Cleaning end point detection method and semiconductor process equipment

Abstract

The invention discloses a detection method for a cleaning end point and semiconductor process equipment. The detection method comprises the following steps: forming a signal film layer covering the whole inner surface of a process chamber before the process chamber executes an atomic layer deposition process; when the process chamber reaches a cleaning condition, introducing a cleaning gas into the process chamber to execute a cleaning process, and generating a cleaned reaction gas; and detecting reactant change information corresponding to the signal film layer in the reactant gas, and determining a cleaning end point according to the reactant change information. The cleaning terminal point can be detected in time, and the problem of excessive cleaning or incomplete cleaning is avoided to the maximum extent.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a cleaning endpoint detection method and semiconductor process equipment. Background Art

[0002] Atomic layer deposition (ALD, hereinafter referred to as this name) is a chemical thin film preparation technology that relies on cyclic gas reactions. The self-limited surface reaction ensures the layer-by-layer growth of ALD deposited films. As the size of microelectronic devices decreases, the titanium oxide (TiO 2 ) films have the advantages of excellent uniformity, precise thickness control and high step coverage, and are increasingly valued and widely used in the fields of integrated circuits and storage.

[0003] ALD TiO is formed on a semiconductor silicon wafer (hereinafter referred to as "wafer"). 2 At the same time as the thin film, the inner wall of the process chamber and the hardware in the chamber will also have TiO 2 Adhesion of thin films, deposition of TiO in chamber 2 When the film is thicker, the adhesion of the outermost film decreases. 2 When thin films are deposited on wafers, thicker TiO 2 The film may peel off and contaminate the wafer. Therefore, the TiO 2 The film needs to be cleaned regularly to ensure that the TiO2 is not peeled off during wafer deposition. 2 Film contamination.

[0004] When cleaning the interior of a process chamber, it is important to detect the appropriate end point of cleaning to avoid problems such as insufficient cleaning, damage to the chamber interior wall due to over-cleaning, and waste of cleaning gas. 2 Nitrogen fluoride (NF) for deposition equipment 3 ) and other low-toxic fluorine-containing gases are ionized into plasma to clean the chamber, and the process chamber TiO is determined by controlling the time. 2 The degree of film cleaning is determined to achieve the expected cleaning effect and meet the subsequent process requirements. This method is difficult to find the cleaning endpoint, and when the cleaning process conditions change, it is easy to cause problems such as insufficient cleaning or excessive cleaning that damages the chamber wall and chamber lining. Summary of the invention

[0005] In view of this, the present application provides a cleaning endpoint detection method and semiconductor process equipment to solve the problem that it is difficult to find the cleaning endpoint in traditional solutions.

[0006] The present application provides a method for detecting a cleaning endpoint, comprising:

[0007] Before the atomic layer deposition process is performed in the process chamber, a signal film layer is formed covering the entire surface inside the process chamber;

[0008] When the process chamber reaches a cleaning condition, a cleaning gas is introduced into the process chamber to perform a cleaning process and generate a cleaned reaction gas;

[0009] The reactant change information corresponding to the signal film layer in the reaction gas is detected, and the cleaning end point is determined according to the reactant change information.

[0010] Optionally, the type of the signal film layer is different from the type of the deposited film layer formed by the atomic layer deposition process; after the signal film layer for providing a cleaning endpoint is formed in the process chamber, the detection method also includes: forming an environmental film layer on the surface of the signal film layer, and the type of the environmental film layer is consistent with the type of the deposited film layer.

[0011] Optionally, the signal film layer includes SiO 2 The environmental film layer and the deposited film layer are both TiO 2 film.

[0012] Optionally, the thickness range of the signal film layer includes 200nm-300nm; the thickness range of the environmental film layer includes 100nm-200nm.

[0013] Optionally, the cleaning gas includes NF 3 ; The detecting the reactant change information corresponding to the signal film layer in the reaction gas and determining the cleaning endpoint according to the reactant change information include: detecting the concentration of Si-F in the reaction gas, and determining the cleaning endpoint when the concentration of Si-F changes from zero to a concentration that is gradually less than a first preset concentration.

[0014] Optionally, when performing the cleaning process, the temperature in the process chamber ranges from 300° C. to 350° C.

