Wafer etching or deposition method, model acquisition method and semiconductor processing apparatus

Abstract

Disclosed in the embodiments of the present application are a wafer etching or deposition method, a model acquisition method and a semiconductor processing apparatus. The present application particularly relates to a temperature control method for each temperature control zone of a multi-temperature-zone electrostatic chuck or a heating substrate. The temperature control method combines the effects of temperature sensitivity and the diffusion distribution of etching byproducts or deposits along with temperature gradients on etching or deposition rates, and therefore can more accurately predict etching or deposition rate distribution data of each position on a wafer at any target temperature in each temperature control zone, or regulate a target temperature control value of each temperature control zone on the basis of target etching or deposition rate distribution data, so as to improve the uniformity of wafer etching or deposition, or enable surfaces of wafers to have expected morphology.

Description

Wafer etching or deposition and model acquisition method, semiconductor process equipment Technical Field

[0001] The present application belongs to the field of semiconductor technology, specifically to the field of temperature control technology of multi-temperature zone electrostatic chucks or heating bases, and more specifically to a wafer etching or deposition method, a method for obtaining an etching or deposition rate prediction model, and semiconductor process equipment. Background Art

[0002] Advanced integrated circuit manufacturing processes typically consist of thousands of steps, including etching, deposition, and cleaning. Etching, as a critical step, determines the critical dimensions of semiconductor devices and ultimately impacts their performance. Etch rate and etch uniformity are key parameters of concern in semiconductor processing. Currently, the etch rate is typically adjusted by adjusting the temperature of each temperature control zone on the wafer carrier to ensure uniform etching across the wafer.

[0003] In related technologies, when the temperature value of a temperature control zone of a wafer carrier changes, the changed etching rate is predicted based on the temperature sensitivity and the temperature difference before and after the change. However, there is a large deviation between the etching rate distribution data predicted by this method and the actually measured etching rate distribution data. Summary of the Invention

[0004] Embodiments of the present application disclose a wafer etching or deposition method, a method for obtaining an etching or deposition rate prediction model, and semiconductor process equipment to solve the problem of large deviation between the predicted value and the measured value of etching or deposition rate distribution data in related technologies.

[0005] In order to solve the above technical problems, according to a first aspect, an embodiment of the present application discloses a wafer etching or deposition method, which is applied to a process chamber having a wafer carrier, wherein the wafer carrier surface of the wafer carrier has multiple main temperature control zones and multiple auxiliary temperature control zones, the multiple main temperature control zones are arranged in sequence in the radial direction of the wafer carrier surface, the main temperature control zones located on the outside in the radial direction are arranged around the main temperature control zones located on the inside in the radial direction, and the multiple auxiliary temperature control zones are arranged along the angular direction of the wafer carrier, and the method includes:

[0006] Obtaining first basic etching or deposition rate distribution data and a temperature sensitivity value along a radial direction of the wafer to be etched or deposited at a basic temperature in each of the main temperature control zones; wherein the first basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values ​​associated with radial positions on the wafer supporting surface, and the temperature sensitivity value is used to characterize the rate of change of the etching or deposition rate with temperature;

[0007] Using a preset first etching or deposition rate prediction model, the target temperature control value of each main temperature control zone is obtained according to the first target etching or deposition rate distribution data, the first basic etching or deposition rate distribution data and the temperature sensitivity value; wherein the first etching or deposition rate prediction model is associated with the diffusion of radial etching by-products or deposits generated during the etching or deposition process, and the first etching or deposition rate prediction model is used to characterize the correspondence between the etching or deposition rate of each position in the radial direction on the wafer carrying surface and the associated position, and the first target etching or deposition rate distribution data includes multiple target etching or deposition rate values ​​associated with the radial positions on the wafer carrying surface.

[0008] According to a second aspect, an embodiment of the present application discloses a wafer etching or deposition method, the method being applied to a process chamber having a wafer carrier, wherein a wafer carrier surface of the wafer carrier has multiple temperature control zones, the method comprising:

[0009] Obtaining basic etching or deposition rate distribution data and temperature sensitivity values ​​of the wafer to be etched or deposited at the basic temperature of each of the temperature control zones; wherein the basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values ​​associated with positions on the wafer supporting surface, and the temperature sensitivity value is used to characterize the rate of change of the etching or deposition rate with temperature;

[0010] Utilizing a preset etching or deposition rate prediction model, target temperature control values ​​for each of the temperature control zones are obtained based on target etching or deposition rate distribution data, the basic etching or deposition rate distribution data, and the temperature sensitivity value; wherein the etching or deposition rate prediction model is associated with the diffusion of etching byproducts or deposits generated during the etching or deposition process, and the etching or deposition rate prediction model is used to characterize the correspondence between the etching or deposition rate of each position on the wafer carrying surface and the associated position, and the target etching or deposition rate distribution data includes a plurality of target etching or deposition rate values ​​associated with positions on the wafer carrying surface.

[0011] According to a third aspect, an embodiment of the present application discloses a wafer etching or deposition method, the method being applied to a process chamber having a wafer carrier, wherein a wafer carrier surface of the wafer carrier has multiple temperature control zones, the method comprising:

[0012] Obtaining basic etching or deposition rate distribution data and temperature sensitivity values ​​of the wafer to be etched or deposited at the basic temperature of each of the temperature control zones; wherein the basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values ​​associated with positions on the wafer supporting surface, and the temperature sensitivity value is used to characterize the rate of change of the etching or deposition rate with temperature;

[0013] A preset etching or deposition rate prediction model is used to obtain a target temperature control value for each of the temperature control zones based on the target etching or deposition rate distribution data, the basic etching or deposition rate distribution data, and the temperature sensitivity distribution data; wherein the etching or deposition rate prediction model is used to characterize that when the temperature control value of any of the temperature control zones changes, all positions on the wafer carrying surface are affected by the changed temperature control zone, and the corresponding relationship between the etching or deposition rate of each position after the change and the corresponding position; the target etching or deposition rate distribution data includes multiple target etching or deposition rate values ​​associated with positions on the wafer carrying surface.

[0014] According to a fourth aspect, an embodiment of the present application discloses a method for obtaining an etching or deposition rate prediction model, the method being applied to a process chamber having a wafer carrier, wherein a wafer carrier surface of the wafer carrier has multiple temperature control zones, the method comprising:

[0015] Obtaining basic etching or deposition rate distribution data and a temperature sensitivity value of the wafer to be etched or deposited when each of the temperature control zones is at a basic temperature; wherein the basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values ​​associated with positions on the wafer supporting surface, and the temperature sensitivity value is used to characterize the rate of change of the etching or deposition rate with temperature;

[0016] Changing the temperature control value of one of the temperature control zones, and maintaining the basic temperature in the remaining temperature control zones, to obtain the changed etching or deposition rate distribution data;

[0017] Obtaining an etching or deposition rate prediction sub-model for the changed temperature control zone, wherein the etching or deposition rate prediction sub-model is related to the basic etching or deposition rate distribution data, the changed etching or deposition rate distribution data, the basic temperature, the temperature control value of the changed temperature control zone, and the temperature sensitivity value;

[0018] Repeatingly changing the temperature control value of another temperature control zone in the temperature control zones, while maintaining the remaining temperature control zones at the basic temperature, obtaining the changed etching or deposition rate distribution data, and obtaining the etching or deposition rate prediction sub-model of the changed temperature control zone, until the etching or deposition rate prediction sub-models of all the temperature control zones are obtained;

[0019] The etching or deposition rate prediction model is obtained according to the etching or deposition rate prediction sub-models of each of the temperature control zones.

[0020] According to a fifth aspect, an embodiment of the present application discloses a wafer etching or deposition method, the method being applied to a process chamber having a wafer carrier, wherein a wafer carrier surface of the wafer carrier has multiple temperature control zones, the method comprising:

[0021] Obtaining basic etching or deposition rate distribution data and temperature sensitivity values ​​of the wafer to be etched or deposited at the basic temperature of each of the temperature control zones; wherein the basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values ​​associated with positions on the wafer supporting surface, and the temperature sensitivity value is used to characterize the rate of change of the etching or deposition rate with temperature;

[0022] Utilizing the etching or deposition rate prediction model obtained according to the method described in the fourth aspect above, the target temperature control value of each temperature control zone is obtained based on the target etching or deposition rate distribution data, the basic etching or deposition rate distribution data, and the temperature sensitivity value; wherein the target etching or deposition rate distribution data includes a plurality of target etching or deposition rate values ​​associated with positions on the wafer carrying surface.

[0023] According to a sixth aspect, an embodiment of the present application discloses a wafer etching or deposition method, the method being applied to a process chamber having a wafer carrier, wherein a wafer carrier surface of the wafer carrier has a plurality of main temperature control zones and a plurality of auxiliary temperature control zones, wherein the plurality of main temperature control zones are sequentially arranged in a radial direction of the wafer carrier surface, the main temperature control zones located on the outside in the radial direction are arranged around the main temperature control zones located on the inside in the radial direction, and the plurality of auxiliary temperature control zones are arranged along the angular direction of the wafer carrier, the method comprising:

[0024] Obtaining first basic etching or deposition rate distribution data and a temperature sensitivity value along a radial direction of the wafer to be etched or deposited at a basic temperature in each of the main temperature control zones; wherein the first basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values ​​associated with radial positions on the wafer supporting surface, and the temperature sensitivity value is used to characterize the rate of change of the etching or deposition rate with temperature;

[0025] Using the first etching or deposition rate prediction model obtained according to the method described in the fourth aspect above, the target temperature control value of each main temperature control zone is obtained according to the first target etching or deposition rate distribution data, the first basic etching or deposition rate distribution data and the temperature sensitivity value; wherein the first target etching or deposition rate distribution data includes multiple target etching or deposition rate values ​​associated with the radial position on the wafer carrying surface.

