and a third electrode plate 243, the hot plate tray and the third electrode plate 243 can be used to provide an electric field. At this time, the hot plate tray serves as One of the electrodes and the third electrode plate 243 form an electrode pair. In this case, the electric field direction of the auxiliary electric field can be adjusted, which can be realized by the movable third electrode plate 243 and/or the hot plate tray. Specifically, the third electrode plate 243 can be designed to be movable, so that the electric field direction of the auxiliary electric field can be adjusted, so that the electric field in different directions can be applied to the sample 22 to be annealed, and the degree of freedom for inducing the crystallization direction of the ferroelectric film layer 23 is improved. , so that the annealing device provided in the embodiment of the present application can be applied to various scenarios, and a set of annealing device can meet the needs of different users, save costs, and improve user experience.

For example, the third electrode plate 243 can form a certain angle with the surface of the sample 22 to be annealed, and the auxiliary electric field provided by the hot plate tray and the third electrode plate 243 intersects the surface of the ferroelectric film layer 23, thereby making the ferroelectric film layer The grain direction of 23 forms a certain angle with the normal direction of the surface of the ferroelectric film layer 23 . Referring to FIG. 9 , which is a schematic structural diagram of another annealing device in the embodiment of the present application, the third electrode plate 243 can be rotated to be located at the position of the dotted line frame, so as to be set at a certain angle with the surface of the sample 22 to be annealed.

In the embodiment of the present application, when the electric field providing part 24 includes the third electrode plate 243, the electric field can be provided by using the hot plate tray and the third electrode plate 243. At this time, the hot plate tray is used as one of the electrodes, and the third electrode plate 243 An electrode pair is formed. In this case, the electric field direction of the auxiliary electric field can be adjusted, which can be realized by a plurality of fixed third electrode plates 243 . Specifically, there are multiple third electrode plates 243, and these third electrode plates 243 can have different orientations, and can also be located at different positions. The auxiliary electrode can be provided by a third electrode plate 243 and a hot plate tray, or can be provided by A plurality of third electrode plates 243 and hot plate trays are provided, thereby improving the degree of freedom to induce the crystallization direction of the ferroelectric film layer 23, and can realize that the direction of the crystal grains in the ferroelectric film layer 23 is unified to more directions to reflect It provides different device performance and improves the user experience.

For example, referring to FIG. 10 , which is a structural schematic diagram of another annealing device in the embodiment of the present application, the third electrode plate 243 may include a fourth sub-electrode plate 2431 located on the upper left of the sample to be annealed 22, and a fourth sub-electrode plate 2431 on the upper right. The fifth sub-electrode plate 2432 and the sixth sub-electrode plate 2433 directly above, that is, three third electrode plates 243 are simultaneously set in the annealing device provided in the embodiment of the present application. The fourth sub-electrode plate 2431 on the upper left and the hot plate tray provide an auxiliary electric field towards the upper left or lower right. When the grain needs to be directed upward, the sixth sub-electrode plate 2433 and the hot plate tray directly above are used to provide For the auxiliary electric field facing directly above or directly below, when it is necessary to direct the crystal grains toward the upper right 2432, the upper right fifth sub-electrode plate 2432 and the hot plate tray are used to provide the auxiliary electric field toward the upper right or lower left.

The annealing device provided in the embodiment of the present application may also include: a sample fixing device 3, which is used to fix at least one sample to be annealed 22, so that the sample to be annealed 22 is located in the auxiliary electric field, as shown in FIG. 7, FIG. 8 and FIG. 11, Referring to FIG. 11 , it is a schematic structural diagram of another annealing device in an embodiment of the present application. In a possible implementation, the sample fixing device 3 can be designed to be movable or rotatable, so that the surface normal direction of the ferroelectric film layer 23 can be adjusted relative to the direction of the auxiliary electric field.

