Wafer adsorption method applied to chuck

Abstract

The wafer adsorption method applied to the chuck comprises the following steps: performing first preheating treatment on a wafer through a heating part of the chuck, gradually raising the heating temperature of the first preheating treatment from a preset initial temperature to a first target temperature, and adsorbing the wafer through an adsorption part after performing the first preheating treatment on the wafer, the wafer is adsorbed on the bearing surface of the chuck; the wafer is subjected to the first preheating treatment, and the heating temperature of the first preheating treatment is gradually increased to the first target temperature from the preset initial temperature, so that the temperature uniformity in the wafer is improved, the thermal stress in the wafer is correspondingly reduced, the probability of deformation of the wafer is reduced, and the yield of the wafer is improved. And when the wafer is adsorbed by the adsorption part, the probability of deformation of the wafer is reduced, so that the friction force between the wafer and the chuck is reduced, particles generated by the friction force are correspondingly reduced, and the problem of particles at the edge of the wafer is solved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of semiconductor manufacturing, and in particular to a wafer adsorption method applied to a chuck. Background Art

[0002] In the field of semiconductor manufacturing, wafer processing is a key step in manufacturing integrated circuits (ICs) and micro-electromechanical systems (MEMS). In order to ensure the production quality of these high-precision devices, during processes such as plasma etching, physical vapor deposition, and chemical vapor deposition, it is necessary to accurately position and fix the wafer to prevent the wafer position from shifting, thereby ensuring accurate execution of the process.

[0003] In these processes, the chuck is an important tool for carrying and positioning the wafer. The chuck can adsorb the wafer on its surface to ensure that the wafer remains stable during the complex process. For example, an electrostatic chuck adsorbs the wafer by applying an adsorption voltage to the adsorption electrode in the electrostatic chuck.

[0004] However, there are still many problems with the wafer adsorption method applied to the chuck. Summary of the invention

[0005] The problem solved by the embodiment of the present invention is to provide a wafer adsorption method applied to a chuck to improve the problem of particles at the edge of the wafer.

[0006] To solve the above problems, an embodiment of the present invention provides a wafer adsorption method applied to a chuck, the wafer adsorption method comprising: under the condition that the adsorption component in the chuck does not adsorb the wafer, performing a first pre-heating treatment on the wafer by a heating component of the chuck, and the heating temperature of the first pre-heating treatment is gradually increased from a preset initial temperature to a first target temperature; after the first pre-heating treatment of the wafer, maintaining the first target temperature, and adsorbing the wafer by the adsorption component, so that the wafer is adsorbed on the carrying surface of the chuck.

[0007] Optionally, the first pre-heating treatment is a step-type heating treatment, which includes alternating heating treatment and heat preservation treatment, wherein the heating temperature of multiple heat preservation treatments is increased, and the heating treatment is used to increase the heating temperature to the heating temperature of successive heat preservation treatments; wherein the starting temperature of the first heating treatment is the preset initial temperature, and the heating temperature of the last heat preservation treatment is the first target temperature.

[0008] Optionally, the temperature increase range between two adjacent insulation treatments is 10 degrees Celsius to 15 degrees Celsius.

[0009] Optionally, the heating rate of the heating treatment is 30 degrees Celsius per minute to 45 degrees Celsius per minute.

[0010] Optionally, the chuck is disposed in a process chamber; in the step of performing a first preheating treatment on the wafer by a heating component of the chuck, the wafer is disposed on a carrying surface of the chuck; before performing the first preheating treatment on the wafer by the heating component of the chuck, it also includes: under the condition that the wafer is not in contact with the carrying surface of the chuck, performing a second preheating treatment on the wafer by the chamber temperature in the process chamber, so that the wafer reaches a second target temperature, wherein the second target temperature is less than or equal to the preset initial temperature.

[0011] Optionally, an ejector pin is provided in the chuck; in the step of performing a second preheating treatment on the wafer by adjusting the chamber temperature in the process chamber, the ejector pin is made to protrude from the carrying surface of the chuck, and the wafer is carried by the ejector pin.

[0012] Optionally, in the step of performing a second preheating treatment on the wafer by adjusting the chamber temperature in the process chamber, the difference between the second target temperature and the preset initial temperature is 0 degrees Celsius to 15 degrees Celsius.

