Annealing method of semiconductor structure

Abstract

The invention provides an annealing method of a semiconductor structure, which comprises the following steps of: providing an annealing system comprising a process control module and an annealing machine, establishing a relationship between the film thickness of the metal work function layers made of different materials and the open-loop power and annealing time during annealing, and writing the relationship into a process control module; providing a wafer to be annealed, wherein a metal work function layer is formed on the upper surface layer of the wafer to be annealed, and conveying the wafer to the annealing machine table; the annealing system obtains the film thickness and the material of the metal work function layer, and feeds back the film thickness and the material of the metal work function layer to the process control module; and the process control module carries out processing based on the relationship to obtain preset power, modifies the open-loop power in the menu into the preset power, and controls the annealing machine to carry out annealing work. According to the invention, the open-loop power is obtained by processing the relationship among the film thickness, the open-loop power and the annealing time, and the open-loop power in the menu is modified by using the process control module, so that the establishment of the menu is reduced.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor integrated circuit manufacturing and relates to an annealing method for semiconductor structures. Background Technology

[0002] With the development of semiconductor technology, transistor sizes are continuously shrinking. To significantly reduce gate leakage current (solving power consumption and heat generation issues) and maintain or improve gate control over the channel (ensuring performance and preventing short-channel effects) while simultaneously shrinking transistor size, and to address the compatibility issues between high-k materials and traditional polysilicon gates, high-k metal gate (HKMG) has become crucial. In the HKMG process, the threshold voltage Vt of the transistor is typically adjusted by regulating the thickness of the top TiN (Cap TiN) metal work function layer. After the metal work function materials are deposited, they undergo varying degrees of annealing to remove stress, repair oxygen vacancies and defects generated during the formation of the metal work function layer, and optimize the material's performance.

[0003] The temperature changes over time at each stage of the rapid annealing (RTP) process are shown in the figure below. Figure 1 As shown, the first few stages are usually the open loop stage, where the power is fixed. Therefore, the heating rate depends entirely on the heat absorption capacity of the wafer itself. When different thicknesses of metal are deposited in the front layer of the wafer, the difference in their emissivity will be very large. The thinner the deposited metal layer, the smaller its emissivity, the slower the heating, and the longer the open loop time. As the number and variety of products in the manufacturing assembly (FAB) end continue to increase, different products will inevitably have different threshold voltage (Vt) requirements, which will require the formation of metal work function layers of different thicknesses. Usually, these products with metal work function layers of different thicknesses will use the same anneal recipe. This results in the open loop time of wafers with metal work function layers of different thicknesses ranging from 20s to 100s (due to the difference in the thickness of the metal deposited in the previous layer). If we want to improve the WPH (wafers per hour annealed), we need to establish many corresponding anneal recipes. This will generate a lot of menu loading and loading risks, which will seriously affect the improvement of WPH and the optimization of the process.

[0004] Therefore, there is an urgent need to find an annealing method that can reduce menu creation, lower menu loading risks, and improve the semiconductor structure of WPH. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide an annealing method for semiconductor structures, which solves the problem that in the prior art, annealing wafers with metal work function layers of different thicknesses on the upper surface requires the creation of separate annealing menus, which can easily cause loading risks and affect the WPH (Work Function Per Scale).

[0006] To achieve the above and other related objectives, the present invention provides an annealing method for a semiconductor structure, comprising the following steps:

[0007] Provide an annealing system including a process control module and an annealing machine, and establish the relationship between the film thickness d of metal work function layers of different materials and the open-loop power P during annealing. OL The relationship between the annealing time t and the annealing time t is written into the process control module;

[0008] A wafer to be annealed is provided with a metal work function layer formed on its upper surface, and the wafer is transferred to the annealing machine.

[0009] The annealing system obtains the film thickness d of the metal work function layer and the material of the metal work function layer, and feeds back the film thickness d and the material of the metal work function layer to the process control module;

[0010] The process control module is based on the film thickness d of the metal work function layer and the open-loop power P during annealing. OL The relationship between the power P and the annealing time t is processed to obtain the preset power P, and the open-loop power P in the menu of the annealing machine is then used. OL The preset power P is modified to control the annealing machine to perform annealing.

[0011] Optionally, the process control module includes a storage unit, wherein the film thickness d of the metal work function layer is related to the open-loop power P during annealing. OL The relationship between the annealing time t and the annealing time t is written into the storage unit.

