Process chamber cleanliness testing method and process chamber

Abstract

Provided in the present application are a process chamber cleanliness testing method and a process chamber. The process chamber comprises a cavity and at least one crystal oscillator, the crystal oscillator being fixedly arranged on the cavity, and the crystal oscillator having a deposit-measuring surface facing the interior of the cavity. The process chamber cleanliness testing method comprises: measuring the current inherent frequency of the crystal oscillator; according to the current inherent frequency of the crystal oscillator, determining the thickness of a deposited film layer on a corresponding inner wall of the cavity; and when the thickness of the deposited film layer is greater than a first preset thickness threshold value, determining that the process chamber needs to be cleaned. In the present application, the thickness of the deposited film layer is determined by means of the crystal oscillator arranged in the process chamber, allowing for real-time, accurate monitoring of the interior state of the process chamber; thus, the method of introducing a testing wafer and carrying out a specific testing process is not needed to confirm the interior state of the chamber, thereby improving the efficiency of process chamber maintenance, ensuring semiconductor process effects, and increasing wafer product yield rate.

Description

Cleanliness detection method of process chamber and process chamber Technical Field

[0001] The present application relates to the field of process chambers, and in particular, to a method for detecting the cleanliness of a process chamber and a process chamber. Background Art

[0002] Semiconductor processing equipment is widely used in the manufacturing of integrated circuits (ICs) and MEMS devices. Plasma contains a large number of active particles, including electrons, ions, excited atoms, molecules, free radicals, and neutral groups. These particles, under the influence of a bias voltage, reach the wafer surface and interact with it, causing various physical and chemical reactions on the material surface, generating a large number of particles. While most of these particles are removed after the process is complete, a small number may still adhere to the inner walls of the process chamber, accumulate, and then fall off or decompose onto the wafer surface during the process, causing wafer etching defects.

[0003] In related processes, to prevent particles attached to the inner wall of the process chamber from causing etching defects on the wafer surface, after the semiconductor process of N wafers is carried out in the process chamber (each wafer is a process cycle), the test wafer is usually introduced for a specific inspection process. After the inspection process is completed, a particle detector is used to detect whether the change in the number of particles larger than 60nm on the surface of the wafer before and after entering the chamber is less than 50, to determine whether the chamber cleanliness meets the process requirements. If it does not meet the requirements, the chamber is subjected to a specific waferless automatic clean (WAC) process until the chamber cleanliness test results meet the process requirements, and then the semiconductor process such as etching is restarted.

[0004] However, the existing process chamber particle detection and cleaning solution requires the use of external equipment at the beginning of each process, and the detection process is time-consuming. At the same time, the cleanliness of the inner wall of the process chamber depends on the accuracy of the wafer-free automatic cleaning process. After cleaning, the accumulation of polymers on the inner wall of the chamber cannot be clearly determined. It can only alleviate the particle problem, but cannot ensure that the process chamber is fully cleaned. As a result, particles on the inner wall of the process chamber still fall onto the wafer surface during the process, causing wafer etching defects and reducing product yield.

[0005] Therefore, how to provide a cleanliness detection method for a process chamber that can ensure the cleanliness of the inner wall of the process chamber has become a technical problem that needs to be solved urgently in this field.

[0006] Summary of the Invention

[0007] The present application aims to provide a method for detecting the cleanliness of a process chamber and a process chamber, wherein the method for detecting the cleanliness of the process chamber can ensure the cleanliness of the inner wall of the process chamber.

[0008] To achieve the above-mentioned objective, as one aspect of the present application, a method for detecting the cleanliness of a process chamber is provided. The process chamber includes a cavity and at least one crystal oscillator. The crystal oscillator is fixedly disposed on the cavity and has a deposition detection surface facing the interior of the cavity. The method for detecting the cleanliness of the process chamber includes:

[0009] Detecting the current natural frequency of the crystal oscillator;

[0010] Determining the thickness of the deposited film layer on the inner wall of the corresponding cavity according to the current natural frequency of the crystal oscillator;

[0011] When the thickness of the deposited film layer is greater than a first preset thickness threshold, it is determined that the process chamber needs to be cleaned.

