Annealing apparatus and method of operation thereof

Abstract

The application provides an annealing device and a working method thereof, and relates to the technical field of semiconductors, and aims to solve the problem of how to improve the annealing process and accurately control the annealing process. The annealing device comprises a chamber, a heating device, a supporting device and an electrical measurement device. The chamber is used for accommodating a device to be annealed; the heating device is used for heating the device to be annealed; the supporting device is arranged in the chamber and is used for supporting the device to be annealed; and the electrical measurement device is arranged outside the chamber and is connected with the device to be annealed through a conductive connecting line. The annealing device can monitor the electrical performance of the device to be annealed during the annealing process, and the annealing process is controlled accordingly, so that the annealing process is more accurate, the response speed is faster, and the production efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to an annealing apparatus and its operating method. Background Technology

[0002] The advent of technologies such as artificial intelligence (AI) big data models and 5G has generated massive amounts of data, making the search for new low-power, high-speed memory technologies urgent. Ferroelectric memory is one such promising non-volatile memory technology. Traditional ferroelectric materials are mainly based on perovskite structures, such as lead zirconate titanate (PZT) ferroelectric materials, which have already been commercially applied in many scenarios. New ferroelectric materials primarily focus on hafnium oxide-based fluorite structures. Compared to traditional ferroelectric materials, hafnium oxide-based ferroelectrics are compatible with advanced manufacturing processes and retain ferroelectric properties even at thicknesses below 10nm.

[0003] Based on the principle, ferroelectric materials have the ability to spontaneously polarize. When the applied electric field is greater than the coercive electric field of the ferroelectric material, the polarization direction of the ferroelectric material is consistent with the direction of the electric field. After the applied electric field is removed, it can still maintain the electric dipole state, hence it is called a non-volatile storage material.

[0004] Therefore, the magnitude of remanent polarization and coercive electric field are key factors affecting the performance of this ferroelectric memory device. The magnitude of remanent polarization directly determines the amount of charge during read and write operations. A larger remanent polarization results in more read and write charges, leading to better signal strength. The magnitude and uniformity of the coercive electric field directly affect the operating voltage of the memory, influencing subsequent power consumption, read / write lifespan, and interference immunity. Therefore, improving the remanent polarization and reducing the coercive electric field of ferroelectric materials are crucial for the widespread application of novel ferroelectric memories. Summary of the Invention

[0005] This application provides an annealing apparatus and its working method to solve the problem of how to improve the annealing process and accurately control the annealing process to improve device performance.

[0006] To achieve the above objectives, the embodiments of this application adopt the following technical solutions:

[0007] In a first aspect, embodiments of this application provide an annealing apparatus, which includes a chamber, a heating device, a support device, and an electrical measuring device. The chamber is used to accommodate the device to be annealed; the heating device is used to heat the device to be annealed; the support device is disposed in the chamber to support the device to be annealed; and the electrical measuring device is disposed outside the chamber and connected to the device to be annealed via a conductive wire.

[0008] Thus, the electrical parameters of the device to be annealed can be measured during or after annealing. Understandably, annealing causes at least a portion of the structure in the device to undergo crystallization and phase transition, both of which alter the device's electrical parameters. Therefore, by measuring the electrical parameters during annealing, data such as the onset and completion times of crystallization and phase transition can be determined. Using this data, along with the device's performance after annealing, the annealing process parameters can be optimized, allowing for precise control of the annealing process to improve device performance. Furthermore, by using the electrical parameters of the device after annealing, the device's performance can be obtained promptly, determining whether the annealing process achieved its intended purpose.

[0009] In one possible implementation of the first aspect, the electrical measuring device is used to measure the electrical parameters of the device to be annealed during the annealing process. This allows for real-time testing of the electrical performance of the device during annealing, and enables timely adjustment of the annealing process parameters, achieving precise control of the annealing process.

[0010] In one possible implementation of the first aspect, the electrical parameters include resistance values, current-voltage cycle curves, or positive and negative bias transient spectra. Thus, different electrical parameters can be measured as needed to control the annealing process. For example, the heating device of the annealing equipment can determine the heating power based on the resistance value; or, for example, when the device to be annealed is a ferroelectric device, the polar axis orientation of the ferroelectric device can be changed by measuring its current-voltage cycle curve or positive and negative bias transient spectrum, thereby enhancing its ferroelectricity.

[0011] In one possible implementation of the first aspect, the heating device is connected to an electrical measuring device; the heating device controls the heating power according to electrical parameters. This allows for timely control of the heating power based on material changes in the device to be annealed, improving the accuracy of the annealing process control and enhancing device performance. For example, when annealing a device including a ferroelectric layer, the heating device can first raise the temperature of the device at a constant heating power, while the electrical measuring device measures the resistance of the ferroelectric layer in real time. Since the ferroelectric layer is initially in an amorphous state with high resistance, it crystallizes as the temperature rises, and the resistance begins to decrease. Upon receiving the signal that the resistance is decreasing, the heating device rapidly increases the heating power, thereby quickly bringing the ferroelectric layer to the phase transition temperature. This ensures that the small crystal grains that are beginning to crystallize grow in the ferroelectric O phase instead of the antiferroelectric T phase, increasing the ferroelectric properties of the ferroelectric layer.