Specifically, the sample fixing device 3 can simultaneously fix a sample 22 to be annealed, for example, the sample fixing device 3 is a quartz bracket, etc., as shown in FIGS. 7 and 8 . When the hot plate tray is used as the heating component 21, it itself serves as a sample fixing device, so no additional sample fixing device may be provided, as shown in FIG. 3 , FIG. 9 and FIG. 10 .

Specifically, the sample fixing device 3 can also fix a plurality of samples 22 to be annealed at the same time, so that multiple samples 22 to be annealed can be thermally annealed at one time, which improves the throughput. In the quartz boat, the side wall of the sample to be annealed 22 is stuck in the groove, and multiple samples to be annealed 22 are arranged in parallel, so that multiple samples to be annealed 22 can be thermally annealed at one time, as shown in FIG. 11 . Referring to FIG. 12 , which is a schematic structural view of a quartz boat in different placement directions in the embodiment of the present application, multiple annealing samples 22 can be fixed in the same sample fixing device, and multiple annealing samples 22 are arranged in parallel.

Depending on the groove design, the sample to be annealed 22 can be fixed at different angles, for example, the sample to be annealed 22 can be arranged perpendicular to the direction of the electric field, referring to the sample to be annealed 22 represented by the solid line in Fig. 11A; The annealing sample 22 is arranged parallel to the direction of the electric field, with reference to the sample 22 to be annealed represented by the solid line in Figure 11B; the sample 22 to be annealed can also be arranged at a certain inclination angle with the direction of the electric field, with reference to the sample 22 to be annealed represented by the dotted line in Figure 11A, And the sample to be annealed 22 indicated by the dotted line in Fig. 11B. Therefore, different angles between the ferroelectric film layer 23 and the auxiliary electric field in the sample to be annealed 22 can be realized by customizing different sample fixtures 3, thereby determining different crystal orientations in the ferroelectric film layer 23, so it can support more flexibly. Electric field induction requirements and scenarios.

In the embodiment of the present application, the annealing device may further include: a cavity 5 for placing the sample to be annealed 22, the sample to be annealed 22 may be arranged in the cavity, the cavity may form a closed space, and gas may pass through the closed space, Specifically, the gas introduced may be a shielding gas, and the sample 22 to be annealed is protected by the shielding gas in the cavity. In addition, the gas in the cavity has the function of heat conduction, so that the temperature of the sample 22 to be annealed is raised or lowered. The material of the cavity can be a metal material or an insulating material. When the material of the cavity is an insulating material, the cavity can be a transparent cavity or an opaque cavity. The cavity can be box type, as shown in Figure 7, Figure 8, Figure 9 and Figure 10, the cavity can also be tubular, as shown in Figure 11, when the cavity is tubular, the annealing device can be called a furnace Tube or tubular annealing furnace.

Specifically, when the heating component 21 heats the sample 22 to be annealed by thermal radiation, the heating component 21 can be arranged outside the cavity, which is beneficial to reduce the volume of the cavity, as shown in FIG. 11; the heating component 21 can also be set in the cavity In the body, the loss of heat is avoided, energy can be saved, and it is beneficial to improve the annealing efficiency. Specifically, when the material of the cavity is a metal material, the electric field providing part 24 can be arranged in the cavity to prevent the metal cavity from shielding the electric field; when the cavity 5 is a non-metallic material, the electric field providing part 24 can be provided 24 is arranged outside the cavity to save space in the cavity 5, and the electric field providing component 24 can also be arranged inside the cavity to reduce energy consumption.

In the embodiment of the present application, the cavity 5 has an air outlet 51 and an air inlet 52 , the air inlet 52 is used to feed gas into the cavity 5 , and the air outlet 51 is used to export the gas in the cavity 5 . The air inlet 51 and the air outlet 52 of the cavity 5 can be arranged on different sides of the cavity 5 , or can be arranged on the same side of the cavity 5 . Referring to Fig. 7, Fig. 8, Fig. 9 and Fig. 10, an air inlet 52 is provided on one side of the cavity 5, and an air outlet 51 is provided on the other side of the cavity 5, so that the process of thermal annealing Introduce gas. Referring to FIG. 11 , the air inlet 51 and the air outlet 52 of the cavity 5 are arranged on the same side of the cavity.