[0012] In some embodiments, it further includes:

[0013] After cleaning the process chamber, detecting the current natural frequency of the crystal oscillator;

[0014] Determining the thickness of the deposited film layer on the inner wall of the corresponding cavity according to the current natural frequency of the crystal oscillator;

[0015] When the thickness of the deposited film layer is greater than a second preset thickness threshold, the process chamber is cleaned again. When the thickness of the deposited film layer is less than or equal to the second preset thickness threshold, the cleaning of the process chamber is terminated.

[0016] As a second aspect of the present application, a process chamber is provided, which includes a cavity and at least one crystal oscillator. The crystal oscillator is fixedly arranged on the cavity and has a deposition detection surface facing the inside of the cavity. The current natural frequency of the crystal oscillator is used to characterize the cleanliness of the process chamber.

[0017] In some embodiments, the cavity includes a cavity body and an upper cover, the upper cover is used to close the top opening of the cavity body, a first mounting groove is formed on the top surface of the upper cover, and a first mounting hole is formed at the bottom of the first mounting groove that penetrates to the bottom surface of the upper cover. The process chamber also includes a plurality of connecting wires, the crystal oscillator is provided in the first mounting hole, and the plurality of connecting wires are connected to the electrodes of the crystal oscillator through the first mounting groove.

[0018] In some embodiments, the process chamber further includes a sleeve, which is disposed in the first mounting groove, the bottom of the sleeve is sealedly connected to the bottom of the first mounting groove, and a first connecting hole extending along the axial direction of the sleeve is formed in the sleeve, and the plurality of connecting wires pass through the first connecting hole and are connected to the electrodes of the crystal oscillator.

[0019] In some embodiments, a second mounting groove is formed on the outer wall of the cavity, and a second mounting hole is formed at the bottom of the second mounting groove that penetrates the inner wall of the cavity. The process chamber also includes a plurality of connecting wires, and the crystal oscillator is arranged in the second mounting hole. The plurality of connecting wires are connected to the electrodes of the crystal oscillator through the second mounting groove.

[0020] In some embodiments, the process chamber also includes an airtight valve plate, which is arranged in the second mounting groove. The airtight valve plate is sealed and connected to the second mounting groove. A second connecting hole is formed in the airtight valve plate, and the plurality of connecting wires are connected to the electrodes of the crystal oscillator through the second connecting hole.

[0021] In some embodiments, the process chamber further comprises a mounting valve plate and a wiring connector, wherein the mounting valve plate is fixedly disposed on the outer wall of the chamber and has a position corresponding to the crystal oscillator. The mounting valve plate is formed with a plurality of avoidance through-holes penetrating the mounting valve plate along a thickness direction of the mounting valve plate, and the plurality of connection wires corresponding to each crystal oscillator are passed through the plurality of avoidance through-holes on the corresponding mounting valve plate in a one-to-one correspondence;

[0022] The wiring connector seals the plurality of avoidance through holes in a one-to-one correspondence and securely connects the connection wires to the mounting valve plate.

[0023] In some embodiments, a protective film is provided on the deposition detection surface of the crystal oscillator, and the material of the protective film includes yttrium oxide.

[0024] In some embodiments, the process chamber further includes a controller, which is electrically connected to the crystal oscillator. The controller is used to detect a current natural frequency of the crystal oscillator and determine whether the process chamber needs to be cleaned based on the current natural frequency.

[0025] In some embodiments, the controller is further configured to detect a current natural frequency of the crystal oscillator after cleaning the process chamber, and determine whether to end cleaning the process chamber based on the current natural frequency.