[0012] In one possible embodiment of the first aspect, the support device includes a support platform and a first electrical connector and a second electrical connector fixed on the support platform. The conductive wires include a first conductive wire, a second conductive wire, a third conductive wire, and a fourth conductive wire. One end of the first conductive wire is used to connect to the device to be annealed, and the other end of the first conductive wire is connected to the first end of the first electrical connector. Both ends of the second conductive wire are respectively connected to the second end of the first electrical connector and an electrical measuring device. One end of the third conductive wire is used to connect to the device to be annealed, and the other end of the third conductive wire is connected to the first end of the second electrical connector. Both ends of the fourth conductive wire are respectively connected to the second end of the second electrical connector and an electrical measuring device. Since one end of the first and third conductive wires is connected to the first electrical connector, and one end of the second and fourth conductive wires is connected to the second electrical connector, and the first and second electrical connectors are fixed on the support platform, direct connection of the conductive wires to the device to be annealed can be avoided, improving the stability of the connection.

[0013] In one possible implementation of the first aspect, the first electrical connector, the second electrical connector, the first conductive wire, the second conductive wire, the third conductive wire, and the fourth conductive wire constitute a pair of detection lines, and the annealing equipment includes multiple pairs of detection lines. Thus, multiple pairs of detection lines can connect multiple components of the device to be annealed to an electrical measuring device, allowing the electrical measuring device to apply electrical signals to each component when measuring electrical parameters, thereby improving the performance of the multiple components and enhancing the uniformity of their performance.

[0014] In one possible implementation of the first aspect, a first electrical connector penetrates the support platform, with its first end located on the same side of the support platform as the device to be annealed, and its second end located on the opposite side of the support platform from the first end. A second electrical connector also penetrates the support platform, with its first end located on the same side of the support platform as the device to be annealed, and its second end located on the opposite side of the support platform from the first end. Thus, the first and third conductive wires are connected to the two ends of the first electrical connector located on the support platform, respectively, and the second and fourth conductive wires are connected to the two ends of the second electrical connector located on the support platform, respectively, improving the stability of the connection.

[0015] In one possible implementation of the first aspect, the annealing apparatus further includes an electrode flange, and a through hole is provided in the chamber wall of the chamber, with the electrode flange sealing the through hole; a conductive wire passes through the electrode flange. This ensures the airtightness of the chamber, allowing the annealing apparatus to be used for annealing under different pressures and gas environments.

[0016] Secondly, this application provides a method for operating an annealing apparatus. The annealing apparatus includes a chamber, a heating device, a support device, and an electrical measuring device. The support device is disposed in the chamber and is used to support the workpiece to be annealed. The operating method includes: the heating device heating the workpiece to be annealed; the electrical measuring device measuring the electrical parameters of the workpiece to be annealed; and the heating device controlling the heating power according to the electrical parameters. Thus, the electrical measuring device can measure the electrical performance of the workpiece to be annealed in real time during the annealing process, and the heating device can adjust the heating power of the annealing in a timely manner accordingly, improving the accuracy of annealing control.

[0017] In one possible implementation of the second aspect, the electrical parameters include resistance values. Controlling the heating power of the heating device based on these electrical parameters includes: increasing the heating power of the heating device when the measured resistance value changes from a first resistance value to a second resistance value, wherein the first resistance value is greater than or less than the second resistance value. Thus, the change in resistance value from the first resistance value to the second resistance value indicates that crystallization has begun in the device to be annealed. Increasing the heating power of the heating device can rapidly raise the temperature of the device to be annealed, promoting rapid crystallization and reducing the possibility of forming large grains.

[0018] In one possible implementation of the second aspect, after increasing the heating power, if the measured resistance value remains stable, the heating device reduces the heating power or stops heating. This allows for timely temperature reduction after crystallization, preventing further transformation of the grains at high temperatures and avoiding degradation of device performance.

[0019] In one possible implementation of the second aspect, after the measured resistance value decreases and remains stable, and before the heating device reduces the heating power or stops heating, the method further includes: using an electrical measuring device to measure the current-voltage cycle curve or the positive and negative bias transient spectrum of the annealed device. Thus, the measurement of the current-voltage cycle curve or the positive and negative bias transient spectrum can be performed at high temperatures. Therefore, when the device to be annealed is a ferroelectric device, the awakening effect of high temperature and low pressure can be utilized to increase the number of ferroelectric domains in the ferroelectric layer of the ferroelectric device whose polarization direction is along the direction of the external electric field, thereby increasing the residual polarization intensity and concentrating the reversal threshold voltage.

[0020] In one possible implementation of the second aspect, the annealing apparatus further includes multiple pairs of detection lines. The device to be annealed comprises multiple elements, and the electrical measuring device applies different signals through the multiple pairs of detection lines to measure the same electrical parameters of the multiple elements respectively. Thus, when the device to be annealed is a ferroelectric device, different electrical signals can be applied to different memory elements for wake-up, thereby controlling the degree of wake-up and reducing the differences in the switching electric field strength and residual polarization strength of different memory cells. Attached Figure Description

[0021] Figure 1This is a schematic diagram of the structure of an annealing device provided in an embodiment of this application;

[0022] Figure 2 A top view of a structure in which a device to be annealed is mounted on a support device, as provided in an embodiment of this application;

[0023] Figure 3 This application provides a schematic diagram of a structure for setting up a device to be annealed in an annealing apparatus according to an embodiment of the present application;

[0024] Figure 4 A flowchart illustrating the operation method of an annealing apparatus provided in this application embodiment;

[0025] Figure 5 A graph showing the power, temperature, and measured resistance values ​​of an annealing apparatus during the initial stage of annealing, provided for an embodiment of this application.

[0026] Figure 6 A graph showing the power, temperature, and measured resistance values ​​of an annealing apparatus during the annealing process, provided for an embodiment of this application.

[0027] Figure 7 A schematic diagram comparing the hysteresis loops before and after measuring the electrical parameters of the device to be annealed during the annealing process, provided as an embodiment of this application;

[0028] Figure 8 This is a connection diagram of a device to be annealed, provided in an embodiment of this application.