[0013] Optionally, in the step of performing a second preheating treatment on the wafer according to the chamber temperature in the process chamber, the heating time of the second preheating treatment is obtained by: acquiring the chamber temperature of the process chamber; and acquiring the heating time for the wafer to reach the second target temperature based on the thermal conductivity coefficient between the air in the process chamber and the wafer, and the chamber temperature of the process chamber.

[0014] Optionally, in the step of performing a second preheating treatment on the wafer by adjusting the chamber temperature in the process chamber, the distance between the back of the wafer and the carrying surface of the chuck is 9 mm to 11 mm.

[0015] Optionally, the heating component of the chuck is a heating electrode; and the wafer is subjected to a first pre-heating treatment by the heating electrode of the chuck.

[0016] Optionally, the chuck is an electrostatic chuck, and the adsorption component of the electrostatic chuck is an adsorption electrode; under the condition that no adsorption voltage is applied to the adsorption electrode in the electrostatic chuck, the wafer is subjected to a first preheating treatment by the heating component of the electrostatic chuck; after the wafer is subjected to the first preheating treatment, the first target temperature is maintained, and an adsorption voltage is applied to the adsorption electrode in the electrostatic chuck so that the wafer is adsorbed on the carrying surface of the electrostatic chuck.

[0017] Optionally, in the step of applying an adsorption voltage to the adsorption electrode in the electrostatic chuck, the adsorption voltage is 1000 volts to 2000 volts.

[0018] Optionally, the step of applying the adsorption voltage to the adsorption electrode in the electrostatic chuck also includes blowing cooling gas to the back of the wafer through the electrostatic chuck; in the step of blowing cooling gas to the back of the wafer through the electrostatic chuck, the pressure of the cooling gas is 5 Torr to 10 Torr.

[0019] Compared with the prior art, the technical solution of the embodiment of the present invention has the following advantages:

[0020] An embodiment of the present invention provides a wafer adsorption method applied to a chuck, the wafer adsorption method comprising: under the condition that the adsorption component in the chuck does not adsorb the wafer, performing a first preheating treatment on the wafer by a heating component of the chuck, the heating temperature of the first preheating treatment gradually increases from a preset initial temperature to a first target temperature, after the wafer is subjected to the first preheating treatment, the wafer is adsorbed by the adsorption component so that the wafer is adsorbed on the carrying surface of the chuck; in this embodiment, by performing the first preheating treatment on the wafer, and the heating temperature of the first preheating treatment gradually increases from a preset initial temperature to the first target temperature, it is beneficial to improve the temperature uniformity inside the wafer, and correspondingly helps to reduce the thermal stress inside the wafer, thereby reducing the probability of deformation of the wafer, and then when the wafer is adsorbed by the adsorption component, since the probability of deformation of the wafer is reduced at this time, the friction between the wafer and the chuck is reduced, and the number of particles generated by the friction is correspondingly reduced, thereby improving the problem of particles at the edge of the wafer.

[0021] In an optional scheme, the first pre-heating treatment is a step-type heating treatment, and the step-type heating treatment includes alternating heating treatment and heat preservation treatment, the heating temperature of multiple heat preservation treatments is increased, and the heating treatment is used to increase the heating temperature to the heating temperature of the successively performed heat preservation treatments; wherein, the starting temperature of the first heating treatment is the preset initial temperature, and the heating temperature of the last heat preservation treatment is the first target temperature; since the step-type heating treatment is followed by heat preservation treatment, sufficient time can be provided for the heat to diffuse evenly inside the wafer, thereby reducing the temperature gradient inside the wafer accordingly, and thereby improving the temperature uniformity inside the wafer.

[0022] In an optional scheme, before the first preheating treatment is performed on the wafer by the heating component of the chuck, it also includes: under the condition that the wafer is not in contact with the carrying surface of the chuck, the wafer is subjected to a second preheating treatment by the chamber temperature in the process chamber to make the wafer reach a second target temperature, wherein the second target temperature is less than or equal to the preset initial temperature; by performing the second preheating treatment on the wafer, the wafer is heated from the initial temperature (for example, room temperature) when it is introduced into the process chamber to the second target temperature, which is beneficial to reduce the probability of cracks or damage to the wafer due to rapid temperature changes.