[0026] According to a seventh aspect, an embodiment of the present application discloses a semiconductor process equipment, including:

[0027] process chamber;

[0028] A wafer carrying device is arranged in the process chamber, and a wafer carrying surface of the wafer carrying device has multiple temperature control zones;

[0029] The control device includes at least one processor and at least one memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, the method described in any one of the first to sixth aspects above is implemented.

[0030] According to an eighth aspect, an embodiment of the present application discloses a semiconductor process equipment, including:

[0031] process chamber;

[0032] A wafer carrying device is arranged in the process chamber, and a wafer carrying surface of the wafer carrying device has multiple temperature control zones;

[0033] The control device includes at least one processor and at least one memory, wherein the memory stores the etching or deposition rate prediction model obtained by the method described in the fourth aspect.

[0034] In the wafer etching or deposition method of the embodiment of the present application, by adopting an etching or deposition rate prediction model associated with the diffusion of etching by-products or deposits generated during the etching or deposition process, compared with the etching rate prediction model in the related art that is only associated with temperature sensitivity, it is possible to compensate for the influence of the diffusion of etching by-products or deposits on the etching or deposition rate distribution, thereby being able to more accurately predict the etching or deposition rate distribution data of each position on the wafer at any target temperature in each temperature control zone, or being able to more accurately calculate the target temperature control value of each temperature control zone based on the target etching or deposition rate distribution data. That is, by controlling the temperature of each temperature control zone of the wafer carrier using the wafer etching or deposition method of the embodiment of the present application, the uniformity of wafer etching or deposition can be improved, or the desired morphology can be obtained on the wafer surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] 1 and 2 are schematic top views of a wafer carrier according to an embodiment of the present application;

[0036] 3A and 3B respectively show a cross-sectional view and a top view of a wafer carrier according to another embodiment of the present application;

[0037] FIG4 shows the etching rate distribution data predicted by the related technology and the etching rate distribution data actually measured;

[0038] FIG5 is a schematic diagram showing the diffusion mechanism of etching byproducts according to an embodiment of the present application;

[0039] FIG6 shows a flow chart of a wafer etching method according to an embodiment of the present application;

[0040] FIG7 shows a flow chart of a method for obtaining an etching rate prediction model according to an embodiment of the present application;

[0041] FIG8 shows an etch rate prediction sub-model using smooth curve fitting in the first temperature control zone;

[0042] FIG9 shows the etching rate distribution data predicted by the etching rate prediction model according to an embodiment of the present application and the actually measured etching rate distribution data;

[0043] FIG10 shows a flow chart of a wafer etching method according to another embodiment of the present application;

[0044] FIG11 shows a flow chart of a method for obtaining an etching rate prediction model according to another embodiment of the present application;

[0045] FIG12 shows a schematic diagram of a semiconductor process equipment according to an embodiment of the present application. DETAILED DESCRIPTION

[0046] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0047] It should be understood by those skilled in the art that the embodiments of the present application are merely illustrations of the structures and methods for which the present application may be implemented in various forms. In addition, each example provided in conjunction with the various embodiments is intended to be illustrative, not restrictive. In addition, the drawings are not necessarily drawn to scale, and some features may be exaggerated to show the details of specific components. Therefore, the specific structural and functional details in the embodiments of the present application should not be interpreted as restrictive, but merely as a representative basis for teaching those skilled in the art to adopt the methods and structures of the embodiments of the present application in different ways. It should also be noted that identical and corresponding elements are represented by the same reference numerals.

[0048] In the following description, many specific details are set forth, such as specific structures, components, materials, dimensions, processing steps and techniques, in order to provide an understanding of the various embodiments of the present application. However, it should be understood by those skilled in the art that the various embodiments of the present application can be practiced without these specific details. In other cases, well-known structures or processing steps are not described in detail to avoid obscuring the present application.

[0049] For the purposes of the following description, the terms "upper," "right," "left," "vertical," "horizontal," "top," "bottom," and their derivatives shall relate to the orientation of the structures and methods disclosed in the drawings of the specification. It will be understood that when an element as a layer, region, or substrate is referred to as being "on" another element, the element can be directly on the other element or intervening elements may be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements between the two. It will also be understood that when an element is referred to as being "under" another element, the element can be directly under the other element or intervening elements may be present. Conversely, when an element is referred to as being "directly under" another element, there are no intervening elements between the two.

[0050] Figures 1 and 2 respectively show a top schematic diagram of a wafer carrying device according to an embodiment of the present application. The wafer carrying device may be, for example, a multi-zone electrostatic chuck or a heating base, and its wafer carrying surface may have multiple temperature control zones. In the example of Figure 1 , the wafer carrying device has four temperature control zones, namely, a first temperature control zone 11, a second temperature control zone 12, a third temperature control zone 13 and a fourth temperature control zone 14 arranged in sequence from the inside to the outside in the radial direction. The first temperature control zone 11 is a circular area located at the center of the wafer carrying surface, and the second temperature control zone 12, the third temperature control zone 13 and the fourth temperature control zone 14 are annular areas arranged sequentially around the first temperature control zone 11 from the inside to the outside, that is, the second temperature control zone 12 is arranged around the first temperature control zone 11, the third temperature control zone 13 is arranged around the second temperature control zone 12, and the fourth temperature control zone 14 is arranged around the third temperature control zone 13. In the example of Figure 2, the wafer carrying device has 9 temperature control zones, namely, a first temperature control zone 21 located at the center of the wafer carrying surface, a second temperature control zone 22, a third temperature control zone 23, a fourth temperature control zone 24 and a fifth temperature control zone 25 distributed around the first temperature control zone 21, and a sixth temperature control zone 26, a seventh temperature control zone 27, an eighth temperature control zone 28 and a ninth temperature control zone 29 distributed around the second to fourth temperature control zones.

[0051] 3A and 3B show schematic diagrams of a wafer carrier device according to another embodiment of the present application, which wafer carrier device may include, for example, a base 31, a heating layer 32, and an electrostatic chuck 33. The heating layer 32 includes a plurality of main heaters corresponding to the main temperature control zones 34 and a plurality of auxiliary heaters corresponding to the auxiliary temperature control zones 35. The plurality of main temperature control zones 34 are arranged in sequence in the radial direction. The main temperature control zones 34 located on the outer side of the radial direction are arranged around the main temperature control zones 34 located on the inner side of the radial direction. The plurality of auxiliary temperature control zones 35 are arranged along the angular direction of the wafer carrier device to locally adjust the temperature on the wafer carrier surface, for example, to adjust the uniformity of the wafer carrier surface in the angular direction. In the examples of FIG. 3A and FIG. 3B , the main heater corresponding to the main temperature control zone 34 is located above the auxiliary heater corresponding to the auxiliary temperature control zone 35. However, the present application is not limited thereto. The main heater corresponding to the main temperature control zone 34 may also be located below the auxiliary heater corresponding to the auxiliary temperature control zone 35. The electrostatic chuck 33 includes an adsorption electrode 36 to provide an electrostatic adsorption force to the wafer on the wafer supporting surface. The adsorption electrode 36 can be set as a unipolar or bipolar electrode, or other suitable settings, and this application does not impose any limitation on this.

[0052] Those skilled in the art should understand that Figures 1, 2, 3A, and 3B are merely examples, and more or fewer temperature control zones are feasible. The temperature control zones can be regularly or irregularly arranged on the wafer carrying surface, and this application does not impose any restrictions on this. For temperature-sensitive etching processes, the plasma generated by the RF source may be unevenly distributed due to various reasons. It is necessary to adjust the temperature of each temperature control zone of the wafer carrying device to compensate for the etching rate difference caused by the uneven distribution of plasma, thereby ensuring the uniformity of wafer etching.

[0053] In the related art, firstly, the temperature of each temperature control zone of the wafer carrier is obtained to be at a high temperature T H and low temperature T L The etch rate distribution data of each position of the etched wafer [ER] H and [ER] L It should be noted that this paper uses [ER] H and [ER] L To represent the etch rate distribution data, the brackets [] are only intended to indicate that multiple etch rate values ​​associated with positions are included. For example, for a wafer with a radius of 150 mm, if a point is collected every 10 mm in the radial direction, 16 etch rate values ​​corresponding to radial positions can be obtained, such as [ER] H =[ER0,ER1,…,ER 15 ], where ER0 represents the etching rate at 0 mm from the center of the circle, ER1 represents the etching rate at 10 mm from the center of the circle, and so on. This representation will be used in the following text. Those skilled in the art will understand that the points collected are not limited to the radial direction, but can be any point on the wafer.

