Atomic layer deposition apparatus and atomic layer deposition method

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to an atomic layer deposition device and an atomic layer deposition method. The atomic layer deposition device comprises a metal inner shell which is enclosed to form a reaction chamber, and the reaction chamber is used for accommodating a wafer; and the electric polarization layer covers the surface of the metal inner shell and is in direct contact connection with the metal inner shell, and the electric polarization layer can form an electrostatic field on the inner wall of the reaction chamber under the action of an external electric field. According to the invention, the deposition of the precursor on the inner wall of the reaction chamber in the implementation process of the atomic layer deposition process is reduced.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to an atomic layer deposition device and an atomic layer deposition method. Background Art

[0002] With the continuous development of the semiconductor industry and the continuous improvement of integrated circuit process technology, the size of the grooves formed by the etching process in the transistor is also constantly decreasing, which makes the coating technology inside the groove and its sidewalls also face severe challenges. CVD (Chemical Vapor Deposition) and PVD (Physical Vapor Deposition) have been unable to meet the requirements of good step coverage under extremely small sizes, and the preparation of high-quality ultra-thin films with controlled nanometer-level thickness has also become a technical difficulty. ALD (Atomic layer deposition) is a gas-based thin film growth technology, which is characterized by alternately passing two or more chemical precursors into the reaction chamber in contact with the substrate to achieve a continuous deposition process of a single atomic film. Due to the self-limiting nature of the surface reaction formed by saturated chemical adsorption on the substrate surface, the ALD process can accurately control the thickness of the film at the atomic scale. Due to the high controllability of its deposition parameters (thickness, composition and structure), excellent uniformity and conformality, it has a wide range of application potential in the field of micro-nano electronics.

[0003] In the atomic layer deposition process, commonly used precursors are metal organic compounds, such as triethylaluminum, tributylaluminum, trimethylaluminum, etc. These organic substances will decompose after heating to produce metal ions and organic groups. The metal ions can be adsorbed on the surface of the substrate to form a monolayer deposition, thereby realizing atomic layer deposition. The uniformity and stability of the precursor distribution in the reaction chamber are crucial to the deposition quality and growth rate. The distribution of the precursor is affected by many factors, among which the most important influencing factor is wall adsorption. Wall adsorption refers to the adsorption of the precursor on the wall surface of the chamber, which will lead to uneven distribution of the precursor concentration; whether it is a cold wall or hot wall reaction chamber, some materials may be deposited on the inner wall of the chamber, which will affect the performance of the equipment, including process consistency, temperature distribution in the chamber, etc. Therefore, the reaction chamber needs to be cleaned regularly.

[0004] During the thin film deposition process, the cleaning and etching of the process chamber will inevitably cause damage to the inner surface of the chamber. In particular, highly reactive etching gases will over-etch the inner surface of the reaction chamber, causing changes in the environment of the process chamber, affecting the reliability of the thin film deposition process, and shortening the service life of the chamber. To solve this problem, a layer of thin film is usually pre-deposited on the inner wall of the chamber before thin film deposition to prevent over-etching. However, the uniformity of this thin film is poor, and its adhesion to the inner wall of the chamber is weak. It may fall off and become a source of particle contaminants during the deposition process. Therefore, it is necessary to use an etching process to remove the pre-deposited film after several process depositions, which seriously reduces the wafer deposition efficiency and film quality.

[0005] Therefore, how to reduce the deposition of precursors on the inner wall of the reaction chamber during the implementation of the atomic layer deposition process, thereby ensuring the uniformity of the film thickness formed by the atomic layer deposition process, improving the quality of film deposition, and ensuring the efficiency of the atomic layer deposition process while avoiding excessive etching of the inner wall of the reaction chamber, is a technical problem that needs to be solved urgently. Summary of the invention

[0006] The present invention provides an atomic layer deposition device and an atomic layer deposition method, which are used to reduce the deposition of precursors on the inner wall of a reaction chamber during the implementation of the atomic layer deposition process, thereby ensuring the uniformity of the thickness of a film layer formed by the atomic layer deposition process, improving the quality of film layer deposition, and ensuring the efficiency of the atomic layer deposition process while avoiding excessive etching of the inner wall of the reaction chamber.

