Atomic layer deposition method and atomic layer deposition device

Abstract

The present application proposes an atomic layer deposition method and an atomic layer deposition device. N wafers are placed on a turntable below a process chamber. In the first step, deposition source gas and purge gas are introduced into the process chamber to perform a deposition reaction, so that an atomic layer deposition film layer of a preset first thickness is formed on each wafer. In the second step, the deposition source gas is stopped from entering the process chamber but purge gas is introduced, and the turntable is controlled to rotate by a first angle θ, where n*θ=360 degrees. The first and second steps are repeated n-1 times. After the repetition is completed, the first step is performed again to form an atomic layer deposition film layer of a preset thickness on each wafer. The present application can improve the thickness difference of the atomic layer deposition film layer on each wafer.

Description

Technical Field

[0001] The present application relates to the technical field of atomic layer deposition (ALD), and in particular to an atomic layer deposition method and an atomic layer deposition device. Background Art

[0002] Atomic layer deposition (ALD) is a method for depositing thin films on substrates (such as wafers) in a very precisely controlled manner. It is mainly controlled by using two or more gaseous chemicals (i.e., "process gases" or "deposition source gases") to allow the process gases to react continuously in a self-limiting manner on the surface of the substrate. This continuous process is repeated to build up the thin film layer by layer.

[0003] The atomic layer deposition process is generally performed through a process chamber and a turntable. The turntable is arranged below the process chamber. The process chamber includes a deposition chamber for introducing a deposition source gas and a purge chamber for introducing a purge gas. The rotation of the turntable drives the multiple wafers carried thereon to move back and forth between the deposition chamber and the purge chamber in turn, so that an atomic layer deposition film of the expected thickness is formed on each wafer. However, before and after the rotation of the turntable, the position of each wafer relative to the process chamber does not change. The same wafer is still located in the same process chamber (or it can be a part of each wafer in two adjacent wafers). Therefore, compared with other wafers on the turntable, the initial position and final position of the wafer are both near the deposition chamber, and the residence time in the deposition chamber is longer. The residual deposition gas will make the atomic layer deposition film deposited thicker, and ultimately the thickness of the atomic layer deposition film formed on each wafer is quite different. Summary of the Invention

[0004] In view of this, the present application provides an atomic layer deposition method and an atomic layer deposition apparatus, which can improve the problem of large differences in thickness of atomic layer deposition films formed on various wafers.

[0005] The present application provides an atomic layer deposition method, comprising:

[0006] Place n wafers on a turntable below the process chamber;

[0007] In the first step, a deposition source gas and a purge gas are introduced into the process chamber to perform a deposition reaction, so that an atomic layer deposition film layer of a preset first thickness is formed on each of the wafers;

[0008] In a second step, the deposition source gas is stopped from flowing into the process chamber, but the purge gas is introduced, and the turntable is controlled to rotate at a first angle θ;

[0009] Repeat the first step and the second step n-1 times, and after completing the n-1 repetitions of the first step and the second step, perform the first step again, where n*θ=360 degrees, so that an atomic layer deposition film layer of a preset thickness is formed on each of the wafers.

[0010] Optionally, the deposition source gas is introduced into the first chamber of the process chamber;

[0011] Placing n wafers on a turntable below a process chamber includes:

[0012] Along the line of sight perpendicular to the turntable, the first chamber accommodates only one wafer, or accommodates a portion of each wafer of two adjacent wafers.

[0013] Optionally, while executing the first step and / or the second step, the method further includes: controlling each of the wafers to rotate around its own central axis.

[0014] Optionally, controlling each wafer to rotate around its own central axis includes the following:

[0015] Controlling the wafer moved into the first chamber to rotate around its central axis;

[0016] Controlling each of the wafers to rotate about its own central axis in a first direction, and the turntable to rotate synchronously in a second direction, wherein the first direction and the second direction are opposite;

[0017] Each wafer is controlled to rotate around its own central axis in a first direction and at a first speed, and the turntable is synchronously rotated in a second direction and at a second speed. The first direction and the second direction are the same, and the first speed and the second speed are different.