[0023] In an optional scheme, in the step of applying an adsorption voltage to the adsorption electrode in the electrostatic chuck, the adsorption voltage is 1000 volts to 2000 volts. By setting the adsorption voltage within this range, on the one hand, it is beneficial to make the electrostatic chuck have sufficient adsorption force on the wafer to keep the wafer stably adsorbed on the electrostatic chuck; on the other hand, it is also beneficial to further reduce the friction between the wafer and the electrostatic chuck, which correspondingly helps to further reduce the number of particles generated by friction, thereby further improving the problem of particles at the edge of the wafer.

[0024] In an optional scheme, the step of applying the adsorption voltage to the adsorption electrode in the electrostatic chuck also includes blowing cooling gas to the back of the wafer through the electrostatic chuck, and the pressure of the cooling gas is 5 to 10 Torr. By setting the pressure of the cooling gas within this range, on the one hand, it is beneficial to enhance the stability of the wafer on the electrostatic chuck, and correspondingly reduces the probability of the wafer position shifting in subsequent process steps, thereby improving the accuracy of the process; on the other hand, it is also beneficial to reduce the leakage of the cooling gas, thereby reducing the probability of particles generated by friction being blown to the edge of the wafer by the cooling gas, thereby further improving the problem of particles at the edge of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the process of an embodiment of a wafer adsorption method of the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of placing a wafer on an ejector pin in the present invention;

[0027] Figure 3 It is a schematic diagram of the structure of placing a wafer on the carrying surface of a chuck according to the present invention;

[0028] Figure 4 It is a temperature curve diagram of the step-by-step heating treatment of the wafer according to the present invention;

[0029] Figure 5It is a graph comparing the number of particles generated at the edge of a wafer by the wafer adsorption method applied to a chuck according to an embodiment of the present invention with the number of particles generated at the edge of a wafer by the wafer adsorption method applied to a chuck according to the prior art. DETAILED DESCRIPTION

[0030] Currently, there are still many problems with the wafer adsorption method applied to the chuck.

[0031] In the prior art, the chuck includes an adsorption component and a heating component, and the wafer adsorption method includes: adsorbing the wafer by the adsorption component in the chuck so that the wafer is adsorbed on the carrying surface of the chuck, and heating the wafer by the heating component of the chuck so that the wafer reaches the target temperature.

[0032] Taking the chuck as an electrostatic chuck as an example, the corresponding adsorption component is an adsorption electrode. Moreover, the step of heating the wafer also includes blowing cooling gas to the back of the wafer through the electrostatic chuck.

[0033] Research has found that when the wafer is adsorbed on the carrying surface of the chuck and the wafer is heated at the same time, the temperature of the wafer is directly heated from the initial temperature when it is introduced into the process chamber (for example, room temperature) to the target temperature. The temperature difference between the initial temperature of the wafer and the target temperature is usually large, and the wafer is easily deformed due to heat, thereby increasing the friction between the back of the wafer and the chuck, and then it is easy to produce more particles due to friction; in addition, the electrostatic chuck will also blow cooling gas to the back of the wafer during the heating process. Due to the airflow of the cooling gas, these particles are blown to the edge of the wafer, which makes it easy for these particles to gather at the edge of the wafer.

[0034] In order to solve the above technical problems, an embodiment of the present invention provides a wafer adsorption method applied to a chuck, and the wafer adsorption method includes the following basic steps:

[0035] Step S1: Under the condition that the adsorption component in the chuck does not adsorb the wafer, the wafer is subjected to a first preheating treatment by the heating component of the chuck, and the heating temperature of the first preheating treatment is gradually increased from a preset initial temperature to a first target temperature.

[0036] Step S2: After performing the first preheating treatment on the wafer, the first target temperature is maintained, and the wafer is adsorbed by the adsorption component so that the wafer is adsorbed on the carrying surface of the electrostatic chuck.

[0037] In the scheme disclosed in the embodiment of the present invention, by performing a first preheating treatment on the wafer, and the heating temperature of the first preheating treatment is gradually increased from a preset initial temperature to a first target temperature, it is beneficial to improve the temperature uniformity inside the wafer, and correspondingly help reduce the thermal stress inside the wafer, thereby reducing the probability of the wafer deforming. When the wafer is adsorbed by the adsorption component, since the probability of the wafer deforming is reduced at this time, the friction between the wafer and the chuck is reduced, and the number of particles generated by the friction is correspondingly reduced, thereby improving the problem of particles at the edge of the wafer.