[0029] Figure 9 A schematic diagram illustrating the annealing of a three-dimensional ferroelectric storage device provided in an embodiment of this application;

[0030] Figure 10 A schematic diagram of a three-dimensional ferroelectric storage device mounted on a support device, provided in an embodiment of this application;

[0031] Figure 11 This is a schematic diagram illustrating the technical effect of improving polar axis orientation by measuring electrical parameters during the annealing process, as provided in an embodiment of this application. Detailed Implementation

[0032] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by those skilled in the art. The terms "first," "second," "third," and similar words used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of embodiments in this application, unless otherwise stated, "a plurality of" means two or more.

[0033] The directional terms such as “left,” “right,” “up,” and “down” are defined relative to the orientation of the device shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the device to be annealed.

[0034] In some related technologies, doping can be used to improve the remanent polarization and reduce the coercive electric field of ferroelectric materials. The principle is mainly to alter the free energy barrier of the ferroelectric material through doping, thereby changing the magnitude of the remanent polarization and coercive electric field. Existing doping elements for hafnium oxide-based ferroelectric materials include zirconium (Zr), yttrium (Y), silicon (Si), and lanthanum (La). This is primarily achieved by depositing other elements as dopants during the deposition of hafnium oxide using atomic layer deposition (ALD) technology. Alternatively, doping chemical elements can be introduced into the initial solution through chemical solution preparation.

[0035] While doping can alter the free energy level, thus changing the electric field required for ferroelectric material to flip, it often changes the intrinsic parameters of the material, introducing many complex situations. For example, defects can lead to amplified leakage current or the emergence of antiferroelectric phenomena. Therefore, it has a significant impact on the performance of ferroelectric memories, resulting in excessive power consumption, severe heat generation, reduced polarization window, and poor polarization retention.

[0036] In some related technologies, oxygen vacancy defects can be artificially introduced to lower the free energy barrier during polarization reversal in ferroelectric materials, thereby altering the electric field required for polarization reversal. Methods for introducing oxygen vacancies mainly include adjusting the oxidant concentration during deposition, such as reducing the oxygen plasma dose when forming ferroelectric materials using atomic layer deposition (ALD) or chemical vapor deposition (CVD). Alternatively, oxygen vacancies can be introduced after deposition using reducing gas annealing. Similar to doping, introducing oxygen vacancies can lead to antiferroelectricity and changes in the ferroelectric phase. Therefore, it has a significant impact on the performance of ferroelectric memories, resulting in a reduced polarization window and poor polarization retention.

[0037] In some related technologies, intercalation layers can be added as interfacial stress layers. These interfacial stresses reduce the free energy of the orthorhombic ferroelectric phase (O phase), making the ferroelectric phase more stable and promoting the transformation of non-ferroelectric phases into ferroelectric phases in the material. Simultaneously, lattice matching induces a unified polarization orientation, increasing the remanent polarization intensity and concentrating the polar axis orientation. Commonly used intercalators include lanthanum-strontium-manganese oxide, strontium ruthenium oxide, and strontium titanate. However, stress intercalation induces the formation of the ferroelectric O phase through interfacial stress. Due to the inconsistency between the two materials' lattices at the interface, there is a risk of crystal structure breakage. Furthermore, to reduce the interfacial energy, a large number of charged defects accumulate at the interface, leading to polarization instability and fatigue under electric field reversal.

[0038] Understandably, for ferroelectric thin films, such as hafnium zirconium oxide (HZO) ferroelectric thin films, crystallization and ferroelectric polarization mainly occur during rapid annealing. For example, the transition from an amorphous state to the antiferroelectric tetragonal phase (T phase), then from the antiferroelectric T phase to the ferroelectric O phase, and the angle between the polar axis and the direction of the external electric field, are all related to the annealing temperature, the isothermal time, and the heating and cooling rates. Therefore, the ferroelectric properties of ferroelectric thin films can be improved by precisely controlling the annealing process.

[0039] Therefore, this application provides an annealing apparatus that can monitor the electrical parameters of ferroelectric materials in real time during the annealing process. Based on these electrical parameters, the apparatus can precisely control the annealing temperature and duration required for the next step, and adjust the heating power, temperature change rate, and temperature control duration of the annealing apparatus to achieve electrically feedback-controlled annealing. This increases the proportion of ferroelectric phase and polarization intensity, thereby improving the ferroelectric performance of the ferroelectric device. It is understood that annealing causes a phase transition in the material, and the electrical properties of the material change before and after the phase transition. Therefore, this annealing apparatus 10 can also be used for annealing other materials.

[0040] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of an annealing apparatus 10 provided in an embodiment of this application. The annealing apparatus 10 may include a chamber 11, a heating device 12, a support device 13, and an electrical measuring device 14.

[0041] The chamber 11 may be airtight, meaning it has the ability to maintain a vacuum, thus allowing it to be used for annealing under different pressures and gas environments. Understandably, the chamber 11 may be made of a material that is resistant to high temperatures; for example, the material may include steel. The chamber 11 may be tubular or of other suitable shape.

[0042] A support device 13 is disposed in the chamber 11, and the support device 13 can be used to support the device 20 to be annealed. Similarly, the support device 13 also needs to be heat resistant, and the materials used for the support device 13 may include steel, graphite, etc.

[0043] Understandably, please combine Figure 2 The support device 13 may include a fixing mechanism 134, which can be used to fix the part to be annealed 20 onto the support device 13. For example, the fixing mechanism 134 may be a screw, and the support device 13 has a screw hole. The screw engages with the screw hole. After the part to be annealed 20 is placed on the support device 13, the screw can be screwed into the screw hole after a portion of the screw head presses against the edge of the part to be annealed 20, thereby fixing the part to be annealed 20 onto the support device 13 with a screw. It is understood that the fixing mechanism 134 may also be other structures, as long as it can fix the part to be annealed 20 onto the support device 13.