[0054] Then, obtain the temperature sensitivity value [Sen] = ([ER] H -[ER] L ) / (T H -T L ), that is, calculate the rate of change of multiple etching rates associated with positions with temperature. Finally, any target temperature [T] can be predicted based on the temperature sensitivity value. target Etch rate distribution data under [ER] target , or according to this formula, the target temperature control value of each temperature control zone is calculated according to the target etching rate distribution data. Where, [ER] target =[ER] base +([T] target -[T] base )·[Sen],[ER] baseThe temperature of each temperature control zone of the wafer carrier is at the basic temperature T base Etching rate distribution data of each position below, [T] target -[T] base It represents the subtraction of the target temperature of the corresponding temperature control zone from the basic temperature, for example, the subtraction of the target temperature from the basic temperature of each temperature control zone shown in FIG. 1 or FIG. 2 or FIG. 3A and FIG. 3B . This expression will be used hereinafter.

[0055] In the process of implementing the above-mentioned related technologies, the inventors of this application found that there is a large deviation between the etching rate distribution data predicted by the above-mentioned related technologies and the etching rate distribution data actually measured. As shown in FIG4 , for the sake of simplicity, the distribution data in the radial direction of the wafer is taken as an example, and the process is collected at the basic temperature [T] base = Basic etch rate distribution data in the radial direction under [60, 60, 60, 60] [ER] base At the same time, the temperature sensitivity value of the process is collected and the etching rate prediction model of the relevant technology is used to predict [T] target Comparing the radial etch rate distribution data at [60, 63, 65, 58] with the measured etch rate distribution data, the hollow circles in Figure 4 represent predicted values, while the solid circles represent measured values. There is a significant deviation between the two. Therefore, the aforementioned related techniques cannot accurately predict the etch rate distribution data, and accordingly, it is impossible to accurately determine the target temperature control values ​​for each temperature control zone based on the target etch rate distribution data.

[0056] In order to solve the above technical problems, the inventors of this application have conducted in-depth research on the plasma etching mechanism. During the plasma etching process, various etching by-products will be continuously produced. When the etching by-products accumulate more, the deposition effect will be aggravated, causing the etching rate to decrease; when the etching by-products accumulate less, the deposition effect will be weakened, etching will be more likely to occur, and the etching rate will increase. The inventors of this application found that when the surface temperature of the wafer carrier is different, the etching by-products will diffuse from the high temperature zone to the low temperature zone along the temperature gradient, as shown in Figure 5, that is, the etching by-products accumulated in the high temperature zone will be less than the etching by-products accumulated in the low temperature zone, which will cause the overall etching rate to change. The above-mentioned related technologies do not take into account the influence of the diffusion of etching by-products, so the predicted etching rate distribution data will deviate from the actually measured etching rate distribution data.

[0057] Based on the above research work of the inventors of this application, an embodiment of this application provides a wafer etching method. This method is applied to a process chamber having a wafer carrier, wherein the wafer carrier surface of the wafer carrier has multiple temperature control zones. The wafer carrier can be, for example, a multi-temperature zone electrostatic chuck or a heating pedestal. This method can be executed by a control device of semiconductor process equipment, such as a host computer or a slave computer of the semiconductor process equipment. As shown in Figure 6, this method can include the following steps:

[0058] S11. Obtain basic etching rate distribution data and temperature sensitivity values ​​of the wafer to be etched at the basic temperature of each temperature control zone.

[0059] In this embodiment, the basic etching rate distribution data includes a plurality of etching rate values ​​associated with positions on the wafer support surface, and the temperature sensitivity value is used to characterize the rate of change of the etching rate with temperature. In this embodiment, the basic etching rate distribution data and the temperature sensitivity value can be pre-stored in the memory of the control device of the semiconductor process equipment. The basic etching rate distribution data is associated with each position on the two-dimensional plane of the wafer support surface. When the basic temperature of each temperature control zone is T base When the temperature sensitivity value is set to [ER]base, multiple basic etch rates [ER]base associated with positions on the wafer carrier surface can be collected; the temperature sensitivity value can be a single value or multiple values ​​associated with positions on the wafer carrier surface, which will be explained in detail below.

[0060] S12. Using a preset etching rate prediction model, according to the target etching rate distribution data, the basic etching rate distribution data and the temperature sensitivity value, the target temperature control value of each temperature control zone is obtained.

[0061] The following function can be used to represent the above relationship:

[0062] [ER] tar get =f([M],[ER] base ,[Sen],[T] tar get ,T base )

[0063] Among them, [ER] target represents the target etching rate distribution data, [M] represents the etching rate prediction model, [ER] base Indicates the basic etching rate distribution data, [Sen] indicates the temperature sensitivity value, [T] target Indicates the target temperature control value of each temperature control zone, T base Indicates the basic temperature. In the above functional relationship, [M], [ER] base 、[Sen]、T baseare all known values. When it is necessary to predict the etch rate distribution data of each position on the wafer at any target temperature in each temperature control zone, [T] target is a known value, according to the above functional relationship, we can get [ER] target When it is necessary to calculate the target temperature control value of each temperature control zone based on the target etching rate distribution data to achieve etching uniformity or obtain the desired morphology on the wafer surface, [ER] target is a known value, according to the above functional relationship, we can get [T] target .

[0064] In this embodiment, the etching rate prediction model [M] is associated with the diffusion of etching byproducts generated during the etching process. The etching rate prediction model [M] is used to characterize the corresponding relationship between the etching rate of each position on the wafer carrier surface and the associated position. The target etching rate distribution data [ER] target A plurality of target etch rate values ​​associated with locations on the wafer carrier surface are included.

[0065] Similarly, the etch rate prediction model [M] can be pre-stored in the memory of the control device of the semiconductor process equipment. In some embodiments, the etch rate prediction model [M] is normalized with respect to the temperature sensitivity value, thereby being universally applicable to various wafers to be etched. In other words, the etch rate prediction model of the embodiments of the present application is applicable to the etching of various materials such as single crystal silicon, polycrystalline silicon, and silicon oxide, without the need to change the model for different etching processes. The etch rate prediction model will be further described in detail below.

[0066] As described above, in the temperature control method of the wafer carrier device in the related art, when the temperature of a certain temperature control zone changes, only the etching rate change of the temperature control zone is taken into account, but it is not realized that when the temperature of the temperature control zone changes, the etching by-products generated during the etching process will diffuse from the high temperature zone to the low temperature zone along the temperature gradient, thereby affecting the etching rate of all positions on the wafer carrier surface. In the wafer etching method of the embodiment of the present application, by adopting an etching rate prediction model associated with the diffusion of etching by-products generated during the etching process, compared with the etching rate prediction model associated only with temperature sensitivity in the related art, it is possible to compensate for the influence of the diffusion of etching by-products on the etching rate distribution, so that the etching rate distribution data of each position on the wafer at any target temperature of each temperature control zone can be more accurately predicted, or the target temperature control value of each temperature control zone can be more accurately calculated based on the target etching rate distribution data. That is, by using the wafer etching method of the embodiment of the present application to control the temperature of each temperature control zone of the wafer carrier device, the uniformity of wafer etching can be improved, or the desired morphology of the wafer surface can be obtained.

[0067] The inventors of the present application further discovered that the temperature control method for multiple temperature control zones in the embodiment of the present application can be applied not only to etching processes, but also to deposition processes. For temperature-sensitive deposition processes, when the surface temperature of the wafer carrier is different, the sediment will diffuse from the high temperature zone to the low temperature zone along the temperature gradient, that is, the sediment accumulated in the high temperature zone will be less than the sediment accumulated in the low temperature zone. Therefore, when the temperature of a certain temperature control zone changes, it will not only affect the deposition rate of the temperature control zone where the temperature changes, but also affect the deposition rate of all positions on the wafer carrier surface. Corresponding to the wafer etching method described above, the embodiment of the present application also provides a wafer deposition method, which may include the following steps:

[0068] S11'. Obtain basic deposition rate distribution data and temperature sensitivity values ​​of the wafer to be deposited at the basic temperature of each temperature control zone. The basic deposition rate distribution data includes multiple deposition rate values ​​associated with positions on the wafer carrying surface. The temperature sensitivity value is used to characterize the rate of change of the deposition rate with temperature.

[0069] S12'. Utilize a preset deposition rate prediction model to obtain target temperature control values ​​for each temperature control zone based on target deposition rate distribution data, basic deposition rate distribution data, and temperature sensitivity values; wherein the deposition rate prediction model is associated with the diffusion of deposits generated during the deposition process, and the deposition rate prediction model is used to characterize the correspondence between the deposition rate of each position on the wafer carrying surface and the associated position, and the target deposition rate distribution data includes multiple target deposition rate values ​​associated with positions on the wafer carrying surface.

[0070] In the wafer deposition method of the embodiment of the present application, by adopting a deposition rate prediction model associated with the diffusion of sediments during the deposition process, compared with the deposition rate prediction model in the related art that is only associated with temperature sensitivity, it is possible to compensate for the impact of sediment diffusion on the deposition rate distribution. Therefore, it is possible to more accurately predict the deposition rate distribution data of each position on the wafer at any target temperature in each temperature control zone, or to more accurately calculate the target temperature control value of each temperature control zone based on the target deposition rate distribution data.