[0038] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] Figure 1 It is a schematic diagram of the process of an embodiment of a wafer adsorption method of the present invention; Figure 2 It is a schematic diagram of the structure of placing a wafer on an ejector pin in the present invention; Figure 3 It is a schematic diagram of the structure of placing a wafer on the carrying surface of a chuck according to the present invention; Figure 4 It is a temperature curve diagram of the step-by-step heating treatment of the wafer according to the present invention; Figure 5 It is a graph comparing the number of particles generated at the edge of a wafer by the wafer adsorption method applied to a chuck according to an embodiment of the present invention with the number of particles generated at the edge of a wafer by the wafer adsorption method applied to a chuck according to the prior art.

[0040] refer to Figure 1 , and combined with Figure 2 and Figure 3 The chuck 101 includes an adsorption component 102 and a heating component (not shown).

[0041] Execute step S1, under the condition that the adsorption component 102 in the chuck 101 does not adsorb the wafer 100, perform a first preheating treatment on the wafer 100 through the heating component of the chuck 101, and the heating temperature of the first preheating treatment is gradually increased from a preset initial temperature to a first target temperature.

[0042] It should be noted that by performing a first preheating treatment on the wafer 100, and gradually increasing the heating temperature of the first preheating treatment from a preset initial temperature to a first target temperature, it is beneficial to improve the temperature uniformity inside the wafer 100, which is correspondingly beneficial to reducing the thermal stress inside the wafer 100, thereby reducing the probability of deformation of the wafer 100.

[0043] In this embodiment, the wafer 100 includes a substrate (not shown), and the material of the substrate is silicon. In other embodiments, the material of the substrate can also be other materials such as germanium, silicon germanium, silicon carbide, gallium arsenide or indium gallium, and the substrate can also be other types of substrates such as silicon on insulator substrates or germanium on insulator substrates. The material of the substrate can be a material suitable for process requirements or easy to integrate.

[0044] The chuck 101 is used to support and fix the wafer 100 .

[0045] Specifically, the chuck 101 utilizes the adsorption effect to adsorb the wafer 100 onto the carrying surface of the chuck 101 .

[0046] The adsorption component 102 is used to provide adsorption force for the chuck 101 so that the wafer 100 is fixed on the chuck 101 .

[0047] The heating component is used to heat the wafer 100 and also to control the temperature of the wafer 100 .

[0048] In this embodiment, the heating component of the chuck 101 is a heating electrode.

[0049] It should be noted that the heating component is not limited to the heating electrode. In other embodiments, the heating component may also be other components with heating function.

[0050] Specifically, the chuck 101 is an electrostatic chuck, and correspondingly, the adsorption component 102 of the electrostatic chuck is an adsorption electrode.

[0051] The chuck 101 can be divided into a unipolar chuck and a bipolar chuck according to the number of adsorption components 102. As an example, the chuck 101 is a unipolar chuck.

[0052] It should be noted that the chuck 101 of this embodiment is an electrostatic chuck. In other embodiments, the chuck may also be other types of chucks, as long as the chuck has the function of adsorbing and heating the wafer; accordingly, according to the specific type of the chuck, the adsorption component is not limited to the adsorption electrode.

[0053] In this embodiment, the chuck 101 is disposed in a process chamber.

[0054] In this embodiment, reference Figure 4 , Figure 4It is a temperature curve diagram of a wafer subjected to a step-by-step heating treatment in an embodiment of the present invention, wherein the horizontal axis represents the time of a first pre-heating treatment, and the vertical axis represents the temperature of the first pre-heating treatment. The first pre-heating treatment is a step-by-step heating treatment, and the step-by-step heating treatment includes alternating heating treatment and heat preservation treatment, and the heating temperature of the heat preservation treatment is increased for multiple times, and the heating treatment is used to increase the heating temperature to the heating temperature of the successively performed heat preservation treatment; wherein the starting temperature of the first heating treatment is the preset initial temperature A, and the heating temperature of the last heat preservation treatment is the first target temperature C.

[0055] It should be noted that since the step-type heating treatment is followed by a heat preservation treatment after each heating treatment, sufficient time can be provided for the heat to diffuse evenly inside the wafer 100 , thereby correspondingly reducing the temperature gradient inside the wafer 100 , thereby improving the temperature uniformity inside the wafer 100 .

[0056] refer to Figure 4 As an example, the number of heat preservation treatments is three times. Among them, line segment 1 represents the first temperature increase treatment, line segment 3 represents the second temperature increase treatment, line segment 5 represents the third temperature increase treatment, line segment 2 represents the first heat preservation treatment, line segment 4 represents the second heat preservation treatment, and line segment 6 represents the third heat preservation treatment.