[0015] Optionally, the type of the signal film layer is consistent with the type of the deposited film layer formed by the atomic layer deposition process.

[0016] Optionally, the signal film layer and the deposition film layer both include TiO 2 Thin film; the thickness range of the signal film layer includes 100nm-200nm.

[0017] Optionally, the cleaning gas includes NF 3; The detecting the reactant change information corresponding to the signal film layer in the reaction gas, and determining the cleaning endpoint according to the reactant change information, includes: detecting the concentration of Ti-F in the reaction gas, and determining the cleaning endpoint when the concentration of Ti-F is less than or equal to a second preset concentration.

[0018] The present application also provides a semiconductor process equipment, including a process chamber, a gas extraction pipeline and a gas concentration monitoring device;

[0019] The process chamber is used to deposit a signal film layer covering the entire surface of the interior thereof before performing an atomic layer deposition process, and when a cleaning condition is reached, receives a cleaning gas, performs a cleaning process, and generates a cleaned reaction gas;

[0020] The exhaust pipeline is used to discharge the reaction gas;

[0021] The gas concentration monitoring device is used to detect the reactant change information in the reaction gas, and the reactant change information is used to detect the cleaning endpoint.

[0022] Optionally, the type of the signal film layer is different from the type of the deposited film layer formed by the atomic layer deposition process; the process chamber is also used to deposit an environmental film layer covering the signal film layer, and the type of the environmental film layer is consistent with the type of the deposited film layer.

[0023] Optionally, the signal film layer includes SiO 2 The environmental film layer and the deposited film layer are both TiO 2 The gas concentration monitoring device is used to detect the concentration of Si-F in the reaction gas.

[0024] Optionally, the signal film layer and the deposition film layer both include TiO 2 The gas concentration monitoring device is used to detect the concentration of Ti-F in the reaction gas.

[0025] The above-mentioned cleaning endpoint detection method and semiconductor process equipment of the present application, by forming a signal film layer covering the entire inner surface of the process chamber before performing the atomic layer deposition process in the process chamber, to provide a reference signal for the cleaning endpoint of the process chamber, when the process chamber reaches the cleaning condition, a cleaning gas is introduced into the process chamber to perform the cleaning process to generate a cleaned reaction gas, and then the reactant change information corresponding to the signal film layer in the reaction gas is detected, and the cleaning endpoint of the cleaning process is accurately determined according to the reactant change information. The cleaning endpoint can be detected in time, and the problem of over-cleaning or incomplete cleaning can be avoided to the greatest extent, the cleanliness of the process chamber can be ensured, and related process problems such as metal contamination caused by excessive etching of the process chamber during the cleaning process can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 A schematic diagram of the structure of a semiconductor process equipment according to an embodiment of the present application;

[0028] Figure 2 It is a schematic flow chart of a method for detecting a cleaning endpoint according to an embodiment of the present application;

[0029] Figure 3 It is a schematic diagram of the structure of a semiconductor process equipment according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application are clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In the absence of conflict, the following embodiments and their technical features can be combined with each other.

[0031] The first aspect of the present application provides a method for detecting a cleaning endpoint, which can detect the cleaning endpoint when a semiconductor process equipment performs a cleaning process after performing an ALD process. Figure 1 As shown, the semiconductor process equipment may include structures such as a plasma source generator 1, an isolation valve 2, a plasma generator power supply 3, a radio frequency power supply feeding device 4, a gas uniform flow device 6, a process chamber, an exhaust pipeline 10 and a gas concentration monitoring device 8; the process chamber includes structures such as a base 9, an upper shield 5 and a lower shield 7, the base 9 is used to support the wafer and heat it, and the upper shield 5 and the lower shield 7 are used to form a deposition environment corresponding to the formation process.

[0032] refer to Figure 2 As shown, the detection method includes steps S210 to S230.

[0033] S210, before performing an atomic layer deposition process in the process chamber, forming a signal film layer covering the entire surface inside the process chamber.

[0034] Specifically, this step can form a signal film layer in a clean process chamber before processing the corresponding wafer. The signal film layer adheres to the process chamber wall and all exposed hardware structure surfaces in the process chamber to provide a reference signal for the cleaning endpoint of the subsequent process chamber.