[0071] The following describes in detail the etch rate prediction model of an embodiment of the present application. The etch rate prediction model is associated with an etch rate prediction sub-model for each temperature control zone. Each etch rate prediction sub-model is used to characterize the corresponding relationship between the etch rate of each position on the wafer support surface and the associated position when the temperature control value of the corresponding temperature control zone changes.

[0072] As shown in FIG7 , a method for obtaining the etching rate prediction model provided in an embodiment of the present application may include the following steps:

[0073] S21. Obtain that the wafer to be etched is at the basic temperature T in each temperature control zone base Basic etch rate distribution data under [ER] base and temperature sensitivity values.

[0074] Those skilled in the art should understand that in order to obtain a more comprehensive etching rate prediction model so as to improve the etching uniformity on the entire wafer plane, it is necessary to collect distribution data of each position on the entire wafer plane. The obtained distribution data can be associated with each position on the two-dimensional plane.

[0075] In the case where the wafer carrier has four temperature control zones as shown in FIG1 , when the basic temperature T base When the temperature is 60℃, the temperature of each temperature control zone of the wafer carrier can be adjusted from the inside to the outside in the following order: [T] base =[60,60,60,60]. Of course, when the wafer carrier has 9 temperature control zones as shown in FIG2, the temperature of each temperature control zone can be represented by [T] base =[T1, T2, T3, T4, T5, T6, T7, T8, T9], and this expression will be used in the following text.

[0076] S22. Change the temperature control value of one temperature control zone to T1, and keep the other temperature control zones at the basic temperature T base , obtain the changed etching rate distribution data [ER]1.

[0077] For example, the temperature control value of the innermost first temperature control zone 11 is changed to 65°C, and the temperature control value of the other temperature control zones remains at 60°C. At this time, the temperature of the wafer carrier is [65, 60, 60, 60]. In this case, the etching rate distribution data of each position on the wafer carrier surface after the change is detected.

[0078] S23. Obtain the etch rate prediction sub-model [M] 1 of the changed temperature control zone, the etch rate prediction sub-model [M] 1 and the basic etch rate distribution data [ER] base , Etching rate distribution data after change [ER] 1, basic temperature T base , the changed temperature control value T1 of the temperature control zone and the temperature sensitivity value [Sen].

[0079] More specifically, the etch rate prediction sub-model [M] sub It can be expressed by the following formula:

[0080] The temperature sensitivity value [Sen] can be expressed as follows:

[0081] [ER]2 represents the etching rate distribution data when the temperature control values ​​of all temperature control zones of the wafer carrier are all T2.

[0082] For example, the temperature control value of the innermost first temperature control zone 11 may be changed to 65°C which is greater than the basic temperature. In other examples, the temperature value may also be changed to a temperature control value which is less than the basic temperature, such as 55°C.

[0083] To obtain the temperature sensitivity value, for example, the temperature control values ​​of the temperature control zones of the wafer carrier can all be set to T2 = 65°C. In this state, the etching rate distribution data [ER]2 is detected, and the etching rate distribution data [ER]2 is also normalized to obtain [Sen]. Similarly, in other examples, the temperature control values ​​of the temperature control zones of the wafer carrier can all be set to temperature control values ​​lower than 60°C, for example, 55°C, and the temperature sensitivity value can also be obtained according to the above formula (2).

[0084] For the sake of simplicity, only the distribution data in the radial direction of the wafer is taken as an example. In fact, the obtained distribution data should be associated with each position on the two-dimensional plane, rather than only with the radial position. The radial direction data calculated according to the above formula (1) is shown as the dots in Figure 8, thereby obtaining the etching rate prediction sub-model [M]1 of the innermost first temperature control zone 11. This etching rate prediction sub-model is used to characterize the corresponding relationship between the etching rate of each position on the wafer support surface and the associated position when the temperature control value of the corresponding first temperature control zone 11 changes. In order to obtain the etching rate corresponding to any position, a smooth curve can be used to fit the data calculated by the above formula (1) as shown in Figure 8, so that the etching rate corresponding to any position can be obtained based on the smooth curve. As shown in Figure 8, when the temperature value of the innermost first temperature control zone 11 changes, the etching rate of each position in the radial direction will change due to the influence of the diffusion of etching by-products.

[0085] It should be noted that if the temperature control value of the innermost first temperature control zone 11 is changed to a temperature value lower than the base temperature, the resulting curve will be a curve symmetrical with respect to the horizontal axis. In order to facilitate computer processing, a piecewise function can be further used to characterize the above-mentioned smooth curve, so that the control device of the semiconductor device can conveniently obtain the etching rate corresponding to any position based on the piecewise function. In some other embodiments, a neural network model can also be obtained by training the data calculated by the above formula (1), so that the control device of the semiconductor device can conveniently obtain the etching rate corresponding to any position based on the neural network model.

[0086] S24. Determine whether the etching rate prediction sub-models of all temperature control zones have been obtained. When the etching rate prediction sub-models of all temperature control zones have not been obtained, return to step S22 to obtain the etching rate prediction sub-model of the next temperature control zone; when the etching rate prediction sub-models of all temperature control zones have been obtained, execute step S25.

[0087] Using the same method, the etching rate prediction sub-model of all temperature control areas can be obtained.

[0088] S25. Obtain an etching rate prediction model based on the etching rate prediction sub-models of each temperature control zone.

[0089] Specifically, when the wafer carrier includes n temperature control zones, where n is an integer greater than or equal to 2, the etching rate prediction model can be expressed by the following formula:

[0090] Among them, [ER] target Indicates the target etch rate distribution data when each temperature control zone of the wafer carrier is at the corresponding target temperature control value, [ER] base Indicates that the temperature control values ​​of all temperature control zones of the wafer carrier are T base Basic etching rate distribution data at , [Sen] represents the temperature sensitivity value;

[0091] T target1 represents the target temperature control value of the first temperature control zone, T target2 Indicates the target temperature control value of the second temperature control zone until T targetn represents the target temperature control value of the nth temperature control zone, [M]1 represents the etching rate prediction sub-model of the first temperature control zone, [M]2 represents the etching rate prediction sub-model of the second temperature control zone, and so on. n Represents the etching rate prediction sub-model of the nth temperature control zone.

[0092] More specifically, for the example of the wafer carrier device shown in FIG1 including four temperature control zones, the above formula (3) can be expressed as:

[0093] In the above formula (4), [Sen], [M]1, [M]2, [M]3, [M]4, T base All of them are known data and can be pre-stored in the memory of the control device of the semiconductor process equipment. When it is necessary to predict the etching rate distribution data at any target temperature in each temperature control zone, T target1 、T target2 、T target3 、T target4 are all known values. Substituting these known values ​​into formula (4) we can get [ER] target The target etching rate distribution data of each temperature control zone under the target temperature control value is obtained. When the target temperature control value of each temperature control zone needs to be calculated based on the target etching rate distribution data, [ER] target For known data, [ER] target Substituting into formula (4) we can calculate T target1 、T target2 、T target3 、T target4 The target temperature control value of each temperature control zone is obtained.

[0094] Taking the wafer carrier shown in FIG1 as an example, which includes four temperature control zones, the receiving process is performed at the basic temperature [T] base = Basic etch rate distribution data in the radial direction under [60, 60, 60, 60] [ER] base , and collect the temperature sensitivity value [Sen] at the same time, and use the etching rate prediction model of the embodiment of the application to predict [T] target =[60,63,65,58], the etch rate distribution data in the radial direction is compared with the measured etch rate distribution data, as shown in FIG9 . The hollow circles in the figure represent the predicted values, and the solid circles represent the measured values. It can be seen that the two are basically consistent, and the predicted deviation is within 2%, which is much better than the related technology shown in FIG4 .

[0095] Correspondingly, for the wafer carrying device including 9 temperature control zones shown in Figure 2, the etching rate prediction sub-models of the 9 temperature control zones can also be obtained, so that when it is necessary to predict the etching rate distribution data at any target temperature of each temperature control zone, the etching rate distribution data at the predetermined target temperature of each temperature control zone can be obtained; when it is necessary to calculate the target temperature control value of each temperature control zone based on the target etching rate distribution data, the target temperature control value of each temperature control zone can be obtained to improve the uniformity of wafer etching or obtain the desired morphology.

[0096] Correspondingly, the deposition rate prediction model of the embodiment of the present application is associated with a deposition rate prediction sub-model for each temperature control zone. Each deposition rate prediction sub-model is used to represent the corresponding relationship between the deposition rate at each location on the wafer support surface and the associated location when the temperature control value of the corresponding temperature control zone changes. Further details can be found in the relevant description above and will not be repeated here.

[0097] Another embodiment of the present application discloses a wafer etching method, which is applied to a process chamber having a wafer carrier, wherein the wafer carrier surface of the wafer carrier has multiple temperature control zones. The wafer carrier may be, for example, a multi-temperature zone electrostatic chuck or a heated pedestal. The method may be executed by a control device of semiconductor process equipment, such as a host computer or a slave computer of the semiconductor process equipment. The method may include the following steps:

[0098] S31. Obtain basic etching rate distribution data and temperature sensitivity values ​​of the wafer to be etched at the basic temperature of each temperature control zone.

[0099] S32. Using a preset etching rate prediction model, according to the target etching rate distribution data, the basic etching rate distribution data and the temperature sensitivity value, the target temperature control value of each temperature control zone is obtained.