In addition, when the heating part 21 heats the sample 22 to be annealed by means of thermal radiation, the annealing device may also include a reflector 4 surrounding the heating part 21, so as to avoid heat loss caused by light overflow, and realize the annealing sample 22 more quickly. 22 heat annealing, saving costs. For example, the reflective plate 4 can be disposed around the heating component 21 , as shown in FIG. 7 and FIG. 8 .

An embodiment of the present application provides an annealing device. The annealing device includes a heating component and an electric field supplying component. The heating component can anneal a sample to be annealed including a ferroelectric film layer to crystallize the ferroelectric film layer. The crystalline and non-ferroelectric crystal phases are crystallized into ferroelectric crystal phases after heat treatment, so that the ferroelectric film layer has ferroelectricity. During the thermal annealing process of the sample to be annealed, the electric field supply component can provide assistance for the ferroelectric film Electric field, the angle between the direction of the auxiliary electric field and the surface of the ferroelectric film layer is a preset angle, so that the orientation of the crystal grains in the ferroelectric film layer tends to be consistent, and the ferroelectricity of the ferroelectric film layer is improved to improve the ferroelectric film based on The performance of the device with the ferroelectric film layer meets more application scenarios.

Based on the annealing device provided in the above embodiment, the embodiment of the present application also provides an annealing method, which can be applied to the annealing device provided in the above embodiment, and the method includes the following steps:

S101: Use the heating part 21 to anneal the sample 22 to be annealed, and use the electric field supply part to provide an auxiliary electric field for the ferroelectric film layer when the sample 22 to be annealed is annealed.

In the embodiment of the present application, the sample 22 to be annealed includes a ferroelectric film layer, which can promote the crystallization of the ferroelectric film layer into a ferroelectric crystal phase and have ferroelectricity, so that the sample 22 to be annealed is based on the ferroelectricity of the ferroelectric film layer. Has storage or other functional properties. Specifically, the material of the ferroelectric film layer may be a perovskite type ferroelectric material, may also be an organic type ferroelectric material, or may be a ferroelectric storage material such as HfO2 base. The sample 22 to be annealed may include storage devices based on ferroelectric film layers such as FERAM, FFET or FTJ, or other new device structures utilizing ferroelectric materials. The sample 22 to be annealed can be applied to products such as embedded storage, DRAM-like storage, and in-storage computing.

Among them, the storage unit of FERAM can include a transistor and a ferroelectric capacitor. A transistor and a ferroelectric capacitor are connected to form a storage unit. The ferroelectric film layer in the ferroelectric capacitor is used as a dielectric layer, and the electrodes on both sides of the ferroelectric film layer form an MFM. , used to store charge capacitance; FEFET uses a ferroelectric film layer to replace the gate dielectric layer of a conventional MOSFET to form an MFS structure, which can include sequentially stacked metal layers, ferroelectric layers, insulator layers, and semiconductor layers. Ferroelectric layers can be used Modulates the conductance of the surface of the semiconductor layer.

In the embodiment of the present application, the heating member 21 can be used to anneal the sample 22 to be annealed, so that the ferroelectric film layer 23 is crystallized into a ferroelectric crystal phase and has ferroelectricity. Wherein, the annealing process may include a heating process, a temperature constant process and a cooling process, and the heating unit 21 may heat the sample 22 to be annealed so that the temperature of the sample 22 to be annealed is raised and kept constant, and the heating of the sample 22 to be annealed can be stopped to make the sample 22 to be annealed heated. The temperature of the annealed sample 22 was decreased.