[0057] In this embodiment, the temperature increase range of two adjacent insulation treatments should not be too large or too small. If the temperature increase range of two adjacent insulation treatments is too large, it is easy to cause the temperature gradient between different areas of the wafer 100 to be too large, which may easily cause the wafer 100 to deform; if the temperature increase range of two adjacent insulation treatments is too small, it is easy to increase the process time of step-by-step heating treatment of the wafer 100, thereby reducing production efficiency. Therefore, in this embodiment, the temperature increase range of two adjacent insulation treatments is 10 degrees Celsius to 15 degrees Celsius.

[0058] In other embodiments, the temperature increase range of two adjacent insulation treatments can be set according to actual process requirements.

[0059] It should be noted that the temperature increase range between two adjacent insulation treatments refers to the difference between the heating temperature of the previous insulation treatment and the heating temperature of the next insulation treatment.

[0060] In this embodiment, the heating rate of the heating treatment should not be too large or too small. If the heating rate of the heating treatment is too large, the temperature gradient inside the wafer 100 will be increased, which will easily lead to poor effect in improving the deformation problem of the wafer 100; if the heating rate of the heating treatment is too small, it will easily increase the process time of step-by-step heating treatment of the wafer 100, thereby reducing production efficiency. Therefore, in this embodiment, the heating rate of the heating treatment is 30 degrees Celsius per minute to 45 degrees Celsius per minute.

[0061] It should be noted that, in this embodiment, the number of heat preservation treatments is three times as an example, and the heating temperature of the third heat preservation treatment is the first target temperature C.

[0062] It should also be noted that, in other embodiments, the number of heat preservation treatments may be other numbers.

[0063] This embodiment is described by taking the first preheating treatment as a step-by-step heating treatment, and the step-by-step heating treatment includes alternating heating treatment and heat preservation treatment as an example. In other embodiments, the first preheating treatment may also include only a heating treatment, gradually heating from a preset initial temperature to a first target temperature. In other embodiments, the first preheating treatment may also include multiple heating treatments and a heat preservation treatment between two adjacent heating treatments.

[0064] In this embodiment, the chuck 101 is disposed in a process chamber so that the chamber temperature in the process chamber can also heat the wafer 100 on the chuck 101 , thereby improving the heating efficiency of the wafer 100 .

[0065] In this embodiment, in the step of performing a first preheating treatment on the wafer 100 by the heating component of the chuck 101 , the wafer 100 is placed on the carrying surface of the chuck 101 , thereby improving the heating efficiency of the wafer 100 .

[0066] Specifically, the chuck 101 is an electrostatic chuck, and the adsorption component 102 of the electrostatic chuck is an adsorption electrode. Therefore, under the condition that no adsorption voltage is applied to the adsorption electrode in the electrostatic chuck, the wafer is subjected to a first preheating treatment by the heating component of the electrostatic chuck.

[0067] Specifically, the heating component of the chuck 101 is a heating electrode, and thus the wafer 100 is subjected to a first preheating process by the heating electrode of the chuck 101 .

[0068] Continue to refer Figure 1In this embodiment, before the wafer 100 is subjected to the first preheating treatment by the heating component of the chuck 101, it also includes: executing step S0, under the condition that the wafer 100 is not in contact with the carrying surface of the chuck 101, the wafer 100 is subjected to a second preheating treatment by the chamber temperature in the process chamber, so that the wafer 100 reaches a second target temperature, wherein the second target temperature is less than or equal to the preset initial temperature A.

[0069] It should be noted that by performing a second preheating treatment on the wafer 100, the wafer 100 is heated from an initial temperature (for example, room temperature) when it is introduced into the process chamber to a second target temperature, which is beneficial to reducing the probability of cracks or damage to the wafer 100 due to rapid temperature changes.

[0070] refer to Figures 2 to 3 In this embodiment, the chuck 101 is provided with an ejector pin 103; in the step of performing a second preheating treatment on the wafer 100 by the chamber temperature in the process chamber, the ejector pin 103 protrudes from the bearing surface (such as Figure 2 As shown), and the wafer 100 is supported by the ejector pin 103.

[0071] The ejector pin 103 is used to receive the wafer 100 , so as to facilitate the wafer 100 to be sent out of the process chamber or to be transferred to the top of the chuck 101 by a transmission device such as a robot arm.