[0012] Optionally, the film thickness d of the metal work function layer of different materials is compared with the open-loop power P during annealing. OL Before the relationship between the annealing time t and the metal work function layer is written into the process control module, the process also includes establishing the relationship between the film thickness d and the emission coefficient E of the metal work function layer for different materials, and the relationship between the emission coefficient E of the metal work function layer and the annealing time t and the open-loop power P during annealing. OL The steps relating to the relationship between them.

[0013] Optionally, the relationship between the film thickness d of the metal work function layer of different materials and the emission coefficient E, as well as the relationship between the emission coefficient E and the annealing time t and the open-loop power P during annealing, are established. OL The relationship between them includes the following steps:

[0014] A batch of annealed samples with metal work function layers of different thicknesses formed on the upper surface are provided, and the annealed samples are divided into multiple groups based on the material of the metal work function layers. The metal work function layers on the upper surface of each group of annealed samples are made of the same material and the thickness of the metal work function layers on the upper surface of each group of annealed samples is different.

[0015] The emission coefficient E of each metal work function layer in each group of the samples to be annealed was measured, and the relationship between the film thickness d and the emission coefficient E of each group of metal work function layers was obtained by fitting the measured data.

[0016] Based on the open-loop power P during annealing of each of the samples to be annealed in each group. OL The annealing time t and the corresponding emission coefficient E data were used to fit the open-loop power P of the metal work function layer with different materials during annealing. OL The relationship between annealing time t and emission coefficient E;

[0017] Based on the open-loop power P during the annealing of the metal work function layer OL The open-loop power P of the metal work function layer during annealing is obtained by relating the annealing time t and the emission coefficient E, and the emission coefficient E of the metal work function layer to the film thickness d. OL The relationship between annealing time t and film thickness d.

[0018] Optionally, the relationship between the film thickness d and the emission coefficient E of the metal work function layer of different materials is as follows: d>d0, E=k2*d+β, β=d0*(k1-k2); d≤d0, E=k1*d, where d0 is the reference thickness, k1 is a constant, and k2 is a constant.

[0019] Optionally, in the relationship between the film thickness d and the emission coefficient E of the metal work function layer of different materials, the values ​​of k1 and k2 are not exactly the same.

[0020] Optionally, the open-loop power P during the annealing of the metal work function layer... OL The relationship between the annealing time t and the corresponding emission coefficient E is 1 / t = k0E*P OL , where k0 is a constant.

[0021] Optionally, the open-loop power P during the annealing of the metal work function layer... OL The relationship between annealing time t and film thickness d is as follows: d>d0, P=1 / [t*k0(k2d+β)]; d≤d0, P=1 / (t*k0*k1*d).

[0022] Optionally, while acquiring the thickness information of the metal work function layer, the method also includes the step of simultaneously acquiring the size and material information of the wafer.

[0023] Optionally, during the annealing process of the wafer by the annealing machine, the annealing time during the open-loop stage remains unchanged.

[0024] As described above, the semiconductor structure annealing method of the present invention first establishes the relationship between the film thickness and emission coefficient of the metal work function layer, and the relationship between the open-loop power of the metal work function layer annealing and the annealing time and emission coefficient. This yields the relationship between the open-loop power of the metal work function layer annealing and the annealing time and the film thickness of the metal work function layer. Then, this relationship is written into the process control module. During wafer annealing, the annealing time is kept constant. The process control module processes the above relationships to obtain the power required for annealing the incoming wafer, and simultaneously modifies the open-loop power in the annealing machine's menu based on the processing results. This ensures the performance of the annealed metal work function layer while improving the efficiency and WPH of the annealing process, reducing the number of menu creations, and lowering the risk of the annealing machine mistakenly loading menus. It has high industrial application value. Attached Figure Description

[0025] Figure 1 The graph shows the temperature changes over time at each stage of annealing the wafer after the metal work function layer is formed.

