Method for monitoring wafer transfer-out temperature of annealing equipment
By preparing a transition layer and a metal layer on a sample wafer and measuring the difference in reflectivity before and after annealing, the problem of accurate monitoring of wafer output temperature in annealing equipment was solved. This ensured that the wafer temperature met the requirements during output, avoided metal oxidation reaction, and improved wafer yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-04
- Publication Date
- 2026-03-13
AI Technical Summary
Existing technologies make it difficult to accurately monitor the wafer exit temperature of annealing equipment, which leads to the reaction between the metal on the wafer surface and oxygen, creating voids, causing circuit failure, and affecting wafer yield.
By preparing a transition layer and a metal layer on a sample wafer, and measuring the difference in reflectivity of the metal layer before and after annealing, it is determined whether the wafer exit temperature of the annealing equipment meets the standard.
It enables precise monitoring of the wafer exit temperature of the annealing equipment, avoids metal oxidation reaction, and improves wafer yield.
Smart Images
Figure CN121665950A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of semiconductor manufacturing technology, and more particularly to a method for monitoring the wafer exit temperature of an annealing equipment. Background Technology
[0002] In semiconductor fabrication, annealing is a process that improves the performance of semiconductor materials and enhances the reliability of semiconductor devices by heating them at a certain temperature for a period of time and then slowly cooling them. When the annealing process is complete, the semiconductor device (e.g., a wafer with a semiconductor structure) needs to be cooled to a certain temperature before being removed from the equipment. If the wafer is removed from the equipment at an excessively high temperature (e.g., >200°C), the metal material on the wafer surface is prone to react with oxygen in the atmosphere, causing metal ions to migrate and create voids, leading to circuit failure.
[0003] However, current technologies struggle to accurately monitor the wafer exit temperature of annealing equipment, making it impossible to determine whether the temperature meets the requirements of the wafer fabrication process, which hinders the improvement of wafer yield. Therefore, a new technology is urgently needed to achieve accurate monitoring of the wafer exit temperature of annealing equipment. Summary of the Invention
[0004] The summary of this application introduces a series of simplified concepts, which will be further explained in detail in the detailed description section. This summary is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.
[0005] This application provides a method for monitoring the wafer exit temperature of an annealing equipment, comprising: providing a sample wafer having a substrate, a transition layer, and a metal layer, wherein the transition layer is fabricated between the substrate and the metal layer; measuring the reflectivity of the metal layer before annealing to obtain a first reflectivity value; placing the sample wafer into a monitored annealing equipment and performing an annealing process on the sample wafer in the annealing equipment; measuring the reflectivity of the metal layer after annealing to obtain a second reflectivity value; calculating the difference between the first reflectivity value and the second reflectivity value; and determining whether the wafer exit temperature of the monitored annealing equipment meets the standard based on the difference.
[0006] The method provided in this application for monitoring the wafer exit temperature of an annealing equipment measures the reflectivity of the metal layer on the surface of a sample wafer before and after annealing, and determines the degree of oxidation of the metal layer based on the difference in reflectivity, thereby determining whether the wafer exit temperature of the annealing equipment meets the standard. Since the metal layer on the surface of the sample wafer is more likely to react with oxygen in the external atmosphere at higher temperatures, generating oxides and causing a decrease in reflectivity, monitoring the change in the reflectivity of the metal layer on the sample wafer surface is sufficient to determine whether the wafer exit temperature of the annealing equipment is within the standard range. This method is simple, easy to implement, and allows for precise monitoring.
[0007] Optionally, the material of the transition layer includes one or more of silicon oxide, silicon dioxide, silicon trioxide, or silicon oxynitride.
[0008] Optionally, the material of the metal layer includes one of copper, lead, nickel, zinc, iron, and silver.
[0009] Optionally, the method for preparing the transition layer includes thermal oxidation, physical vapor deposition, chemical vapor deposition, and atomic layer deposition.
[0010] Optionally, the method for preparing the metal layer includes physical vapor deposition, magnetron sputtering, and atomic layer deposition.