[0072] In this embodiment, the ejector pins 103 can also be used to create a gap between the wafer 100 and the carrying surface of the chuck 101 during the second preheating process on the wafer 100 .

[0073] It should be noted that, during the second preheating process, the wafer 100 is supported by the ejector pins 103 , thereby reducing the modification of the process chamber by the second preheating process.

[0074] Specifically, when the wafer 100 is introduced into the process chamber, Figure 2 As shown, the ejector pin 103 rises relative to the carrying surface and receives the wafer 100, and performs a second preheating treatment on the wafer 100. After the second preheating treatment, as shown in FIG. Figure 3 As shown, the ejector pin 103 falls relative to the supporting surface, placing the wafer 100 on the supporting surface of the chuck 101, which is conducive to accurately placing the wafer 100 in the area to be processed of the chuck 101, and in the subsequent process flow, further improving the position stability of the wafer 100 and the accuracy of the process.

[0075] It should be noted that the wafer 100 is subjected to a second preheating treatment to make the wafer 100 reach a second target temperature, and then the wafer 100 is set on the carrying surface of the chuck 101 and the wafer 100 is subjected to a first preheating treatment by the heating component of the chuck 101. Therefore, by reasonably controlling the second target temperature, it is beneficial to make the temperature difference between the second target temperature and the preset initial temperature A within a reasonable and safe range, further reducing the probability of deformation of the wafer 100 after being set on the chuck 101, and further reducing the friction between the wafer 100 and the chuck 101.

[0076] As an example, the difference between the second target temperature and the preset initial temperature A is 0 degrees Celsius to 10 degrees Celsius.

[0077] In other embodiments, the difference between the second target temperature and the preset initial temperature may be set according to actual process requirements.

[0078] In a specific embodiment, the second target temperature is 15 degrees Celsius to 20 degrees Celsius.

[0079] In the present embodiment, in the step of performing a second preheating treatment on the wafer 100 according to the chamber temperature in the process chamber, the heating time of the second preheating treatment is obtained in the following manner: acquiring the chamber temperature of the process chamber; and acquiring the heating time for the wafer 100 to reach the second target temperature based on the thermal conductivity coefficient between the air in the process chamber and the wafer 100, and the chamber temperature of the process chamber.

[0080] It should be noted that by obtaining the heating time for the wafer 100 to reach the second target temperature through the chamber temperature of the process chamber and the thermal conductivity coefficient between the air in the process chamber and the wafer 100, it is beneficial to accurately control the process of the second preheating treatment, thereby facilitating improving the efficiency of the second preheating treatment and correspondingly reducing energy waste.

[0081] In this embodiment, in the step of performing a second preheating treatment on the wafer 100 by adjusting the chamber temperature in the process chamber, the distance between the back of the wafer 100 and the carrying surface of the chuck 101 is 9 mm to 11 mm.

[0082] In other embodiments, the distance between the back of the wafer and the bearing surface of the chuck may also be other values.

[0083] As an example, the distance that the ejector pin protrudes from the chuck is usually preset, so the distance between the back of the wafer and the bearing surface of the chuck can be obtained according to the distance that the ejector pin protrudes from the chuck.

[0084] It should be noted that, in other embodiments, the step of performing the second preheating treatment on the wafer by adjusting the chamber temperature in the process chamber may not be performed.

[0085] It should also be noted that, in other embodiments, the wafer may be subjected to the first preheating treatment by the heating component of the chuck under the condition that the wafer is not in contact with the carrying surface of the chuck.

[0086] Continue to refer Figure 1 , execute step S2, after performing the first preheating treatment on the wafer 100, maintain the first target temperature C, and adsorb the wafer 100 through the adsorption component 102 so that the wafer 100 is adsorbed on the carrying surface of the chuck 101.

[0087] It should be noted that, after the wafer 100 is subjected to the first preheating treatment, the first target temperature C is maintained, and the probability of deformation of the wafer 100 is reduced. Therefore, when the wafer 100 is adsorbed by the adsorption component 102, the friction between the wafer 100 and the chuck 101 is reduced, and the number of particles generated by the friction is correspondingly reduced, thereby improving the problem of particles at the edge of the wafer 100.

[0088] Specifically, the chuck 101 is an electrostatic chuck, and the adsorption component 102 of the electrostatic chuck is an adsorption electrode. Therefore, after the wafer 100 is subjected to the first preheating treatment, the first target temperature C is maintained, and an adsorption voltage is applied to the adsorption electrode in the electrostatic chuck so that the wafer 100 is adsorbed on the carrying surface of the electrostatic chuck.