[0100] In this embodiment, the etching rate prediction model is used to characterize that when the temperature control value of any temperature control zone changes, the etching rates of all positions on the wafer carrying surface are affected by the changed temperature control zone, and the corresponding relationship between the etching rate of each position after the change and the corresponding position.

[0101] In the wafer etching method of the embodiment of the present application, the etching rate prediction model used is used to characterize that when the temperature control value of any temperature control zone changes, the etching rate of all positions on the wafer carrier surface is affected by the changed temperature control zone, and the corresponding relationship between the etching rate of each position after the change and the corresponding position, that is, when the temperature control value of one or several temperature control zones in the etching rate prediction model of the embodiment of the present application changes, it will not only affect the etching rate value of the changed temperature control zone, but also affect the etching rate values ​​of other temperature control zones. This is based on the inventors of the present application finding that when the surface temperature of the wafer carrier device is different, the etching by-products will diffuse from the high temperature zone to the low temperature zone along the temperature gradient, and the etching by-products accumulated in the high temperature zone will be less than the etching by-products accumulated in the low temperature zone, causing the etching rate of the entire wafer to change. However, the etching rate prediction model associated only with temperature sensitivity in the related art only considers the influence of temperature. For the temperature control zone where the temperature does not change, since the temperature does not change, it is considered that its etching rate does not change. Since the etching rate prediction model in the related art does not take into account the influence of the diffusion of etching by-products, the predicted etching rate distribution data will deviate from the actual measured etching rate distribution data. The etching rate prediction model adopted by the wafer etching method of the embodiment of the present application takes into account that when the temperature control value of one or several temperature control zones changes, it will also affect the etching rate values ​​of various positions in other temperature control zones, and can compensate for the influence of the diffusion of etching by-products on the etching rate distribution. Therefore, it can more accurately predict the etching rate distribution data of various positions on the wafer at any target temperature in each temperature control zone, or can more accurately calculate the target temperature control value of each temperature control zone based on the target etching rate distribution data.

[0102] For further details of this embodiment, please refer to the corresponding description in the previous embodiment, which will not be repeated here. Correspondingly, the temperature control method in this embodiment can also be applied to the deposition process, and the specific details can be referred to the corresponding description above, which will not be repeated here.

[0103] In the above embodiment, the etching rate prediction model can be associated with each position on the two-dimensional plane of the wafer carrying surface, but such an etching rate prediction model is relatively complex, which is not conducive to quickly predicting the etching rate distribution data of each position on the wafer, or calculating the target temperature control value of each temperature control zone. In order to simplify the etching rate prediction model, the embodiment of the present application also provides a wafer etching method, which is applied to a process chamber with a wafer carrying device, as shown in Figures 3A and 3B, the wafer carrying surface of the wafer carrying device has a plurality of main temperature control zones 34 and a plurality of auxiliary temperature control zones 35, and the plurality of main temperature control zones 34 are arranged in sequence in the radial direction of the wafer carrying surface, and the main temperature control zone 34 located on the outside of the radial direction is arranged around the main temperature control zone 34 located on the inside of the radial direction, and the plurality of auxiliary temperature control zones 35 are arranged along the angular direction of the wafer carrying device, and the wafer carrying device can be, for example, a multi-temperature zone electrostatic chuck or a heating base. The method can be executed by a control device of a semiconductor process equipment, and the control device can be, for example, a host computer or a slave computer of a semiconductor process equipment. As shown in Figure 10, the method may include the following steps:

[0104] S31. Obtain first basic etching rate distribution data and temperature sensitivity values ​​of the wafer to be etched along the radial direction at the basic temperature of each main temperature control zone.

[0105] In this embodiment, the first basic etching rate distribution data includes multiple etching rate values ​​associated with radial positions on the wafer support surface, and the temperature sensitivity value is used to characterize the rate of change of the etching rate with temperature. For further details, please refer to the corresponding description in step S11.

[0106] S32. Using a preset first etching rate prediction model, according to the first target etching rate distribution data, the first basic etching rate distribution data and the temperature sensitivity value, obtain the target temperature control value of each main temperature control zone.

[0107] In this embodiment, the first etch rate prediction model is associated with the radial diffusion of etching byproducts generated during the etching process. The first etch rate prediction model is used to characterize the correspondence between the etch rate of each radial position on the wafer support surface and the associated position. The first target etch rate distribution data includes multiple target etch rate values ​​associated with radial positions on the wafer support surface. For further details, refer to the corresponding description of step S12.

[0108] In this embodiment, the first etching rate prediction model is only associated with each position in the radial direction on the wafer supporting surface. The model is relatively simple and can quickly predict the etching rate distribution data of each position in the radial direction of the wafer, or calculate the target temperature control value of each main temperature control zone to achieve etching uniformity in the radial direction of the wafer, or obtain the desired morphology in the radial direction.

[0109] S33. Obtain second basic etching rate distribution data and temperature sensitivity values ​​along the angular direction of the wafer to be etched at the basic temperature of each auxiliary temperature control zone.

[0110] In this embodiment, the second basic etching rate distribution data includes a plurality of etching rate values ​​associated with positions in an angular direction on the wafer carrying surface.

[0111] S34. Using the preset second etching rate prediction model, according to the second target etching rate distribution data, the second basic etching rate distribution data and the temperature sensitivity value, obtain the target temperature control value of each auxiliary temperature control zone.

[0112] This step is used to adjust the etching uniformity in the angular direction of the wafer. In the example of Figure 3B, there are 3 main temperature control zones, and each main temperature control zone has multiple auxiliary temperature control zones. Therefore, 3 second etching rate prediction models are required. The second etching rate prediction models corresponding to the 4 auxiliary temperature control zones in the inner area are used to adjust the angular etching uniformity of the inner area, the second etching rate prediction models corresponding to the 8 auxiliary temperature control zones in the middle area are used to adjust the angular etching uniformity of the middle area, and the second etching rate prediction models corresponding to the 16 auxiliary temperature control zones in the outer area are used to adjust the angular etching uniformity of the outer area.

[0113] In this embodiment, the second etching rate prediction model is associated with the diffusion of etching by-products in the angular direction generated during the etching process. The second etching rate prediction model is used to characterize the correspondence between the etching rate of each position in the angular direction on the wafer carrier surface and the associated position. The second target etching rate distribution data includes multiple target etching product rate values ​​associated with the positions in the angular direction on the wafer carrier surface.

[0114] In this embodiment, the second etching rate prediction model is only associated with each position in the angular direction of the wafer carrying surface. The model is relatively simple and can quickly predict the etching rate distribution data of each position in the angular direction of the wafer, or calculate the target temperature control value of each auxiliary temperature control zone to achieve etching uniformity in the angular direction of the wafer, or obtain the desired morphology in the angular direction.

[0115] In the wafer etching method of the embodiment shown in FIG10 , the target temperature control value of each main temperature control zone is obtained through the first stage, i.e., steps S31 and S32, so that the etching uniformity in the radial direction of the wafer can be adjusted or the desired morphology in the radial direction can be obtained. Then, the target temperature control value of each auxiliary temperature control zone is obtained through the second stage, i.e., steps S33 and S34, so that the etching uniformity in the angular direction of the wafer can be adjusted or the desired morphology in the angular direction can be obtained. The above-mentioned wafer etching method achieves etching uniformity across the entire wafer plane or obtains the desired morphology across the entire wafer plane through these two stages. The first and second etching rate prediction models used in these two stages are only associated with each position in one direction on the wafer support surface. Compared with the etching rate prediction model associated with each position on the two-dimensional plane of the wafer support surface, the model used in this embodiment is simpler, thereby enabling rapid temperature control.

[0116] Further details of the embodiments of the present application can be found in the relevant description above, which will not be repeated here. Those skilled in the art should understand that the temperature control method in this embodiment can also be applied to the deposition process, and the specific details can be found in the corresponding description above, which will not be repeated here.

[0117] Another embodiment of the present application also discloses a method for obtaining an etching rate prediction model. This method can be applied, for example, to a process chamber having a wafer carrier as shown in Figures 3A and 3B. The wafer carrier surface of the wafer carrier has multiple main temperature control zones 34 and multiple auxiliary temperature control zones 35. The multiple main temperature control zones 34 are arranged in sequence in the radial direction of the wafer carrier surface. The main temperature control zones 34 located on the outer side of the radial direction are arranged around the main temperature control zone 34 located on the inner side of the radial direction. The multiple auxiliary temperature control zones 35 are arranged along the angular direction of the wafer carrier. As shown in Figure 11, the method may include the following steps:

[0118] S41. Obtain first basic etch rate distribution data along a radial direction of the wafer to be etched when all primary temperature control zones are at a basic temperature. The first basic etch rate distribution data includes a plurality of etch rate values ​​associated with radial positions on the wafer support surface. For further details, refer to the corresponding description of step S21.

[0119] S42. Change the temperature control value of one of the main temperature control zones, and keep the other main temperature control zones at the basic temperature, and obtain the changed etching rate distribution data in the radial direction. For further details, please refer to the corresponding description of step S22.

[0120] S43. Obtain a first etch rate prediction sub-model for the changed main temperature control zone. The first etch rate prediction sub-model is associated with the first basic etch rate distribution data, the changed etch rate distribution data, the basic temperature, the changed temperature control value of the main temperature control zone, and the temperature sensitivity value. For further details, refer to the corresponding description of step S23.