[0018] Optionally, when executing the first step each time, the turntable rotates for the number of turns x1, x2...x n The rotation time of the turntable is t1, t2...t n The turntable rotates at a constant speed r when performing the first step and the second step. When the turntable rotates at a constant speed r for M turns to form an atomic layer deposition film of a preset thickness, the time is T, T = M / r. Then x1+x2+...+x n =M, and t1+t2+...+t n =T.

[0019] Optionally, in the first step and the second step, the flow rate of the purge gas is the same.

[0020] Optionally, while controlling the turntable to rotate, the method further includes:

[0021] At the junction of two chambers into which the deposition source gas and the purge gas are respectively introduced, the gas diffused from one chamber toward the other chamber is extracted.

[0022] Optionally, the deposition source gas includes a first process gas and a second process gas, the first process gas includes a gas containing zirconium, manganese, zinc sulfide or aluminum, the second process gas includes ozone, and the purge gas includes an inert gas.

[0023] The present application provides an atomic layer deposition apparatus for performing the atomic layer deposition method as described in any one of the above items, the apparatus comprising:

[0024] The process chamber comprises a first chamber for introducing a deposition source gas and a second chamber for introducing a purge gas, wherein the first chamber and the second chamber are separated by a partition;

[0025] The turntable is arranged below the process chamber and is used for carrying and rotating n wafers so that each wafer moves between the first chamber and the second chamber to form an atomic layer deposition film.

[0026] Optionally, the device further comprises: a pump for extracting gas diffused from one of the first chamber and the second chamber toward the other.

[0027] Optionally, the deposition source gas includes a first process gas and a second process gas, the first process gas contains a metal element, and the second process gas is an oxygen-containing gas;

[0028] The first chamber includes a first deposition chamber and a second deposition chamber, the first deposition chamber is used to introduce the first process gas, and the second deposition chamber is used to introduce the second process gas;

[0029] The second chamber includes a first purge chamber and a second purge chamber;

[0030] The process chamber further comprises a third chamber for loading and unloading the wafer;

[0031] The first purge chamber, the first deposition chamber, the second purge chamber, the second deposition chamber and the third chamber are sequentially arranged along the rotation direction of the turntable;

[0032] Along the line of sight perpendicular to the wafer, the first deposition chamber is fan-shaped with an angle of θ1, the second deposition chamber is fan-shaped with an angle of θ2, the first purge chamber and the second purge chamber are both fan-shaped with an angle of θ3, the third chamber is fan-shaped with an angle of θ4, and θ1=60°, θ2=120°, θ3=60°, and θ4=60°.

[0033] As described above, after completing the first step and the second step repeated n-1 times, the position of each wafer is one wafer different from that before the turntable rotates, so that the time each wafer is in the process chamber is equal, and then the first step is performed. The first step will not cause the position of each wafer relative to the process chamber to change, so that the position of each wafer is still one wafer different from that before the turntable rotates; here, in the entire deposition reaction process, the starting position and final position of each wafer are changed n-1 times, so the residence time of each wafer in the deposition chamber is equal, resulting in equal length of time for the deposition reaction, which can improve and even eliminate the thickness difference of the atomic layer deposition film on each wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of a process for atomic layer deposition provided in an embodiment of the present application;

[0035] Figure 2 A structural perspective diagram of an atomic layer deposition device provided in an embodiment of the present application;

[0036] Figure 3 A top view of the structure of an atomic layer deposition device provided in an embodiment of the present application;

[0037] Figure 4 A top view of a turntable provided in an embodiment of the present application on which multiple wafers are placed;

[0038] Figure 5 Based on Figure 1 Schematic diagram of the scenario of atomic layer deposition by the method;

[0039] Figure 6 A top view of the structure of another atomic layer deposition device provided in an embodiment of the present application;

[0040] Figure 7 Graph showing thickness variation of the atomic layer deposition films of Comparative Example 1 and Example 1. DETAILED DESCRIPTION

[0041] To make the objectives, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly described below in conjunction with specific embodiments and corresponding drawings. Obviously, the embodiments described below are only some of the embodiments of this application, not all of them. Unless there is a conflict, the following embodiments and their technical features can be combined with each other and also belong to the technical solutions of this application.