[0011] Optionally, the thickness of the transition layer is
[0012] Optionally, the thickness of the metal layer is
[0013] Optionally, the process parameters of the annealing process include annealing temperature, annealing pressure, reaction gas flow rate, and cooling time.
[0014] Optionally, the process parameters of the annealing process satisfy one or more of the following: the annealing temperature is 300℃~500℃; the annealing pressure is 0~5Torr; and the reaction gas flow rate is 1000~2000sccm.
[0015] Optionally, the step of determining whether the wafer output temperature of the monitored annealing equipment meets the standard based on the difference includes: determining whether the difference between the first reflectivity and the second reflectivity is within a preset range; when the difference is within the preset range, the wafer output temperature of the annealing equipment meets the standard. Attached Figure Description
[0016] The following drawings, which are incorporated herein by reference and are used to understand this application, illustrate embodiments of the invention and their descriptions, thereby explaining the apparatus and principles of the invention.
[0017] Figure 1 A schematic diagram showing the measurement results of existing wafer exit temperature detection methods in annealing equipment;
[0018] Figure 2 A simplified flowchart of a wafer exit temperature monitoring method for an annealing apparatus according to this application;
[0019] Figure 3 This is a schematic diagram of a sample wafer structure according to a preferred embodiment of this application.
[0020] Figure 4 This is a schematic diagram of the measurement results of a wafer output temperature monitoring method for an annealing equipment according to an embodiment of this application.
[0021] Explanation of reference numerals in the attached figures:
[0022] 11. Thickness before measurement; 12. Thickness after measurement; 100. Sample wafer; 101. Substrate; 102. Transition layer; 103. Metal layer; 301. First reflectivity value; 302. Second reflectivity value. Detailed Implementation
[0023] The following description provides numerous specific details to offer a more thorough understanding of this application. However, it will be apparent to those skilled in the art that this application can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with this application.
[0024] To fully understand this application, detailed portions will be set forth in the following description in order to illustrate it. Obviously, implementation of this application is not limited to the specific details familiar to those skilled in the art. Preferred embodiments of this application are described in detail below; however, other embodiments may exist besides these detailed descriptions, and should not be construed as being limited to the embodiments set forth herein.
[0025] It should be understood that the terminology used herein is intended only to describe particular embodiments and is not intended to limit the scope of this application. The singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. When the terms “comprising” and / or “including” are used in this specification, they indicate the presence of the stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or combinations thereof. The terms “upper,” “lower,” “front,” “rear,” “left,” “right,” and similar expressions used in this application are for illustrative purposes only and are not intended to be limiting.
[0026] The ordinal numbers such as "first" and "second" used in this application are merely identifiers and have no other meaning, such as a specific order. In this application, unless otherwise expressly specified and limited, "above" or "below" a second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of a second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" of a second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0027] The specific embodiments of this application will be described in more detail below with reference to the accompanying drawings, which illustrate representative embodiments of this application and are not intended to limit this application.
[0028] In semiconductor fabrication, annealing is a process that improves semiconductor material performance and enhances the reliability of semiconductor devices by heating the semiconductor material at a specific temperature for a period of time followed by slow cooling. Annealing typically includes a heating stage, a holding stage, and a cooling stage. Specifically, after the semiconductor device to be processed (e.g., a wafer with a semiconductor structure) is transported to the annealing equipment, the equipment runs an annealing program, heating the wafer to a specific temperature (the annealing temperature) and holding it at that temperature for a period of time, followed by slow cooling. During the heating and holding stages, the atoms in the wafer move and rearrange, helping to eliminate lattice defects and increase grain size. During the cooling stage, the cooling rate affects the final crystal structure and performance within the wafer. The annealing equipment can perform rapid or slow cooling of the wafer depending on the specific circumstances. Slow cooling helps maintain the desired crystal structure, while rapid cooling can more ideally achieve the final crystal structure.
[0029] When the annealing process is complete, the wafer must be cooled to a certain temperature before being removed from the equipment. If the wafer leaves the equipment at too high a temperature (e.g., >200°C), the metal material on the wafer surface is prone to react with oxygen in the atmosphere, causing metal ions to migrate and create voids, leading to circuit failure. When the annealing equipment experiences excessively high wafer removal temperatures, this is generally resolved by extending the cooling time of the annealing process's cooling phase.