[0026] In the cleanliness detection method and process chamber of the process chamber provided in the present application, the crystal oscillator has a deposition detection surface facing the inside of the cavity, so that when the inner wall of the cavity is deposited with particles or polymers to form a thin film in the semiconductor process, the thin film will also be deposited on the deposition detection surface of the crystal oscillator, thereby changing the overall thickness of the crystal oscillator, and then changing the natural frequency of the crystal oscillator. The natural frequency of the crystal oscillator changes linearly with its thickness, and then the thickness of the deposited film layer on the corresponding inner wall of the cavity can be determined according to the current natural frequency of the crystal oscillator. When the thickness of the deposited film layer is greater than the first preset thickness threshold, it is promptly determined that the process chamber needs to be cleaned.

[0027] The present application determines the thickness of the deposited film layer by setting up a crystal oscillator in the process chamber, and can accurately monitor the internal conditions of the process chamber in real time. There is no need to confirm the internal conditions of the chamber by passing in a test wafer and performing a specific test process, which improves the efficiency of maintaining the process chamber, ensures the semiconductor process effect, and improves the wafer product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the following detailed description, they are used to explain the present application but do not constitute a limitation of the present application. In the accompanying drawings:

[0029] FIG1 is a schematic structural diagram of a process chamber provided in an embodiment of the present application;

[0030] FIG2 is a partial enlarged schematic diagram of the process chamber in area A in FIG1 ;

[0031] FIG3 is a partial enlarged schematic diagram of the process chamber in area B in FIG1 ;

[0032] FIG4 is a schematic diagram of a partial structure of a process chamber provided in an embodiment of the present application;

[0033] FIG5 is a schematic structural diagram of a process chamber provided by an embodiment of the present application;

[0034] FIG6 is a schematic structural diagram of a process chamber provided in another embodiment of the present application;

[0035] FIG7 is a schematic flow chart of a method for detecting the cleanliness of a process chamber provided in one embodiment of the present application;

[0036] FIG8 is a schematic flow chart of a method for detecting the cleanliness of a process chamber according to another embodiment of the present application;

[0037] FIG9 is a schematic flow chart of a method for detecting the cleanliness of a process chamber according to another embodiment of the present application;

[0038] FIG10 is a curve showing the variation of the natural frequency of a crystal oscillator component with its thickness.

[0039] Explanation of reference numerals: 100: cavity 110: cavity body 120: upper cover 210: crystal oscillator 220: connecting wire 310: mounting valve plate 311: fixing through hole 320: wiring connector 410: sleeve 420: airtight gasket 430: airtight valve plate 10: wafer 1: industrial computer 2: control module DETAILED DESCRIPTION

[0040] The following describes the specific embodiments of the present application in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application.

[0041] To solve the above technical problems, as one aspect of the present application, a method for detecting the cleanliness of a process chamber is provided. The method for detecting the cleanliness of a process chamber is used for a process chamber, as shown in FIG1 . The process chamber is used to accommodate wafers 10 and perform semiconductor processing on the wafers 10 introduced therein. The process chamber includes a chamber 100 and at least one crystal oscillator 210. The crystal oscillator 210 is fixedly disposed on the chamber 100 and has a deposition detection surface facing the interior of the chamber 100. As shown in FIG7 , the method for detecting the cleanliness of the process chamber includes:

[0042] Step S1, detecting the current natural frequency of the crystal oscillator 210;

[0043] Step S2: determining the thickness of the deposited film layer on the inner wall of the corresponding cavity 100 according to the current natural frequency of the crystal oscillator 210;

[0044] Step S3: When the thickness of the deposited film layer is greater than a first preset thickness threshold, it is determined that the process chamber needs to be cleaned.

[0045] The natural frequency of the piezoelectric effect of the crystal oscillator 210 depends on its geometric dimensions, cutting type and thickness, and is calculated as follows: f·d=v / 2;

[0046] Wherein, f is the natural frequency of the crystal oscillator 210 , d is the thickness of the crystal oscillator 210 , and v is the shear velocity of the crystal oscillator 210 .