[0042] In the description of the embodiments of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the technical solutions of the corresponding embodiments, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and should not be understood as a limitation on the present application.

[0043] like Figure 1 FIG. 1 is a flow chart of an atomic layer deposition method provided in an embodiment of the present application. The atomic layer deposition method includes at least the following steps S11 to S13.

[0044] S11: Place n wafers on a turntable below the process chamber.

[0045] S12: introducing deposition source gas and purge gas into the process chamber to perform a deposition reaction, so as to form an atomic layer deposition film layer with a preset first thickness on each wafer.

[0046] S13: Stop introducing the deposition source gas into the process chamber but introduce the purge gas, and control the turntable to rotate by a first angle θ, where n*θ=360 degrees.

[0047] After each execution of step S12, step S13 is executed once until step S12 and step S13 are repeated n-1 times. After completing the n-1 and n-1 repetitions of step S12 and step S13, step S12 is executed once more until an atomic layer deposition film layer of a preset thickness is formed on each wafer, thereby completing the atomic layer deposition process.

[0048] In step S12, the turntable drives the wafer to rotate so as to move back and forth between the chambers into which the deposition source gas and the purge gas are introduced respectively, to perform a deposition reaction, which can be regarded as a traditional ALD process.

[0049] The deposition source gas can form a film layer on the wafer surface through a chemical reaction, and form a film layer on the ALD film layer formed on the wafer surface. The deposition source gas includes one or more gases, for example, the deposition source gas includes a first process gas and a second process gas, the first process gas is a gas containing, for example, zirconium, manganese, zinc sulfide, or aluminum, including but not limited to a gas containing any of Al2O3 (aluminum oxide), ZrO2 (zirconium oxide), TiO2 (titanium oxide), HfO2 (hafnium dioxide), MnO (manganese oxide), and ZnS (zinc sulfide), and the second process gas is ozone.

[0050] The purge gas is a non-reactive gas that does not chemically react in any substantial way with the wafer surface or the ALD film formed thereon. In this implementation, the purge gas includes, but is not limited to, at least one of nitrogen and an inert gas.

[0051] In step S12, the turntable rotates an integer number of circles. However, no matter how many circles the turntable rotates, the position of each wafer relative to the process chamber (including the position relative to the deposition chamber) does not change before and after the rotation.

[0052] In step S13, only the purge gas is introduced, so no deposition reaction occurs. In one example, the flow rate of the purge gas in step S12 and step S13 is the same, for example, both are 5000 sccm.

[0053] Since the turntable carries n wafers, based on n*θ=360 degrees, the turntable is controlled to rotate clockwise by θ degrees. Each time step S13 is executed once, the position of each wafer relative to the process chamber differs by one wafer compared to the previous step S12. That is, along the direction of turntable rotation, for any two adjacent wafers, the latter wafer replaces the position of the previous wafer. Similarly, each wafer advances one wafer position along the direction of turntable rotation. Next, step S12 and step S13 are executed for the second time; and so on, until after the n-1th step S12 and step S13 are executed, the position of n wafers relative to the process chamber has retreated one wafer position along the direction of rotation. Finally, step S12 is executed for the nth time, the turntable rotates clockwise and drives each wafer to rotate an integer number of circles. After stopping, each wafer still maintains the position after the n-1th step S13.

[0054] The entire ALD process executes step S12 n times and step S13 n-1 times. Each wafer enters the deposition chamber an equal number of times, and the starting position and final position of each wafer change n-1 times. Therefore, the residence time of each wafer in the deposition chamber is equal, so that the length of time for the deposition reaction of each wafer is equal, thereby improving or even eliminating the thickness difference of the atomic layer deposition film on each wafer.

[0055] The atomic layer deposition method of the present application is implemented by a process chamber and a turntable. Figure 2 and Figure 3 The atomic layer deposition apparatus shown is described.