[0030] Existing technologies typically use silicon wafers to test the wafer exit temperature of annealing equipment. The change in the thickness of the natural oxide layer on the silicon wafer's surface before and after the annealing process is measured to determine whether the wafer exit temperature meets the standard. However, since silicon is the primary material of silicon wafers, the oxidation rate of silicon does not change significantly in the vicinity of the annealing equipment's wafer exit temperature range. This means that the thickness of the natural oxide layer on the silicon wafer's surface before and after annealing is largely unaffected by the equipment's wafer exit temperature. Therefore, existing methods cannot accurately determine whether the wafer exit temperature of the annealing equipment meets the standard. Figure 1 The example illustrates a schematic diagram of measurement results from an annealing apparatus used to detect when the wafer exit temperature is below standard. This prior art embodiment uses the annealing apparatus to perform annealing processes on multiple silicon wafers and measures the thickness of the natural oxide layer on the surface of each wafer before and after the annealing process. Line 11 shows the natural oxide layer thickness curve for each wafer before annealing, and line 12 shows the natural oxide layer thickness curve for each wafer after annealing. Compared to line 11, line 12 shows little difference in the natural oxide layer thickness of each silicon wafer before and after annealing. This indicates that the wafer exit temperature of the annealing apparatus does not significantly affect the thickness of the natural oxide layer on the silicon wafer. Therefore, it is difficult to detect whether the wafer exit temperature of the annealing apparatus meets the process requirements using existing techniques.
[0031] Therefore, this application provides a method for monitoring the wafer exit temperature of an annealing equipment, the flowchart of which is shown below. Figure 2 As shown, it includes:
[0032] Step S201: Provide a sample wafer, the sample wafer having a substrate, a transition layer and a metal layer, the transition layer being fabricated between the substrate and the metal layer;
[0033] Step S202: Measure the reflectivity of the metal layer before annealing to obtain a first reflectivity value;
[0034] Step S203: Place the sample wafer into a monitored annealing device and perform an annealing process on the sample wafer in the annealing device;
[0035] Step S204: Measure the reflectivity of the annealed metal layer to obtain a second reflectivity value;
[0036] Step S205: Calculate the difference between the first reflectance value and the second reflectance value;
[0037] Step S206: Based on the difference, determine whether the wafer output temperature of the monitored annealing equipment meets the standard.
[0038] Figure 3A schematic diagram of the sample wafer 100 used in the monitoring method of an embodiment of this application is shown: The sample wafer 100 includes a substrate 101, a transition layer 102, and a metal layer 103, wherein the transition layer 102 covers the substrate 101, and the metal layer 103 covers the transition layer 102, that is, the transition layer 102 and the metal layer 103 are sequentially prepared along a direction away from the substrate 101. In this embodiment of the application, the substrate 101 is made of silicon, which has the advantage of good chemical stability.
[0039] Further, in this embodiment, the material of the transition layer 102 includes one or more of silicon oxide, silicon dioxide, silicon trioxide, or silicon oxynitride. The material of the transition layer 102 is close to the material of the substrate 101, which reduces the impact on the substrate 101 material, allowing the transition layer 102 and the metal layer 103 to be removed after testing, thereby enabling wafer reuse. In some embodiments, the transition layer 102 is a single-layer structure, and the material of the transition layer can be any of the above-mentioned materials; in some other embodiments, the transition layer 102 can be multilayered, formed by stacking multiple layers of different materials, and this embodiment does not limit this. In some embodiments, the method for preparing the transition layer 102 can be a thin film preparation method such as thermal oxidation, physical vapor deposition (PVD), chemical vapor deposition (CVD), or atomic layer deposition (ALD).
