Semiconductor device and preparation method of copper interconnection structure

Abstract

The invention provides a semiconductor device and a preparation method of a copper interconnection structure, the semiconductor device comprises a process chamber, and a vapor deposition area and an electroplating area are formed in the process chamber. When the semiconductor equipment is used for preparing a copper interconnection structure, a semiconductor structure is made to form a copper seed crystal layer in the vapor deposition area through vapor deposition, then the semiconductor structure with the copper seed crystal layer is made to flow in the process cavity and reach the electroplating area, electroplating is conducted in the electroplating area, and a copper plating layer is formed on the copper seed crystal layer. The vapor deposition region and the electroplating region are integrated in the process chamber of the same semiconductor device, so that a semiconductor structure with a copper seed crystal layer is directly transferred to the electroplating region in the process chamber without being exposed to air, and is not oxidized in the transfer process, thereby being beneficial to improving the electroplating quality and improving the electroplating efficiency. And the reliability and the stability of the copper interconnection structure are further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a method for preparing a semiconductor device and a copper interconnection structure. Background Art

[0002] Copper has gradually replaced aluminum as the main material for manufacturing interconnection structures of integrated electronic devices due to its low resistivity, high reliability and excellent scalability. The currently commonly used method for preparing copper interconnection structures includes first forming a copper seed layer on a semiconductor structure in a vapor deposition device, and then taking out the semiconductor structure formed with the copper seed layer and transferring it to an electroplating device for electroplating to form a copper plating layer on the copper seed layer. In the process of transferring the semiconductor structure from the vapor deposition device to the electroplating device, the surface of the copper seed layer is exposed to air and is naturally oxidized, which seriously affects the quality of the copper plating layer formed by subsequent electroplating, and further seriously affects the reliability and stability of the copper interconnection structure. Summary of the invention

[0003] The object of the present invention is to provide a semiconductor device and a method for preparing a copper interconnect structure, aiming to improve the reliability and stability of the prepared copper interconnect structure.

[0004] To achieve the above-mentioned objectives, the present invention provides a semiconductor device, including a process chamber, a first valve and a first exhaust device, wherein a vapor deposition area and an electroplating area are formed in the process chamber; the first valve is arranged between the vapor deposition area and the electroplating area, and the opening and closing of the first valve controls the connection and disconnection between the vapor deposition area and the electroplating area; the first exhaust device is connected to the electroplating area.

[0005] Optionally, it further includes a first transfer mechanism, which is movably disposed in the process chamber; the first transfer mechanism is configured to carry the target object from the vapor deposition area to the electroplating area.

[0006] Optionally, a cleaning area is further formed in the process chamber; the cleaning area is isolated from the vapor deposition area when the first valve is closed.

[0007] Optionally, the semiconductor device further comprises a second valve, which is arranged between the cleaning area and the electroplating area, and the semiconductor device is configured to control the connection and disconnection of the cleaning area and the electroplating area by opening and closing the second valve.

[0008] Optionally, a second exhaust device is further included, and the second exhaust device is connected to the cleaning area.

[0009] Optionally, a second transfer mechanism is further included, and the second transfer mechanism can be movably arranged in the process chamber; the second transfer mechanism is configured to carry the target object from the electroplating area to the cleaning area.

[0010] To achieve the above-mentioned objectives, the present invention also provides a method for preparing a copper interconnect structure, which is performed based on the semiconductor device as described above and includes: providing a semiconductor structure; positioning the semiconductor structure in the vapor deposition area and forming a copper seed layer on the semiconductor structure by vapor deposition; opening the first valve; allowing the semiconductor with the copper seed layer to flow in the process chamber and reach the electroplating area; closing the first valve and forming a copper plating layer on the copper seed layer by electroplating; and performing an exhaust operation using the first exhaust device.

[0011] Optionally, a cleaning area is formed in the process chamber; the preparation method further comprises: allowing the semiconductor structure formed with the copper plating layer to flow in the process chamber and reach the cleaning area; and cleaning the semiconductor structure formed with the copper plating layer.