[0047] When the particle accumulation thickness on the deposition detection surface of the crystal oscillator 210 changes by Δd, a mass loading effect will occur, causing the natural frequency of the crystal oscillator 210 to change by Δf, which is calculated as follows:

[0048] That is, there is a linear relationship between the change in the particle aggregation thickness (Δd) on the deposition detection surface of the crystal oscillator 210 and the change in the natural frequency of the crystal oscillator (Δf). As the degree of particle aggregation on the inner wall of the chamber increases, the polymer thickness on the deposition detection surface of the crystal oscillator 210 increases, and the natural frequency of the crystal oscillator 210 decreases monotonically and linearly (when the natural frequency range of the crystal oscillator 210 is theoretically selected to be 5MHz to 10MHz, the maximum allowable decrease in the fundamental frequency is 2% to 3%, and the thickness variation range of the crystal oscillator 210 is 0.1nm to 10μm). Figure 10 shows a curve of the natural frequency of the crystal oscillator 210 changing with its thickness.

[0049] In the embodiment of the present application, the crystal oscillator 210 has a deposition detection surface facing the interior of the cavity 100. Therefore, when particles or polymers are deposited on the inner wall of the cavity 100 to form a thin film during the semiconductor process, the thin film will also be deposited on the deposition detection surface of the crystal oscillator 210, thereby changing the overall thickness of the crystal oscillator 210 and further changing the natural frequency of the crystal oscillator 210. From the above analysis, it can be seen that the natural frequency of the crystal oscillator 210 changes linearly with its thickness.

[0050] Therefore, the cleanliness detection method of the process chamber provided in the present application can be based on the pre-stored parameters of the linear relationship between the natural frequency of the crystal oscillator 210 and the film thickness, and determine the thickness of the deposited film layer on the inner wall of the corresponding cavity 100 according to the current natural frequency of the crystal oscillator 210, and then when the thickness of the deposited film layer is greater than the first preset thickness threshold, it is determined in time that the process chamber needs to be cleaned.

[0051] In some embodiments, when the thickness of the deposited film layer is less than or equal to a first preset thickness threshold, there is no need to clean the process chamber, and semiconductor processing can continue to be performed on the wafer.

[0052] The cleanliness detection method of the process chamber provided in the present application determines the thickness of the deposited film layer by means of a crystal oscillator 210 arranged in the process chamber, and can accurately monitor the internal conditions of the process chamber in real time. There is no need to confirm the internal conditions of the chamber by introducing a test wafer and performing a specific test process, thereby improving the efficiency of maintaining the process chamber, ensuring the semiconductor process effect, and improving the wafer product yield.

[0053] As an optional embodiment of the present application, as shown in FIG8 , the cleanliness detection method of the process chamber further includes:

[0054] Step S4: When it is determined that the process chamber needs to be cleaned, the process chamber is cleaned.

[0055] In order to ensure the cleaning effect of the cavity 100, as a preferred embodiment of the present application, as shown in FIG9 , it further includes:

[0056] Step S41: After cleaning the process chamber (i.e., after completing step S4), detecting the current natural frequency of the crystal oscillator 210;

[0057] Step S42: determining the thickness of the deposited film layer on the inner wall of the corresponding cavity 100 according to the current natural frequency of the crystal oscillator 210;

[0058] Step S43: When the thickness of the deposited film layer is greater than the second preset thickness threshold, the process chamber is cleaned again (ie, go to step S4); when the thickness of the deposited film layer is less than or equal to the second preset thickness threshold, the cleaning of the process chamber is terminated.

[0059] In an embodiment of the present application, after the interior of the cavity 100 is cleaned, the thickness of the deposited film layer on the inner wall of the cavity 100 is determined again, and by comparing the thickness of the deposited film layer with a second preset thickness threshold, it is determined whether the chamber cleaning effect meets the requirements, thereby ensuring the cleaning effect of the cavity 100 and further ensuring the semiconductor process effect.

