Cleanness detection method of process chamber and process chamber

Abstract

The invention provides a process chamber cleanliness detection method and a process chamber, 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 interior of the cavity, and the process chamber cleanliness detection method comprises the following steps: detecting the current inherent frequency of the crystal oscillator; determining the thickness of a deposited film layer on the inner wall of the corresponding cavity according to the current inherent frequency of the crystal oscillator; when the thickness of the deposited film layer is larger than a first preset thickness threshold value, it is judged that the process cavity needs to be cleaned. The thickness of the deposited film layer is determined through the crystal oscillator arranged in the process chamber, the internal condition of the process chamber can be accurately monitored in real time, the internal condition of the chamber does not need to be confirmed in a mode of introducing a detection wafer and carrying out a specific detection process, the maintenance efficiency of the process chamber is improved, the semiconductor process effect is ensured, and the production cost is reduced. And the yield of wafer products is improved.

Description

Technical Field

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

[0002] Semiconductor process equipment is widely used in the manufacturing process of integrated circuits (ICs) or MEMS devices. Plasma contains a large number of active particles such as electrons, ions, excited atoms, molecules, free radicals and neutral groups. These particles reach the surface of the wafer under the action of bias voltage, interact with the wafer, and cause various physical and chemical reactions on the surface of the material, thereby generating a large number of particles. Most of the particles will be cleaned up after the process is completed, but a small number of particles will still adhere to the inner wall of the process chamber, fall off after accumulation, or decompose to the wafer surface during the process, causing wafer etching defects.

[0003] In related processes, in order to prevent particles attached to the inner wall of the process chamber from causing etching defects on the wafer surface, usually after N wafer processes (each wafer is a process cycle) are carried out in the process chamber, the inspection wafer is 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, so as to determine whether the cleanliness of the chamber meets the process requirements. If it does not meet the requirements, the chamber is subjected to a specific waferless automatic cleaning (waferless automatic cleaning).

[0004] Automatic clean (WAC) process is used until the chamber cleanliness test results meet the process requirements and then the etching and other semiconductor processes are started again.

[0005] However, the existing process chamber particle detection and cleaning solutions require 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 waferless automatic cleaning process. The accumulation of polymers on the inner wall of the chamber after cleaning 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.

[0006] 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 the field. Summary of the invention

[0007] The present invention aims to provide a cleanliness detection method for a process chamber and a process chamber. The cleanliness detection method for the process chamber can ensure the cleanliness of the inner wall of the process chamber.

[0008] To achieve the above object, as one aspect of the present invention, a cleanliness detection method for a process chamber is provided, wherein 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, and the cleanliness detection method for the process chamber comprises:

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

[0010] 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;

[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] Optionally, it also includes:

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

[0014] 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;

[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 invention, 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] Optionally, 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.

[0018] Optionally, the process chamber also includes a sleeve, which is arranged in the first mounting groove, and 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, and a plurality of connecting wires pass through the first connecting hole to be connected to the electrodes of the crystal oscillator.

[0019] Optionally, a second mounting groove is formed on the outer wall of the cavity, 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, the crystal oscillator is arranged in the second mounting hole, and the plurality of connecting wires are connected to the electrodes of the crystal oscillator through the second mounting groove.

[0020] Optionally, 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] Optionally, 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;

[0022] The wiring connector seals the plurality of avoidance through holes one by one and fixes the connection wire to the mounting valve plate.

[0023] Optionally, a protective film is attached to the deposition detection surface of the crystal oscillator, and a material of the protective film includes yttrium oxide.

[0024] Optionally, the process chamber further includes a controller, which is electrically connected to the crystal oscillator, and 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.

[0025] Optionally, the controller is further used to detect a 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.

[0026] In the cleanliness detection method and process chamber of the process chamber provided by the present invention, 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 timely determined that the process chamber needs to be cleaned.

[0027] The present invention determines the thickness of the deposited film layer by means of a crystal oscillator 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. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0029] Figure 1 is a schematic structural diagram of a process chamber provided by an embodiment of the present invention;

[0030] Figure 2 yes Figure 1 A partial enlarged schematic diagram of the process chamber in area A;

[0031] Figure 3 yes Figure 1 A partial enlarged schematic diagram of the process chamber in area B;

[0032] Figure 4 is a schematic diagram of a partial structure of a process chamber provided in an embodiment of the present invention;

[0033] Figure 5 is a schematic structural diagram of a process chamber provided by an embodiment of the present invention;

[0034] Figure 6 is a schematic structural diagram of a process chamber provided by another embodiment of the present invention;

[0035] Figure 7 It is a schematic flow chart of a method for detecting the cleanliness of a process chamber provided by an embodiment of the present invention;

[0036] Figure 8 is a flow chart of a method for detecting the cleanliness of a process chamber provided by another embodiment of the present invention;

[0037] Fig. 9 is a flow chart of a method for detecting the cleanliness of a process chamber provided by another embodiment of the present invention;

[0038] Fig.10 It is a curve that shows how the natural frequency of a crystal component changes with its thickness.