[0007] According to some embodiments, the present invention provides an atomic layer deposition apparatus, comprising:

[0008] A metal inner shell, wherein the metal inner shell encloses a reaction chamber, and the reaction chamber is used to accommodate the wafer;

[0009] The electric polarization layer covers the surface of the metal inner shell and is directly in contact with the metal inner shell. The electric polarization layer can form an electrostatic field on the inner wall of the reaction chamber under the action of an external electric field.

[0010] In some embodiments, it also includes:

[0011] a power supply structure, electrically connected to the electric polarization layer, and used for applying the external electric field to the electric polarization layer;

[0012] A controller is connected to the power supply structure and is used to adjust the intensity and / or direction of the external electric field applied by the power supply structure to the polarized layer, wherein the direction of the external electric field includes a forward electric field and a reverse electric field.

[0013] In some embodiments, it also includes:

[0014] A metal shell, the metal shell is located on a side of the metal inner shell away from the reaction chamber, and the metal shell is distributed around the circumference of the metal inner shell;

[0015] The electric polarization layer is sandwiched between the metal inner shell and the metal outer shell, and the electric polarization layer covers a surface of the metal inner shell facing the metal outer shell and a surface of the metal outer shell facing the metal inner shell.

[0016] In some embodiments, the electric polarization layer is a ferroelectric material layer.

[0017] In some embodiments, the material of the ferroelectric material layer is any one of lithium niobate, barium titanate and potassium sodium niobate, or a combination of two or more thereof.

[0018] In some embodiments, the electric polarization layer covers the inner surface of the metal inner shell facing the reaction chamber.

[0019] In some embodiments, the electrodeposition layer is an aluminum oxide ceramic film.

[0020] According to some other embodiments, the present invention further provides an atomic layer deposition method, comprising the following steps:

[0021] An atomic layer deposition device is provided, the atomic layer deposition device comprising a metal inner shell and an electric polarization layer covering a surface of the metal inner shell and directly contacting and connected with the metal inner shell, wherein the metal inner shell encloses a reaction chamber;

[0022] Placing a wafer into the reaction chamber;

[0023] An external electric field is applied to the electric polarization layer to form an electrostatic field on the inner wall of the reaction chamber, and a precursor is transmitted into the reaction chamber to form an atomic layer deposition film on the surface of the wafer.

[0024] In some embodiments, the specific steps of applying an external electric field to the electric polarization layer to form an electrostatic field on the inner wall of the reaction chamber and transferring the precursor into the reaction chamber include:

[0025] Applying the external electric field in a first direction to the electric polarization layer to form a first electrostatic field on the inner wall of the reaction chamber;

[0026] The precursor is transported into the reaction chamber to form precursor molecules with a first electrical property, and the first electrostatic field and the precursor molecules repel each other.

[0027] In some embodiments, the specific steps of applying the external electric field in a first direction to the electric polarization layer to form a first electrostatic field on the inner wall of the reaction chamber include:

[0028] The intensity of the external electric field in the first direction applied to the electric polarization layer is adjusted to adjust the intensity of the first electrostatic field.

[0029] In some embodiments, after forming an atomic layer deposition film on the surface of the wafer, the method further includes the following steps:

[0030] The reaction chamber is purged with gas.

[0031] In some embodiments, while the reaction chamber is being purged with gas, the following steps are also included:

[0032] The application of the external electric field in the first direction to the electric polarization layer is stopped.

[0033] In some embodiments, while the reaction chamber is being purged with gas, the following steps are also included:

[0034] The external electric field in a second direction is applied to the polarized layer to form a second electrostatic field on the inner wall of the reaction chamber. The second electrostatic field and the byproduct molecules generated during the atomic layer deposition film formation process repel each other. The first direction and the second direction are opposite to each other.

[0035] In some embodiments, the atomic layer deposition apparatus further comprises a metal outer shell located on a side of the metal inner shell away from the reaction chamber, and the metal outer shell is distributed around the periphery of the metal inner shell;

[0036] The electric polarization layer is a ferroelectric material layer sandwiched between the metal inner shell and the metal outer shell, and the electric polarization layer covers a surface of the metal inner shell facing the metal outer shell and a surface of the metal outer shell facing the metal inner shell.

[0037] In some embodiments, the electrode layer covers the inner surface of the metal inner shell facing the reaction chamber, and the electrode layer is an aluminum oxide ceramic film.