[0040] By fabricating a transition layer 102 between the substrate 101 and the metal layer 103 of the sample wafer 100, damage to the substrate 101 can be prevented during subsequent metal layer 103 fabrication processes, thereby protecting the substrate 101. Furthermore, fabricating the transition layer 102 between the substrate 101 and the metal layer 103 facilitates the reuse of the sample wafer 100. Since the surface metal of the metal layer 103 on the surface of the sample wafer 100 will be oxidized to varying degrees after the wafer exit temperature test in the annealing equipment, to avoid affecting subsequent test results, the metal layer 103 on the surface of the sample wafer 100 needs to be removed and re-fabricated after each test. Therefore, fabricating the transition layer 102 between the substrate 101 and the metal layer 103 facilitates the removal of the metal layer 103, thereby enabling the reuse of the sample wafer 100 and saving costs.
[0041] Furthermore, in the embodiments of this application, the material of the metal layer 103 includes one of copper, lead, nickel, zinc, iron, and silver. Methods for preparing the metal layer 103 include physical vapor deposition, magnetron sputtering, and atomic layer deposition.
[0042] Since the metal layer 103 is made of metal, the metal it contains is prone to react with oxygen in the air at high temperatures (e.g., temperatures exceeding 200°C), combining and forming oxides, which causes a change in the reflectivity of the metal layer. This embodiment of the application utilizes this characteristic of metallic materials. A sample wafer 100 with the metal layer 103 is used to test the wafer exit temperature of the annealing equipment. By measuring the difference in reflectivity of the metal layer 103 on the surface of the sample wafer 100 before and after the annealing process, the degree of oxidation of the metal layer 103 is determined, and thus, whether the wafer exit temperature of the annealing equipment is too high (not up to standard) is inferred. This achieves the purpose of monitoring the wafer exit temperature of the annealing equipment. When the test results show that the wafer exit temperature of the annealing equipment is too high, using the equipment in the formal process flow may lead to wafer damage and reduced yield. Therefore, it is necessary to shut down the equipment for debugging and modify the setting program to adjust the wafer exit temperature of the equipment.
[0043] In one embodiment of this application, as an optional implementation, the transition layer 102 is made of silicon dioxide, and the metal layer 103 is made of copper. The transition layer 102 is prepared by thermal oxidation, and the metal layer 103 is prepared by magnetron sputtering. Exemplarily, the copper metal layer is formed from a copper target by glow discharge under a preset pressure, for example, 1 Torr to 5 Torr.
[0044] Furthermore, in some embodiments, the thickness of the transition layer 102 is... With this configuration, the transition layer 102 has sufficient thickness to effectively protect the substrate 101 from damage and facilitates the removal of the subsequent metal layer 103.
[0045] Furthermore, in some embodiments, the thickness of the metal layer 103 is... With this configuration, the metal layer 103 has sufficient thickness and an intact surface, which is beneficial for measuring the reflectivity parameters of the metal layer.
[0046] In this embodiment, a sample wafer 100 is used to monitor the wafer output temperature of the annealing equipment. The annealing equipment used for testing is the annealing equipment for which the wafer output temperature needs to be monitored. The specific monitoring method is described in detail below:
[0047] First, according to step S201, a sample wafer 100 is provided. The specific structure of the sample wafer 100 is described above and will not be elaborated here.
[0048] Then, in step S202, the reflectivity of the metal layer 103 of the sample wafer 100 before annealing is measured to obtain a first reflectivity value. The first reflectivity value is used to compare with the reflectivity value of the metal layer 103 of the sample wafer 100 after the annealing process to determine the degree of oxidation of the metal layer 103.
[0049] Then, in step S203, the sample wafer 100 is placed in the monitored annealing equipment, and the sample wafer 100 is subjected to the annealing process in the annealing equipment.
[0050] As mentioned above, the annealing process typically includes a heating stage, a holding stage, and a cooling stage. In this embodiment, exemplarily, after the sample wafer 100 is sent to the monitored annealing equipment, the annealing equipment first heats the sample wafer 100 to the annealing temperature. Then, the sample wafer 100 is held at a certain temperature (e.g., the annealing temperature) for a period of time. Next, the annealing equipment controls the sample wafer 100 to cool at a controlled rate. Finally, the annealing equipment removes the sample wafer 100 from the equipment after it has cooled to a certain temperature. The temperature at which the sample wafer 100 leaves the annealing equipment is the wafer exit temperature of the annealing equipment to be monitored in this embodiment.