[0089] In this embodiment, in the step of applying an adsorption voltage to the adsorption electrode in the electrostatic chuck, the adsorption voltage is 1000 volts to 2000 volts.

[0090] It should be noted that by setting the adsorption voltage within this range, on the one hand, it is beneficial for the electrostatic chuck to have sufficient adsorption force on the wafer 100 to keep the wafer 100 stably adsorbed on the carrying surface of the electrostatic chuck; on the other hand, the adsorption voltage will not be too large, and thus it is also beneficial to reduce the friction between the wafer 100 and the carrying surface of the electrostatic chuck, and correspondingly reduce the particles generated by friction, thereby improving the problem of particles on the edge of the wafer 100.

[0091] In this embodiment, the step of applying the adsorption voltage to the adsorption electrode in the electrostatic chuck further includes blowing cooling gas to the back of the wafer through the electrostatic chuck.

[0092] Blowing cooling gas to the back of the wafer through the electrostatic chuck is beneficial for transferring the heat of the wafer 100 to the electrostatic chuck during the processing of the wafer 100, thereby reducing the temperature of the wafer 100. At the same time, the temperature of the wafer 100 can be evenly distributed, thereby more effectively controlling the temperature of the wafer 100.

[0093] In this embodiment, the cooling gas includes helium.

[0094] It should be noted that since helium has a high thermal conductivity, the heat of the wafer 100 can be conducted out through the helium flowing through the wafer 100, thereby making the temperature distribution inside the wafer 100 uniform, thereby correspondingly reducing the probability of deformation of the wafer 100. When the adsorption voltage is applied to the adsorption component 102 in the electrostatic chuck, the friction between the wafer 100 and the electrostatic chuck is further reduced.

[0095] In other embodiments, other gases with better heat conduction efficiency may be blown to the back of the wafer through the electrostatic chuck.

[0096] In this embodiment, the pressure of the cooling gas is 5 Torr to 10 Torr.

[0097] It should be noted that by setting the pressure of the cooling gas within this range, on the one hand, it is beneficial to enhance the stability of the wafer 100 on the electrostatic chuck, and correspondingly reduces the probability of the wafer 100 shifting in position in subsequent process steps, thereby improving the accuracy of the process; on the other hand, it is also beneficial to reduce the leakage of the cooling gas, thereby reducing the probability of particles generated by friction being blown to the edge of the wafer 100 by the cooling gas, thereby improving the problem of particles at the edge of the wafer 100.

[0098] In one embodiment, the adsorption voltage is 1000 volts to 2000 volts, so the pressure of the cooling gas is set to 5 Torr to 10 Torr, so that the adsorption voltage and the pressure of the cooling gas are adapted to each other, while reducing the friction between the wafer 100 and the bearing surface of the electrostatic chuck, and enhancing the stability of the wafer 100 on the electrostatic chuck.

[0099] Combined with reference Figure 5 , Figure 5: is a curve chart of the number of particles generated at the edge of the wafer by the wafer adsorption method applied to the chuck according to the embodiment of the present invention, and a comparison chart of the curve chart of the number of particles generated at the edge of the wafer by the wafer adsorption method applied to the chuck according to the prior art. The horizontal axis is the wafer sample, and the vertical axis is the number of particles generated at the edge of the wafer. The horizontal axis represents the wafer sample, and the curve L1 represents the number of particles corresponding to each wafer sample. The straight line L2 parallel to the horizontal axis represents the standard value of the number of particles. The curve in the solid line box in the figure represents the curve chart of the number of particles generated at the edge of the wafer by the wafer adsorption method applied to the chuck according to the embodiment of the present invention, and the curve in the dotted line box in the figure represents the curve chart of the number of particles generated at the edge of the wafer by the wafer adsorption method applied to the chuck according to the prior art. From Figure 5 It can be seen that compared with the number of particles in the dotted box, the number of particles in the solid box is less, that is, the number of particles generated at the edge of the wafer by the wafer adsorption method applied to the chuck in the embodiment of the present invention is less than the number of particles generated at the edge of the wafer by the wafer adsorption method applied to the chuck in the prior art, and the number of particles in the solid box is less than the standard value.