[0038] The atomic layer deposition device and atomic layer deposition method provided by the present invention cover the surface of the metal inner shell that encloses the reaction chamber with an electric polarization layer, and the electric polarization layer is electrically connected to the metal inner shell. When an external electric field is applied to the electric polarization layer, the polarization direction of the molecules inside the electric polarization layer will change, thereby forming an electrostatic field on the inner wall of the reaction chamber. The electrostatic field can produce a repulsive effect with the precursor used in the atomic layer deposition process, thereby reducing the deposition of the precursor on the inner wall of the reaction chamber during the implementation of the atomic layer deposition process, ensuring the uniformity of the thickness of the film formed by the atomic layer deposition process, and improving the quality of film deposition. At the same time, because the present invention reduces the deposition of the precursor on the inner wall of the reaction chamber through electrostatic repulsion, there is no need to use an etchant to clean and etch the reaction chamber, thereby increasing the service life of the atomic layer deposition device and improving the efficiency of atomic layer deposition. Moreover, since the present invention does not need to use an etchant to clean and etch the reaction chamber, there is no need to form a film layer on the inner wall of the reaction chamber to prevent over-etching, thereby avoiding the risk of film layer shedding and avoiding particulate contamination during the atomic layer deposition process caused by film layer shedding, thereby further improving the quality of the atomic layer deposition film layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a schematic structural diagram of an atomic layer deposition device in a specific embodiment of the present invention;

[0040] Figure 2 is a schematic diagram of the relative position relationship between a metal inner shell and an electric polarization layer in a specific embodiment of the present invention;

[0041] Figure 3 It is a polarization principle diagram of an electric polarization layer covering the surface of a metal inner shell in a specific embodiment of the present invention;

[0042] Figure 4 is a schematic structural diagram of another atomic layer deposition device in a specific embodiment of the present invention;

[0043] Figure 5 is a schematic diagram of the relative position relationship between another metal inner shell and the electric polarization layer in a specific embodiment of the present invention;

[0044] Figure 6 is a schematic structural diagram of another embodiment of the present invention in which the inner wall of the reaction chamber adsorbs byproducts;

[0045] Figure 7 It is a flow chart of the atomic layer deposition method in a specific embodiment of the present invention.

[0046] Description of Reference Numerals

[0047] 10 Reaction chamber

[0048] 11 Metal inner shell

[0049] 12. Polarization layer

[0050] 13 Metal housing

[0051] 14 Wafer

[0052] 30 External electric field

[0053] 31 Electrostatic field

[0054] 60 Precursor molecules

[0055] 61 Film-forming target molecules

[0056] 62 Byproduct molecules DETAILED DESCRIPTION

[0057] The specific implementation modes of the atomic layer deposition device and the atomic layer deposition method provided by the present invention are described in detail below with reference to the accompanying drawings.

[0058] This specific embodiment provides an atomic layer deposition device, Figure 1 is a schematic structural diagram of an atomic layer deposition device in a specific embodiment of the present invention, Figure 2 Schematic diagram of the relative position relationship between a metal inner shell and an electric polarization layer in a specific embodiment of the present invention. Figure 1 and Figure 2 As shown, the atomic layer deposition device comprises:

[0059] A metal inner shell 11, wherein the metal inner shell 11 encloses a reaction chamber 10, and the reaction chamber 10 is used to accommodate a wafer 14;

[0060] The electric polarization layer 12 covers the surface of the metal inner shell 11 and is in direct contact with the metal inner shell 11 . The electric polarization layer 12 can form an electrostatic field on the inner wall of the reaction chamber 10 under the action of an external electric field.

[0061] For example, the atomic layer deposition device includes the metal inner shell 11 and the electrodeposition layer 12 covering the surface of the metal inner shell 11, and the electrodeposition layer 12 is distributed around the periphery of the reaction chamber 10. In one example, the electrodeposition layer 12 directly covers the surface of the metal inner shell 11, that is, the electrodeposition layer 12 is in direct contact and electrically connected with the metal inner shell 11. The metal inner shell 11 encloses and forms the reaction chamber 10, and the reaction chamber 10 is used to accommodate the wafer 14, so as to perform an atomic layer deposition process on the wafer 14 in the reaction chamber 10 to form an atomic layer deposition film.