[0056] For ease of description and understanding of the present application, the height direction of the process chamber and the turntable (i.e., the gravity direction g) is referred to as the second direction y below, and a three-dimensional rectangular coordinate system is established with the second direction y as one of the coordinate axes. The positive directions of the other two coordinate axes of the three-dimensional rectangular coordinate system are respectively referred to as the first direction x and the third direction z, and the first direction x, the second direction y, and the third direction z are perpendicular to each other. It should be understood that the so-called perpendicularity in the entire application does not require that the angle between the two must be 90°, but rather allows for a deviation of, for example, ±10°, i.e., the so-called perpendicularity can be understood as the angle between any two directions being 80° to 100°. Similarly, the so-called parallelism in the entire application does not require that the angle between the two must be 0° or 180°, but rather allows for a deviation of, for example, ±10°, i.e., the so-called parallelism can be understood as the angle between any two directions being 0° to 10° or 170° to 190°.

[0057] Combine Figure 2 and Figure 3 As shown, the process chamber 2 includes a shell 21, and the shell 21 has a side wall 211 and a top wall 212. In order to facilitate the display of the structural design inside the shell 21, Figure 3 The top wall 212 is not shown in the top view of the structure. The side wall 211 is a structure connected end to end, and forms the overall appearance of the process chamber 2. The side wall 211 and the shell 21 have a central axis O1; in one example, the side wall 211 is cylindrical and has a circular cross-section, that is, the xz cross-section is circular; in another example, the side wall 211 of the shell 21 can have any suitable cross-sectional (i.e., xz cross-section) shape, such as any suitable polygon such as a hexagon. The top and bottom ends of the side walls 211 connected end to end are both open, and the edge of the top wall 212 is connected to the side wall 211 to cover the opening at the top, while the bottom end is not provided with a shielding structure, so it is still open. The shell 21 of the process chamber 2 is hollow inside and has a height (which can be called internal height) H, that is, the minimum distance between the top wall 212 and the bottom end of the shell 21.

[0058] A plurality of partitions 22 are disposed within the housing 21. In one example, each partition 22 is a plate-like or sheet-like member with two opposite side surfaces being planar. Each partition 22 extends radially from the central axis O1 (or central axis O2) to the inner surface of the sidewall 211 of the housing 21. The plurality of partitions 22 define a plurality of chambers within the housing 21, including a process chamber and a purge chamber. For ease of description, the chamber for introducing deposition source gas may be referred to as a first chamber, and the chamber for introducing purge gas may be referred to as a second chamber. The first and second chambers are separated by the partitions 22. The number, size, and shape of each type of chamber may be determined based on the specific type of deposition source gas.

[0059] exist Figure 2 In an example shown, four partitions 22 are provided inside the shell 21, which are marked as 22A, 22B, 22C and 22D respectively. The four partitions 22 are arranged in sequence in the clockwise direction and define four chambers arranged in sequence in the clockwise direction, which are marked as 21A, 21B, 21C and 21D respectively; wherein, the partition 22A and the partition 22B cooperate with the side wall 211 to define the chamber 21A, the partition 22B and the partition 22C cooperate with the side wall 211 to define the chamber 21B, the partition 22C and the partition 22D cooperate with the side wall 211 to define the chamber 21C, the partition 22D and the partition 22A cooperate with the side wall 211 to define the chamber 21D, the chamber 21A and the chamber 21C can be the first chamber for introducing the deposition source gas, and the chamber 21B and the chamber 21D can be the second chamber for introducing the purge gas. In other examples, the partitions 22 may be arranged such that all chambers have substantially the same size and shape.

[0060] The cross-sectional shapes of the turntable 3 and the process chamber 2 can be the same, for example, Figure 2 The central axis O3 of the turntable 3 can be located on the same straight line as the central axis O1 of the process chamber 2 along the second direction y, and the radius of the turntable 3 is greater than or equal to the cross-sectional radius of the sidewall 211. The central axis O3 of the turntable 3. The upper surface of the turntable 3 is configured to support a plurality of wafers to be processed (e.g. Figure 3 six wafers shown). Figure 3 This is a view observed along the line of sight of the housing 21 toward the turntable 3 , in which the four dotted lines show exemplary positions of the four partitions 22 above the turntable 3 .