[0121] S44. Repeat changing the temperature control value of another main temperature control zone in the main temperature control zone, and keep the remaining main temperature control zones at the basic temperature, obtain the changed etching rate distribution data in the radial direction, and obtain the etching rate prediction sub-model of the changed main temperature control zone, until the etching rate prediction sub-models of all main temperature control zones are obtained.

[0122] S45. Obtain second basic etching rate distribution data along the angular direction of the wafer to be etched when each auxiliary temperature control zone is at the basic temperature, wherein the second basic etching rate distribution data includes multiple etching rate values ​​associated with the position in the angular direction on the wafer carrying surface.

[0123] S46. Change the temperature control value of one of the auxiliary temperature control zones, and keep the other auxiliary temperature control zones at the basic temperature, and obtain the changed etching rate distribution data in the angular direction.

[0124] S47. Obtain a second etch rate prediction sub-model of the changed auxiliary temperature control zone, where the second etch rate prediction sub-model is related to the second basic etch rate distribution data, the changed etch rate distribution data, the basic temperature, the changed temperature control value of the auxiliary temperature control zone, and the temperature sensitivity value.

[0125] S48. Repeat changing the temperature control value of another auxiliary temperature control zone in the auxiliary temperature control zone, and keep the remaining main temperature control zones at the basic temperature, obtain the changed etching rate distribution data in the radial direction, and obtain the etching rate prediction sub-model of the changed main temperature control zone, until the etching rate prediction sub-models of all main temperature control zones are obtained.

[0126] S49. Obtain a first etching rate prediction model based on the first etching rate prediction sub-model of each main temperature control zone, and obtain a second etching rate prediction model based on the second etching rate prediction sub-model of each auxiliary temperature control zone.

[0127] In the example of FIG3B , there are three main temperature control zones and 28 auxiliary temperature control zones, each of which has multiple auxiliary temperature control zones. The second etch rate prediction sub-models of the 28 auxiliary temperature control zones can, for example, obtain three second etch rate prediction models. The second etch rate prediction models corresponding to the four auxiliary temperature control zones in the inner region are used to adjust the angular etching uniformity of the inner region, the second etch rate prediction models corresponding to the eight auxiliary temperature control zones in the middle region are used to adjust the angular etching uniformity of the middle region, and the second etch rate prediction models corresponding to the 16 auxiliary temperature control zones in the outer region are used to adjust the angular etching uniformity of the outer region. For further details, please refer to the corresponding description in step S25.

[0128] For further details of this embodiment, please refer to the relevant description above, which will not be repeated here. Those skilled in the art will understand that the method for obtaining the etch rate prediction model in this embodiment can also be applied to deposition processes, and the specific details can be referred to the corresponding description above, which will not be repeated here.

[0129] Another embodiment of the present application further provides a wafer etching or deposition method, which is applied to a process chamber having a wafer carrier, wherein the wafer carrier has a wafer carrier surface with multiple temperature control zones, and the wafer carrier may be, for example, a multi-temperature zone electrostatic chuck or a heating pedestal. The method may be executed by a control device of semiconductor process equipment, and the control device may be, for example, a host computer or a slave computer of the semiconductor process equipment. The method may include the following steps:

[0130] S51. Obtaining basic etching or deposition rate distribution data and temperature sensitivity values ​​of the wafer to be etched or deposited at the basic temperature of each temperature control zone; wherein the basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values ​​associated with positions on the wafer carrier surface, and the temperature sensitivity values ​​include a plurality of temperature sensitivity values ​​associated with positions on the wafer carrier surface;

[0131] S52. Utilize the etching or deposition rate prediction model obtained by the method described in the above method embodiment for obtaining an etching or deposition rate prediction model, and obtain the target temperature control value of each temperature control zone according to the target etching or deposition rate distribution data, the basic etching or deposition rate distribution data, and the temperature sensitivity value; wherein the target etching or deposition rate distribution data includes a plurality of target etching rate values ​​associated with positions on the wafer carrying surface.

[0132] For further detailed description of this embodiment, please refer to the relevant content above and will not be repeated here.

[0133] Another embodiment of the present application also discloses a semiconductor process equipment, as shown in Figure 12, the semiconductor process equipment may include: a process chamber 41, a wafer carrier 42 and a control device 43. The wafer carrier 42 may be, for example, a multi-temperature zone electrostatic chuck or a heating base, which is arranged in the process chamber 41, and the wafer carrying surface of the wafer carrier 42 has multiple temperature control zones; the control device 43 includes at least one processor and at least one memory, and the memory stores a computer program, and when the computer program is executed by the processor, it implements the methods described in the various embodiments above. In other embodiments, the memory stores the etching or deposition rate prediction model obtained in the embodiment of the method for obtaining the etching or deposition rate prediction model described above.

[0134] Exemplarily, the control device 43 can be either a host computer or a slave computer. In addition to controlling the target control temperatures of each temperature control zone on the wafer support surface, the control device 43 can also control the opening of the valve of the semiconductor process equipment's inlet assembly to introduce the corresponding process gas into the process chamber 41. The control device 43 can also control the opening and closing of the valve of the inlet assembly to control the flow rate of the process gas. The control device 43 can also control the exhaust assembly to exhaust the interior of the process chamber, for example, by controlling the valve opening of the exhaust assembly or the speed of the exhaust pump, thereby controlling the pressure within the process chamber 41 and removing reaction byproducts. The semiconductor process equipment may also include a radio frequency coil. The control device 43 is further configured to control the radio frequency power supply to provide radio frequency power to the radio frequency coil to excite the process gas within the process chamber 41 to generate plasma. The control device 43 is also configured to control the radio frequency power supply to provide radio frequency power to the wafer support assembly 42 to provide an radio frequency bias voltage. Thus, the semiconductor process equipment can process wafers on the wafer support assembly 42.

[0135] The above embodiments of this application focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0136] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A wafer etching or deposition method, which is applied to a process chamber having a wafer carrier device. The wafer carrier surface of the wafer carrier device has a plurality of main temperature control zones and a plurality of auxiliary temperature control zones. The plurality of main temperature control zones are sequentially arranged in the radial direction of the wafer carrier surface, and the main temperature control zone located on the outer side in the radial direction surrounds the main temperature control zone located on the inner side in the radial direction. The plurality of auxiliary temperature control zones are arranged along the angular direction of the wafer carrier device, and it is characterized in that, The method includes: Obtaining first basic etching or deposition rate distribution data in the radial direction and a temperature sensitivity value at the basic temperature of a wafer to be etched or deposited in each of the main temperature control regions; wherein, the first basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values associated with positions in the radial direction on the wafer bearing surface, and the temperature sensitivity value is used to characterize the change rate of the etching or deposition rate with temperature; Using a preset first etching or deposition rate prediction model, obtaining a target temperature control value for each of the main temperature control regions according to first target etching or deposition rate distribution data, the first basic etching or deposition rate distribution data, and the temperature sensitivity value; wherein, the first etching or deposition rate prediction model is associated with the diffusion of etching by-products or deposits in the radial direction during the etching or deposition process, the first etching or deposition rate prediction model is used to characterize the corresponding relationship between the etching or deposition rates at various positions in the radial direction on the wafer bearing surface and the associated positions, and the first target etching or deposition rate distribution data includes a plurality of target etching or deposition rate values associated with positions in the radial direction on the wafer bearing surface.

2. The wafer etching or deposition method according to claim 1, characterized in that The method further includes: Obtaining second basic etching or deposition rate distribution data in the angular direction and the temperature sensitivity value at the basic temperature of a wafer to be etched or deposited in each of the auxiliary temperature control regions; wherein, the second basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values associated with positions in the angular direction on the wafer bearing surface; Using a preset second etching or deposition rate prediction model, obtaining a target temperature control value for each of the auxiliary temperature control regions according to second target etching or deposition rate distribution data, the second basic etching or deposition rate distribution data, and the temperature sensitivity value; wherein, the second etching or deposition rate prediction model is associated with the diffusion of etching by-products or deposits in the angular direction during the etching or deposition process, the second etching or deposition rate prediction model is used to characterize the corresponding relationship between the etching or deposition rates at various positions in the angular direction on the wafer bearing surface and the associated positions, and the second target etching or deposition rate distribution data includes a plurality of target etching or deposition rate values associated with positions in the angular direction on the wafer bearing surface.

3. The wafer etching or deposition method according to claim 2, wherein The first etching or deposition rate prediction model is associated with first etching or deposition rate prediction sub-models for each of the main temperature control regions, and each of the first etching or deposition rate prediction sub-models is respectively used to characterize the corresponding relationship between the etching or deposition rates at various positions in the radial direction on the wafer bearing surface and the associated positions when the temperature control value of the corresponding main temperature control region changes; Or The second etching or deposition rate prediction model is associated with the second etching or deposition rate prediction sub-models of the respective auxiliary temperature control zones. Each of the second etching or deposition rate prediction sub-models is respectively used to characterize the corresponding relationship between the etching or deposition rates at various positions in the angular direction on the wafer bearing surface when the temperature control value of the corresponding auxiliary temperature control zone changes.