[0035] S220, when the process chamber reaches a cleaning condition, a cleaning gas is introduced into the process chamber to perform a cleaning process to generate a cleaned reaction gas.

[0036] The above cleaning conditions include that after the atomic layer deposition process is performed in the process chamber, a thin film is adhered to the inner wall of the process chamber and the surface of related hardware, and the cleaning process needs to be adjusted. 2 When the thickness of the deposited film adhered to the process chamber reaches 1000-1500nm, the process chamber reaches the cleaning condition and needs to be cleaned. For example, the wafer to be processed is transferred to the process chamber, and the atomic layer deposition process is performed on the wafer to form TiO 2 When such films are formed, the inner wall of the process chamber and the hardware in the chamber will also be adhered to the films. When the above-mentioned films accumulate thicker in the process chamber, the adhesion of the outermost film decreases, causing the outer film to fall off and other problems. These problems are likely to contaminate the atomic layer deposition process of subsequent wafers and affect the quality of subsequent atomic layer deposition processes. After the deposited film layer is formed on the wafer, the wafer is output from the process chamber, and the process chamber reaches the cleaning conditions. The corresponding cleaning process can be performed to remove the films adhered to the inner wall of the process chamber and the surfaces of related hardware.

[0037] S230, detecting reactant change information corresponding to the signal film layer in the reaction gas, and determining a cleaning endpoint according to the reactant change information.

[0038] Specifically, step S230 can determine that the cleaning endpoint has been reached when the time point when the reactant change information corresponding to the signal film layer in the reaction gas changes from presence to absence is detected, and the cleaning process can be stopped to accurately determine the endpoint of the cleaning process.

[0039] The above-mentioned method for detecting the cleaning endpoint forms a signal film layer covering the entire surface inside the process chamber before performing the atomic layer deposition process in the process chamber to provide a reference signal for the cleaning endpoint of the process chamber. When the process chamber reaches the cleaning condition, a cleaning gas is introduced into the process chamber to perform the cleaning process to generate a cleaned reaction gas, and then the reactant change information corresponding to the signal film layer in the reaction gas is detected. The cleaning endpoint of the cleaning process is accurately determined based on the reactant change information. The cleaning endpoint can be detected in time, and the problem of over-cleaning or incomplete cleaning can be avoided to the greatest extent. The cleanliness of the process chamber can be ensured, and related process problems such as metal contamination caused by excessive etching of the process chamber during the cleaning process can be avoided.

[0040] In one embodiment, the type of the signal film layer is different from the type of the deposited film layer formed by the atomic layer deposition process; for example, the signal film layer includes SiO 2 Thin film; the deposited film layer includes TiO 2 Films, etc.

[0041] Accordingly, after a signal film layer for providing a cleaning endpoint is formed in the process chamber, the detection method further includes: forming an environmental film layer on the surface of the signal film layer to prepare a deposition environment for the atomic layer deposition process subsequently performed in the process chamber, thereby avoiding contamination caused by plasma bombarding the process chamber wall and other structures inside the chamber during the deposition process (for example, plasma directly bombarding the inside of the process chamber is prone to metal contamination, etc.), thereby ensuring the process quality of the atomic layer deposition process subsequently performed. The type of the environmental film layer is consistent with the type of the deposition film layer, for example, the environmental film layer and the deposition film layer are both TiO 2 film.

[0042] Optionally, the thickness of the signal film layer ranges from 200nm to 300nm, so that the signal film layer participates in the cleaning reaction for a long enough time, and the reactants corresponding to the signal film layer can be successfully detected when detecting the reaction gas, and the problem of the cleaning process taking too long due to the signal film layer being too thick can be avoided. The thickness of the environmental film layer ranges from 100nm to 200nm, so as to fully cover the signal film layer, provide a stable process environment for the subsequent atomic layer deposition process, and avoid the signal film layer from contaminating the subsequent atomic layer deposition process. The plasma power corresponding to the cleaning process can be selected between 150W and 300W.