[0051] Furthermore, in some embodiments, the process parameters of the annealing process include annealing temperature, annealing pressure, reactant gas flow rate, and cooling time. By adjusting the process parameters of the above annealing procedure, the final process effect of the annealing process can be changed.
[0052] For example, the process parameters of the annealing procedure meet one or more of the following: annealing temperature 300℃~500℃; annealing pressure 0~5 Torr; reaction gas flow rate 1000~2000 sccm. This setting firstly simulates the annealing process under the monitored annealing equipment in the actual wafer fabrication process, obtaining a wafer exit temperature close to that of the real annealing equipment, thus enhancing the reference value of the monitoring results obtained according to the monitoring method of this embodiment; secondly, controlling the annealing temperature within a reasonable range can prevent the sample wafer 100 from being damaged by high temperatures, which is beneficial for the recycling and reuse of the sample wafer 100.
[0053] Furthermore, the cooling time of the annealing process is related to the wafer exit temperature of the annealing equipment: with other annealing process parameters being the same, the longer the cooling time, the lower the wafer exit temperature of the annealing equipment. Because the wafer surface material at high temperatures is prone to react with oxygen in the atmosphere outside the machine, leading to wafer surface metal oxidation and reduced yield, if the wafer exit temperature of the annealing equipment is detected to be too high (e.g., >200℃), the cooling time is generally increased to further reduce the wafer exit temperature, thereby preventing wafer damage in subsequent processes.
[0054] Next, step S204 is performed to measure the reflectivity of the annealed metal layer 103 and obtain a second reflectivity value.
[0055] As mentioned above, after the annealing process of sample wafer 100 is completed, the annealing equipment will remove the sample wafer 100 from the machine after it has been cooled to a certain temperature. Since the sample wafer 100 still has a certain temperature after annealing (e.g., around 200°C), the metal contained in its surface metal layer 103 may react with oxygen in the atmosphere, thereby generating oxides. The higher the temperature of the sample wafer 100 when it leaves the machine, the greater the degree of oxidation of the metal in its surface metal layer 103, and the greater the change in the reflectivity of the metal layer 103. Therefore, the change in the reflectivity of the metal layer 103 of the sample wafer 100 before and after the annealing process can, to some extent, reflect the temperature of the sample wafer 100 when it leaves the annealing equipment. Furthermore, it can be used to determine whether the wafer exit temperature of the annealing equipment meets the standard.
[0056] Then, proceed to step S205 to calculate the difference between the first reflectivity value and the second reflectivity value.
[0057] Finally, in step S206, the difference between the first reflectivity and the second reflectivity is used to determine whether the wafer output temperature of the monitored annealing equipment meets the standard.
[0058] In some embodiments, the wafer exit temperature of the annealing equipment can be directly determined based on the difference between the first reflectance and the second reflectance of a single sample wafer 100 before and after the annealing process. Specifically, when the difference between the first reflectance value and the second reflectance value is small, equal to zero, or approximately zero, it indicates that the metal layer 103 after annealing has not undergone oxidation or the oxidation reaction is slight. This indicates that the temperature of the sample wafer 100 when exiting the annealing equipment is within the acceptable range, meaning that at this exit temperature, there will be no severe oxidation of the surface metal of the wafer undergoing the annealing process and a decrease in yield, and the wafer exit temperature is qualified. When the difference between the first reflectance value and the second reflectance value is large, it indicates that the metal layer 103 after annealing has undergone a strong oxidation reaction. This indicates that at this exit temperature, the annealing equipment may cause severe oxidation of the surface metal of the wafer undergoing the annealing process and a decrease in yield, and the wafer exit temperature is not qualified or is about to be unqualified. In order to avoid affecting the process yield of subsequent annealing processes, it is recommended to shut down the annealing equipment for maintenance and adjust the setting program to reduce the wafer exit temperature.