[0044] The heating device 12 is used to heat the workpiece 20 to be annealed. The heating device 12 may include a power controller 121, which controls the heating power of the heating device 12; that is, the heating power of the heating device 12 is adjustable. The heating device 12 may also include a power supply module 122, which is connected to the power controller 121 and receives control from the power controller 121 to change the power supply level, thereby controlling the heating power. The heating type of the heating device 12 can be resistance heating, laser heating, or inductive heating, thereby enabling rapid thermal annealing, pulse thermal annealing, laser annealing, and other annealing processes. For example, when resistance heating is used, the heating device 12 may also include a resistance wire 123, which is connected to the power supply module 122, so that heating can occur after current is applied.

[0045] Understandably, depending on the heating type of the heating device 12, the device to be annealed 20 can be heated indirectly or directly. For example, when the heating type is resistance heating, the device to be annealed 20 can be heated indirectly, that is, the device to be annealed 20 is indirectly heated by heating the chamber 11 through the resistance wire 123. As another example, when the heating type is laser heating, the device to be annealed 20 can be heated directly, that is, the device to be annealed 20 is directly heated by irradiating it with a laser.

[0046] At least a portion of the heating device 12 may be disposed in the chamber 11, for example, when heating is performed using a resistance wire 123, the resistance wire 123 may be disposed in the chamber 11.

[0047] The electrical measuring device 14 is connected to the device to be annealed 20 via a conductive wire 140, and the electrical measuring device 14 can be located outside the chamber 11. The electrical measuring device 14 can be used to measure one or more of the electrical parameters of the device to be annealed 20, such as resistance, capacitance, inductance, current-voltage cycle curve, or positive and negative bias transient spectrum.

[0048] For example, the electrical measuring device 14 can be used to measure the electrical parameters of the device 20 to be annealed during the annealing process. This allows for monitoring of changes in the electrical parameters of the device 20 during annealing. As mentioned earlier, during annealing, due to temperature effects, the internal structure, physical properties, or chemical state of the materials constituting the device 20 undergoes abrupt or continuous transformations, thereby affecting the electrical parameters of the device 20. In other words, the electrical parameters of the device 20 change during annealing. Furthermore, the extent and rate of change in the internal structure, physical properties, or chemical state of the materials constituting the device 20 also affect the performance of the device 20 after annealing. Therefore, the electrical parameters during annealing are directly related to the material properties of the device 20.

[0049] Therefore, the annealing process can be optimized based on the electrical parameters of the device 20 to be annealed during the annealing process and its final performance after annealing. For example, multiple devices 20 to be annealed can be annealed with different process parameters to obtain their electrical parameters during annealing. Then, the performance of the devices 20 after annealing can be evaluated. By analyzing the corresponding electrical parameters, the trend of electrical performance changes corresponding to the devices 20 with better performance can be determined. Finally, the optimization direction of the corresponding annealing process parameters can be determined based on the trend of electrical performance changes, thereby improving the efficiency of optimization.

[0050] For example, the electrical measuring device 14 can be used to measure the electrical parameters of the device 20 to be annealed after annealing. Understandably, since annealing changes the internal structure of the materials that make up the device 20 to be annealed, the performance of the annealed device can also be preliminarily judged by the electrical parameters of the device 20 to be annealed after annealing.

[0051] In some embodiments, the electrical measuring device 14 can also be used to measure the current-voltage cycle curve or the positive and negative bias transient spectrum of the device 20 to be annealed. During the measurement process, the electrical measuring device 14 applies current and / or voltage signals to the device 20 to be annealed in a regular manner, thereby changing the physical properties of the device 20. For example, the current-voltage cycle curve or the positive and negative bias transient spectrum of the device 20 can be measured after the materials constituting the device 20 have completed crystallization and phase transformation. Understandably, the device 20 to be annealed can still be at a relatively high temperature at this time, that is, the device 20 to be annealed is still in the annealing process.

[0052] In some embodiments, the electrical measuring device 14 is connected to the heating device 12, and the heating device 12 controls the heating power according to the electrical parameters measured by the electrical measuring device 14. In this way, the heating power can be controlled in a timely manner according to the material changes of the device 20 to be annealed, improving the accuracy of the annealing process control. For example, when annealing the device 20 including a ferroelectric thin film, the heating device 12 can first heat the device 20 to be annealed with a constant heating power, while simultaneously measuring the resistance value of the ferroelectric thin film through the electrical measuring device 14. Since the ferroelectric thin film is initially in an amorphous state, its resistance value is high. When the temperature rises to a certain level, the ferroelectric thin film will crystallize, and the resistance value will begin to decrease. After receiving the signal that the resistance value begins to decrease, the heating device 12 quickly increases the heating power, thereby enabling the ferroelectric thin film to reach the phase transition temperature in a short time. This allows the small crystal grains that begin to crystallize to grow in the ferroelectric O phase instead of the antiferroelectric T phase, increasing the ferroelectric properties of the ferroelectric thin film.

[0053] Please continue reading Figure 1 The conductive wire 140 may include a first conductive wire 141, a second conductive wire 142, a third conductive wire 143, and a fourth conductive wire 144; the support device 13 may include a support platform 131 and a first electrical connector 132 and a second electrical connector 133 fixed on the support platform 131. The conductive wire 140, the first electrical connector 132, and the second electrical connector 133 may all be made of high-temperature resistant materials.