[0043] In one example, the cleaning gas includes a plasma-state NF 3; The detecting of the reactant change information corresponding to the signal film layer in the reaction gas and determining the cleaning endpoint according to the reactant change information include: detecting the concentration of Si-F in the reaction gas, and determining the cleaning endpoint when the concentration of Si-F changes from zero to a certain concentration and gradually changes to less than a first preset concentration. Wherein Si-F may include SiF generated by the cleaning process. 4 Silicon-containing gases such as silicon. The first preset concentration can be set according to the detection accuracy of the corresponding gas concentration monitoring device, and can usually be set to the minimum concentration that the corresponding gas concentration monitoring device can detect. Optionally, the first preset concentration can be set to a concentration value close to 0, and the concentration of Si-F in the reaction gas changes from zero to a certain value, indicating that the signal film layer begins to participate in the reaction, and the concentration of Si-F gradually changes to less than the first preset concentration, indicating that the signal film layer has just been cleaned and the cleaning end point has been reached.

[0044] Optionally, when performing the cleaning process, the temperature in the process chamber ranges from 300° C. to 350° C., so that the reaction gas generated by the cleaning process is in a gaseous state and is discharged through the exhaust pipeline of the process chamber.

[0045] Specifically, if the signal film layer includes SiO 2 Thin films, ambient layers and deposited layers including TiO 2 Thin films, clean gases including plasma NF 3 , the following combination Figure 3 The semiconductor process equipment describes in detail the above-mentioned cleaning endpoint detection method, which may include the following multiple stages:

[0046] The first stage: introduce argon, oxygen and silicon source reaction gas into the clean process chamber. The silicon source reaction gas can be a series of organic reaction gases containing Si such as silane. Figure 3 As shown, under the action of plasma, the above mixed gas reacts in the process chamber to generate SiO 2 Film 11, the SiO 2 The film 11 adheres to the process chamber wall and all exposed hardware structure surfaces in the chamber. 2 The main function of the film 11 is to serve as a signal film layer at the end of the chamber cleaning. It reacts with the F plasma generated by the remote plasma source generator 1 during the subsequent chamber cleaning process to generate Si-F. Si-F and other mixed gases are discharged through the exhaust pipe 10. When the mixed gas passes through the gas concentration monitoring device 8, the signal of Si-F can be detected by the gas concentration monitoring device 8. The signal strength of the gas concentration monitoring device 8 is used to feedback the concentration of Si-F in the mixed gas. At this stage, the flow rate of the reaction gas and the power of the plasma can be controlled to change the SiO 2 The thickness and quality of the film. Optionally, SiO2 The film thickness is between 200nm and 300nm. 2 The film participates in the cleaning reaction long enough to detect SiO2 successfully when detecting the reaction gas. 2 The corresponding Si-F reactant can avoid SiO 2 The problem of too thick film causing the cleaning process to take too long. The plasma power should be between 150W and 300W.

[0047] The second stage: After a certain thickness of SiO has been deposited 2 A layer of TiO is continuously deposited in the chamber environment of film 11. 2 The film 12 forms an environmental film layer of the same type as the subsequent deposited film layer, so as to prepare the deposition environment for the subsequent atomic layer deposition process in the process chamber, avoid plasma bombardment of the process chamber wall and other structures inside the chamber during the deposition process to cause contamination, and ensure the process quality of the subsequent atomic layer deposition process. 2 The deposition thickness of the film 12 is generally between 100 nm and 200 nm, which can fully cover the SiO 2 The signal film 11 avoids SiO 2 The thin film 11 contaminates the atomic layer deposition process performed subsequently.