[0012] Compared with the prior art, the semiconductor device and the method for preparing a copper interconnect structure of the present invention have the following advantages: the aforementioned semiconductor device includes a process chamber, a first valve and a first exhaust device, wherein a vapor deposition area and an electroplating area are formed in the process chamber; the first valve is arranged between the vapor deposition area and the electroplating area, and the opening and closing of the first valve controls the connection and disconnection of the vapor deposition area and the electroplating area; the first exhaust device is connected to the electroplating area. When the copper interconnect structure is prepared by using the semiconductor device, under the premise that the first valve is closed, the semiconductor structure is firstly formed into a copper seed layer by vapor deposition in the vapor deposition area, and then the first valve is opened, and the semiconductor structure formed with the copper seed layer is circulated in the process chamber and reaches the electroplating area, and then the first valve is closed, and the semiconductor structure is electroplated in the electroplating area to form a copper plating layer on the copper seed layer. In the above process, the first exhaust device is also used to perform exhaust operation. The vapor deposition area and the electroplating area are integrated into the process chamber of the same semiconductor device, so that the semiconductor structure formed with the copper seed layer is directly transferred to the electroplating area in the process chamber without being exposed to the air, and will not be oxidized during the transfer process, which is conducive to improving the quality of electroplating, and further improving the reliability and stability of the copper interconnection structure. The provision of the first valve and the first exhaust device can reduce or even avoid the first type of gas generated in the electroplating area from polluting the vapor deposition area. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are used to better understand the present invention and shall not constitute improper limitations of the present invention.

[0014] Figure 1 It is a schematic structural diagram of a semiconductor device provided according to an embodiment of the present invention.

[0015] Figure 2 It is a schematic structural diagram of a semiconductor device provided according to another embodiment of the present invention.

[0016] [The illustration marks are explained as follows]: 100 - process chamber, 101 - vapor deposition area, 102 - electroplating area, 103 - cleaning area, 200 - first transfer mechanism, 300 - first valve, 400 - first exhaust device, 410 - exhaust pipe, 420 - exhaust pump, 500 - second transfer mechanism, 600 - second valve, 700 - second exhaust device. DETAILED DESCRIPTION

[0017] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the present embodiment only illustrate the basic concept of the present invention in a schematic manner, and only the components related to the present invention are shown in the figure instead of being drawn according to the number, shape and size of the components in the actual implementation. The type, quantity and proportion of each component in the actual implementation can be a random change, and the component layout type may also be more complicated.

[0018] In addition, each embodiment of the following description has one or more technical features, but this does not mean that the user of the present invention must implement all the technical features in any embodiment at the same time, or can only implement part or all of the technical features in different embodiments separately. In other words, under the premise of being possible to implement, those skilled in the art can selectively implement part or all of the technical features in any embodiment according to the disclosure of the present invention and according to the design specifications or implementation requirements, or selectively implement a combination of part or all of the technical features in multiple embodiments, thereby increasing the flexibility of the implementation of the present invention.

[0019] As used in this specification, the singular forms "one", "an", and "the" include plural objects, and the plural form "a plurality" includes more than two objects, unless the content clearly indicates otherwise. As used in this specification, the term "or" is generally used in a sense that includes "and / or", unless the content clearly indicates otherwise, and the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium, and it can be a connection between two elements or an interactive relationship between two elements. Relational terms such as the terms "first", "second", etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor do they indicate or imply relative importance or implicitly indicate the number of technical features indicated. It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In order to make the purpose, advantages and features of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. The same or similar reference numerals in the drawings represent the same or similar components.

[0021] like Figure 1 and Figure 2 As shown, the semiconductor device provided by the embodiment of the present invention includes a process chamber 100 , in which a vapor deposition area 101 and an electroplating area 102 are formed.