[0026] Figure 2 The diagram shows the process flow of the annealing method for the semiconductor structure of the present invention. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] Please see Figure 2 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0029] Example 1

[0030] This embodiment provides an annealing method for semiconductor structures, such as Figure 2 The diagram shown is a process flow chart of the annealing method for the semiconductor structure, including the following steps:

[0031] S1: Provide an annealing system including a process control module and an annealing machine, and establish the film thickness d of metal work function layers of different materials and the open-loop power P during annealing. OL The relationship between the annealing time t and the annealing time t is written into the process control module;

[0032] S2: Provide a wafer to be annealed with a metal work function layer formed on its upper surface, and transfer the wafer to the annealing machine;

[0033] S3: The annealing system obtains the film thickness d of the metal work function layer and the material of the metal work function layer, and feeds back the film thickness d and the material of the metal work function layer to the process control module;

[0034] S4: The process control module is based on the film thickness d of the metal work function layer and the open-loop power P during annealing. OL The relationship between the power P and the annealing time t is processed to obtain the preset power P, and the open-loop power P in the menu of the annealing machine is then used. OL The preset power P is modified to control the annealing machine to perform annealing.

[0035] Execution steps S1 and S2: Provide an annealing system including a process control module and an annealing machine, and establish the film thickness d of metal work function layers of different materials and the open-loop power P during annealing. OL The relationship between the annealing time and t is written into the process control module; a wafer with a metal work function layer formed on its upper surface is provided and the wafer is transferred to the annealing machine.

[0036] It should be noted that the annealing system includes the entire wafer annealing process section's transport system, annealing machine, and process control module. The process control module controls the operation of the transport system and annealing machine.

[0037] As an example, the process control module includes a storage unit, the film thickness d of the metal work function layer, and the open-loop power P during annealing. OL The relationship between the annealing time t and the annealing time t is written into the storage unit.

[0038] Specifically, the process control module also includes a processing control unit, which is used to process various feedback signals in the annealing system during the annealing process and to control the annealing machine and conveying system based on the feedback signals.

[0039] Specifically, the annealing machine performs annealing based on the control signals transmitted by the process control module, and its specific model, structure, and performance can be selected according to the actual situation.

[0040] As an example, the film thickness d of metal work function layers of different materials and the open-loop power P during annealing are established. OL Before establishing the relationship between the annealing time t and the film thickness d of metal work function layers of different materials and the emission coefficient E, as well as the relationship between the emission coefficient E of the metal work function layer and the annealing time t and the open-loop power P during annealing, this also includes establishing the relationship between the film thickness d of the metal work function layer of different materials and the emission coefficient E of the metal work function layer and the annealing time t and the open-loop power P during annealing. OL The steps relating to the relationship between them.

[0041] Specifically, since the emission coefficient of the metal work function layer is not only related to the film thickness d of the metal work function layer, but also to the material of the metal work function layer, the relationship between the emission coefficient E of the metal work function layer and the film thickness d of the metal work function layer is different for metal work function layers of different materials.

[0042] It should be noted that during the annealing process, the open-loop power P during annealing... OL It is also related to the emission coefficient E and the annealing time t.

[0043] Specifically, the materials for the metal work function layer include titanium nitride, tantalum nitride, titanium aluminum nitride, tantalum aluminum nitride, or other suitable materials.

[0044] Specifically, while ensuring device performance, the thickness of the metal work function layer in the wafer can be selected according to the actual situation.

[0045] As an example, the relationship between the film thickness d and the emission coefficient E of metal work function layers of different materials is established, as well as the relationship between the emission coefficient E and the annealing time t and the open-loop power P during annealing. OL The relationship between the two groups includes the following steps: providing a batch of annealed samples with metal work function layers of different thicknesses on their upper surfaces, and dividing the annealed samples into multiple groups based on the material of the metal work function layers. Each group of annealed samples has the same material for the metal work function layers on their upper surfaces, but the thickness of the metal work function layers on the upper surfaces of each annealed sample is different. The emission coefficient E of each metal work function layer in each group of annealed samples is measured, and the relationship between the film thickness d corresponding to each group of metal work function layers and the emission coefficient E is fitted based on the measured data. The open-loop power P during annealing of each annealed sample in each group is then determined. OL By fitting the annealing time t and the corresponding emission coefficient E data, the open-loop power P of the annealed metal work function layer of different materials is obtained. OL Relationship between annealing time t and emission coefficient E; open-loop power P during metal work function layer annealing OL The open-loop power P of the metal work function layer during annealing is obtained by relating the annealing time t and the emission coefficient E, and the emission coefficient E of the metal work function layer to the film thickness d. OLThe relationship between annealing time t and film thickness d.