[0062] During the process of implementing the atomic layer deposition process in the reaction chamber 10 of the atomic layer deposition device, a precursor is transferred into the reaction chamber 10, and the precursor is decomposed into precursor molecules with different electrical properties (for example, positive or negative) by heat inside the reaction chamber 10. At the same time, by applying the external electric field to the polarized layer 12, the polarization direction of the polarized layer 12 is changed, thereby generating the electrostatic field (i.e., surface electric field) on the inner wall of the reaction chamber 10. According to the positive and negative charges carried by the precursor molecules after thermal decomposition, the direction of the external electric field is adjusted (for example, a forward electric field or a reverse electric field), so that the electrostatic field generated by the inner wall of the reaction chamber 10 and the precursor molecules formed after thermal decomposition can repel each other, thereby reducing the deposition of the precursor on the inner wall of the reaction chamber during the implementation of the atomic layer deposition process, ensuring the uniformity of the thickness of the film formed by the atomic layer deposition process, and improving the quality of film deposition. At the same time, since the present embodiment reduces the deposition of the precursor on the inner wall of the reaction chamber by electrostatic repulsion, there is no need to use an etchant to clean and etch the reaction chamber, thereby increasing the service life of the atomic layer deposition device and improving the efficiency of atomic layer deposition. Moreover, since the present embodiment does not need to use an etchant to clean and etch the reaction chamber, there is no need to form a film layer on the inner wall of the reaction chamber to prevent over-etching, thereby avoiding the risk of film layer shedding, and avoiding particulate contamination during the atomic layer deposition process caused by film layer shedding, thereby further improving the quality of the atomic layer deposition film layer.

[0063] In some embodiments, the atomic layer deposition apparatus further comprises:

[0064] A power supply structure, electrically connected to the electric polarization layer 12, and used for applying the external electric field to the electric polarization layer 12;

[0065] A controller is connected to the power supply structure and is used to adjust the intensity and / or direction of the external electric field applied by the power supply structure to the polarization layer 12, wherein the direction of the external electric field includes a forward electric field and a reverse electric field.

[0066] Specifically, by controlling the power supply structure by the controller to adjust the strength and / or direction (i.e., any one of the strength and direction or a combination of both) of the external electric field applied by the power supply structure to the polarized layer 12, it is not only possible to adjust the magnitude of the repulsive force between the electrostatic field on the inner wall of the reaction chamber 10 and the precursor molecules, but also possible to adsorb impurities such as byproducts generated in the atomic layer deposition process, reduce the content of impurities in the atomic layer deposition film, and further improve the quality of the atomic layer deposition film. Moreover, after the atomic layer deposition process is completed, the power supply structure can be controlled by the controller to stop applying the external electric field to the polarized layer 12 or adjust the direction of the applied external electric field, so that the impurities adsorbed on the inner wall of the reaction chamber 10 fall off from the inner wall of the reaction chamber 10, thereby facilitating the direct cleaning of the inner wall of the reaction chamber 10 by the purge process, avoiding the damage to the inner wall of the reaction chamber 10 caused by etching the inner wall of the reaction chamber 10 with a chemical etchant, and improving the service life of the atomic layer deposition device.

[0067] In some embodiments, the atomic layer deposition apparatus further comprises:

[0068] A metal shell 13, wherein the metal shell 13 is located at a side of the metal inner shell 11 away from the reaction chamber 10, and the metal shell 13 is distributed around the outer circumference of the metal inner shell 11;

[0069] The electrically polarized layer 12 is sandwiched between the metal inner shell 11 and the metal outer shell 13 , and covers the surface of the metal inner shell 11 facing the metal outer shell 13 and the surface of the metal outer shell 13 facing the metal inner shell 11 .

[0070] In some embodiments, the polarization layer 12 is a ferroelectric material layer.

[0071] In some embodiments, the material of the ferroelectric material layer is any one of lithium niobate, barium titanate and potassium sodium niobate, or a combination of two or more thereof.

[0072] For example, the ferroelectric material layer as the polarization layer 12 is sandwiched between the metal outer shell 13 and the metal inner shell 11, and the ferroelectric material layer directly covers the surface of the metal inner shell 11 facing the metal outer shell 13 and the surface of the metal outer shell 13 facing the metal inner shell 11. The ferroelectric material layer is formed by any one or more ferroelectric materials selected from lithium niobate, barium titanate and potassium sodium niobate. The ferroelectric material has an adjustable electric dipole moment. When the external electric field is applied to the ferroelectric material layer, the electric dipole moment inside the ferroelectric material will be rearranged through polarization to generate induced charges. The induced charges cause charge accumulation on the surface of the metal inner shell 11, thereby forming a surface electric field (i.e., the electrostatic field) on the surface of the metal inner shell 11 (i.e., the inner wall of the reaction chamber 10). Ferroelectric materials such as lithium niobate, barium titanate or potassium sodium niobate have spontaneous polarization characteristics and can exhibit a permanent electric dipole moment (i.e., continue to maintain its polarization state) even after the external electric field is removed, thereby continuously preventing the precursor from being deposited on the inner wall of the reaction chamber 10.