[0059] Therefore, this embodiment of the application uses the difference in reflectivity of the metal layer 103 on the surface of the sample wafer 100 before and after the annealing process in the annealing equipment to determine the degree of oxidation of the metal layer 103, and then to determine whether the wafer output temperature of the annealing equipment meets the requirements. This method is simple, easy to implement, and can be accurately monitored.
[0060] Furthermore, in some embodiments, step S206, which involves determining whether the wafer exit temperature of the monitored annealing equipment meets the standard based on the difference between the first reflectivity and the second reflectivity, includes: determining whether the difference between the first reflectivity and the second reflectivity is within a preset range; and determining that the wafer exit temperature of the annealing equipment meets the standard when the difference is within the preset range. This setting facilitates the determination of whether the wafer exit temperature of the annealing equipment meets the standard. For example, in one embodiment, the preset range of reflectivity difference can be set to 0-0.2%. In this case, when the reflectivity difference of the metal layer before and after annealing of a certain sample wafer is 0.05%, since the difference is within the preset range, it can be determined that the metal layer of the sample wafer has a slight degree of oxidation, and the wafer output temperature of the annealing equipment meets the standard. When the reflectivity difference of the metal layer before and after annealing of a certain sample wafer is 0.25%, since the difference is outside the preset range, it can be determined that the metal layer of the sample wafer has a severe degree of oxidation, and the wafer output temperature of the annealing equipment does not meet the standard. The annealing equipment needs to be shut down for maintenance, the annealing program needs to be reset, and the wafer output temperature of the annealing equipment needs to be adjusted.
[0061] Furthermore, in some other embodiments, multiple sample wafers in batches can be used for testing, and the overall difference in reflectance can be used to determine whether the wafer exit temperature of the monitored annealing equipment meets the standard. For example, for the same batch of sample wafers, if the reflectance difference before and after the annealing process in the monitored annealing equipment exceeds a preset range by more than 10%, then the wafer exit temperature of the annealing equipment does not meet the standard, and the annealing equipment needs to be stopped for repair or program adjustment.
[0062] Specifically, the first reflectivity value of the surface metal layer of multiple sample wafers is measured sequentially before annealing. Then, the multiple sample wafers are simultaneously placed into a monitored annealing device for annealing. After the sample wafers exit the annealing device, the second reflectivity value of their surface metal layer is measured sequentially. The difference between the first and second reflectivity values of each sample wafer is calculated. Based on the difference between the first and second reflectivity values of each sample wafer, it is determined whether the exit temperature corresponding to that sample wafer meets the standard. If the proportion of non-compliance cases is greater than 10%, it is determined that the wafer exit temperature of the annealing device is not up to standard, and the annealing device needs to be repaired or the program adjusted.
[0063] In some other embodiments, the annealing equipment can be continuously monitored. The wafer exit temperature can be monitored based on the change in the reflectivity difference of the metal layer before and after annealing of the sample wafers over a certain time period to determine if it meets the standard. For example, a batch of sample wafers is annealed daily in the monitored annealing equipment, and the non-compliance of the reflectivity difference for each batch is recorded. When the recorded non-compliance of the reflectivity difference exceeds a preset limit, the annealing equipment is immediately stopped and repaired. If the recorded non-compliance of the reflectivity difference is still within the preset limit, but the test results have continued to deteriorate over the past 3, 5, or N days (N being an integer greater than 1), it may indicate a malfunction in the annealing equipment or a need for program adjustment, requiring the machine to be shut down for maintenance.
[0064] Figure 4 This is a schematic diagram illustrating the measurement results of a wafer exit temperature monitoring method for an annealing equipment according to an embodiment of this application. In this embodiment, 10 sample wafers are used in a batch, and annealing processes are performed simultaneously in a monitored annealing equipment. The reflectivity difference of the metal layer of each sample wafer before and after the annealing process is measured. The metal layer material of the sample wafers is copper. In the diagram, line 301 represents the first reflectivity value of each sample wafer, and line 302 represents the second reflectivity value. The preset range for the metal layer reflectivity difference is 0–0.2%.