[0060] As an optional embodiment of the present application, the cleanliness detection method of the process chamber further includes:

[0061] The semiconductor process is performed in a cycle, and steps S1 to S3 are performed before each semiconductor process to ensure that the process chamber meets the cleanliness requirement before the semiconductor process is performed.

[0062] As a second aspect of the present application, a process chamber is provided, which includes a cavity 100 and at least one crystal oscillator 210. The crystal oscillator 210 is fixedly arranged on the cavity 100 and has a deposition detection surface facing the interior of the cavity 100. The current natural frequency of the crystal oscillator 210 is used to characterize the cleanliness of the process chamber.

[0063] In an embodiment of the present application, the crystal oscillator 210 has a deposition detection surface facing the interior of the cavity 100, and the current natural frequency of the crystal oscillator 210 is used to characterize the cleanliness of the process chamber. Therefore, when particles or polymers are deposited on the inner wall of the cavity 100 to form a thin film during a semiconductor process, the thin film will also be deposited on the deposition detection surface of the crystal oscillator 210, thereby changing the overall thickness of the crystal oscillator 210, and then changing the natural frequency of the crystal oscillator 210. Based on the pre-stored parameters regarding the linear relationship between the natural frequency of the crystal oscillator 210 and the film thickness, the thickness of the deposited film layer on the corresponding inner wall of the cavity 100 can be determined according to the current natural frequency of the crystal oscillator 210, and when the thickness of the deposited film layer is greater than the first preset thickness threshold, it is promptly determined that the process chamber needs to be cleaned.

[0064] The process chamber provided in the present application determines the thickness of the deposited film layer by means of a crystal oscillator 210 arranged in the process chamber, and can accurately monitor the internal conditions of the process chamber in real time. There is no need to confirm the internal conditions of the chamber by introducing a test wafer and performing a specific test process, thereby improving the efficiency of maintaining the process chamber, ensuring the semiconductor process effect, and improving the wafer product yield.

[0065] As an optional embodiment of the present application, as shown in FIG1 , the cavity 100 includes a cavity body 110 and an upper cover 120 , and the upper cover 120 is used to close the top opening of the cavity body 110 .

[0066] As an optional embodiment of the present application, the process chamber also includes a controller, which is electrically connected to the crystal oscillator 210 (via a connecting line 220). The controller is used to detect the current natural frequency of the crystal oscillator 210 and determine whether the process chamber needs to be cleaned based on the current natural frequency, thereby realizing the cleanliness detection method of the process chamber provided in the embodiment of the present application.

[0067] As an optional embodiment of the present application, the controller is further configured to detect the current natural frequency of the crystal oscillator after cleaning the process chamber, and determine whether to terminate the cleaning of the process chamber based on the current natural frequency, so as to ensure the cleaning effect of the cavity 100 and further ensure the effect of the semiconductor process. For example, the thickness of the deposited film layer on the inner wall of the corresponding cavity 100 is determined based on the current natural frequency of the crystal oscillator 210. When the thickness of the deposited film layer is greater than a second preset thickness threshold, the process chamber is cleaned again (i.e., proceeding to step S4). When the thickness of the deposited film layer is less than or equal to the second preset thickness threshold, the cleaning of the process chamber is terminated.

[0068] As an optional embodiment of the present application, as shown in Figures 5 and 6, the controller may include an industrial computer 1 and a control module 2. The control module 2 has an internal oscillation circuit for collecting the current natural frequency of the crystal oscillator 210, calculating the thickness of the film layer on the surface of the crystal oscillator 210, and transmitting the data to the industrial computer 1. The industrial computer 1 is used to compare the data and determine the next process step (for example, whether to perform a semiconductor process or clean the process chamber).