The heating component 21 can heat the sample 22 to be annealed by heat radiation, heat conduction and the like. Specifically, the heating part 21 can be a hot plate tray, and the hot plate tray is used to fix the sample to be annealed 22 on it, and the hot plate tray can be in contact with the sample to be annealed 22 on it, and then the sample to be annealed can be heated by heat conduction 22. The annealing device can be a hot plate annealing furnace, as shown in FIG. 3; the heating component 21 can include at least one of a radiation filament, a halogen lamp, a resistance wire, a flash lamp, and a laser, so that heat radiation can be used to heat the sample 22 to be annealed. Heating, as shown in Figure 2. In actual operation, the device that uses laser for thermal annealing is a laser annealing furnace, and the common one is a laser spike annealing furnace; a rapid thermal annealing (rapid temperature processing) furnace can be a tungsten-halogen filament for radiation heating Device; flash lamp annealing (flash lamp annealing) device can use a xenon flash lamp for heating.

In the embodiment of the present application, the heating member 21 may include one or multiple heating members 21 may be arranged on different sides of the sample to be annealed 22, or may be arranged on the same side of the sample to be annealed 22, so that The heating and annealing of the sample 22 to be annealed is carried out from multiple directions, so that the sample 22 to be annealed is heated evenly, and the crystallization quality of the ferroelectric film layer is improved. The extending direction of the heating member 21 may be parallel to the extending direction of the sample to be annealed 22, so that the ferroelectric film layer can be evenly heated.

The annealing device provided in the embodiment of the present application may further include: a sample fixing device 3, configured to fix at least one sample to be annealed 22, so that the sample to be annealed 22 is located in the auxiliary electric field. In a possible implementation manner, the sample fixing device 3 can be designed to be movable or rotatable, so that the normal direction of the surface of the ferroelectric film layer relative to the direction of the auxiliary electric field can be adjusted.

Specifically, the sample fixing device 3 can simultaneously fix a sample 22 to be annealed, for example, the sample fixing device 3 is a quartz bracket or the like. When the hot plate tray is used as the heating component 21, it itself serves as a sample fixing device, so an additional sample fixing device may not be provided.

Specifically, the sample fixing device 3 can also fix a plurality of samples 22 to be annealed at the same time, so that multiple samples 22 to be annealed can be thermally annealed at one time, which improves the throughput. In the quartz boat, the side walls of the samples 22 to be annealed are stuck in the groove, and multiple samples 22 to be annealed are arranged in parallel, so that multiple samples 22 to be annealed can be thermally annealed at one time. According to the difference of groove design, the sample 22 to be annealed can be fixed with different angles, for example, the sample 22 to be annealed can be arranged perpendicular to the direction of the electric field; the sample 22 to be annealed can also be arranged parallel to the direction of the electric field; The annealed sample 22 is arranged at a certain oblique angle to the direction of the electric field. Therefore, different angles between the ferroelectric film layer and the auxiliary electric field in the sample to be annealed 22 can be realized by customizing different sample fixtures 3, thereby determining different crystal orientations in the ferroelectric film layer, so that a wider range of electric fields can be supported more flexibly Induce needs and scenarios.

In the embodiment of the present application, the annealing device may further include: a cavity 5 for placing the sample to be annealed 22, the sample to be annealed 22 may be arranged in the cavity, the cavity may form a closed space, and gas may pass through the closed space, Specifically, the gas introduced may be a shielding gas, and the sample 22 to be annealed is protected by the shielding gas in the cavity. In addition, the gas in the cavity has the function of heat conduction, so that the temperature of the sample 22 to be annealed is raised or lowered. The material of the cavity can be a metal material or an insulating material. When the material of the cavity is an insulating material, the cavity can be a transparent cavity or an opaque cavity. The cavity can be box-type, or the cavity can be tube-type. When the cavity is tube-type, the annealing device can be called a furnace tube or a tube-type annealing furnace.