[0046] It should be noted that, in order to improve the correlation of the fitting results, the materials, sizes and shapes of the samples to be annealed are the same. Usually, wafers that need to be annealed after the metal work function layer is formed on the production line are selected as the samples to be annealed.

[0047] Specifically, while ensuring the accuracy of the fitting results, the number of samples to be annealed in each group can be selected according to the actual situation.

[0048] Specifically, methods for measuring the thickness of the metal work function layer on the surface of each sample to be annealed in each group include ellipsometrics, reflectance measurement, or other suitable methods.

[0049] Specifically, the method for measuring the emission coefficient E of the metal work function layer on the upper surface of each sample to be annealed is a commonly used method for measuring emission coefficient, which will not be elaborated here.

[0050] As an example, the relationship between the film thickness d and the emission coefficient E of metal work function layers of different materials is as follows: d>d0, E=k2*d+β, β=d0*(k1-k2); d≤d0, E=k1*d, where d0 is the reference thickness, k1 is a constant, and k2 is a constant. That is, through fitting, when the film thickness d of the metal work function layer is not greater than the reference thickness d0, the relationship between the film thickness d and the emission coefficient E is highly correlated and linear with a slope of k1. When the film thickness d of the metal work function layer is greater than the reference thickness d0, the relationship between the film thickness d and the emission coefficient E is also highly correlated and linear with a slope of k2.

[0051] It should be noted that the value of k1 is usually greater than the value of k2. That is, the reference thickness d0 divides the relationship curve between the film thickness d of the metal work function layer and the emission coefficient E into two linear functions with different slopes. The slope of the linear function when the film thickness d of the metal work function layer is less than or equal to the reference thickness d0 is greater than the slope when the film thickness d is greater than the reference thickness d0.

[0052] Specifically, the correlation R of the linear function obtained by fitting when the film thickness d of the metal work function layer is less than or equal to the reference thickness d0. 2 The correlation R of the linear function obtained by fitting the slope when the actual thickness d is greater than the reference thickness d0 is greater than the actual thickness d0. 2 .

[0053] As an example, in the relationship between the film thickness d and the emission coefficient E of metal work function layers of different materials, the values ​​of k1 and k2 are not exactly the same.

[0054] As an example, the open-loop power P during metal work function layer annealing OL The relationship between the annealing time t and the corresponding emission coefficient E is 1 / t = k0E*P OL Where k0 is a constant, i.e., the open-loop power P of the metal work function layer annealing process with different emission coefficients obtained by fitting. OL The relationship between it and the emission coefficient E is an inverse proportional function.

[0055] Specifically, the open-loop power P during the metal work function layer annealing process. OL Typically, it refers to the power during the open-loop phase of the annealing process, while the annealing time is the time taken for the sample to be annealed during the annealing process.

[0056] It should be noted that after annealing, data from wafers that do not meet quality standards after annealing need to be removed to ensure the correlation of the fitting results.

[0057] As an example, the open-loop power P during metal work function layer annealing OL The relationship between annealing time t and film thickness d is as follows: d>d0, P=1 / [t*k0(k2d+β)]; d≤d0, P=1 / (t*k0*k1*d).

[0058] It should be noted that, since the relationship between the film thickness d of the metal work function layer and the emission coefficient E is a piecewise function, and the open-loop power P... OL If the relationship between the emission coefficient E and the annealing time t is an inverse proportional function, then the obtained open-loop power P OL The relationship between the annealing time t and the film thickness d of the metal work function layer is also a piecewise function.

[0059] Specifically, a wafer with a metal work function layer typically formed on its upper surface and a film layer thickness d used to fit the metal work function layer to the open-loop power P during annealing are typically used. OL The annealed samples of the two groups are the same in size and shape.

[0060] Specifically, the conveying system that transfers wafers to the annealing machine is a commonly used conveying equipment and transfer robotic arm on the production line. For example, the conveying equipment can transfer the wafer cassette containing the wafer with the metal work function layer formed on the upper surface to the loading area of ​​the annealing machine, and the transfer robotic arm can transfer the wafer at the loading area to the process chamber of the annealing machine.

[0061] Please execute steps S3 and S4: The annealing system obtains the film thickness d and material of the metal work function layer, and feeds back the film thickness d and material of the metal work function layer to the process control module; the process control module, based on the film thickness d of the metal work function layer and the open-loop power P during annealing... OLThe relationship between the power P and the annealing time t is processed to obtain the preset power P, and the open-loop power P in the annealing machine's menu is then used. OL The preset power P is used to control the annealing machine to perform the annealing operation.