[0069] As an optional embodiment of the present application, as shown in Figure 2, a first mounting groove is formed on the top surface of the upper cover 120, and a first mounting hole is formed at the bottom of the first mounting groove, which penetrates into the bottom surface of the upper cover 120. The process chamber also includes a plurality of connecting wires 220, and a crystal oscillator 210 is arranged in the first mounting hole. The plurality of connecting wires 220 are connected to the electrodes of the crystal oscillator 210 through the first mounting groove.

[0070] In order to ensure the airtightness of the cavity 100, as a preferred embodiment of the present application, as shown in Figure 2, the process chamber also includes a sleeve 410, which is arranged in the first mounting groove, and the bottom of the sleeve 410 is sealed and connected to the bottom of the first mounting groove. A first connecting hole extending along the axial direction of the sleeve 410 is formed in the sleeve 410, and a plurality of connecting wires 220 pass through the first connecting hole to be connected to the electrodes of the crystal oscillator 210.

[0071] In an embodiment of the present application, a sleeve 410 is provided in the first mounting groove. The sleeve 410 can be sealed and connected to the bottom of the first mounting groove while protecting the connecting wire 220, thereby preventing the internal environment of the cavity 100 from communicating with the outside through the gap between the crystal oscillator 210 and the first mounting hole, thereby ensuring the airtightness of the cavity 100.

[0072] As a preferred embodiment of the present application, as shown in Figure 2, the deposition detection surface of the crystal oscillator 210 is flush with the bottom surface of the upper cover 120 to ensure the consistency between the thickness of the film layer deposited on the deposition detection surface and the thickness of the film layer deposited on the inner wall of the cavity 100.

[0073] To further ensure the airtightness of the cavity 100, as a preferred embodiment of the present application, the sleeve 410 includes a main body and a positioning portion sequentially connected along the axial direction of the sleeve 410. The main body is disposed in the first mounting groove, and the cross-sectional shape of the main body corresponds to the cross-sectional shape of the first mounting groove. The cross-sectional shape of the positioning portion corresponds to the cross-sectional shape of the first mounting hole, and the bottom end of the positioning portion is inserted into the first mounting hole.

[0074] The process chamber further includes an airtight gasket 420 , which is sleeved on the positioning portion to seal the bottom of the sleeve 410 with the bottom of the first mounting groove.

[0075] In the embodiment of the present application, the sleeve 410 adopts a stepped design, and the step is sealed and connected to the bottom of the first mounting groove through an airtight gasket 420, further ensuring the airtightness of the cavity 100.

[0076] As an optional embodiment of the present application, the sleeve 410 is made of ceramic.

[0077] As an optional embodiment of the present application, as shown in Figure 3, a second mounting groove is formed on the outer wall of the cavity 100, and a second mounting hole is formed at the bottom of the second mounting groove that penetrates to the inner wall of the cavity 100. The process chamber also includes a connecting wire 220, and a crystal oscillator 210 is arranged in the second mounting hole. A plurality of connecting wires 220 are connected to the electrodes of the crystal oscillator 210 through the second mounting groove.

[0078] To ensure the airtightness of the chamber 100, as a preferred embodiment of the present application, as shown in FIG3 , the process chamber further includes an airtight valve plate 430. The airtight valve plate 430 is disposed in the second mounting groove and is sealed therewith. The airtight valve plate 430 has a second connection hole formed therein, through which a plurality of connection wires 220 are connected to the electrodes of the crystal oscillator 210. Each electrode of the crystal oscillator 210 is connected to the controller via a connection wire 220.

[0079] As a preferred embodiment of the present application, as shown in FIG3 , the deposition detection surface of the crystal oscillator 210 is flush with the inner wall of the cavity 100 to ensure consistency between the thickness of the film deposited on the deposition detection surface and the thickness of the film deposited on the inner wall of the cavity 100 .