[0048] The third stage: After completing the preparations in the above two stages, TiO 2 Deposition process, when the deposition process is completed and the process chamber reaches the cleaning condition, such as accumulated TiO 2 When the film thickness is 1000-1500nm, the process chamber needs to be cleaned. At the beginning of the cleaning process, argon (Ar) first enters the remote plasma source generator 1 to complete the dissociation. Ar atoms are ionized into Ar + and e - After the ignition is completed, argon and fluorine-containing low-toxic gas nitrogen fluoride (NF 3 ) The mixed gas is introduced into the plasma source generator 1, and the reaction occurs at this time. - +NF 3 →NF 2 +F - , and is also accompanied by the separation excitation reaction e - +NF 3 →NF 2 +F+e - and e - +NF 3 →NF+F+F - . Ar as NF 3 Ionized initiator, NF 3After being ionized, the cleaning gas is composed of Ar and NF 3 The mixed gas is converted into NF 3 Single gas, plasma NF 3 The gas flows into the process chamber through the gas flow equalizer 6, and the TiO 2 The reaction product is TiF 4 The simplified reaction process is: 4F - +TiO 2 →TiF 4 (g)+2O 2- Due to TiF 4 The sublimation temperature of TiF is 284℃ and the decomposition temperature is 400℃, so the cleaning process temperature is set between 300℃-350℃ to make TiF 4 It is in a gaseous state and will not condense or decompose, ensuring a good cleaning effect. 2 After the film 12 is cleaned, NF 3 The plasma continues to interact with the bottom layer of SiO 2 Film 11 reacts to generate SiF 4 , and is also discharged from the chamber through the exhaust pipe 10 in a gaseous state.

[0049] At the beginning of the cleaning process, the angle valve between the exhaust pipeline 10 and the branch with the gas concentration monitoring device 8 can be opened. When the cleaned reaction gas is discharged through the exhaust pipeline 10, part of the reaction gas flows through the gas concentration monitoring device 8. The gas concentration monitoring device 8 of this embodiment cannot capture the signal of Ti-F. In the first stage of the cleaning process, i.e., NF 3 TiO adhered to the chamber 2 When clean, there is no signal fluctuation, TiO 2 After being cleaned, NF 3 Continue with the bottom layer of SiO 2 The reaction produces SiF 4 When the reaction gas flows through the gas concentration monitoring device 8, a Si-F detection signal is generated. When the Si-F concentration drops to zero, it indicates that the film adhered to the inside of the process chamber is cleaned, and the corresponding cleaning endpoint can be determined.

[0050] In this example, before the atomic layer deposition process is performed, a certain thickness of SiO is first deposited on the bottom layer. 2 Film 11, continue on SiO 2 A certain thickness of TiO is deposited on the film 11 2 Film 12, after completing the pre-deposition treatment inside the process chamber, an atomic layer deposition process is performed to deposit TiO on the surface of the wafer 2During the cleaning process of the process chamber, the gas concentration monitoring device 8 can be used to timely detect the cleaning endpoint, end the corresponding cleaning process, minimize the occurrence of over-etching or incomplete cleaning, ensure the cleanliness of the process chamber, and avoid subsequent process problems such as metal contamination caused by excessive etching of the process chamber.

[0051] In one embodiment, the type of the signal film layer is consistent with the type of the deposited film layer formed by the atomic layer deposition process; for example, the signal film layer and the deposited film layer both include TiO 2 Thin film, so that the process chamber only needs to deposit a signal film layer in the pretreatment stage before performing the atomic layer deposition process, and does not need to deposit an environmental film layer, which can simplify the pretreatment stage.

[0052] Optionally, the thickness of the signal film layer ranges from 100 nm to 200 nm, so as to fully cover the entire inner surface of the process chamber and provide a stable process environment for a subsequent atomic layer deposition process.

[0053] In one example, the cleaning gas includes a plasma-state NF 3 .

[0054] Accordingly, the detecting the reactant change information corresponding to the signal film layer in the reaction gas and determining the cleaning endpoint according to the reactant change information includes: detecting the concentration of Ti-F in the reaction gas, and determining the cleaning endpoint when the concentration of Ti-F is less than or equal to a second preset concentration. Ti-F may include TiF generated by the cleaning process. 4 For titanium-containing gases, the second preset concentration can be set to a concentration value close to 0. The concentration of Ti-F in the reaction gas is less than or equal to the second preset concentration, indicating that the signal film layer has been cleaned and the cleaning endpoint has been reached.

[0055] Specifically, if the signal film layer and the deposited film layer include TiO 2 Thin films, clean gases including plasma NF 3 , the following combination Figure 1 The semiconductor process equipment describes in detail the above-mentioned cleaning endpoint detection method, which may include the following multiple stages:

[0056] The first stage: Deposit a certain thickness of TiO in a clean process chamber 2 Thin film, the TiO 2 The film covers the entire surface of the process chamber. 2 The film is deposited to a thickness of 100nm-200nm to completely cover the entire internal surface of the process chamber and prepare the TiO2 for deposition in the process chamber. 2environment to avoid contamination caused by plasma bombardment of the process chamber wall and the internal structure of the chamber during the deposition process.