[0054] One end of the first conductive wire 141 is connected to the device 20 to be annealed, and the other end of the first conductive wire 141 is connected to the first end of the first electrical connector 132. One end of the third conductive wire 143 is connected to the device 20 to be annealed, and the other end of the third conductive wire 143 is connected to the first end of the second electrical connector 133. The two ends of the second conductive wire 142 are respectively connected to the second end of the first electrical connector 132 and the electrical measuring device 14; the two ends of the fourth conductive wire 144 are respectively connected to the second end of the second electrical connector 133 and the electrical measuring device 14. In this way, the electrical measuring device 14 can be connected to the device 20 to be annealed.

[0055] Thus, the first conductive wire 141 is first connected to the first electrical connector 132, and the first electrical connector 132 is then connected to the electrical measuring device 14 through the second conductive wire 142; the third conductive wire 143 is first connected to the second electrical connector 133, and the second electrical connector 133 is then connected to the electrical measuring device 14 through the fourth conductive wire 144. As a result, the first conductive wire 141 and the third conductive wire 143 can have a relatively short length, and one end of them is fixed, so that the connection between the electrical measuring device 14 and the device to be annealed 20 is stable and reliable.

[0056] Understandably, the annealing process can be performed only on the key structures in the device to be annealed 20. For example, the ferroelectric layer 22 in the device to be annealed 20 can be annealed. Therefore, when measuring the electrical parameters of the device to be annealed 20 by the electrical measuring device 14, only the ferroelectric layer 22 can be measured.

[0057] like Figure 1 As shown, the device to be annealed 20 may include a planar ferroelectric device, which may include a first electrode 21, a second electrode 23, and a ferroelectric layer 22, with the ferroelectric layer 22 disposed between the first electrode 21 and the second electrode 23. One end of the first conductive line 141 is connected to the first electrode 21, and one end of the third conductive line 143 is connected to the second electrode 23. Exemplarily, one end of the first conductive line 141 can be connected to the first electrode 21 by pressure welding, and one end of the third conductive line 143 can be connected to the second electrode 23 by pressure welding.

[0058] Understandably, the thickness of the ferroelectric layer 22 may be very small; therefore, the ferroelectric layer 22 may be broken down during electrical parameter measurements. For this purpose, please refer to [link to relevant documentation]. Figure 3 and combined Figure 1 The area of ​​the first electrode 21 can be smaller than the area of ​​the second electrode 23, and the area of ​​the ferroelectric layer 22 is equal to the area of ​​the second electrode 23, thus exposing the portion of the ferroelectric layer 22 that is opposite to the second electrode 23. The third conductive wire 143 is directly connected to the exposed portion of the ferroelectric layer 22, and the first conductive wire 141 is connected to the first electrode 21. This allows for the measurement of the electrical parameters of the ferroelectric layer 22 while preventing breakdown of the ferroelectric layer 22.

[0059] like Figure 3 The fabrication process of the planar ferroelectric device shown may include depositing a second electrode 23 of a certain thickness on a silicon wafer using a physical vapor deposition (PVD) process, for example, the material of the second electrode 23 being tungsten. Then, a ferroelectric layer 22 is deposited on the second electrode 23 using an atomic layer deposition (ALD) process. The material of the ferroelectric layer 22 may be a mixture of hafnium (Hf) and zirconium (Zr) in a 1:1 ratio.0.5 Zr 0.5 O2. On top of the ferroelectric material, an intercalation layer 24 and a first electrode 21 are deposited. The deposition of the intercalation layer 24 and the first electrode 21 can be performed using chemical vapor deposition (CVD). The material of the intercalation layer 24 can be TiN with a thickness of 5 nm; the material of the first electrode 21 can be tungsten with a thickness of 30 nm. After the planar device is fabricated, photoresist can be uniformly coated onto its surface, and then a mask can be used to cover half of its exposure area. Exposure, etching, and photoresist removal are then performed sequentially to make the areas of the first electrode 21 and the second electrode 23 different.

[0060] Understandably, the dimensions of the first electrode 21 and the second electrode 23 of the device to be annealed 20 may be small, and the diameters of the first conductive wire 141 and the third conductive wire 143 also need to be small, so that one end of the first conductive wire 141 and the third conductive wire 143 can be connected to the first electrode 21 and the second electrode 23 respectively. Since the other end of the first conductive wire 141 is connected to the first end of the first electrical connector 132, and the other end of the third conductive wire 143 is connected to the first end of the second electrical connector 133, the span of the first conductive wire 141 and the third conductive wire 143 is small. Therefore, the mechanical strength requirements of the first conductive wire 141 and the second conductive wire 142 are also lower, which is conducive to selecting a small-diameter conductive wire 140.

[0061] Furthermore, since the electrical measuring device 14 is located outside the chamber 11, the second conductive wire 142 and the fourth conductive wire 144 are relatively long. To ensure the mechanical strength of the second conductive wire 142 and the fourth conductive wire 144, their diameters can be relatively large. Based on this, the diameter of the first conductive wire 141 can be smaller than the diameter of the second conductive wire 142, and the diameter of the third conductive wire 143 can be smaller than the diameter of the fourth conductive wire 144.

[0062] Understandably, the chamber 11 may contain high temperatures, which could be transmitted to the electrical measuring device 14 via the second conductive wire 142 and the fourth conductive wire 144, affecting the measurement accuracy and lifespan of the electrical measuring device 14. Therefore, the lengths of the second conductive wire 142 and the fourth conductive wire 144 can be increased to reduce the heat transmitted to the electrical measuring device 14. For example, the lengths of both the second conductive wire 142 and the fourth conductive wire 144 can be twice or more the distance from the electrical measuring device 14 to the chamber 11. High-temperature thermocouple extension wires can be used for the second conductive wire 142 and the fourth conductive wire 144, thus avoiding the influence of differences between them on the measurement results. The electrical measuring device 14 can also be located at a greater distance from the chamber 11, ensuring that the interface used by the electrical measuring device 14 to connect the second conductive wire 142 and the fourth conductive wire 144 remains at room temperature.