[0022] The semiconductor device can be used to prepare a copper interconnection structure in an integrated circuit device. When in use, the air in the process chamber 100 is first evacuated to make the process chamber 100 oxygen-free, and then the semiconductor structure is placed in the vapor deposition area 101 to form a copper seed layer on the semiconductor structure based on vapor deposition, and then the semiconductor structure formed with the copper seed layer is circulated in the process chamber 100 and reaches the electroplating area 102, and then the semiconductor structure is electroplated in the electroplating area 102 to form a copper plating layer on the copper seed layer. That is, the transfer of the semiconductor structure between the vapor deposition area 101 and the electroplating area 102 is carried out in the process chamber 100 without being exposed to the air. In this way, the copper seed layer on the semiconductor structure will not contact the air during the transfer process, and natural oxidation will not occur, avoiding the reduction of the quality of the copper plating layer due to the oxidation of the surface of the copper seed layer, which is conducive to improving the reliability and stability of the copper interconnection structure finally prepared.

[0023] Optionally, the semiconductor device forms a copper seed layer on the semiconductor structure by physical vapor deposition. The optional physical vapor deposition method is magnetron sputtering. Therefore, the vapor deposition area 101 includes a magnetron sputtering component, specifically including a magnetron (not shown in the figure), an upper electrode power supply (not shown in the figure), a target material (not shown in the figure) and other components. The embodiment of the present invention has no special restrictions on the structure and arrangement of the magnetron, the upper electrode power supply and the target material and other components, as long as the copper atoms on the target material can escape and be deposited on the semiconductor structure when the magnetron and the upper electrode power supply are working, and a copper seed layer is formed on the semiconductor structure.

[0024] It can be understood that the electroplating area 102 includes electroplating components, specifically including an electroplating solution tank, an anode, etc. The electroplating solution tank contains an electroplating solution, and the semiconductor structure is electroplated in the electroplating solution tank to form a copper plating layer. The embodiment of the present invention has no special restrictions on the structure and arrangement of the electroplating solution tank, the anode, etc., as long as the semiconductor structure can be electroplated in the electroplating area 102.

[0025] Furthermore, the semiconductor device further comprises a first transfer mechanism 200. The first transfer mechanism 200 is movably disposed in the process chamber 100. The first transfer mechanism 200 is configured to carry the semiconductor structure from the vapor deposition area 101 to the electroplating area 102.

[0026] Optionally, in some embodiments, the first transfer mechanism 200 includes a manipulator, and a part of the structure of the manipulator can move between the vapor deposition area 101 and the electroplating area 102. For example, the manipulator includes a connecting arm and a gripping portion (not shown in the figure), the connecting arm is rotatably arranged in the process chamber 100, and the gripping portion is connected to one end of the connecting arm. The gripping portion can be moved between the vapor deposition area 101 and the electroplating area 102 by rotating the connecting arm.

[0027] Thus, the process of transferring the semiconductor structure from the vapor deposition area 101 to the electroplating area 102 by using the first transfer mechanism 200 includes: after the grasping part grasps the semiconductor structure on which the copper seed crystal layer has been formed, controlling the connecting arm to rotate by a predetermined angle in a direction close to the electroplating area 102 so that the grasping part reaches the electroplating area 102; then, the grasping part transfers the semiconductor structure on which the copper seed crystal layer has been formed to the electroplating area 102. It can be understood that after the semiconductor structure on which the copper seed crystal layer has been formed is transferred to the electroplating area 102, the connecting arm can be controlled to rotate in a direction close to the vapor deposition area 101, and the grasping part can be returned to the vapor deposition area 101, so as to facilitate the transfer of the next semiconductor structure on which the copper seed crystal layer has been formed.

[0028] In other embodiments, the first transfer mechanism 200 may include more than two manipulators, and the semiconductor structure is transferred from the vapor deposition area 101 to the electroplating area 102 through the cooperation of the two or more manipulators.