[0062] It should be noted that the thickness of the metal work function layer can be obtained based on process information fed back from the previous process, or it can be obtained by setting up a thickness measurement device in the annealing system and obtaining the thickness based on the measurement of the thickness measurement device. Preferably, in this embodiment, the thickness and material information of the metal work function layer are obtained by capturing the measurement results of the previous process.

[0063] As an example, obtaining information on the thickness and material of the metal work function layer also includes the step of simultaneously obtaining information on the size and material of the wafer.

[0064] Specifically, the annealing system acquires wafer size and material information simultaneously with the information on the metal work function layer, so that the subsequent process control module can retrieve the appropriate metal work function layer thickness d and the open-loop power P during annealing. OL The relationship between the preset power P is used to calculate the power P.

[0065] Specifically, the methods for feeding back the film thickness d of the metal work function layer and the material information of the metal work function layer to the process control module include wired communication, wireless communication, or other suitable methods.

[0066] Specifically, after the annealing system feeds back the captured metal work function layer and wafer-related information to the process control module, the processing control unit in the process control module receives the feedback signal and compares it with the metal work function layer thickness d and the open-loop power P during annealing stored in the storage unit. OL Matching the relationship between the annealing time t and the corresponding metal work function layer thickness d and the open-loop power P during annealing are retrieved from the memory cell. OL The relationship between the annealing time and the annealing time t is determined, and the annealing time t set in the annealing machine's menu is obtained. Then, based on this relationship and related data, the preset power P is obtained. Finally, based on the processing result, the annealing machine's menu is retrieved, and the open-loop power P in the menu is selected. OL The value is modified to the preset power P value, and finally the annealing machine is controlled to start the annealing program to anneal the wafer with the metal work function layer formed on the upper surface.

[0067] It should be noted that during the annealing process, only a few parameters in the annealing machine's menu need to be changed, as these parameters have a significant impact on the annealing quality.

[0068] As an example, during the annealing process of the annealing machine on the wafer, the annealing time in the open-loop stage remains unchanged. That is, before the annealing machine anneals the wafer, the process control module does not need to modify the annealing time in the menu.

[0069] Specifically, the relationship between the film thickness d and the emission coefficient E of metal work function layers made of different materials, and the open-loop power P of annealed metal work function layers are used. OL By combining the relationship between annealing time t and emission coefficient E, the open-loop power P corresponding to the work function layer of metals of different materials during annealing can be obtained. OL The relationship between the annealing time t and the film thickness d of the metal work function layer is used. Then, the annealing system captures the material and actual thickness information of the incoming wafer. Based on this relationship and related data (annealing time t and film thickness d in the menu), the process control module processes the data to obtain the preset power P for annealing the wafer and displays the open-loop power P in the annealing machine's menu. OL The preset power P was changed, which reduced the creation of identical menus, eliminated the need for manual menu selection, and reduced the amount of menu loading and the risk of menu loading errors.

[0070] Specifically, based on open-loop power P OL The relationship between annealing time t and the film thickness d of the metal work function layer is used to ensure that the annealing time of each incoming wafer is the same, and the process control module only changes the open-loop power P. OL This avoids the problem of excessively long annealing time for thicker incoming wafers, ensuring annealing quality while increasing the process's WPH (number of wafers annealed per hour) and improving annealing efficiency.

[0071] In summary, the semiconductor structure annealing method of the present invention improves the process by first determining the relationship between the open-loop power of the metal work function layer annealing, the annealing time, and the film thickness of the metal work function layer based on the relationship between the film thickness and the emission coefficient of the metal work function layer, and the relationship between the open-loop power of the metal work function layer annealing and the annealing time and emission coefficient. During the wafer annealing process, the annealing time is kept constant, and the process control module only processes the open-loop power required for the incoming wafer annealing based on the relationship between the open-loop power of the metal work function layer annealing, the annealing time, and the film thickness of the metal work function layer. Simultaneously, the process control module modifies the open-loop power in the annealing machine's menu based on the processing results. This ensures the quality of the annealed wafer while improving the efficiency of the annealing process, increasing the WPH of the process, reducing the number of menu creations, and lowering the risk of the annealing machine misloading menus. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0072] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An annealing method for a semiconductor structure, characterized in that, Includes the following steps: Provide an annealing system including a process control module and an annealing machine, and establish the relationship between the film thickness d of metal work function layers of different materials and the open-loop power P during annealing. OL The relationship between the annealing time t and the annealing time t is written into the process control module; A wafer to be annealed is provided with a metal work function layer formed on its upper surface, and the wafer is transferred to the annealing machine. The annealing system obtains the film thickness d of the metal work function layer and the material of the metal work function layer, and feeds back the film thickness d and the material of the metal work function layer to the process control module; The process control module is based on the film thickness d of the metal work function layer and the open-loop power P during annealing. OL The relationship between the power P and the annealing time t is processed to obtain the preset power P, and the open-loop power P in the menu of the annealing machine is then used. OL The preset power P is modified to control the annealing machine to perform annealing.