[0063] Understandably, the first electrical connector 132, the second electrical connector 133, the first conductive wire 141, the second conductive wire 142, the third conductive wire 143, and the fourth conductive wire 144 constitute a pair of detection lines, and the annealing equipment 10 may include multiple pairs of detection lines. That is, the first conductive wire 141, the first electrical connector 132, and the third conductive wire 143 constitute one detection line, and the second conductive wire 142, the second electrical connector 133, and the fourth conductive wire 144 constitute another detection line; these two detection lines form a pair of detection lines. The electrical parameters of a key structure of the device 20 to be annealed can be measured through this pair of detection lines. The annealing equipment 10 may include multiple pairs of detection lines, thus allowing the measurement of electrical parameters of multiple key structures of the device 20 to be annealed through multiple pairs of detection lines.

[0064] In some embodiments, the annealing apparatus 10 may further include an electrode flange 15. The electrode flange 15 is used to allow the conductive wire 140 to pass through the wall of the chamber 11. Exemplarily, a through hole is provided in the wall of the chamber 11, the electrode flange 15 blocks the through hole, and the conductive wire 140 passes through the electrode flange 15, thereby enabling the connection of components in the chamber 11 to the electrical measuring device 14 outside the chamber 11 through the conductive wire 140 under sealed conditions.

[0065] In addition, please see Figure 4 , Figure 4This is a flowchart illustrating the operation of an annealing apparatus 10 according to an embodiment of this application. The annealing apparatus 10 may include a chamber 11, a heating device 12, a support device 13, and an electrical measuring device 14. The support device 13 is disposed in the chamber 11 and is used to support the device 20 to be annealed. It is understood that the annealing apparatus 10 can be any of the aforementioned annealing apparatuses. For ease of explanation, the following example uses the device 20 to be annealed as including a ferroelectric layer 22, with the aim of improving the ferroelectric properties of the ferroelectric layer 22.

[0066] The working method of the annealing equipment 10 includes the following steps:

[0067] S100, heating device 12 heats the part to be annealed 20.

[0068] Please see Figure 5 and combined Figure 1 When annealing the workpiece 20 using the annealing equipment 10, the heating device 12 first heats the workpiece 20. The initial heating stage can be called the initial stage.

[0069] For example, in the initial stage of heating the annealing device 20 by the heating device 12, the heating device 12 can heat the annealing device 20 with a constant heating power P, so that the temperature T of the annealing device 20 rises at a slow rate.

[0070] Heating the workpiece 20 to be annealed by the heating device 12 can cause the temperature T of the workpiece 20 to rise at a constant rate with time t, that is, the increase in temperature T of the workpiece 20 per unit time remains constant. For example, under ideal conditions, the heating device 12 can heat the workpiece 20 to be annealed by a constant heating power P, causing the temperature T of the workpiece 20 to rise at a constant rate. It can be understood that, under ideal conditions, the temperature T of the workpiece 20 to be annealed can be kept consistent with the temperature of the chamber 11 of the annealing equipment 10.

[0071] S200, Electrical measuring device 14 measures the electrical parameters of the device 20 to be annealed.

[0072] During the annealing process, the electrical measuring device 14 can monitor the electrical parameters of the device 20 to be annealed in real time. That is, after the heating device 12 starts heating, the electrical measuring device 14 can start measuring the electrical parameters of the device 20 to be annealed in real time. For example, the electrical measuring device 14 measures the resistance value R of the device 20 to be annealed in real time.

[0073] As the temperature T of the device to be annealed 20 rises to a certain level, the resistance R of the device to be annealed 20 remains unchanged because the material of the device to be annealed 20 has not undergone crystallization or phase transition. For example, when the electrical measuring device 14 measures the resistance R of the ferroelectric layer 22 in the device to be annealed 20, the resistance R is relatively high because the ferroelectric layer 22 is initially in an amorphous state. Subsequently, as the temperature continues to rise, the material of the device to be annealed 20 undergoes crystallization and phase transition, and the resistance R changes. For example, after the ferroelectric layer 22 begins to crystallize and undergo phase transition, the resistance R begins to decrease. Figure 5 As shown.

[0074] S300, heating device 12 controls heating power P according to electrical parameters.

[0075] As described above, after the structure of the device 20 to be annealed undergoes changes such as crystallization or phase transition, the resistance value R of the device 20 to be annealed will change. The heating device 12 can control the heating power P according to the change in resistance value R. It is understandable that temperature cannot accurately determine the time when the structure of the device 20 to be annealed changes, but the change in resistance value R of the device 20 to be annealed can reflect the structural change of the device 20 to be annealed in real time.

[0076] For example, the electrical parameters include a resistance value R. Controlling the heating power P of the heating device 12 according to the electrical parameters may include: when the measured resistance value R changes from a first resistance value to a second resistance value, the heating device 12 increases the heating power P, wherein the first resistance value is greater than or less than the second resistance value.

[0077] Please see Figure 6 and combined Figure 5 and Figure 1 When the electrical measuring device 14 measures the resistance R of the ferroelectric layer 22 in the device 20 to be annealed, the ferroelectric layer 22 will crystallize after the temperature T rises to a certain level, causing the resistance R to decrease. At this time, the heating device 12 receives a signal that the resistance R has decreased. For example, if the measured resistance R changes from a first resistance value to a second resistance value, the heating power P of the heating device 12 can be increased, that is, the heating power P is increased to reduce the time required for the ferroelectric layer 22 to reach the phase transition temperature, so that the small grains that are beginning to crystallize can grow in the ferroelectric O phase instead of the antiferroelectric T phase, thereby improving the ferroelectric properties of the ferroelectric layer 22. During the grain growth process of the ferroelectric layer 22, the resistance R will change slowly. When the ferroelectric layer 22 has completely crystallized, the resistance R will no longer change.