[0065] Comparing line graphs 301 and 302, it can be seen that the difference in metal layer reflectivity between the 5th and 10th sample wafers is significant, and both are outside the preset range for the difference in metal layer reflectivity. Therefore, it can be determined that the wafer output temperature of the annealing equipment corresponding to the 5th and 10th sample wafers is substandard, and the annealing equipment needs to be shut down for maintenance. Furthermore, based on the test results of the 10 sample wafers in this batch, the substandard rate is 20%. When the substandard rate is set to trigger an alarm if it exceeds 10%, according to the measurement results of this embodiment, the wafer output temperature of the annealing equipment is substandard, which poses a risk of wafer damage and reduced wafer yield in subsequent processes, requiring the annealing equipment to be shut down for maintenance.
[0066] Therefore, the embodiments of this application monitor the wafer output temperature of the annealing equipment by preparing a batch of sample wafers with copper metal layers. By comparing the difference in reflectivity of the copper metal layer before and after the annealing process in the monitored annealing equipment, it is determined whether the wafer output temperature meets the requirements. The wafer output temperature compliance rate in a batch of tests is used to determine whether the annealing equipment needs to be shut down for maintenance. This method is simple, easy to implement, and can accurately monitor the process.
[0067] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for descriptive purposes only and is not intended to limit the scope of this application. Terms such as “part” or “component” appearing herein can refer to a single part or a combination of multiple parts. Terms such as “installation” or “installation” appearing herein can refer to one component being directly attached to another component or one component being attached to another component via an intermediary. A feature described in one embodiment herein may be applied, alone or in combination with other features, to another embodiment, unless that feature is not applicable in that other embodiment or is otherwise stated.
[0068] This application has been described through the above embodiments; however, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit this application to the described embodiments. Furthermore, those skilled in the art will understand that this application is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of this application, all of which fall within the scope of protection claimed in this application. The scope of protection of this application is defined by the appended claims and their equivalents.
Claims
1. A method for monitoring the wafer exit temperature of an annealing equipment, characterized in that, include: A sample wafer is provided, the sample wafer having a substrate, a transition layer and a metal layer, wherein the transition layer is formed between the substrate and the metal layer; The reflectivity of the metal layer before annealing is measured to obtain a first reflectivity value; The sample wafer is placed in a monitored annealing device, where the sample wafer is subjected to an annealing process. The reflectivity of the annealed metal layer is measured to obtain a second reflectivity value; Calculate the difference between the first reflectance value and the second reflectance value; Based on the difference, it is determined whether the wafer output temperature of the monitored annealing equipment meets the standard.
2. The method according to claim 1, characterized in that, The material of the transition layer includes one or more of silicon oxide, silicon dioxide, silicon trioxide, or silicon oxynitride.
3. The method according to claim 1, characterized in that, The material of the metal layer includes one of copper, lead, nickel, zinc, iron, and silver.
4. The method according to claim 1, characterized in that, The methods for preparing the transition layer include thermal oxidation, physical vapor deposition, chemical vapor deposition, and atomic layer deposition.
5. The method according to claim 1, characterized in that, The methods for preparing the metal layer include physical vapor deposition, magnetron sputtering, and atomic layer deposition.
6. The method according to claim 1, characterized in that, The thickness of the transition layer is 7. The method according to claim 1, characterized in that, The thickness of the metal layer is 8. The method according to claim 1, characterized in that, The process parameters of the annealing process include annealing temperature, annealing pressure, reaction gas flow rate, and cooling time.
9. The method according to claim 8, characterized in that, The process parameters of the annealing process satisfy one or more of the following: The annealing temperature is 300℃~500℃; The annealing pressure is 0–5 Torr. The flow rate of the reaction gas is 1000-2000 sccm.
10. The method according to claim 1, characterized in that, The step of determining whether the wafer exit temperature of the monitored annealing equipment meets the standard based on the difference includes: Determine whether the difference between the first reflectivity and the second reflectivity is within a preset range. When the difference is within the preset range, the wafer exit temperature of the annealing equipment meets the standard.