[0061] In one example, the turntable 3 is an electrostatic chuck for holding the wafer in place and keeping the wafer flat. The turntable 3 is arranged adjacent to the bottom end of the shell 21 and is spaced apart from the bottom end along the second direction y to define a gap. Optionally, the gap is between 50 microns and 500 microns. In another example, the upper surface of the turntable 3 can be provided with recesses (not shown), each recess can accommodate a wafer, so that the upper surface of the wafer accommodated in the corresponding groove can be flush with the upper surface of the turntable 3, or lower than the upper surface of the turntable 3. In one example, at least one of the turntable 3 and the shell 21 of the process chamber 2 can be moved along the second direction y, so that the gap between the turntable 3 and the bottom end of the shell 21 can be adjusted, and the wafer can be operably arranged on the upper surface of the turntable 3.

[0062] In one example, the wafers may be fixed relative to the turntable 3 , and the turntable 3 rotates to synchronously drive the wafers to rotate synchronously, that is, the rotation speed and rotation direction of the two are exactly the same.

[0063] In another example, while executing step S12 and step S13, the present application may control each wafer to rotate around its own central axis, including at least one of the following situations:

[0064] Case 1: The wafer moved into the first chamber is controlled to rotate around its own central axis.

[0065] Combine Figure 4 as well as Figure 5 As shown in the first figure, at the current moment, wafers 1, 6, and 3 are moved into the first chamber, and wafers 1, 6, and 3 rotate around their respective central axes (i.e., rotate on their own). The rotation directions and rotation rates of the three can be the same or different; the other wafers 2, 4, and 5 are in the second chamber and do not rotate on their own, but are only driven to rotate by the turntable 3.

[0066] Case 2: Each wafer is controlled to rotate around its own central axis in a first direction, and the turntable 3 rotates synchronously in a second direction, wherein the first direction and the second direction are opposite.

[0067] Case 3: Control each wafer to rotate around its own central axis in a first direction and at a first speed, and the turntable 3 rotates synchronously in a second direction and at a second speed. The first direction and the second direction are the same, and the first speed and the second speed are different.

[0068] In Case 2 and Case 3, the rotation of any wafer and the turntable 3 are different, and the two do not rotate synchronously, which can make the film layers deposited on each wafer more uniform.

[0069] While controlling the turntable 3 to rotate, the present application can extract the gas that diffuses from one chamber toward the other chamber at the junction of the two chambers into which the deposition source gas and the purge gas are respectively introduced. For example, a pump is set at the bottom (or top) of part or all of the partition 22, and extraction is performed through the pump to prevent the gas from any chamber from diffusing into other chambers (including adjacent chambers), thereby avoiding contamination caused by the mutual circulation of gases between chambers and adverse effects on the deposition reaction.

[0070] In the present application, when executing any step S12 and any step S13, the number of revolutions that the turntable 3 drives each wafer to rotate can be determined according to the thickness and / or duration of the atomic layer deposition film to be formed, but must be an integer number of revolutions. For example, when executing each step S12, the number of revolutions that the turntable 4 rotates is x1, x2...x n The rotation time of the turntable 4 is t1, t2...t n ; The turntable 3 rotates at a constant speed r when executing step S12 and step S13; when the turntable 3 rotates at a constant speed r for M turns to form an atomic layer deposition film of a preset thickness, the time is T, and the relationship T=M / r is satisfied; then x1+x2+...+x n =M, and t1+t2+...+t n = T. For another example, the first thickness of the atomic layer deposition film formed by each execution of step S12 may be equal or unequal.

[0071] It should be understood that Figures 2 to 5 The structural designs of the process chamber 2 and the turntable 3 shown in the figure are merely exemplary and do not limit the atomic layer deposition apparatus.