[0039] Description of reference numerals:

[0040] 100: Cavity 110: Cavity body

[0041] 120: Upper cover 210: Crystal oscillator

[0042] 220: Connecting wire 310: Install valve plate

[0043] 311: Fixed through hole 320: Wiring connector

[0044] 410: Casing 420: Airtight gasket

[0045] 430: airtight valve plate 10: wafer DETAILED DESCRIPTION

[0046] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0047] To solve the above technical problems, as one aspect of the present invention, 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, such as Figure 1 As shown, the process chamber includes a process chamber, the process chamber is used to accommodate the wafer 10 and perform semiconductor processing on the wafer 10 introduced into the process chamber, the process chamber includes a cavity 100 and at least one crystal oscillator 210, the crystal oscillator 210 is fixedly arranged on the cavity 100 and the crystal oscillator 210 has a deposition detection surface facing the interior of the cavity 100, as shown in FIG. Figure 7 As shown, the cleanliness detection method of the process chamber includes:

[0048] Step S1, detecting the current natural frequency of the crystal oscillator 210;

[0049] 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;

[0050] 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.

[0051] The natural frequency of the piezoelectric effect of the crystal oscillator 210 depends on its geometric dimensions, cutting type and thickness, and its calculation formula is:

[0052] f·d=v / 2;

[0053] Among them, f is the natural frequency of the crystal oscillator, d is the thickness of the crystal oscillator element itself, and v is the shear velocity of the crystal oscillator element.

[0054] When the thickness of the particles on the surface of the crystal oscillator changes by Δd, a mass load effect will occur, causing the natural frequency of the crystal oscillator 210 to change by Δf, which is calculated as follows:

[0055]

[0056] That is, there is a linear relationship between the change in thickness and the change in the natural frequency of the crystal. As the degree of aggregation of the particles on the inner wall of the chamber increases, the thickness of the polymer on the surface of the crystal element increases, and the crystal frequency decreases linearly and monotonically (theoretically, when the crystal frequency is 5 to 10 MHz, the maximum drop in the fundamental frequency is allowed to be 2 to 3%, and the crystal thickness range is 0.1 nm to 10 μm). Fig.10 It is a curve showing how the natural frequency of a crystal oscillator component changes with its thickness.

[0057] In an embodiment of the present invention, the crystal oscillator 210 has a deposition detection surface facing the interior of the cavity 100, so that when the inner wall of the cavity 100 is deposited with particles or polymers to form a thin film in 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 further changing the natural frequency of the crystal oscillator 210. According to the above analysis, the natural frequency of the crystal oscillator 210 changes linearly with its thickness.

[0058] Therefore, the cleanliness detection method of the process chamber provided by the present invention can be based on the pre-stored parameters recording 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 timely determined that the process chamber needs to be cleaned.

[0059] The cleanliness detection method for the process chamber provided by the present invention 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 condition of the process chamber in real time. There is no need to confirm the internal condition of the chamber by introducing a detection wafer and performing a specific detection process, thereby improving the efficiency of maintaining the process chamber, ensuring the semiconductor process effect, and improving the wafer product yield.

[0060] As an optional embodiment of the present invention, Figure 8 As shown, the cleanliness detection method of the process chamber also includes:

[0061] Step S4: When it is determined that the process chamber needs to be cleaned, the process chamber is cleaned.

[0062] In order to ensure the cleaning effect of the cavity 100, as a preferred embodiment of the present invention, Fig. 9 As shown, it also includes:

[0063] Step S41, after cleaning the process chamber, detecting the current natural frequency of the crystal oscillator 210;

[0064] 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;

[0065] 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.

[0066] In an embodiment of the present invention, after cleaning the interior of the cavity 100, 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.

[0067] As an optional embodiment of the present invention, the cleanliness detection method of the process chamber further includes:

[0068] The semiconductor process is performed cyclically, 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.

[0069] As a second aspect of the present invention, 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 inside of the cavity 100. The current natural frequency of the crystal oscillator 210 is used to characterize the cleanliness of the process chamber.

[0070] In an embodiment of the present invention, 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 in 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 then changing the natural frequency of the crystal oscillator 210. Based on the pre-stored parameters recording 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.

[0071] The process chamber provided by the present invention 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.

[0072] As an optional embodiment of the present invention, Figure 1As shown, 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 .

[0073] As an optional embodiment of the present invention, 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 implementing the cleanliness detection method of the process chamber provided in an embodiment of the present invention.

[0074] As an optional embodiment of the present invention, 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 based on the current natural frequency to ensure the cleaning effect of the cavity 100 and further ensure the semiconductor process effect.