[0078] After increasing the heating power P, if the measured resistance value R remains stable, the heating device 12 can reduce the heating power P or stop heating. In this way, the ferroelectric layer 22 can be cooled to room temperature as quickly as possible, avoiding the formation of a non-ferroelectric monoclinic structure phase, i.e., the M phase, thereby increasing the proportion of ferroelectric phase in the final ferroelectric layer 22.

[0079] In some embodiments, after the measured resistance value R decreases and stabilizes, and before the heating device 12 reduces the heating power P or stops heating, the method may further include: the electrical measuring device 14 measuring the current-voltage cycle curve or the positive and negative bias transient spectrum of the annealed device. It is understood that during the measurement of the current-voltage cycle curve or the positive and negative bias transient spectrum of the annealed device, the electrical measuring device 14 may apply direct current or alternating current, and the alternating current may be high-frequency or low-frequency.

[0080] Understandably, after the measured resistance value R decreases and remains stable, the ferroelectric layer 22 has completed crystallization and phase transition. In the initial state after crystallization and phase transition, the ferroelectric domains of the ferroelectric layer 22 tend to be randomly distributed, with a wide current peak and a large flip angle. At this time, the hysteresis loop is as follows: Figure 7 As shown in Figure (a), the device exhibits a large switching electric field strength Er and a small residual polarization strength Pr, resulting in a significant tilt of the hysteresis loop. As the current-voltage cycle curve or the positive and negative bias transient spectrum is measured, the device 20 to be annealed remains in a high-temperature environment. Therefore, the high-temperature, low-voltage wakeup effect can be utilized to increase the number of ferroelectric domains in the ferroelectric layer 22 with polarization directions along the external electric field, thereby increasing the polarization strength and concentrating the switching threshold voltage. In other words, the residual polarization strength Pr can be increased while the switching electric field strength Er is decreased, resulting in a smaller tilt of the hysteresis loop. Figure 7 As shown in Figure (b). This facilitates wake-up under high temperature and low pressure conditions, avoiding damage to the device caused by wake-up under room temperature and high pressure conditions. In addition, during the measurement process, the polar axis distribution in the ferroelectric layer 22 can be determined based on the current peak width or hysteresis loop reversal angle, allowing for timely cessation of wake-up and improving production efficiency.

[0081] For example, see Figures 8-10 , Figure 8 This is a connection diagram of a three-dimensional ferroelectric storage device 20 to be annealed, provided in an embodiment of this application. Figure 9 This is a schematic diagram illustrating the annealing of a three-dimensional ferroelectric storage device according to an embodiment of this application. Figure 10This is a schematic diagram of a three-dimensional ferroelectric memory device disposed on a support device 13 according to an embodiment of this application. The device to be annealed 20 is a three-dimensional ferroelectric memory device. The fabrication process of the three-dimensional ferroelectric memory device may include depositing a stacked structure of a first electrode 21 and an insulating dielectric 25, and creating openings in the stacked structure by photolithography and high aspect ratio dry etching to obtain columnar deep trenches. Ferroelectric layers 22 and intercalation layers 24 are sequentially deposited on the sidewalls of the columnar deep trenches. The thickness of the ferroelectric layer 22 may be 6nm to 10nm, and the thickness of the intercalation layer 24 may be 5nm. Then, metal material is deposited to fill the columnar deep trenches to form second electrodes 23. Finally, metal is deposited to connect all the first electrodes 21 and all the second electrodes 23. Understandably, the first electrodes 21 may be connected to bit lines, which may be led out from the top of the stacked structure for connection with peripheral circuits; similarly, the second electrodes 23 may be connected to word lines, which may also be led out from the top of the stacked structure for connection with peripheral circuits. Therefore, metal can be deposited in the top regions corresponding to the word lines and the top regions corresponding to the bit lines to connect all the first electrodes 21 and all the second electrodes 23. Furthermore, pads 25 and 26 can be formed on the deposited metal to facilitate connection. Thus, by connecting all the first electrodes 21 to the first electrical connector 132 via the first conductive line 141 and all the second electrodes 23 to the second electrical connector 133 via the second conductive line 142, the electrical performance of the three-dimensional ferroelectric memory device can be monitored during annealing. Understandably, the chamber 11 can be provided with an inlet and an outlet, allowing specific gases to be introduced during annealing to achieve a specific annealing process.

[0082] Please see Figure 11 , Figure 11 Figure (a) shows the polar axis PA orientation after the radial distribution of the polar axis PA is induced by the measurement of electrical parameters during the annealing process of the three-dimensional ferroelectric storage device. It can be seen that the polar axis PA orientation is consistent with the direction of the electric field E generated by the measurement. Figure 11 Figure (b) shows the percentage of ferroelectric domains with different angles between the polar axis PA orientation and the electric field E direction after measuring electrical parameters during the annealing process of a three-dimensional ferroelectric storage device. The angle between the polar axis PA orientation and the electric field E direction is represented by cosθ. The closer the value of cosθ is to 1, the closer the polar axis PA orientation and the electric field E direction are to being the same. It can be seen that the smaller the angle between the polar axis PA orientation and the electric field E direction, the greater the number of ferroelectric domains. Therefore, measuring electrical parameters can improve the performance of three-dimensional ferroelectric storage devices.