[0072] For example, in a scenario where the deposition source gas includes a first process gas and a second process gas, the first process gas contains a metal element, and the second process gas is an oxygen-containing gas; see Figure 6As shown, another example of an atomic layer deposition apparatus provided by the present application includes five partitions 22 , which are marked as 22E, 22F, 22G, 22H, and 22J in a clockwise direction. Among them, partition 22E and partition 22F cooperate with the corresponding area of ​​side wall 211 to define chamber 21E, partition 22F and partition 22G cooperate with the corresponding area of ​​side wall 211 to define chamber 21F, partition 22G and partition 22H cooperate with the corresponding area of ​​side wall 211 to define chamber 21G, partition 22H and partition 22J cooperate with the corresponding area of ​​side wall 211 to define chamber 21H, and partition 22J and partition 22E cooperate with the corresponding area of ​​side wall 211 to define chamber 21J; chamber 21E and chamber 21H can be the first chamber for introducing deposition source gas, and chamber 21F and chamber 21J can be the second chamber for introducing purge gas.

[0073] Chamber 21E is the first deposition chamber, used to introduce the first process gas; chamber 21H is the second deposition chamber, used to introduce the second process gas. Chamber 21F is the first purge chamber, and chamber 21J is the second purge chamber, both of which are used to introduce purge gas. Chamber 21G can be called the third chamber, used for loading and unloading any of the aforementioned wafers. The first purge chamber, first deposition chamber, second purge chamber, second deposition chamber, and third chamber are arranged in sequence along the rotation direction (clockwise) of turntable 3.

[0074] Along the line of sight of the second direction y, chamber 21E is fan-shaped with an angle of θ1, chamber 21H is fan-shaped with an angle of θ2, chamber 21F and chamber 21J are both fan-shaped with an angle of θ3, and chamber 21G is fan-shaped with an angle of θ4. In one example, θ1 = 60°, θ2 = 120°, θ3 = 60°, and θ4 = 60°.

[0075] Should Figure 6 The atomic layer deposition apparatus shown in FIG. 1 performs the specific process and principle of the atomic layer deposition method described above, which can be referred to in the aforementioned Figures 2 to 5 The examples shown are not repeated here.

[0076] The embodiments of the present application also provide other examples of atomic layer deposition devices for performing the atomic layer deposition method described in any of the above embodiments, and the device also includes a process chamber and a turntable.

[0077] The process chamber includes a first chamber for introducing a deposition source gas and a second chamber for introducing a purge gas, wherein the first chamber and the second chamber are separated by a partition.

[0078] The turntable is arranged below the process chamber and is used for carrying and rotating n wafers so that each wafer moves between the first chamber and the second chamber to form an atomic layer deposition film layer.

[0079] It should be understood that the atomic layer deposition device provided in the embodiment of the present application is a complete atomic layer deposition device, and also has the structure of a known atomic layer deposition device. This article only describes the components of the atomic layer deposition device involved in atomic layer deposition, and does not elaborate on other components.

[0080] The atomic layer deposition apparatus and the atomic layer deposition method are based on the same concept and solve problems in substantially the same or similar ways. The embodiments of each claimed subject matter may refer to each other. For example, the atomic layer deposition apparatus further includes a pump configured to extract gas diffusing from one of the first chamber and the second chamber toward the other. Therefore, the two claimed subjects have at least the same beneficial effects, and any repetitions are omitted here.

[0081] The following is an exemplary description of the technical solution of this application through specific embodiments:

[0082] Example 1

[0083] Atomic layer deposition equipment and ALD process used:

[0084] Combine Figure 2 and Figure 3 The process chamber 2 and the turntable 3 are shown, and Figure 4 and Figure 5 The atomic layer deposition process is described by taking six wafers as an example. In this example, the deposition source gases include ZrO2 (ie, the first process gas) and ozone (ie, the second process gas), and the purge gas is nitrogen.