4. The wafer etching or deposition method according to claim 3, wherein The steps of obtaining the first etching or deposition rate prediction sub-model include: Obtaining the first basic etching or deposition rate distribution data and the temperature sensitivity value of the wafer to be etched or deposited; Changing the temperature control value of one of the main temperature control zones in the main temperature control zone and keeping the remaining main temperature control zones at the basic temperature, and obtaining the changed etching or deposition rate distribution data in the radial direction; Obtaining the first etching or deposition rate prediction sub-model of the changed main temperature control zone, where the first etching or deposition rate prediction sub-model is related to the first basic etching or deposition rate distribution data, the changed etching or deposition rate distribution data, the basic temperature, the temperature control value of the changed main temperature control zone, and the temperature sensitivity value.

5. The wafer etching or deposition method according to claim 3, wherein The steps of obtaining the second etching or deposition rate prediction sub-model include: Obtaining the second basic etching or deposition rate distribution data and the temperature sensitivity value of the wafer to be etched or deposited; Changing the temperature control value of one of the auxiliary temperature control zones in the auxiliary temperature control zone and keeping the remaining auxiliary temperature control zones at the basic temperature, and obtaining the changed etching or deposition rate distribution data in the angular direction; Obtaining the second etching or deposition rate prediction sub-model of the changed auxiliary temperature control zone, where the second etching or deposition rate prediction sub-model is related to the second basic etching or deposition rate distribution data, the changed etching or deposition rate distribution data, the basic temperature, the temperature control value of the changed auxiliary temperature control zone, and the temperature sensitivity value.

6. A wafer etching or deposition method, which is applied to a process chamber having a wafer carrier device, and the wafer carrier surface of the wafer carrier device has a plurality of temperature control zones, characterized in that, The method includes: Obtaining the basic etching or deposition rate distribution data and the temperature sensitivity value of the wafer to be etched or deposited at the basic temperature of each of the temperature control zones; wherein, the basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values associated with the positions on the wafer bearing surface, and the temperature sensitivity value is used to characterize the change rate of the etching or deposition rate with temperature; Using a preset etching or deposition rate prediction model, according to the target etching or deposition rate distribution data, the basic etching or deposition rate distribution data, and the temperature sensitivity value, obtaining the target temperature control value of each of the temperature control zones; wherein, the etching or deposition rate prediction model is associated with the diffusion of etching by-products or deposits generated during the etching or deposition process, the etching or deposition rate prediction model is used to characterize the corresponding relationship between the etching or deposition rates at various positions on the wafer bearing surface, and the target etching or deposition rate distribution data includes a plurality of target etching or deposition rate values associated with the positions on the wafer bearing surface.

7. A wafer etching or deposition method, which is applied to a process chamber having a wafer carrier device, and the wafer carrier surface of the wafer carrier device has a plurality of temperature control zones, characterized in that, The method includes: Obtain the basic etching or deposition rate distribution data and temperature sensitivity values of the wafer to be etched or deposited at the basic temperatures in each of the temperature control zones; wherein, the basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values associated with positions on the wafer carrier surface, and the temperature sensitivity value is used to characterize the change rate of the etching or deposition rate with temperature; Utilize a preset etching or deposition rate prediction model to obtain the target temperature control values for each of the temperature control zones according to the target etching or deposition rate distribution data, the basic etching or deposition rate distribution data, and the temperature sensitivity distribution data; wherein, the etching or deposition rate prediction model is used to characterize that when the temperature control value of any of the temperature control zones changes, all positions on the wafer carrier surface are affected by the changed temperature control zone, and the corresponding relationship between the changed etching or deposition rate and the corresponding positions, and the target etching or deposition rate distribution data includes a plurality of target etching or deposition rate values associated with positions on the wafer carrier surface.

8. The wafer etching or deposition method according to claim 6 or 7, characterized in that The etching or deposition rate prediction model is associated with the etching or deposition rate prediction sub-models of each of the temperature control zones, and each of the etching or deposition rate prediction sub-models is respectively used to characterize the corresponding relationship between the etching or deposition rate of each position on the wafer carrier surface and the associated position when the temperature control value of the corresponding temperature control zone changes.

9. The wafer etching or deposition method according to claim 6 or 7, characterized in that, The steps of obtaining the etching or deposition rate prediction sub-model include: Obtain the basic etching or deposition rate distribution data and temperature sensitivity values of the wafer to be etched or deposited when each of the temperature control zones is at the basic temperature; Change the temperature control value of one of the temperature control zones and keep the remaining temperature control zones at the basic temperature, and obtain the changed etching or deposition rate distribution data; Obtain the etching or deposition rate prediction sub-model of the changed temperature control zone, and the etching or deposition rate prediction sub-model is related to the basic etching or deposition rate distribution data, the changed etching or deposition rate distribution data, the basic temperature, the temperature control value of the changed temperature control zone, and the temperature sensitivity value.

10. The wafer etching or deposition method according to claim 9, characterized in that The etching or deposition rate prediction sub-model [M] sub is expressed by the following formula: where, T base represents the base temperature, T1 represents the temperature control value of the changed temperature control zone, [ER]1 represents the etched or deposited rate distribution data after the change, [ER] base represents that the temperature control values of all the temperature control zones of the wafer carrier device are all T base when the basic etched or deposited rate distribution data, [Sen] represents the temperature sensitivity value; The temperature sensitivity value [Sen] is represented by the following formula: Wherein, [ER]2 represents the etching or deposition rate distribution data when the temperature control values of all the temperature control zones of the wafer carrier device are T2.

11. The wafer etching or deposition method according to claim 10, characterized in that, The steps of obtaining the etching or deposition rate prediction sub-model further include: Use a smooth curve to fit the data calculated by the formula (1) and use a piecewise function to characterize the smooth curve; or Train a neural network model with the data calculated by the formula (1).

12. The wafer etching or deposition method according to claim 9, wherein, The wafer carrier device includes n temperature control zones, where n is an integer greater than or equal to 2, and the etching or deposition rate prediction model is represented by the following formula: Among them, [ER] target represents the target etching or deposition rate distribution data when each of the temperature control zones of the wafer carrier device is at a corresponding target temperature control value, [ER] base represents the basic etching or deposition rate distribution data when the temperature control values of all the temperature control zones of the wafer carrier device are T base at this time, and [Sen] represents the temperature sensitivity value; T target1 represents the target temperature control value of the first temperature control zone, T target2 represents the target temperature control value of the second temperature control zone, up to T targetn represents the target temperature control value of the nth temperature control zone, [M]1 represents the etching or deposition rate prediction sub-model of the first temperature control zone, [M]2 represents the etching or deposition rate prediction sub-model of the second temperature control zone, up to [M] n represents the etching or deposition rate prediction sub-model of the nth temperature control zone.

13. The wafer etching or deposition method according to claim 10 or 11, characterized in that, The wafer carrier device includes n temperature control zones, where n is an integer greater than or equal to 2, and the etching or deposition rate prediction model is represented by the following formula: Among them, [ER] target represents the target etching or deposition rate distribution data when each of the temperature control zones of the wafer carrier device is at a corresponding target temperature control value, [ER] base represents the basic etching or deposition rate distribution data when the temperature control values of all the temperature control zones of the wafer carrier device are all T base at this time, and [Sen] represents the temperature sensitivity value; T target1 represents the target temperature control value of the first temperature control zone, T target2 represents the target temperature control value of the second temperature control zone, up to T targetn represents the target temperature control value of the nth temperature control zone, [M]1 represents the etching or deposition rate prediction sub-model of the first temperature control zone, [M]2 represents the etching or deposition rate prediction sub-model of the second temperature control zone, up to [M] n represents the etching or deposition rate prediction sub-model of the nth temperature control zone.

14. A method for obtaining an etching or deposition rate prediction model, the method being applied to a process chamber having a wafer carrier device, the wafer carrier surface of the wafer carrier device having a plurality of temperature control zones, characterized in that, The method includes: Obtain the basic etching or deposition rate distribution data and temperature sensitivity values of the wafer to be etched or deposited when each of the temperature control zones is at the basic temperature; wherein, the basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values associated with positions on the wafer carrier surface, and the temperature sensitivity value is used to characterize the change rate of the etching or deposition rate with temperature; Change the temperature control value of one of the temperature control zones in the temperature control zone, and keep the remaining temperature control zones at the basic temperature, and obtain the etched or deposited rate distribution data after the change; Obtain the etched or deposited rate prediction sub-model of the changed temperature control zone, where the etched or deposited rate prediction sub-model is related to the basic etched or deposited rate distribution data, the etched or deposited rate distribution data after the change, the basic temperature, the temperature control value of the changed temperature control zone, and the temperature sensitivity value; Repeat to change the temperature control value of another temperature control zone in the temperature control zone, and keep the remaining temperature control zones at the basic temperature, obtain the etched or deposited rate distribution data after the change, and obtain the etched or deposited rate prediction sub-model of the changed temperature control zone until the etched or deposited rate prediction sub-models of all the temperature control zones are obtained; Obtain the etched or deposited rate prediction model according to the etched or deposited rate prediction sub-models of each of the temperature control zones.