[0080] As a preferred embodiment of the present application, as shown in Figures 2 to 4, the process chamber also includes a mounting valve plate 310 and a wiring connector 320. The mounting valve plate 310 is fixedly arranged on the outer wall of the cavity 100, and its position corresponds one-to-one to the crystal oscillator 210. A plurality of avoidance holes are formed in the mounting valve plate 310 and pass through the mounting valve plate 310 along the thickness direction of the mounting valve plate 310. The plurality of connecting wires 220 corresponding to each crystal oscillator 210 pass through the corresponding plurality of avoidance holes on the mounting valve plate 310 one-to-one; the wiring connector 320 seals the plurality of avoidance holes one-to-one and fixedly connects the connecting wires 220 to the mounting valve plate 310.

[0081] Specifically, as shown in Figure 2, a first mounting groove is formed on the top surface of the upper cover 120. When the sleeve 410 is arranged in the first mounting groove, the mounting valve plate 310 corresponding to the sleeve 410 is fixedly arranged on the top surface of the upper cover 120 and seals the opening of the first mounting groove on the top surface of the upper cover 120.

[0082] As shown in Figure 3, a second mounting groove is formed on the outer wall of the cavity 100. When the airtight valve plate 430 is arranged in the second mounting groove, the mounting valve plate 310 corresponding to the airtight valve plate 430 is fixedly set on the outer wall of the cavity 100 and seals the opening of the second mounting groove on the outer wall of the cavity 100.

[0083] In the embodiment of the present application, a mounting valve plate 310 is further mounted on the outside of the sleeve 410 and / or the airtight valve plate 430. The mounting valve plate 310 can be fixedly connected to the surface of the chamber 100 from the outside and seal the opening of the first mounting groove or the second mounting groove, further ensuring the airtightness of the chamber 100. In addition, the wiring connector 320 fixedly connects the connecting wire 220 to the mounting valve plate 310, so that the portion of the connecting wire 220 located between the crystal oscillator 210 and the mounting valve plate 310 can be fixed by the mounting valve plate 310, preventing vibration and torsion of the connecting wire 220 in this area from causing displacement of the crystal oscillator 210, thereby ensuring the stability of the position of the crystal oscillator 210 and, in turn, the stability of the monitoring results inside the chamber.

[0084] As an optional embodiment of the present application, as shown in Figure 4, a plurality of fixing through holes 311 are formed on the mounting valve plate 310 and pass through the mounting valve plate 310 along the thickness direction of the mounting valve plate 310, and a plurality of fixing holes are formed on the outer wall of the cavity 100. The mounting valve plate 310 is fixedly connected to the cavity 100 by fasteners that pass through the fixing through holes 311 and the corresponding fixing holes in sequence.

[0085] As an optional embodiment of the present application, the wiring connector 320 is welded to the connecting line 220 and the mounting valve plate 310 .

[0086] As an optional embodiment of the present application, a protective film is provided on the deposition detection surface of the crystal oscillator 210 , and the material of the protective film includes yttrium oxide.

[0087] As an optional embodiment of the present application, high-purity thin films can be prepared by vacuum electron beam evaporation. Specifically, yttrium oxide (white powder at room temperature) can be bombarded with a high-energy electron beam in a high vacuum environment to make it reach a molten state. When the saturated vapor pressure is reached, the material evaporates and fills the chamber in a gaseous state. The crystal oscillator element is placed above the inside of the chamber. At this time, the gaseous yttrium oxide particles condense into a film on the surface of the crystal oscillator element, gradually forming an yttrium oxide film of a certain thickness.

[0088] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present application, and the present application is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present application, and such modifications and improvements are also considered to be within the scope of protection of the present application.

Claims

1. A method for detecting the cleanliness of a process chamber, characterized in that: The process chamber comprises a cavity and at least one crystal oscillator, wherein the crystal oscillator is fixedly arranged on the cavity and has a deposition detection surface facing the inside of the cavity. The cleanliness detection method of the process chamber comprises: Detecting the current natural frequency of the crystal oscillator; Determine the thickness of the deposited film layer on the inner wall of the corresponding cavity according to the current natural frequency of the crystal oscillator; When the thickness of the deposited film layer is greater than a first preset thickness threshold, it is determined that the process chamber needs to be cleaned.