[0083] For example, the annealing apparatus 10 may also include multiple pairs of detection lines as described above. The device to be annealed 20 may include multiple components, and the electrical measurement device 14 can apply different signals through multiple pairs of detection lines to measure the same electrical parameters of multiple components respectively. In this way, current-voltage cycle curves or positive and negative bias transient spectra can be measured for multiple components respectively. Different electrical signals can be applied to different components for measurement to achieve a wake-up effect, so that the switching electric field strength Er and remanent polarization intensity Pr of different components have high consistency, thereby improving the quality of the device to be annealed 20.

[0084] Understandably, during the formation of a three-dimensional ferroelectric memory device, the columnar deep trenches obtained by drilling holes in the stacked structure are typically larger at the top and smaller at the bottom. This results in different dimensions of the ferroelectric layer 22 and the corresponding electrodes of multiple memory cells (corresponding to the elements of the device 20 to be annealed) in the three-dimensional ferroelectric memory device, leading to inconsistencies in the switching electric field intensity Er and remanent polarization intensity Pr of the ferroelectric layer 22 in different memory cells. After the ferroelectric layer 22 is crystallized, different signals can be applied to multiple pairs of detection lines to measure the same electrical parameters of multiple memory cells, such as measuring current-voltage cycle curves or positive and negative bias transient spectra. By utilizing the wakeup effect, the number of ferroelectric domains with the polar axis PA orientation along the direction of the electric field E in the ferroelectric layer 22 can be increased. Since different electrical signals can be applied to different memory cells for wakeup, the degree of wakeup can be controlled, reducing the differences in the switching electric field intensity Er and remanent polarization intensity Pr of different memory cells.

[0085] For example, please continue to see Figure 8 In this design, multiple memory cells at the same height in the stacked structure can be connected to a pair of detection lines, while memory cells at different heights can be connected to different detection lines. This means that multiple memory cells on the same layer can be connected to a pair of detection lines, while memory cells on different layers can be connected to different detection lines. In this way, different electrical signals can be applied to memory cells on different layers to wake them up, while the same electrical signal can be applied to memory cells on the same layer in batches to wake them up, thus improving production efficiency.

[0086] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An annealing apparatus, characterized in that, include: A chamber for containing components to be annealed; A heating device is used to heat the device to be annealed; A support device is disposed in the chamber to support the device to be annealed; An electrical measuring device is installed outside the cavity and connected to the device to be annealed via a conductive wire.

2. The annealing equipment as described in claim 1, characterized in that, The electrical measuring device is used to measure the electrical parameters of the device to be annealed during the annealing process.

3. The annealing equipment as described in claim 1 or 2, characterized in that, The electrical parameters include resistance values, current-voltage cycle curves, or transient spectra under positive and negative bias.

4. The annealing equipment according to any one of claims 1 to 3, characterized in that, The heating device is connected to the electrical measuring device; the heating device controls the heating power according to the electrical parameters.

5. The annealing equipment according to any one of claims 1 to 4, characterized in that, The support device includes a support platform and a first electrical connector and a second electrical connector fixed on the support platform. The conductive wires include a first conductive wire, a second conductive wire, a third conductive wire, and a fourth conductive wire. One end of the first conductive wire is used to connect to the device to be annealed, and the other end of the first conductive wire is connected to the first end of the first electrical connector. The two ends of the second conductive wire are respectively connected to the second end of the first electrical connector and the electrical measuring device; One end of the third conductive wire is used to connect to the device to be annealed, and the other end of the third conductive wire is connected to the first end of the second electrical connector. The two ends of the fourth conductive wire are respectively connected to the second end of the second electrical connector and the electrical measuring device.

6. The annealing equipment as described in claim 5, characterized in that, The first electrical connector, the second electrical connector, the first conductive wire, the second conductive wire, the third conductive wire, and the fourth conductive wire constitute a pair of detection circuits, and the annealing equipment includes multiple pairs of such detection circuits.

7. The annealing equipment as described in claim 5 or 6, characterized in that, The first electrical connector passes through the support platform. The first end of the first electrical connector is located on the same side of the support platform as the device to be annealed, and the second end of the first electrical connector is located on the opposite side of the support platform from the first end. The second electrical connector passes through the support platform. The first end of the second electrical connector is located on the same side of the support platform as the device to be annealed, and the second end of the second electrical connector is located on the opposite side of the support platform from the first end.

8. The annealing equipment according to any one of claims 1 to 7, characterized in that, It also includes an electrode flange, and the chamber wall of the chamber is provided with a through hole, and the electrode flange blocks the through hole; The conductive wire passes through the electrode flange.

9. A method for operating an annealing apparatus, characterized in that, The annealing equipment includes: a chamber, a heating device, a support device, and an electrical measuring device. The support device is disposed in the chamber and is used to support the device to be annealed. The working method includes: The heating device heats the component to be annealed; The electrical measuring device measures the electrical parameters of the device to be annealed; The heating device controls and changes the heating power according to the electrical parameters.

10. The working method as described in claim 9, characterized in that, The electrical parameters include resistance values, and controlling the heating power of the heating device based on these electrical parameters includes: When the measured resistance value changes from a first resistance value to a second resistance value, the heating device increases the heating power, wherein the first resistance value is greater than or less than the second resistance value.

11. The working method as described in claim 10, characterized in that, After increasing the heating power, if the measured resistance value remains stable, the heating device reduces the heating power or stops heating.

12. The working method as described in claim 11, characterized in that, After the measured resistance value decreases and remains stable, and before the heating device reduces its heating power or stops heating, the process further includes: The electrical measuring device measures the current-voltage cycle curve or the positive and negative bias transient spectrum of the annealed device.

13. The working method as described in claim 12, characterized in that, The annealing equipment also includes multiple pairs of detection lines, the annealing device includes multiple components, and the electrical measuring device applies different signals through the multiple pairs of detection lines to measure the same electrical parameters of the multiple components respectively.

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