[0073] Figure 3 It is a polarization principle diagram of an electric polarization layer covering the surface of a metal inner shell in a specific embodiment of the present invention. The ferroelectric material layer is sandwiched between the metal inner shell 11 and the metal outer shell 13, so that the metal inner shell 11, the ferroelectric material layer and the metal outer shell 13 together constitute a ferroelectric capacitor structure. In order to make the ferroelectric material layer reach the desired polarization state (i.e., generate the induced charge), a voltage can be applied to the metal inner shell 11 and the metal outer shell 13, for example, by connecting the metal inner shell 11 to the negative pole of the power supply structure and the metal outer shell 13 to the positive pole of the power supply structure, thereby forming the external electric field 30 applied to the ferroelectric material layer, as shown in FIG. Figure 3 As shown in (a) in the figure. The external electric field induces the electric dipole moment of the ferroelectric material in the ferroelectric material layer to align so that its polarization direction is consistent with the direction of the external electric field. At this time, the positive charge σ in the ferroelectric material i With negative charge -σ i will be separated, such as Figure 3 As shown in (b) in FIG. 1 , an induced charge is accumulated at the interface where the ferroelectric material layer contacts the metal shell 13, and then an electrostatic field 31 is generated on the surface of the metal shell 13 (for example, the surface of the metal shell 13 facing the reaction chamber 10), as shown in FIG. Figure 3 At the same time, by applying voltage to the metal inner shell 11, the charge distribution and electronic state density on the surface of the metal inner shell 11 will also be changed, thereby affecting the interaction between the precursor and the metal inner shell 11, and further reducing the deposition of the precursor on the surface of the metal inner shell 11.

[0074] For example, the precursor is introduced into the reaction chamber 10 and is decomposed into precursor molecules with different charges by heat. If the precursor molecules are positively charged, a positive electric field is applied to the ferroelectric material layer to repel the precursor molecules, reduce their adsorption on the inner wall of the reaction chamber 10 (i.e., the surface of the metal inner shell 11), and adsorb the negatively charged free by-product molecules on the inner wall of the reaction chamber 10, reduce their contact probability with the surface of the wafer 14, and allow more precursor molecules to contact the surface of the wafer 14. After the precursor is ventilated, the reaction chamber 10 is purged with gas, and a reverse electric field is applied to the ferroelectric material layer, and the by-product molecules adsorbed on the inner wall of the reaction chamber 10 are removed by the electric field repulsion force, and the reaction chamber 10 is withdrawn. On the contrary, if the precursor molecules are negatively charged, a reverse electric field can be applied to reduce the probability of the precursor molecules being adsorbed on the inner wall of the reaction chamber 10, thereby reducing the deposition of the atomic layer deposition film on the inner wall of the reaction chamber 10. This specific embodiment can reverse the polarity direction of the ferroelectric material by applying the external electric field of different strengths and directions, so that the electrostatic field on the surface of the metal inner shell 11 is reversed, and different polarity electric fields are applied in coordination with different stages of the atomic layer deposition process (such as the deposition stage and the purge stage), thereby reducing wall deposition and reducing the risk of particle contamination.

[0075] Figure 4 is a schematic structural diagram of another atomic layer deposition device in a specific embodiment of the present invention, Figure 5 is a schematic diagram of the relative position relationship between another metal inner shell and the electric polarization layer in a specific embodiment of the present invention, Figure 6 It is a schematic diagram of the structure when the inner wall of another reaction chamber adsorbs byproducts in a specific embodiment of the present invention. In other embodiments, the electrodeposition layer 12 covers the inner surface of the metal inner shell 11 facing the reaction chamber 10 .

[0076] In some embodiments, the electrodeposition layer 12 is an aluminum oxide ceramic film.