2. The annealing method for a semiconductor structure according to claim 1, characterized in that: The process control module includes a storage unit, and the film thickness d of the metal work function layer is related to the open-loop power P during annealing. OL The relationship between the annealing time t and the annealing time t is written into the storage unit.

3. The annealing method for a semiconductor structure according to claim 1, characterized in that: Establish the film thickness d of the metal work function layer with different materials and the open-loop power P during annealing. OL Before establishing the relationship between the annealing time t and the film thickness d of the metal work function layer with different materials and the emission coefficient E, the relationship between the emission coefficient E of the metal work function layer and the annealing time t and the open-loop power P during annealing is also included. OL The steps relating to the relationship between them.

4. The annealing method for a semiconductor structure according to claim 3, characterized in that, Establish the relationship between the film thickness d and the emission coefficient E of the metal work function layer of different materials, and the relationship between the emission coefficient E and the annealing time t and the open-loop power P during annealing. OL The relationship between them includes the following steps: A batch of annealed samples with metal work function layers of different thicknesses formed on the upper surface are provided, and the annealed samples are divided into multiple groups based on the material of the metal work function layers. The metal work function layers on the upper surface of each group of annealed samples are made of the same material and the thickness of the metal work function layers on the upper surface of each group of annealed samples is different. The emission coefficient E of each metal work function layer in each group of the samples to be annealed was measured, and the relationship between the film thickness d and the emission coefficient E of each group of metal work function layers was obtained by fitting the measured data. Based on the open-loop power P during annealing of each of the samples to be annealed in each group. OL The annealing time t and the corresponding emission coefficient E data were used to fit the open-loop power P of the metal work function layer with different materials during annealing. OL The relationship between annealing time t and emission coefficient E; Based on the open-loop power P during the annealing of the metal work function layer OL The open-loop power P of the metal work function layer during annealing is obtained by relating the annealing time t and the emission coefficient E, and the emission coefficient E of the metal work function layer to the film thickness d. OL The relationship between annealing time t and film thickness d.

5. The annealing method for a semiconductor structure according to claim 4, characterized in that: The relationship between the film thickness d and the emission coefficient E of the metal work function layer of different materials is as follows: d>d0, E=k2*d+β, β=d0*(k1-k2); d≤d0, E=k1*d, where d0 is the reference thickness, k1 is a constant, and k2 is a constant.

6. The annealing method for a semiconductor structure according to claim 5, characterized in that: In the relationship between the film thickness d and the emission coefficient E of the metal work function layer of different materials, the values ​​of k1 and k2 are not exactly the same.

7. The annealing method for a semiconductor structure according to claim 5, characterized in that, The open-loop power P during the annealing of the metal work function layer OL The relationship between the annealing time t and the corresponding emission coefficient E is 1 / t = k0E*P OL , where k0 is a constant.

8. The annealing method for a semiconductor structure according to claim 7, characterized in that, The open-loop power P during the annealing of the metal work function layer OL The relationship between annealing time t and film thickness d is as follows: d>d0, P=1 / [t*k0(k2d+β)]; d≤d0, P=1 / (t*k0*k1*d).

9. The annealing method for a semiconductor structure according to claim 1, characterized in that: The process of obtaining the thickness information of the metal work function layer also includes the step of simultaneously obtaining the size and material information of the wafer.

10. The annealing method for a semiconductor structure according to claim 1, characterized in that: During the annealing process of the wafer by the annealing machine, the annealing time in the open-loop stage remains unchanged.

Images