[0085] like Figure 4 As shown, in step S11, six wafers are placed on the upper surface of the turntable 3, where n=6. The six wafers are marked as 1 to 6 along the rotation direction of the turntable 3 (taking the clockwise direction as shown by the arrow in the figure as an example). Figure 4 In the illustrated example, along a line of sight perpendicular to turntable 3, chamber 21C accommodates only one wafer (e.g., wafer 3 shown in the figure), while chamber 21A accommodates a portion of each of two adjacent wafers (e.g., wafers 1 and 6 shown in the figure). In other examples, a single deposition chamber of process chamber 2 may accommodate only one wafer, or may accommodate a portion of each of two adjacent wafers.

[0086] Combine Figure 2 、 Figure 3 and Figure 5As shown, in step S12 executed for the first time, the wafers 1 to 6 are driven by the turntable 3 to move back and forth between the chambers of the process chamber 2, for example, the turntable 3 rotates 9 times, so that the atomic layer deposition film layer of the preset first thickness is reached on the surface of the wafers 1 to 6.

[0087] Then execute the first step S13. Since the turntable 3 carries six wafers, based on n*θ=360 degrees, the first angle θ is 60 degrees; the turntable 3 is controlled to rotate 60 degrees clockwise, and the position of each wafer relative to the process chamber 2 is one wafer different from that after the previous step S12. For example, wafer 1 replaces the position of wafer 6, wafer 2 replaces the position of wafer 1, and so on. Each wafer advances the position of one wafer along the rotation direction of the turntable 3.

[0088] Then, the second step S12 and the second step S13 are executed; and so on, until the fifth step S12 and the fifth step S13 are executed, the positions of the wafers 1 to 6 relative to the process chamber 2 are as follows: Figure 5 As shown in the last figure, each wafer retreats one wafer position along the rotation direction. Finally, the sixth step S12 is executed, the turntable 3 rotates clockwise and drives the wafers 1 to 6 to rotate an integer number of circles. After stopping, the wafers 1 to 6 remain as shown. Figure 5 The position shown in the last picture.

[0089] The entire ALD process executes step S12 six times and step S13 five times. The residence time of each wafer in the deposition chamber is equal, so that the deposition reaction time of each wafer is equal, thereby improving or even eliminating the thickness difference of the atomic layer deposition film on each wafer.

[0090] Comparative Example 1

[0091] The atomic layer deposition apparatus, wafers undergoing deposition, deposition source gas, purge gas, and total deposition time used in Comparative Example 1 and Example 1 are identical. The difference lies in the atomic layer deposition method. Comparative Example 1 employs a conventional ALD process, i.e., step S12 of the present application. Therefore, the position of each wafer relative to the process chamber remains unchanged before and after the turntable rotates.

[0092] Deposition time (s) 2080 Rotation speed (rpm) 1.5 Chamber pressure (Torr) 2 <![CDATA[ZrO2 flow rate (sccm)]]> 500 <![CDATA[N2 flow rate (sccm)]]> 5000 <![CDATA[O3 flow rate (sccm)]]> 100

[0093] Table 1

[0094] First step S12 First step S13 Second step S12 Second step S13 The third step S12 The third step S13 4th step S12 4th step S13 5th step S12 5th step S13 6th step S12 Deposition time (s) 360 6.7 360 6.7 360 6.7 360 6.7 320 6.7 320 Rotation speed (rpm) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Chamber pressure (Torr) 2 2 2 2 2 2 2 2 2 2 2 <![CDATA[ZrO2 flow rate (sccm)]]> 500 0 500 0 500 0 500 0 500 0 500 <![CDATA[N2 flow rate (sccm)]]> 5000 5000 5000 5000 5000 5000 5000 5000 5000 5000 5000 <![CDATA[O3 flow rate (sccm)]]> 100 100 100 100 100 100 100 100 100 100 100

[0095] Table 2

[0096] As shown in Tables 1 and 2, in Comparative Example 1 and Example 1, the turntable rotated at a speed of 1.5 rpm, 40 seconds per revolution, and a 60° rotation took 6.7 seconds, resulting in a total deposition time of 2080 seconds for the entire ALD process. In Example 1, step S12 was performed six times, with the number of revolutions being 9, 9, 9, 9, 8, and 8, respectively, for deposition times of 360, 360, 360, 360, 320, and 320 seconds, respectively. Step S13 was performed five times, each lasting 6.7 seconds. During each execution of step S13, the first process gas (ZrO2) was stopped, while the second process gas (O3) was continued.