[0075] As an optional embodiment of the present invention, Figure 5 , Figure 6 As shown, the controller may include an industrial computer 1 and a control module 2. The control module 2 has an oscillation circuit inside, which is used to collect the vibration frequency of the crystal oscillator 210, calculate the thickness of the film layer on the surface of the crystal oscillator 210, and transmit the data to the industrial computer. The industrial computer 1 is used to compare the data and decide the next process (for example, whether to perform a semiconductor process or clean the process chamber).

[0076] As an optional embodiment of the present invention, Figure 2 As shown, 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 and penetrates to 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.

[0077] In order to ensure the airtightness of the cavity 100, as a preferred embodiment of the present invention, Figure 2 As shown, the process chamber also includes a sleeve 410, which is arranged in the first mounting groove. 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.

[0078] In an embodiment of the present invention, 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 being connected to the outside through the gap between the crystal oscillator 210 and the first mounting hole, thereby ensuring the airtightness of the cavity 100.

[0079] As a preferred embodiment of the present invention, Figure 2 As shown, the deposition detection surface of the crystal oscillator 210 is flush with the bottom surface of the upper cover 120 to ensure 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 .

[0080] To further ensure the airtightness of the cavity 100, as a preferred embodiment of the present invention, the sleeve 410 includes a main body and a positioning part which are sequentially connected along the axial direction of the sleeve 410, the main body is arranged 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 part corresponds to the cross-sectional shape of the first mounting hole and the bottom end of the positioning part is inserted into the first mounting hole;

[0081] 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.

[0082] In the embodiment of the present invention, the sleeve 410 adopts a stepped design, and the step is sealed and connected with the bottom of the first installation groove through an airtight gasket 420, which further ensures the airtightness of the cavity 100.

[0083] As an optional implementation of the present invention, the sleeve 410 is made of ceramic.

[0084] As an optional embodiment of the present invention, Figure 3 As shown, 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 and 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.

[0085] In order to ensure the airtightness of the cavity 100, as a preferred embodiment of the present invention, Figure 3 As shown, the process chamber also includes an airtight valve plate 430, and each electrode of the crystal oscillator 210 is connected to the controller through a connecting wire 220. The airtight valve plate 430 is arranged in a second mounting groove, and the airtight valve plate 430 is sealed and connected to the second mounting groove. A second connecting hole is formed in the airtight valve plate 430, and a plurality of connecting wires 220 are connected to the electrodes of the crystal oscillator 210 through the second connecting hole.

[0086] As a preferred embodiment of the present invention, Figure 3 As shown, 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 layer deposited on the deposition detection surface and the thickness of the film layer deposited on the inner wall of the cavity 100 .

[0087] As a preferred embodiment of the present invention, Figures 2 to 4 As shown, the process chamber further 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 chamber 100, and its position corresponds to the crystal oscillator 210 one by one. A plurality of avoidance through holes penetrating the mounting valve plate 310 along the thickness direction of the mounting valve plate 310 are formed in the mounting valve plate 310. The plurality of connecting wires 220 corresponding to each crystal oscillator 210 all pass through the plurality of avoidance through holes on the corresponding mounting valve plate 310 one by one.

[0088] The wiring connector 320 seals the plurality of avoidance through holes in a one-to-one correspondence, and fixedly connects the connection line 220 to the mounting valve plate 310 .

[0089] Specifically, Figure 2 As shown, 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.

[0090] like Figure 3 As shown, 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 arranged 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.

[0091] In the embodiment of the present invention, a mounting valve plate 310 is further installed on the outer side of the sleeve 410 or the airtight valve plate 430. The mounting valve plate 310 can be fixedly connected to the surface of the cavity 100 from the outer side and seal the openings of the first mounting groove and the second mounting groove, further ensuring the airtightness of the cavity 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 between the crystal oscillator 210 and the mounting valve plate 310 can be fixed by the mounting valve plate 310, so as to avoid the vibration and torsion of the connecting wire 220 in this area causing the crystal oscillator 210 to be displaced, thereby ensuring the stability of the position of the crystal oscillator 210, and further ensuring the stability of the monitoring results inside the chamber.

[0092] As an optional embodiment of the present invention, Figure 4 As shown, a plurality of fixing through holes 311 penetrating the mounting valve plate 310 along the thickness direction of the mounting valve plate 310 are formed on 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 passing through the fixing through holes 311 and the corresponding fixing holes in sequence.

[0093] As an optional embodiment of the present invention, the wiring connector 320 is connected to the connecting line 220 and the mounting valve plate 310 by welding.

[0094] As an optional implementation of the present invention, a protective film is attached to the deposition detection surface of the crystal oscillator 210, and the material of the protective film includes yttrium oxide.

[0095] As an optional embodiment of the present invention, a high-purity thin film 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.

[0096] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

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 attached to 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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