Specifically, when the heating element 21 heats the sample 22 to be annealed by thermal radiation, the heating element 21 can be arranged outside the cavity, which is conducive to reducing the volume of the cavity; the heating element 21 can also be arranged in the cavity, avoiding heat dissipation Loss can save energy and help improve annealing efficiency. Specifically, when the material of the cavity is a metal material, the electric field providing part 24 can be arranged in the cavity to prevent the metal cavity from shielding the electric field; when the cavity 5 is a non-metallic material, the electric field providing part 24 can be provided 24 is arranged outside the cavity to save space in the cavity 5, and the electric field providing component 24 can also be arranged inside the cavity to reduce energy consumption.

In the embodiment of the present application, the cavity 5 has an air outlet 51 and an air inlet 52 , the air inlet 52 is used to feed gas into the cavity 5 , and the air outlet 51 is used to export the gas in the cavity 5 . The air inlet 51 and the air outlet 52 of the cavity 5 can be arranged on different sides of the cavity 5, or can be arranged on the same side of the cavity 5. Then, when the heating component is used to anneal the sample 22 to be annealed, the gas inlet can be used to feed the protective gas into the cavity, and the gas outlet can be used to export the gas in the cavity.

In addition, when the heating part 21 heats the sample 22 to be annealed by means of thermal radiation, the annealing device may also include a reflector 4 surrounding the heating part 21, so as to avoid heat loss caused by light overflow, and realize the annealing sample 22 more quickly. 22 heat annealing, saving costs. For example, the reflective plate 4 can be disposed around the heating component 21 .

In the embodiment of the present application, the electric field providing part 24 can be used to provide an auxiliary electric field for the ferroelectric film layer when annealing the sample 22 to be annealed, so that the direction of the crystal grains in the ferroelectric film layer is along the direction of the electric field, so that the ferroelectric film layer The angle between the crystal grains in the layer and the surface of the ferroelectric film layer is a preset angle, which can improve the ferroelectricity of the ferroelectric film layer to improve the performance of devices based on the ferroelectric film layer and meet more applications. Scenes. The auxiliary electric field can exist in at least one of the heating process, temperature constant process and cooling process of the annealing process, for example, the auxiliary electric field can exist in the entire annealing process to effectively improve the orientation consistency of the grains in the ferroelectric film layer. The auxiliary electric field can be a direct current electric field, an alternating current electric field or a mixed electric field of direct current and alternating current, etc., wherein the direct electric field can be a positive electric field or a negative electric field, and the alternating electric field can have a certain intensity and a certain frequency.

Wherein, the electric field providing part 24 may include a plurality of electrode plates, for example, may include a first electrode plate 241 and a second electrode plate 242, as shown in FIG. When different voltages are applied to the first electrode plate 241 and the second electrode plate 242, an auxiliary electric field is formed between the two, and the annealed sample 22 is placed between the first electrode plate 241 and the second electrode plate 242, and the annealed sample 22 is placed between In the auxiliary electric field; when the heating part 21 is a hot plate tray, the electric field providing part 24 can include a heating tray and at least one electrode plate, for example, include a heating tray and a third electrode plate 243, and the third electrode plate 243 is opposite to the hot plate tray set, jointly realize the stable control of the auxiliary electric field, when the third electrode plate 243 and the hot plate tray are applied with different voltages, an auxiliary electric field is formed between the two, and the sample 22 to be annealed is placed on the third electrode plate 243 and the hot plate tray Between, the sample 22 to be annealed is placed in the auxiliary electric field.