[0077] For example, the alumina ceramic film is a polar material. When the external electric field is applied to the alumina ceramic film, the polarity of its molecules will be adjusted, resulting in the formation of an electric dipole moment inside and on the surface of the alumina ceramic film, thereby generating the electrostatic field on the surface of the alumina ceramic film. At the same time, under the action of the external electric field, the anions and cations on the surface of the alumina ceramic film facing the reaction chamber 10 are unevenly distributed, thereby also forming a surface electric field, further reducing the deposition of the precursor on the surface of the alumina ceramic film (i.e., the inner wall of the reaction chamber 10).

[0078] For example, by adjusting the direction of the applied electric field, the electrostatic field can repel the precursor molecules 60 and the film-forming target molecules 61 (i.e., the molecules used to form the atomic layer deposition film), reduce their adsorption on the surface of the alumina ceramic film, and adsorb the negatively charged free by-product molecules 62 on the surface of the alumina ceramic film, reduce their contact probability with the surface of the wafer 14, and allow more of the precursor molecules 60 and the film-forming target molecules 61 to contact the surface of the wafer 14. After the precursor ventilation is completed, when the reaction chamber 10 is gas purged, a reverse electric field is applied to the alumina ceramic film, and the by-product molecules 62 adsorbed on the surface of the alumina ceramic film are removed by the repulsive force between the electrostatic field and the by-product molecules 62, and the reaction chamber 10 is withdrawn. If the precursor molecules 60 and the film-forming target molecules 61 are negatively charged, a reverse electric field can be applied to reduce the probability of the precursor molecules 60 and the film-forming target molecules 61 being adsorbed on the surface of the alumina ceramic film, thereby reducing the deposition of the atomic layer deposition film on the inner wall of the reaction chamber. In the deposition phase of the atomic layer deposition process, changing the direction of the electric field can obtain a clean inner wall of the reaction chamber 10 without atomic layer film deposition. At the same time, a larger suction force can be applied in the purge phase, which can eliminate the risk of the film on the inner wall of the reaction chamber 10 falling off while evacuating residual process gases and by-product molecules, greatly reducing the occurrence of particulate contaminants and effectively shortening the purge time.

[0079] This specific embodiment also provides an atomic layer deposition method, Figure 7 is a flow chart of an atomic layer deposition method in a specific embodiment of the present invention. The atomic layer deposition method can be used as follows Figure 1-Figure 6 The atomic layer deposition apparatus shown is implemented. Figure 1-Figure 7 As shown, the atomic layer deposition method comprises the following steps:

[0080] Step S71, providing an atomic layer deposition device, the atomic layer deposition device comprising a metal inner shell 11 and an electric polarization layer 12 covering the surface of the metal inner shell 11 and directly contacting and connected with the metal inner shell 11, the metal inner shell 11 encloses a reaction chamber 10;

[0081] Step S72, placing the wafer 14 into the reaction chamber 10;

[0082] In step S73 , an external electric field is applied to the electric polarization layer 12 to form an electrostatic field on the inner wall of the reaction chamber 10 , and a precursor is transmitted into the reaction chamber 10 to form an atomic layer deposition film on the surface of the wafer 14 .

[0083] In some embodiments, the specific steps of applying an external electric field to the electric polarization layer 12 to form an electrostatic field on the inner wall of the reaction chamber 10 and transmitting the precursor into the reaction chamber 10 include:

[0084] Applying the external electric field in a first direction to the electric polarization layer 12 to form a first electrostatic field on the inner wall of the reaction chamber 10;

[0085] The precursor is transported into the reaction chamber 10 to form precursor molecules 60 with a first electrical property, and the first electrostatic field and the precursor molecules 60 repel each other.

[0086] In some embodiments, the specific steps of applying the external electric field in a first direction to the electric polarization layer 12 to form a first electrostatic field on the inner wall of the reaction chamber 10 include:

[0087] The intensity of the external electric field applied to the electric polarization layer 12 in the first direction is adjusted to adjust the intensity of the first electrostatic field.