[0057] In the second stage, after completing the above preparations, TiO 2 Deposition process, when the deposition process is completed and the process chamber reaches the cleaning condition, such as accumulated TiO 2 When the film thickness is 1000-1500nm, the chamber needs to be cleaned. At the beginning of the cleaning process, argon (Ar) first enters the remote plasma source generator 1 to complete the dissociation. Ar atoms are ionized into Ar + and e - After the ignition is completed, argon and fluorine-containing low-toxic gas nitrogen fluoride (NF 3 ) The mixed gas is introduced into the plasma source generator 1, and the reaction occurs at this time. - +NF 3 →NF 2 +F - , and is also accompanied by the separation excitation reaction e - +NF 3 →NF 2 +F+e - and e - +NF 3 →NF+F+F - . Ar as NF 3 Ionized initiator, NF 3 After being ionized, the cleaning gas is composed of Ar and NF 3 The mixed gas is converted into NF 3 Single gas, plasma NF 3 The gas flows into the process chamber through the gas flow equalizer 6, and the TiO 2 The reaction product is TiF 4 The simplified reaction process is: 4F - +TiO 2 →TiF 4 (g)+2O 2- The mixed gas containing Ti-F is discharged from the process chamber through the exhaust pipe 10. When the mixed gas passes through the gas concentration monitoring device 8 which can directly detect the Ti-F concentration, the concentration of Ti-F is fed back. When no Ti-F signal is observed in the gas concentration monitoring device 8, it proves that the process chamber is cleaned and the cleaning end point can be determined. This detection method is used to obtain TiO 2 Cleaning endpoints for semiconductor process equipment such as deposition equipment.

[0058] The above-mentioned method for detecting the cleaning endpoint forms a signal film layer covering the entire surface inside the process chamber before executing the atomic layer deposition process in the process chamber, so as to provide a reference signal for the cleaning endpoint of the process chamber. When the process chamber reaches the cleaning condition, a cleaning gas is introduced into the process chamber to execute the cleaning process to generate a cleaned reaction gas, and then the reactant change information corresponding to the signal film layer in the reaction gas is detected. The cleaning endpoint of the cleaning process is accurately determined based on the reactant change information. The cleaning endpoint can be detected in time, and the problem of over-cleaning or incomplete cleaning can be avoided to the greatest extent. The cleanliness of the process chamber can be ensured, and related process problems such as metal contamination caused by excessive etching of the process chamber during the cleaning process can be avoided.

[0059] The second aspect of the present application also provides a semiconductor process equipment, which can detect the cleaning endpoint of its cleaning process by using the cleaning endpoint detection method described in any of the above embodiments when performing a cleaning process. Specifically, the semiconductor process equipment includes a process chamber, a gas extraction pipeline, and a gas concentration monitoring device;

[0060] The process chamber is used to deposit a signal film layer covering the entire surface of the interior thereof before performing an atomic layer deposition process, and when a cleaning condition is reached, receives a cleaning gas, performs a cleaning process, and generates a cleaned reaction gas;

[0061] The exhaust pipeline is used to discharge the reaction gas;

[0062] The gas concentration monitoring device is used to detect the reactant change information in the reaction gas, and the reactant change information is used to detect the cleaning endpoint.

[0063] The type of the signal film layer is different from the type of the deposited film layer formed by the atomic layer deposition process;

[0064] The process chamber is also used to deposit an environmental film layer covering the signal film layer, and the type of the environmental film layer is consistent with the type of the deposited film layer.

[0065] In one example, the type of the signal film layer is different from the type of the deposited film layer formed by the atomic layer deposition process; the process chamber is also used to deposit an environmental film layer covering the signal film layer, and the type of the environmental film layer is consistent with the type of the deposited film layer.

[0066] Optionally, the signal film layer includes SiO 2 The environmental film layer and the deposited film layer are both TiO 2 The gas concentration monitoring device is used to detect the concentration of Si-F in the reaction gas. The gas concentration monitoring device is easy to implement and has high stability during the gas concentration monitoring process.