[0029] Furthermore, the semiconductor device further comprises a first valve 300, which is arranged between the vapor deposition area 101 and the electroplating area 102. When the first valve 300 is opened, the vapor deposition area 101 is connected with the electroplating area 102, and when the first valve 300 is closed, the vapor deposition area 101 is isolated from the electroplating area 102. When the semiconductor device is used, it is preferred to control the first valve 300 to be closed in other time periods except for the process of the grabbing part moving toward the electroplating area 102 and the process of the grabbing part moving toward the vapor deposition area 101. The reason for doing so is that the plating solution in the electroplating area 102 may generate a first type of gas. By closing the first valve 300 to isolate the vapor deposition area 101 from the electroplating area 102, the first type of gas can be effectively reduced from entering the vapor deposition area 101 and causing contamination to the vapor deposition area 101. The specific type of the first type of gas is related to the composition of the electroplating solution.

[0030] Furthermore, the semiconductor device further includes a first exhaust device 400, which is connected to the electroplating area 102 and is used to exhaust the first type of gas. The arrangement of the first exhaust device 400 can, on the one hand, prevent the electroplating area 102 from accumulating too much of the first type of gas, and on the other hand, when the first exhaust device 400 is operated when the first valve 300 is opened, it can effectively reduce or even prevent the first type of gas from entering the vapor deposition area 101. Preferably, the connection portion between the first exhaust device 400 and the electroplating area 102 is located on the opposite side of the first valve 300.

[0031] In a non-limiting embodiment, the first exhaust device 400 includes an exhaust pipe 410 and an exhaust pump 420. One end of the exhaust pipe 410 is connected to the electroplating area 102, and the other end extends outside the semiconductor device and can be connected to an exhaust gas collection device. The exhaust pump 420 can be arranged on the exhaust pipe 410.

[0032] Optionally, a cleaning area 103 is further formed in the process chamber 100 , and the cleaning area 103 is used to clean the semiconductor structure on which the copper plating layer has been formed, so as to remove excess copper residue on the semiconductor structure.

[0033] The distance from the cleaning area 103 to the electroplating area 102 is shorter than the distance from the cleaning area 103 to the vapor deposition area 101 , so that the semiconductor structure can be easily transferred to the cleaning area 103 .

[0034] Furthermore, the semiconductor device further includes a second transfer mechanism 500, which is rotatably disposed in the process chamber 100 and is configured to transfer the semiconductor structure having the copper plating layer formed thereon to the cleaning area 103. The structure of the second transfer mechanism 500 may refer to the first transfer mechanism 200, and will not be described in detail herein.

[0035] Further, the semiconductor device is configured to isolate the cleaning area 103 from the vapor deposition area 101 when the first valve 300 is closed. The reason for this is that the cleaning liquid in the cleaning area 103 used to clean the semiconductor structure includes some corrosive and volatile components, such as hydrogen peroxide, sulfuric acid, etc. These components evaporate to form a second type of gas, which is easy to diffuse. By controlling the cleaning area 103 to be isolated from the vapor deposition area 101, the second type of gas can be prevented from entering the vapor deposition area 101.

[0036] Further, the semiconductor device further comprises a second valve 600, and the second valve 600 is arranged between the cleaning area 103 and the electroplating area 102. When the second valve 600 is opened, the cleaning area 103 and the electroplating area 102 are connected, and when the second valve 600 is closed, the cleaning area 103 and the electroplating area 102 are isolated. When the semiconductor device is used, it is preferred to control the second valve 600 to be closed in other time periods except for the process in which the partial structure of the second transfer mechanism 500 moves toward the cleaning area 103 and the process in which the partial structure of the second transfer mechanism 500 moves toward the electroplating area 102. In this way, the amount of the second type of gas entering the electroplating area 102 can be reduced, thereby reducing the adverse effect of the second type of gas on the electroplating solution.

[0037] Furthermore, the semiconductor device further includes a second exhaust device 700, which is connected to the cleaning area 103 and is used to exhaust the second type of gas. The second exhaust device 700 can prevent the cleaning area 103 from accumulating too much of the second type of gas, and can effectively reduce or even prevent the second type of gas from entering the electroplating area 102 when the second exhaust device 700 is operated when the second valve 600 is opened.