[0100] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A wafer adsorption method applied to a chuck, characterized in that: The wafer adsorption method comprises: Under the condition that the adsorption component in the chuck does not adsorb the wafer, the wafer is subjected to a first preheating treatment by the heating component of the chuck, wherein the heating temperature of the first preheating treatment is gradually increased from a preset initial temperature to a first target temperature; After the wafer is subjected to the first preheating treatment, the first target temperature is maintained, and the wafer is adsorbed by the adsorption component so that the wafer is adsorbed on the carrying surface of the chuck.

2. The wafer adsorption method according to claim 1, characterized in that: The first pre-heating treatment is a step-type heating treatment, which includes alternating heating treatment and heat preservation treatment, wherein the heating temperature of the heat preservation treatment is increased for multiple times, and the heating treatment is used to increase the heating temperature to the heating temperature of the successively performed heat preservation treatment; wherein the starting temperature of the first heating treatment is the preset initial temperature, and the heating temperature of the last heat preservation treatment is the first target temperature.

3. The wafer adsorption method according to claim 2, characterized in that: The temperature increase range between two adjacent insulation treatments is 10 degrees Celsius to 15 degrees Celsius.

4. The wafer adsorption method according to claim 2, characterized in that: The heating rate of the heating treatment is 30 degrees Celsius per minute to 45 degrees Celsius per minute.

5. The wafer adsorption method according to claim 1, characterized in that: The chuck is arranged in the process chamber; In the step of performing a first preheating treatment on the wafer by the heating component of the chuck, the wafer is placed on the carrying surface of the chuck; Before the wafer is subjected to the first preheating treatment by the heating component of the chuck, the method also includes: under the condition that the wafer is not in contact with the carrying surface of the chuck, the wafer is subjected to a second preheating treatment by the chamber temperature in the process chamber, so that the wafer reaches a second target temperature, wherein the second target temperature is less than or equal to the preset initial temperature.

6. The wafer adsorption method according to claim 5, characterized in that: An ejector pin is arranged in the chuck; In the step of performing a second preheating process on the wafer by using the chamber temperature in the process chamber, the ejector pins are made to protrude from the bearing surface of the chuck, and the wafer is supported by the ejector pins.

7. The wafer adsorption method according to claim 5, characterized in that: In the step of performing a second preheating process on the wafer by adjusting the chamber temperature in the process chamber, the difference between the second target temperature and the preset initial temperature is 0 degrees Celsius to 10 degrees Celsius.

8. The wafer adsorption method according to claim 5, characterized in that: In the step of performing a second preheating treatment on the wafer by using the chamber temperature in the process chamber, the heating time of the second preheating treatment is obtained by: acquiring the chamber temperature of the process chamber; and acquiring the heating time for the wafer to reach the second target temperature based on the thermal conductivity coefficient between the air in the process chamber and the wafer, and the chamber temperature of the process chamber.

9. The wafer adsorption method according to claim 6, characterized in that: In the step of performing a second preheating treatment on the wafer by using the chamber temperature in the process chamber, the distance between the back of the wafer and the carrying surface of the chuck is 9 mm to 11 mm.

10. The wafer adsorption method according to claim 1, characterized in that: The heating component of the chuck is a heating electrode; The wafer is subjected to a first preheating process by means of a heating electrode of the chuck.

11. The wafer adsorption method according to any one of claims 1 to 10, characterized in that: The chuck is an electrostatic chuck, and the adsorption component of the electrostatic chuck is an adsorption electrode; Under the condition that no adsorption voltage is applied to the adsorption electrode in the electrostatic chuck, performing a first preheating process on the wafer by a heating component of the electrostatic chuck; After the wafer is subjected to the first preheating treatment, the first target temperature is maintained, and an adsorption voltage is applied to an adsorption electrode in the electrostatic chuck so that the wafer is adsorbed on a carrying surface of the electrostatic chuck.

12. The wafer adsorption method according to claim 11, characterized in that: In the step of applying an adsorption voltage to the adsorption electrode in the electrostatic chuck, the adsorption voltage is 1000 volts to 2000 volts.

13. The wafer adsorption method according to claim 12, characterized in that: The step of applying the adsorption voltage to the adsorption electrode in the electrostatic chuck further includes blowing cooling gas to the back of the wafer through the electrostatic chuck; In the step of blowing cooling gas to the back of the wafer through the electrostatic chuck, the pressure of the cooling gas is 5 Torr to 10 Torr.

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