[0067] In one example, the type of the signal film layer is consistent with the type of the deposited film layer formed by the atomic layer deposition process.

[0068] Optionally, the signal film layer and the deposition film layer both include TiO 2 The gas concentration monitoring device is used to detect the concentration of Ti-F in the reaction gas. The gas concentration monitoring device can directly detect the concentration of clean TiO 2 The concentration of reactants produced by the equal deposited film layer can make the type of the signal film layer in the detection process of the cleaning endpoint consistent with the type of the deposited film layer formed by the atomic layer deposition process. In this way, the pretreatment stage before the process chamber performs the atomic layer deposition process only needs to deposit a signal film layer, and there is no need to deposit an environmental film layer, which can simplify the corresponding pretreatment stage.

[0069] In one example, reference Figure 1 and Figure 3 As shown, the semiconductor process equipment mentioned above may further include a plasma source generator 1, a gas flow equalization device 6, a plasma generator power supply 3, and a radio frequency power supply feeding device 4 in addition to including a process chamber, a gas extraction pipeline 10, and a gas concentration monitoring device 8.

[0070] The plasma source generator 1 is arranged at the gas inlet of the gas flow equalization device 6, and is used to 3 The cleaning gas is dissociated into a plasma state, and the cleaning gas in the plasma state can be transported to the process chamber through the relevant air inlet pipeline to etch the thin film adhered inside the process chamber. Optionally, an isolation valve 2 can be provided on the air inlet pipeline below the plasma source generator 1, and the isolation valve 2 can be used to control the on-off of the air inlet pipeline.

[0071] The gas flow equalization device 6 is disposed at the first end of the process chamber, and is used to transmit the gas introduced into its gas inlet into the process chamber.

[0072] The plasma generator power supply 3 is used to supply power to the radio frequency power supply feeding device 4; the frequency of the plasma generator power supply 3 may be 13.56 Hz.

[0073] The RF power supply feeding device 4 is used to provide RF energy, so that the RF energy is transmitted to the gas flow equalization device 6 to dissociate the precursor and form a corresponding plasma; the above-mentioned precursor may include Ar, O 2 The gases required for the reaction in the process chamber.

[0074] The process chamber is also used to provide a corresponding process environment; specifically, the process chamber includes structures such as a base 9, an upper shield 5 and a lower shield 7. The base 9 is used to deposit and heat the wafer, and the upper shield 5 and the lower shield 7 are used to form a deposition environment corresponding to the forming process. Specifically, the signal model can be adhered to the wall of the process chamber and the exposed surface of the hardware structure such as the base 9 in the chamber.

[0075] The exhaust pipeline 10 may be disposed at the second end of the process chamber to exhaust the reaction gas.

[0076] The gas concentration monitoring device 8 can detect the reactant change information in the reaction gas to determine the cleaning end point of the cleaning process according to the reactant change information. Optionally, the gas concentration monitoring device 8 includes an infrared gas concentration monitoring device, which can detect the concentration of reactants such as Si-F or Ti-F in the reaction gas.

[0077] When the above semiconductor process equipment performs a cleaning process, the cleaning endpoint detection method described in any of the above embodiments may be used to detect the cleaning endpoint of its cleaning process, and all the beneficial effects of the cleaning endpoint detection method described in any of the above embodiments are not repeated here.

[0078] The above is a detailed introduction to a cleaning endpoint detection method and semiconductor process equipment provided by the present application. This article uses specific examples to illustrate the principles and implementation methods of the present application. It should be noted that in the present application, the descriptions of each embodiment have their own emphasis. For parts that are not described or recorded in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0079] Although the present application has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art based on reading and understanding of this specification and the accompanying drawings. The present application includes all such modifications and variations and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the above-mentioned components, the terms used to describe such components are intended to correspond to any component (unless otherwise indicated) that performs the specified function of the component (e.g., it is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the functions in the exemplary implementation of this specification shown herein.

[0080] That is, the above description is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the specification and drawings of the present application, such as the mutual combination of technical features between the embodiments, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

[0081] In addition, although the terms first, second, etc. may be used to describe various information in this article, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. The terms "first" and "second" should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0082] In this application, the word "exemplary" is used to mean "used as an example, illustration or description". Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or more advantageous than other embodiments. In order to enable any technician in the field to implement and use the present application, the present application provides the above description. In the above description, various details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other embodiments, well-known structures and processes will not be elaborated in detail to avoid unnecessary details that make the description of the present application obscure. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest range of principles and features disclosed in the present application.