[0038] The structure of the second exhaust device 700 can refer to the first exhaust device 400 , which will not be described in detail. In addition, as an example, the communicating portion between the second exhaust device 700 and the cleaning area 103 is located on the opposite side of the second valve 600 .

[0039] Furthermore, an embodiment of the present invention also provides a method for preparing a copper interconnect structure based on the above-mentioned semiconductor device, and the preparation method includes the following steps: Step S1, providing a semiconductor structure, and making the semiconductor structure located in the vapor deposition area 101, and forming a copper seed layer on the semiconductor structure by vapor deposition. Step S2, opening the first valve 300, and making the semiconductor structure formed with the copper seed layer flow in the process chamber 100 and reach the electroplating area 102. Step S3, closing the first valve 300, and forming a copper plating layer on the copper seed layer by electroplating. Step S4, performing an exhaust operation using the first exhaust device 400. Step S4 can be performed during the execution of Steps S1, S2 and S3.

[0040] It should be understood that the step S1 is performed under the premise that the oxygen in the process chamber 100 is exhausted.

[0041] Further, the preparation method further includes: step S5, opening the second valve 600, and allowing the semiconductor structure formed with the copper plating layer to flow in the process chamber 100 and reach the cleaning area 103. Step S6, closing the second valve 600, and cleaning the semiconductor structure formed with the copper plating layer in the cleaning area 103. And step S7, performing an exhaust operation using the second exhaust device 700. Step S7 can be performed at any appropriate time period, for example, when at least one of step S1, step S2, step S3, step S5, and step S6 is performed.

[0042] Although the present invention is disclosed as above, it is not limited thereto. Those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A semiconductor device, characterized in that: It includes a process chamber, a first valve and a first exhaust device, wherein a vapor deposition area and an electroplating area are formed in the process chamber; the first valve is arranged between the vapor deposition area and the electroplating area, and the opening and closing of the first valve controls the connection and disconnection between the vapor deposition area and the electroplating area; the first exhaust device is connected to the electroplating area.

2. The semiconductor device according to claim 1, wherein: Also included is a first transfer mechanism, which is movably disposed in the process chamber; The first transfer mechanism is configured to carry the target object from the vapor deposition area to the electroplating area.

3. The semiconductor device according to claim 1, wherein: A cleaning area is also formed in the process chamber; the cleaning area is isolated from the vapor deposition area when the first valve is closed.

4. The semiconductor device according to claim 3, characterized in that The semiconductor device further includes a second valve, which is disposed between the cleaning area and the electroplating area, and the semiconductor device is configured to control the connection and disconnection between the cleaning area and the electroplating area by opening and closing the second valve.

5. The semiconductor device according to claim 4, characterized in that Also included is a second exhaust device, which is in communication with the cleaning area.

6. The semiconductor device according to claim 5, characterized in that Also comprising a second transfer mechanism, the second transfer mechanism being movably disposed in the process chamber; The second transfer mechanism is configured to carry the target object from the electroplating area to the cleaning area.

7. A method for preparing a copper interconnect structure, characterized in that: The preparation method is performed based on the semiconductor device according to any one of claims 1 to 6, and the preparation method comprises: Providing a semiconductor structure; Positioning the semiconductor structure in the vapor deposition region and forming a copper seed layer on the semiconductor structure by vapor deposition; Opening the first valve; Allowing the semiconductor formed with the copper seed layer to flow in the process chamber and reach the electroplating area; closing the first valve and forming a copper plating layer on the copper seed crystal layer by electroplating; An exhaust operation is performed using the first exhaust device.

8. The method for preparing a copper interconnect structure according to claim 7, characterized in that: A cleaning area is also formed in the process chamber; The preparation method further comprises: Allowing the semiconductor structure with the copper plating layer to flow in the process chamber and reach the cleaning area; The semiconductor structure with the copper plating layer formed thereon is cleaned.

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