In the embodiment of the present application, the ferroelectric device is generally formed by stacking the ferroelectric film layer 23 and the electrode layers on both sides. The thickness of each layer in the ferroelectric film layer 23 and the electrode layer can be on the order of 10nm. The electrode layer is generally a metal layer. When the ferroelectric device is working, the electrode layers on both sides of the ferroelectric film layer 23 are used as the operating electrodes of the ferroelectric device to provide an operating voltage for the ferroelectric film layer 23. The direction of the operating voltage is perpendicular to the ferroelectric film. On the surface of the layer 23, the operating voltage can act on the electric dipole in the ferroelectric film layer 23, causing the electric dipole to reverse, driving the ferroelectric film layer 23 to change the polarization direction of the electric dipole, and then making the iron The electrical film layer 23 exhibits different storage states. In different scenarios, the direction of the operating voltage and the electric dipole can be set at different angles, so that the device has different performance characteristics. Since the direction of the operating voltage is perpendicular to the surface of the ferroelectric film layer 23, the direction of the electric dipole ( That is, the orientation of the crystal grains) is affected by the auxiliary electric field and the crystallization process. In different scenarios, the electric dipoles in the ferroelectric film layer 23 can have different angles by setting the ferroelectric film layer 23 and the auxiliary electric field. Direction, so that the angle between the operating voltage and the electric dipole is set differently to meet more diverse needs. For example, the electric dipole direction regulated by the auxiliary electric field can be perpendicular to the surface of the ferroelectric film layer 23, or not perpendicular to the surface of the ferroelectric film layer 23, and the angle of the auxiliary electric field can be adjusted according to actual needs, so that the ferroelectric film layer 23 The angle between the surface and the auxiliary electric field is a preset angle, and the preset angle is greater than or equal to 0° and less than or equal to 90°.

Concretely, the more components of the electric dipole on the electrode normal direction (Y direction), the higher the effective ferroelectric polarization of the ferroelectric film layer 23, then the electric dipole and the electrode normal direction (Y direction) can be set. The included angle α is smaller, that is, a larger preset included angle can be set, and the preset included angle can be set to be greater than or equal to 45° and less than or equal to 90°, so that the electric dipole in the ferroelectric film layer 23 is in the There are more components in the normal direction of the electrode (Y direction), so that the effective ferroelectric polarization of the ferroelectric film layer 23 is relatively large, and the electric field required for electric dipole reversal is relatively low, thereby greatly reducing the operating voltage of the ferroelectric device , to improve the circuit integrability of ferroelectric devices.

In the embodiment of the present application, when the electric field providing part 24 includes the first electrode plate 241 and the second electrode plate 242, when the sample 22 to be annealed is annealed, the electric field providing part is used to provide an auxiliary electric field for the ferroelectric film layer, which can be specifically , when the sample 22 to be annealed is annealed, different voltages are applied to the first electrode plate 241 and the second electrode plate 242 to generate an auxiliary electric field. In addition, the electric field direction of the auxiliary electric field is adjustable, which can be realized by movable or rotatable electrode plates. Specifically, at least one of the first electrode plate 241 and the second electrode plate 242 may be moved or rotated, and/or the sample fixing device 3 used to fix the sample to be annealed 22 may be moved or rotated, so that the surface of the ferroelectric film layer The included angle between and the auxiliary electric field is a preset included angle.

In the embodiment of the present application, when the electric field providing part 24 includes the third electrode plate 243, the electric field can be provided by using the hot plate tray and the third electrode plate 243. At this time, the hot plate tray is used as one of the electrodes, and the third electrode plate 243 To form an electrode pair, when the sample 22 to be annealed is annealed, the electric field providing component is used to provide an auxiliary electric field for the ferroelectric film layer. Specifically, when the sample 22 to be annealed is annealed, apply different electric forces to the hot plate tray and the third electrode plate. voltage to generate an auxiliary electric field. In addition, the direction of the electric field of the auxiliary electric field can be adjusted, which can be realized by the movable or rotatable third electrode plate 243 and/or the hot plate tray. Specifically, the third electrode plate 243 can be moved or rotated so that the angle between the surface of the ferroelectric film layer and the auxiliary electric field is a preset angle.