15. The method according to claim 14, wherein The etching or deposition rate prediction sub-model [M] sub is represented by the following formula: Among them, T base represents the base temperature, T1 represents the temperature control value of the changed temperature control zone, [ER]1 represents the etched or deposited rate distribution data after the change, [ER] base represents that the temperature control values of all the temperature control zones of the wafer carrier device are all T base when the basic etched or deposited rate distribution data, [Sen] represents the temperature sensitivity value; The temperature sensitivity value [Sen] is represented by the following formula: Wherein, [ER]2 represents the etched or deposited rate distribution data when the temperature control values of all the temperature control zones of the wafer carrier device are T2.

16. The method according to claim 15, wherein Obtaining the etched or deposited rate prediction sub-model further includes: Using a smooth curve to fit the data calculated by the formula (1), and using a piecewise function to characterize the smooth curve; or Training a neural network model with the data calculated by the formula (1).

17. The method according to claim 14, characterized in that The wafer carrier device includes n temperature control zones, where n is an integer greater than or equal to 2, and the etching or deposition rate prediction model is expressed by the following formula: Among them, [ER] target represents the target etching or deposition rate distribution data when each of the temperature control regions of the wafer carrier device is at a corresponding target temperature control value, [ER] base represents the basic etching or deposition rate distribution data when the temperature control values of all of the temperature control regions of the wafer carrier device are T base at this time, and [Sen] represents the temperature sensitivity value; T target1 represents the target temperature control value of the first temperature control zone, T target2 represents the target temperature control value of the second temperature control zone, up to T targetn represents the target temperature control value of the nth temperature control zone, [M]1 represents the etching or deposition rate prediction sub-model of the first temperature control zone, [M]2 represents the etching or deposition rate prediction sub-model of the second temperature control zone, up to [M] n represents the etching or deposition rate prediction sub-model of the nth temperature control zone.

18. The method according to any one of claims 14 to 17, characterized in that, The multiple temperature control zones include multiple main temperature control zones and multiple auxiliary temperature control zones. The multiple main temperature control zones are arranged in sequence in the radial direction of the wafer carrier surface, and the main temperature control zone located outside the radial direction surrounds the main temperature control zone located inside the radial direction. The multiple auxiliary temperature control zones are arranged along the angular direction of the wafer carrier device; the etched or deposited rate prediction model includes a first etched or deposited rate prediction model, and the first etched or deposited rate prediction model is used to characterize the correspondence between the etched or deposited rates at each position in the radial direction on the wafer carrier surface and the associated positions; Obtaining the basic etched or deposited rate distribution data of the wafer to be etched or deposited when each of the temperature control zones is at the basic temperature includes: obtaining the first basic etched or deposited rate distribution data along the radial direction when each of the main temperature control zones of the wafer to be etched or deposited is at the basic temperature, where the first basic etched or deposited rate distribution data includes multiple etched or deposited rate values associated with the positions in the radial direction on the wafer carrier surface; Obtaining the etched or deposited rate distribution data after the change includes: changing the temperature control value of one of the main temperature control zones in the main temperature control zone, and keeping the remaining main temperature control zones at the basic temperature, and obtaining the etched or deposited rate distribution data after the change along the radial direction; The obtaining of the etching or deposition rate prediction sub-model for the changed temperature control zone includes: obtaining a first etching or deposition rate prediction sub-model for the changed main temperature control zone, where the first etching or deposition rate prediction sub-model is related to the first basic etching or deposition rate distribution data, the changed etching or deposition rate distribution data, the basic temperature, the temperature control value of the changed main temperature control zone, and the temperature sensitivity value; The obtaining of the etching or deposition rate prediction model based on the etching or deposition rate prediction sub-models of the respective temperature control zones includes: obtaining the first etching or deposition rate prediction model based on the first etching or deposition rate prediction sub-models of the respective main temperature control zones.

19. The method according to any one of claims 14 to 17, characterized in that, The multiple temperature control zones include multiple main temperature control zones and multiple auxiliary temperature control zones. The multiple main temperature control zones are sequentially arranged in the radial direction of the wafer bearing surface. The main temperature control zone located on the outer side in the radial direction surrounds the main temperature control zone located on the inner side in the radial direction. The multiple auxiliary temperature control zones are arranged in the angular direction of the wafer bearing device; The etching or deposition rate prediction model further includes a second etching or deposition rate prediction model, which is used to characterize the correspondence between the etching or deposition rates at various positions in the angular direction on the wafer bearing surface and the associated positions; The obtaining of the basic etching or deposition rate distribution data of the wafer to be etched or deposited when each of the temperature control zones is at the basic temperature further includes: obtaining the second basic etching or deposition rate distribution data in the angular direction when each of the auxiliary temperature control zones of the wafer to be etched or deposited is at the basic temperature, where the second basic etching or deposition rate distribution data includes multiple etching or deposition rate values associated with the positions in the angular direction on the wafer bearing surface; The obtaining of the changed etching or deposition rate distribution data further includes: changing the temperature control value of one of the auxiliary temperature control zones in the auxiliary temperature control zones and keeping the remaining auxiliary temperature control zones at the basic temperature, and obtaining the changed etching or deposition rate distribution data in the angular direction; The obtaining of the etching or deposition rate prediction sub-model for the changed temperature control zone further includes: obtaining a second etching or deposition rate prediction sub-model for the changed auxiliary temperature control zone, where the second etching or deposition rate prediction sub-model is related to the second basic etching or deposition rate distribution data, the changed etching or deposition rate distribution data, the basic temperature, the temperature control value of the changed auxiliary temperature control zone, and the temperature sensitivity value; The obtaining of the etching or deposition rate prediction model based on the etching or deposition rate prediction sub-models of the respective temperature control zones includes: obtaining the second etching or deposition rate prediction model based on the second etching or deposition rate prediction sub-models of the respective auxiliary temperature control zones.

20. A wafer etching or deposition method, which is applied to a process chamber having a wafer carrier device, and the wafer carrier surface of the wafer carrier device has a plurality of temperature control zones, characterized in that, The method includes: Obtain the basic etching or deposition rate distribution data and temperature sensitivity values of the wafer to be etched or deposited at the basic temperatures of each of the temperature control zones; wherein, the basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values associated with positions on the wafer bearing surface, and the temperature sensitivity value is used to characterize the change rate of the etching or deposition rate with temperature; Using the etching or deposition rate prediction model obtained by the method according to any one of claims 14 to 19, obtain the target temperature control values of each of the temperature control zones according to the target etching or deposition rate distribution data, the basic etching or deposition rate distribution data, and the temperature sensitivity value; wherein, the target etching or deposition rate distribution data includes a plurality of target etching or deposition rate values associated with positions on the wafer bearing surface.

21. A wafer etching or deposition method, which is applied to a process chamber having a wafer carrier device. The wafer carrier surface of the wafer carrier device has a plurality of main temperature control zones and a plurality of auxiliary temperature control zones. The plurality of main temperature control zones are sequentially arranged in the radial direction of the wafer carrier surface, and the main temperature control zone located on the outer side in the radial direction surrounds the main temperature control zone located on the inner side in the radial direction. The plurality of auxiliary temperature control zones are arranged along the angular direction of the wafer carrier device, and it is characterized in that, The method includes: Obtain the first basic etching or deposition rate distribution data and temperature sensitivity value along the radial direction at the basic temperatures of each of the main temperature control zones of the wafer to be etched or deposited; wherein, the first basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values associated with positions in the radial direction on the wafer bearing surface, and the temperature sensitivity value is used to characterize the change rate of the etching or deposition rate with temperature; Using the first etching or deposition rate prediction model obtained by the method according to claim 18, obtain the target temperature control values of each of the main temperature control zones according to the first target etching or deposition rate distribution data, the first basic etching or deposition rate distribution data, and the temperature sensitivity value; wherein, the first target etching or deposition rate distribution data includes a plurality of target etching or deposition rate values associated with positions in the radial direction on the wafer bearing surface.

22. The method according to claim 21, characterized in that, It further includes: Obtain the second basic etching or deposition rate distribution data and temperature sensitivity value along the radial direction at the basic temperatures of each of the auxiliary temperature control zones of the wafer to be etched or deposited; wherein, the second basic etching or deposition rate distribution data includes a plurality of etching or deposition rate values associated with positions in the angular direction on the wafer bearing surface, and the temperature sensitivity value is used to characterize the change rate of the etching or deposition rate with temperature; Using the second etching or deposition rate prediction model obtained by the method according to claim 19, obtain the target temperature control values of each of the auxiliary temperature control zones according to the second target etching or deposition rate distribution data, the second basic etching or deposition rate distribution data, and the temperature sensitivity value; wherein, the second target etching or deposition rate distribution data includes a plurality of target etching or deposition rate values associated with positions in the angular direction on the wafer bearing surface.

23. A semiconductor process equipment, characterized in that, It includes: A process chamber; A wafer carrier device disposed in the process chamber, and the wafer bearing surface of the wafer carrier device has a plurality of temperature control zones; A control device including at least one processor and at least one memory, and a computer program is stored in the memory, and when the computer program is executed by the processor, it implements the method according to any one of claims 1 to 22.

24. A semiconductor processing apparatus, characterized in that, It includes: A process chamber; A wafer carrier device is disposed in the process chamber, and a wafer carrying surface of the wafer carrier device has a plurality of temperature control zones; A control device includes at least one processor and at least one memory, and an etching or deposition rate prediction model obtained by the method according to any one of claims 14 to 19 is stored in the memory.

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