[0088] Specifically, during the atomic layer deposition process in the reaction chamber 10 of the atomic layer deposition device, a precursor is transferred into the reaction chamber 10, and the precursor is decomposed into the precursor molecules 60 with a first electrical property (e.g., positive or negative) by heat inside the reaction chamber 10. The external electric field is applied to the polarized layer 12, and the polarity of the molecules inside the polarized layer 12 is adjusted, thereby generating the electrostatic field on the inner wall of the reaction chamber 10. A repulsive effect is generated between the electrostatic field and the precursor molecules 60, thereby reducing or even avoiding the adsorption of the precursor molecules 60 on the inner wall of the reaction chamber 10, ensuring the uniformity of the thickness of the film layer formed by the atomic layer deposition process, and improving the quality of film deposition. At the same time, the electrostatic field generates an attractive effect on the by-product molecules 62 generated during the implementation of the atomic layer deposition process, so as to adsorb the by-product molecules 62 on the inner surface of the reaction chamber 10, thereby reducing the probability of the by-product molecules 62 contacting the surface of the wafer 14 and improving the purity of the atomic layer deposition film formed on the surface of the wafer 14.

[0089] In some embodiments, after forming an atomic layer deposition film on the surface of the wafer 14, the following steps are further included:

[0090] The reaction chamber 10 is purged with gas.

[0091] In some embodiments, while the reaction chamber 10 is being purged with gas, the following steps are also included:

[0092] Stop applying the external electric field in the first direction to the electric polarization layer 12 .

[0093] In some embodiments, while the reaction chamber 10 is being purged with gas, the following steps are also included:

[0094] The external electric field in a second direction is applied to the electrodeposition layer 12 to form a second electrostatic field on the inner wall of the reaction chamber 10. The second electrostatic field and the byproduct molecules 62 generated during the atomic layer deposition film formation process repel each other. The first direction and the second direction are opposite to each other.

[0095] Specifically, after the deposition phase of the atomic layer deposition process is completed, the reaction chamber 10 is purged with gas (i.e., the purging phase) to remove impurities remaining in the reaction chamber 10. By stopping the application of the external electric field in the first direction to the polarized layer 12 or applying the external electric field in the second direction to the polarized layer 12, the adsorption force between the by-product molecules 62 and the inner wall of the reaction chamber 10 can be reduced, so that the by-product molecules can be quickly purged to the outside of the reaction chamber, which helps to shorten the gas purging time and further improve the efficiency of the atomic layer deposition process.

[0096] In some embodiments, the atomic layer deposition apparatus further includes a metal outer shell 13 located on a side of the metal inner shell 11 away from the reaction chamber 10 , and the metal outer shell 13 is distributed around the periphery of the metal inner shell 11 ;

[0097] The polarized layer 12 is a ferroelectric material layer sandwiched between the metal inner shell 11 and the metal outer shell 13, and the polarized layer 12 covers the surface of the metal inner shell 11 facing the metal outer shell 13 and the surface of the metal outer shell 13 facing the metal inner shell 11, see Figure 1-Figure 3 .

[0098] In some other embodiments, the electrode layer 12 covers the inner surface of the metal inner shell 11 facing the reaction chamber 10, and the electrode layer 12 is an aluminum oxide ceramic film, see Figure 4-Figure 6 .

[0099] The atomic layer deposition device and atomic layer deposition method provided in this specific embodiment are provided by covering the surface of the metal inner shell that encloses the reaction chamber with an electric polarization layer, and the electric polarization layer is electrically connected to the metal inner shell. When an external electric field is applied to the electric polarization layer, the polarization direction of the molecules inside the electric polarization layer will change, thereby forming an electrostatic field on the inner wall of the reaction chamber. The electrostatic field can produce a repulsive effect with the precursor used in the atomic layer deposition process, thereby reducing the deposition of the precursor on the inner wall of the reaction chamber during the implementation of the atomic layer deposition process, ensuring the uniformity of the thickness of the film formed by the atomic layer deposition process, and improving the deposition quality of the film. At the same time, because the present specific embodiment reduces the deposition of the precursor on the inner wall of the reaction chamber through electrostatic repulsion, there is no need to use an etchant to clean and etch the reaction chamber, thereby increasing the service life of the atomic layer deposition device and increasing the efficiency of atomic layer deposition. Moreover, since the present specific embodiment does not require the use of an etchant to clean and etch the reaction chamber, there is no need to form a film layer on the inner wall of the reaction chamber to prevent over-etching, thereby avoiding the risk of film layer shedding and particulate contamination during the atomic layer deposition process caused by film layer shedding, thereby further improving the quality of the atomic layer deposition film layer.

[0100] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An atomic layer deposition device, characterized in that: include: A metal inner shell, wherein the metal inner shell encloses a reaction chamber, and the reaction chamber is used to accommodate the wafer; The electric polarization layer covers the surface of the metal inner shell and is directly in contact with the metal inner shell. The electric polarization layer can form an electrostatic field on the inner wall of the reaction chamber under the action of an external electric field.