In the embodiment of the present application, the annealing process of the sample 22 to be annealed includes a heating process, a temperature constant process and a cooling process, and an electric field providing component is used to provide an auxiliary electric field for the ferroelectric film layer. During the heating process, the temperature constant process and the cooling process, at least Execute in one process, for example, the auxiliary electric field can exist in the entire annealing process. In specific implementation, the generation time of the auxiliary electric field can be set earlier than the start time of the heating process, and the withdrawal time of the auxiliary electric field is later than the end time of the cooling process. Refer to the figure As shown in 13, it is a schematic diagram of electric field control provided by the embodiment of the present application, wherein the abscissa is time, and the ordinate is quantity, and the three lines respectively correspond to the air flow of the protective gas, the auxiliary electric field and temperature, the heating process, the temperature constant process and the cooling process. The process is defined based on the change of temperature, and the change of temperature is determined based on the control time of the heating component 21. The air flow exists in the whole annealing process, as a protective gas, the generation time of the auxiliary electric field is earlier than the start time of the heating process, so that the ferroelectric The film layer is crystallized based on the auxiliary electric field during the heating process, and the withdrawal time of the auxiliary electric field is later than the end time of the cooling process, so that the ferroelectric film layer is crystallized based on the auxiliary electric field during the temperature constant process and the cooling process, which is conducive to the realization of the ferroelectric film layer. more consistent crystallographic orientation.

The embodiment of the present application provides an annealing method, which uses heating components to anneal the sample to be annealed. The sample to be annealed includes a ferroelectric film layer, and the interior of the ferroelectric film layer is composed of amorphous and non-ferroelectric crystal phases that are crystallized into ferroelectric phases after heat treatment. Crystal phase, so that the ferroelectric film layer has ferroelectricity. In the process of thermal annealing of the sample to be annealed, the electric field supply component can be used to provide an auxiliary electric field for the ferroelectric film layer. The direction of the auxiliary electric field is consistent with the surface of the ferroelectric film layer. The angle between them is a preset angle, so that the orientation of the grains in the ferroelectric film layer tends to be consistent, and the ferroelectricity of the ferroelectric film layer is improved to improve the performance of devices based on the ferroelectric film layer and meet more requirements. Application scenarios.

Each embodiment in this specification is described in a progressive manner, the same and similar parts of each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the method embodiment, since it is basically similar to the device embodiment, the description is relatively simple, and for relevant parts, please refer to part of the description of the device embodiment.

The above is the specific implementation manner of the present application. It should be understood that the above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still The technical solutions described in the foregoing embodiments are modified, or some of the technical features are replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present application.

Claims (23)