Claims

1. A method for detecting a cleaning endpoint, characterized in that: The detection method comprises: Before the atomic layer deposition process is performed in the process chamber, a signal film layer is formed covering the entire surface inside the process chamber; When the process chamber reaches a cleaning condition, a cleaning gas is introduced into the process chamber to perform a cleaning process and generate a cleaned reaction gas; The reactant change information corresponding to the signal film layer in the reaction gas is detected, and the cleaning end point is determined according to the reactant change information.

2. The method for detecting the cleaning endpoint according to claim 1, characterized in that: The type of the signal film layer is different from the type of the deposited film layer formed by the atomic layer deposition process; After forming a signal film layer for providing a cleaning endpoint in the process chamber, the detection method further comprises: forming an environmental film layer on the surface of the signal film layer, wherein the type of the environmental film layer is consistent with the type of the deposited film layer.

3. The method for detecting the cleaning endpoint according to claim 2, characterized in that: The signal film layer includes a SiO2 film; the environmental film layer and the deposition film layer are both TiO2 films.

4. The method for detecting the cleaning endpoint according to claim 3, characterized in that: The thickness of the signal film layer ranges from 200nm to 300nm; the thickness of the environmental film layer ranges from 100nm to 200nm.

5. The method for detecting the cleaning endpoint according to claim 3, characterized in that: The cleaning gas includes NF3 in a plasma state; The detecting the reactant change information corresponding to the signal film layer in the reaction gas and determining the cleaning endpoint according to the reactant change information includes: detecting the concentration of Si-F in the reaction gas, and determining the cleaning endpoint when the concentration of Si-F changes from zero to a concentration and gradually changes to less than a first preset concentration.

6. The method for detecting the cleaning endpoint according to claim 1, characterized in that: When performing the cleaning process, the temperature in the process chamber ranges from 300°C to 350°C.

7. The method for detecting the cleaning endpoint according to claim 1, characterized in that: The type of the signal film layer is consistent with the type of the deposited film layer formed by the atomic layer deposition process.

8. The method for detecting the cleaning endpoint according to claim 7, characterized in that: The signal film layer and the deposited film layer both include a TiO2 film; the thickness of the signal film layer ranges from 100nm to 200nm.

9. The method for detecting the cleaning endpoint according to claim 8, characterized in that: The cleaning gas includes NF3 in a plasma state; The detecting the reactant change information corresponding to the signal film layer in the reaction gas and determining the cleaning endpoint according to the reactant change information includes: detecting the concentration of Ti-F in the reaction gas, and determining the cleaning endpoint when the concentration of Ti-F is less than or equal to a second preset concentration.

10. A semiconductor process equipment, characterized in that: It includes a process chamber, a gas extraction pipeline and a gas concentration monitoring device; The process chamber is used to deposit a signal film layer covering the entire surface of the interior thereof before performing an atomic layer deposition process, and when a cleaning condition is reached, receives a cleaning gas, performs a cleaning process, and generates a cleaned reaction gas; The exhaust pipeline is used to discharge the reaction gas; The gas concentration monitoring device is used to detect the reactant change information in the reaction gas, and the reactant change information is used to detect the cleaning endpoint.

11. The semiconductor process equipment according to claim 10, characterized in that: The type of the signal film layer is different from the type of the deposited film layer formed by the atomic layer deposition process; The process chamber is also used to deposit an environmental film layer covering the signal film layer, and the type of the environmental film layer is consistent with the type of the deposited film layer.

12. The semiconductor process equipment according to claim 11, characterized in that: The signal film layer comprises a SiO2 film; the environmental film layer and the deposition film layer are both TiO2 films; The gas concentration monitoring device is used to detect the concentration of Si-F in the reaction gas.

13. The semiconductor process equipment according to claim 10, characterized in that: The signal film layer and the deposited film layer both include a TiO2 thin film; The gas concentration monitoring device is used to detect the concentration of Ti—F in the reaction gas.

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