2. The atomic layer deposition device according to claim 1, characterized in that: Also includes: a power supply structure, electrically connected to the electric polarization layer, and used for applying the external electric field to the electric polarization layer; A controller is connected to the power supply structure and is used to adjust the intensity and / or direction of the external electric field applied by the power supply structure to the polarized layer, wherein the direction of the external electric field includes a forward electric field and a reverse electric field.

3. The atomic layer deposition device according to claim 1, characterized in that: Also includes: A metal shell, the metal shell is located on a side of the metal inner shell away from the reaction chamber, and the metal shell is distributed around the outer circumference of the metal inner shell; The electric polarization layer is sandwiched between the metal inner shell and the metal outer shell, and the electric polarization layer covers a surface of the metal inner shell facing the metal outer shell and a surface of the metal outer shell facing the metal inner shell.

4. The atomic layer deposition device according to claim 3, characterized in that: The electric polarization layer is a ferroelectric material layer.

5. The atomic layer deposition device according to claim 4, characterized in that: The material of the ferroelectric material layer is any one of lithium niobate, barium titanate and potassium sodium niobate, or a combination of two or more thereof.

6. The atomic layer deposition device according to claim 1, characterized in that: The electric polarization layer covers the inner surface of the metal inner shell facing the reaction chamber.

7. The atomic layer deposition device according to claim 6, characterized in that: The electrode layer is an aluminum oxide ceramic film.

8. An atomic layer deposition method, characterized in that: The steps include: An atomic layer deposition device is provided, the atomic layer deposition device comprising a metal inner shell and an electric polarization layer covering a surface of the metal inner shell and directly contacting and connected with the metal inner shell, wherein the metal inner shell encloses a reaction chamber; Placing a wafer into the reaction chamber; An external electric field is applied to the electric polarization layer to form an electrostatic field on the inner wall of the reaction chamber, and a precursor is transmitted into the reaction chamber to form an atomic layer deposition film on the surface of the wafer.

9. The atomic layer deposition method according to claim 8, characterized in that: The specific steps of applying an external electric field to the electric polarization layer, forming an electrostatic field on the inner wall of the reaction chamber, and transmitting the precursor into the reaction chamber include: Applying the external electric field in a first direction to the electric polarization layer to form a first electrostatic field on the inner wall of the reaction chamber; The precursor is transported into the reaction chamber to form precursor molecules with a first electrical property, and the first electrostatic field and the precursor molecules repel each other.

10. The atomic layer deposition method according to claim 9, characterized in that: The specific steps of applying the external electric field in a first direction to the electric polarization layer to form a first electrostatic field on the inner wall of the reaction chamber include: The intensity of the external electric field in the first direction applied to the electric polarization layer is adjusted to adjust the intensity of the first electrostatic field.

11. The atomic layer deposition method according to claim 9, characterized in that: After forming an atomic layer deposition film on the surface of the wafer, the method further includes the following steps: The reaction chamber is purged with gas.

12. The atomic layer deposition method according to claim 11, characterized in that: While the reaction chamber is being purged with gas, the following steps are also included: The application of the external electric field in the first direction to the electric polarization layer is stopped.

13. The atomic layer deposition method according to claim 11, characterized in that: While the reaction chamber is being purged with gas, the following steps are also included: The external electric field in a second direction is applied to the polarized layer to form a second electrostatic field on the inner wall of the reaction chamber. The second electrostatic field and the byproduct molecules generated during the atomic layer deposition film formation process repel each other. The first direction and the second direction are opposite to each other.

14. The atomic layer deposition method according to claim 8, characterized in that: The atomic layer deposition device further comprises a metal outer shell located on a side of the metal inner shell away from the reaction chamber, and the metal outer shell is distributed around the periphery of the metal inner shell; The electric polarization layer is a ferroelectric material layer sandwiched between the metal inner shell and the metal outer shell, and the electric polarization layer covers a surface of the metal inner shell facing the metal outer shell and a surface of the metal outer shell facing the metal inner shell.

15. The atomic layer deposition method according to claim 8, characterized in that: The electrode polarization layer covers the inner surface of the metal inner shell facing the reaction chamber, and the electrode polarization layer is an aluminum oxide ceramic film.

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