An annealing device is characterized in that it comprises: A heating component is used to anneal the sample to be annealed; the sample to be annealed includes a ferroelectric film layer; An electric field providing component is used to provide an auxiliary electric field for the ferroelectric film layer when the sample to be annealed is annealed, and the included angle between the direction of the auxiliary electric field and the surface of the ferroelectric film layer is preset angle. The device according to claim 1, wherein the electric field providing part comprises a first electrode plate and a second electrode plate oppositely arranged, and the first electrode plate and the second electrode plate are used for When the samples to be annealed are annealed, different voltages are applied to generate an auxiliary electric field. The device according to claim 2, wherein at least one of the first electrode plate and the second electrode plate is designed to be movable or rotatable, so that the direction of the electric field of the auxiliary electric field can be adjusted. The device according to claim 2 or 3, wherein the heating component comprises at least one of a halogen lamp, a resistance wire, a flash lamp, and a laser. The device according to any one of claims 2-4, further comprising: The sample fixing device is used to fix at least one of the samples to be annealed, so that the samples to be annealed are located in the auxiliary electric field. The device according to claim 5, wherein the sample fixing device is designed to be movable or rotatable, so that the normal direction of the surface of the ferroelectric film layer relative to the direction of the auxiliary electric field can be adjusted. The device according to claim 1, wherein the heating component is a hot plate tray, and the heating component is also used to fix the sample to be annealed thereon; The electric field providing part includes a third electrode plate, and the hot plate tray is arranged opposite to the third electrode plate, and is used for applying different voltages to generate an auxiliary electric field when annealing the sample to be annealed. The device according to claim 7, wherein the third electrode plate is designed to be movable or rotatable, so that the direction of the electric field of the auxiliary electric field can be adjusted. The device according to any one of claims 1-8, wherein the preset included angle is greater than or equal to 45° and less than or equal to 90°. The device according to any one of claims 1-9, further comprising: a cavity for placing the sample to be annealed; The cavity has an air outlet and an air inlet, the air inlet is used for introducing gas into the cavity, and the air outlet is used for leading out the gas in the cavity. The device according to claim 10, characterized in that, the electric field providing part is arranged in the cavity; the heating part is arranged in or outside the cavity. The device according to any one of claims 1-11, characterized in that, the material of the ferroelectric film layer is a perovskite type ferroelectric material, an organic type ferroelectric material or an HfO2-based ferroelectric storage material. The device according to any one of claims 1-12, characterized in that the auxiliary electric field is a direct current electric field, an alternating current electric field or a mixed electric field of direct current and alternating current. An annealing method, characterized in that it is applied to the annealing device described in any one of claims 1-13, comprising: Use heating components to anneal the sample to be annealed; the sample to be annealed includes a ferroelectric film layer; when annealing the sample to be annealed, use an electric field providing component to provide an auxiliary electric field for the ferroelectric film layer, the auxiliary The included angle between the direction of the electric field and the surface of the ferroelectric film layer is a preset included angle. The method according to claim 14, wherein the electric field providing component comprises a first electrode plate and a second electrode plate oppositely arranged, and when the sample to be annealed is annealed, the electric field providing component is The ferroelectric film layer provides an auxiliary electric field, including: When annealing the sample to be annealed, different voltages are applied to the first electrode plate and the second electrode plate to generate an auxiliary electric field. The method according to claim 15, further comprising: Moving or rotating at least one of the first electrode plate and the second electrode plate, and/or moving or rotating the sample fixing device used to fix the sample to be annealed, so that the surface of the ferroelectric film layer and the The included angle between the aforementioned auxiliary electric fields is a preset included angle. The method according to claim 14, wherein the heating component is a hot plate tray, the heating component is also used to fix the sample to be annealed thereon, and the electric field providing component includes a third electrode plate, The hot plate tray and the third electrode plate are arranged oppositely; when the sample to be annealed is annealed, using an electric field providing component to provide an auxiliary electric field for the ferroelectric film layer includes: When annealing the sample to be annealed, different voltages are applied to the hot plate tray and the third electrode plate to generate an auxiliary electric field. The method according to claim 17, further comprising: The third electrode plate is moved or rotated so that the angle between the surface of the ferroelectric film layer and the auxiliary electric field is a preset angle. The method according to any one of claims 14-18, wherein the preset included angle is greater than or equal to 45° and less than or equal to 90°. The method according to any one of claims 14-19, characterized in that, the annealing process for the sample to be annealed includes a heating process, a temperature constant process and a cooling process, and an electric field providing component is used to provide the ferroelectric film layer The auxiliary electric field is performed during at least one of the heating process, the temperature constant process and the cooling process. The method according to claim 20, wherein the generation time of the auxiliary electric field is earlier than the start time of the heating process, and the withdrawal time of the auxiliary electric field is later than the end time of the cooling process. The method according to any one of claims 14-21, wherein the annealing device further comprises a cavity, the cavity has an air outlet and an air inlet, and the method further comprises: The gas is introduced into the cavity through the gas inlet, and the gas in the cavity is led out through the gas outlet. The method according to any one of claims 14-22, characterized in that the auxiliary electric field is a direct current electric field, an alternating current electric field or a mixed electric field of direct current and alternating current.

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