[0097] like Figure 7 The figure shows the thickness variation trend of the ALD films in Comparative Example 1 and Example 1. The vertical axis represents the thickness of the ALD films, and the horizontal axis represents the process time of six wafers. The results show that compared with the traditional ALD method (Comparative Example 1), the thickness of the ALD films formed on each wafer in the embodiment of the present application has less variation.

[0098] The above descriptions are only some embodiments of the present application and do not limit the patent scope of the present application. For ordinary technicians in this field, any equivalent structural changes made using the contents of this specification and drawings are also included in the patent protection scope of the present application.

[0099] Although the terms "first," "second," and the like are used herein to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. In addition, the singular forms "a," "an," and "the" are intended to include the plural forms as well. The terms "or" and "and / or" are to be interpreted as inclusive, meaning any one or any combination. Exceptions to this definition occur only when a combination of elements, functions, steps, or operations is inherently mutually exclusive in some manner.

Claims

1. An atomic layer deposition method, characterized in that: include: placing n wafers on a turntable below a process chamber, wherein the process chamber includes a first chamber for introducing a deposition source gas and a second chamber for introducing a purge gas, wherein the first chamber and the second chamber are separated by a partition; In the first step, a deposition source gas and a purge gas are introduced into the process chamber to perform a deposition reaction, and the turntable is rotated to move each of the wafers between the first chamber and the second chamber, and an atomic layer deposition film layer having a preset first thickness is formed on each of the wafers; In a second step, the deposition source gas is stopped from flowing into the process chamber, but the purge gas is introduced, and the turntable is controlled to rotate at a first angle θ; Repeat the first step and the second step n-1 times. After completing the n-1 repetitions of the first step and the second step, perform the first step again, wherein the turntable rotates an integer number of circles, n*θ=360 degrees, and each wafer enters the process chamber an equal number of times, so that an atomic layer deposition film layer of a preset thickness is formed on each wafer.

2. The method according to claim 1, characterized in that Placing n wafers on a turntable below a process chamber includes: Along the line of sight perpendicular to the turntable, the first chamber accommodates only one wafer, or accommodates a portion of each wafer of two adjacent wafers.

3. The method according to claim 1 or 2, characterized in that While performing the first step and / or the second step, the method further includes: Each of the wafers is controlled to rotate around its own central axis.

4. The method according to claim 3, characterized in that The controlling each wafer to rotate around its own central axis includes the following: Controlling the wafer moved into the first chamber to rotate around its central axis; Controlling each of the wafers to rotate about its own central axis in a first direction, and the turntable to rotate synchronously in a second direction, wherein the first direction and the second direction are opposite; Each wafer is controlled to rotate around its own central axis in a first direction and at a first speed, and the turntable is synchronously rotated in a second direction and at a second speed. The first direction and the second direction are the same, and the first speed and the second speed are different.

5. The method according to claim 1, wherein When executing the first step each time, the turntable rotates for x1, x2...x n The rotation time of the turntable is t1, t2...t n The turntable rotates at a constant speed r when performing the first step and the second step; the time it takes for the turntable to rotate M times at a constant speed r to form an atomic layer deposition film of a preset thickness is T, T=M / r; then x1+x2+...+x n =M, and t1+t2+...+t n =T.

6. The method according to claim 5, characterized in that In the first step and the second step, the flow rate of the purge gas is the same.

7. The method according to claim 1, characterized in that While controlling the turntable to rotate, the method further includes: At the junction of two chambers into which the deposition source gas and the purge gas are respectively introduced, the gas diffused from one chamber toward the other chamber is extracted.

8. The method according to claim 1, characterized in that The deposition source gas includes a first process gas and a second process gas, the first process gas includes a gas containing zirconium, manganese, zinc sulfide, or aluminum, the second process gas includes ozone, and the purge gas includes an inert gas.

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