2. The cleanliness detection method of a process chamber according to claim 1, characterized in that: Also includes: After cleaning the process chamber, detecting the current natural frequency of the crystal oscillator; Determine the thickness of the deposited film layer on the inner wall of the corresponding cavity according to the current natural frequency of the crystal oscillator; When the thickness of the deposited film layer is greater than a second preset thickness threshold, the process chamber is cleaned again; when the thickness of the deposited film layer is less than or equal to the second preset thickness threshold, the cleaning of the process chamber is terminated.

3. A process chamber, characterized in that: The process chamber comprises a cavity and at least one crystal oscillator. The crystal oscillator is fixedly arranged on the cavity and has a deposition detection surface facing the inside of the cavity. The current natural frequency of the crystal oscillator is used to characterize the cleanliness of the process chamber.

4. The process chamber according to claim 3, characterized in that: The cavity includes a cavity body and an upper cover, the upper cover is used to close the top opening of the cavity body, a first mounting groove is formed on the top surface of the upper cover, a first mounting hole is formed at the bottom of the first mounting groove and penetrates to the bottom surface of the upper cover, the process chamber also includes a plurality of connecting wires, the crystal oscillator is arranged in the first mounting hole, and the plurality of connecting wires are connected to the electrodes of the crystal oscillator through the first mounting groove.

5. The process chamber according to claim 4, characterized in that: The process chamber also includes a sleeve, which is arranged in the first mounting groove. The bottom of the sleeve is sealed and connected to the bottom of the first mounting groove. A first connecting hole extending along the axial direction of the sleeve is formed in the sleeve. The plurality of connecting wires pass through the first connecting hole and are connected to the electrodes of the crystal oscillator.

6. The process chamber according to claim 3, characterized in that: A second mounting groove is formed on the outer wall of the cavity, and a second mounting hole is formed at the bottom of the second mounting groove and penetrates to the inner wall of the cavity. The process chamber also includes a plurality of connecting wires, and the crystal oscillator is arranged in the second mounting hole. The plurality of connecting wires are connected to the electrodes of the crystal oscillator through the second mounting groove.

7. The process chamber according to claim 6, characterized in that: The process chamber also includes an airtight valve plate, which is arranged in the second mounting groove. The airtight valve plate is sealed and connected to the second mounting groove. A second connecting hole is formed in the airtight valve plate, and the plurality of connecting wires are connected to the electrodes of the crystal oscillator through the second connecting hole.

8. The process chamber according to any one of claims 4 to 7, characterized in that: The process chamber further comprises a mounting valve plate and a wiring connector, wherein the mounting valve plate is fixedly arranged on the outer wall of the chamber and its position corresponds one-to-one with the crystal oscillator, and a plurality of avoidance through holes penetrating the mounting valve plate along the thickness direction of the mounting valve plate are formed in the mounting valve plate, and a plurality of connecting wires corresponding to each of the crystal oscillators pass through the plurality of avoidance through holes on the corresponding mounting valve plate one-to-one; The wiring connector seals the plurality of avoidance through holes one by one and fixes the connection wire to the mounting valve plate.

9. The process chamber according to any one of claims 3 to 7, characterized in that: A protective film is arranged on the deposition detection surface of the crystal oscillator, and the material of the protective film includes yttrium oxide.

10. The process chamber according to any one of claims 3 to 7, characterized in that: The process chamber further includes a controller, which is electrically connected to the crystal oscillator. The controller is used to detect a current natural frequency of the crystal oscillator and determine whether the process chamber needs to be cleaned according to the current natural frequency.

11. The process chamber according to claim 10, characterized in that: The controller is also used to detect the current natural frequency of the crystal oscillator after cleaning the process chamber, and determine whether to end cleaning the process chamber according to the current natural frequency.

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