Vacuum transfer chamber, process platform and method of controlling the same

Abstract

The present application relates to a vacuum transfer chamber and a process platform. The vacuum transfer chamber comprises a chamber having a plurality of interfaces, at least some of which are used to connect a chemical vapor deposition chamber; a purge device located outside the chamber and connected to the chamber, for providing a gas to make the chamber form a positive pressure to the chemical vapor deposition chamber; and a vacuum pumping device located outside the chamber and connected to the chamber. The process platform comprises the vacuum transfer chamber, a chemical vapor deposition chamber and a non-chemical vapor deposition chamber connected to the chamber; and a controller for controlling the purge device to make the chamber form a positive pressure to the chemical vapor deposition chamber. The present application can reduce the risk of the chamber being contaminated by the chemical vapor deposition chamber, and can improve the wafer processing efficiency.

Description

Technical Field

[0001] This invention relates to the field of semiconductors, and more specifically to a vacuum transmission cavity, a process platform, and a control method thereof. Background Technology

[0002] In logic chip manufacturing, copper seed layer deposition is a critical step that directly impacts subsequent copper filling processes and the overall chip performance. To achieve high-performance copper seed layer deposition, various process chambers are required, including but not limited to degassing chambers, pre-cleaning chambers, atomic layer deposition chambers, physical vapor deposition chambers, and chemical vapor deposition chambers. These chambers typically operate in a high-vacuum environment to ensure process accuracy and chip quality.

[0003] While existing systems can implement the aforementioned processes, they typically require complex transfer and docking between different cavities. This not only increases manufacturing costs but can also lead to contamination and yield losses during the process. In particular, after the physical vapor deposition (PVD) copper cavity process, the copper seed layer is highly sensitive to residual gases in the chemical vapor deposition (CVD) cavity. Any contamination can severely affect the copper filling process, thereby causing a decrease in chip yield.

[0004] Therefore, there is a need to provide a vacuum transfer chamber to reduce atmospheric contamination in chemical vapor deposition chambers, and a high-vacuum process platform for the deposition of copper seed layers. Summary of the Invention

[0005] To address these issues, a new integration solution is needed that can integrate multiple different process cavities on a single process platform. This would reduce transfer steps in the process, lower contamination risks, and improve the rationality of capacity allocation. Furthermore, the solution must ensure that the copper seed layer is not affected by residual gases during chemical vapor deposition to guarantee chip yield and performance.

[0006] The present invention aims to provide an advanced wafer processing flow that reduces contamination in the chemical vapor deposition chamber and improves wafer processing efficiency.

[0007] The present invention provides a vacuum transmission cavity, comprising:

[0008] The cavity includes multiple interfaces, at least some of which are used to connect to the chemical vapor deposition cavity;

[0009] A purging device, connected to the cavity, is used to provide purging gas to create positive pressure in the chemical vapor deposition cavity.

[0010] A vacuum pumping device connected to the cavity.

[0011] Furthermore, the vacuum pumping device includes a molecular pump and a cryogenic condensation pump.

[0012] Furthermore, the vacuum pumping device also includes a first valve and a second valve, the molecular pump is connected to the cavity through the first valve, and the cryogenic condensation pump is connected to the cavity through the second valve.

[0013] Furthermore, the molecular pump is connected to the first region of the cavity.

[0014] Furthermore, the purging device is connected to the second region of the cavity.

[0015] Furthermore, the cavity has n interfaces, and n is not less than 7.

[0016] Furthermore, the purging device is connected to an inert gas source.

[0017] In addition, the present invention also proposes a process platform, including the vacuum transfer cavity, wherein the first part of the cavity is connected to at least one chemical vapor deposition cavity.

[0018] The second part of the cavity is connected to at least one non-chemical vapor deposition cavity;

[0019] The controller is used to control the purging device to create positive pressure in the chemical vapor deposition chamber.

[0020] Furthermore, the non-chemical vapor deposition chamber is a physical vapor deposition chamber.

[0021] Furthermore, the physical vapor deposition chamber is used to deposit thin films containing metal elements.

[0022] Furthermore, the metallic element is copper.

[0023] Furthermore, it also includes a buffer cavity and a second vacuum transmission cavity connected to the buffer cavity, the second vacuum transmission cavity being connected to the loading locking cavity.

[0024] In addition, the present invention also proposes a control method for the process platform, comprising the following steps:

[0025] Before connecting the cavity to the chemical vapor deposition chamber, start the purging device to ensure that the cavity forms a positive pressure relative to the chemical vapor deposition chamber during the connection process.

[0026] Furthermore, starting the vacuum pumping device includes: first starting the molecular pump to bring the cavity to a predetermined vacuum level, and then starting the cryogenic condensation pump.

[0027] Furthermore, the predetermined vacuum level is 10. -5 Torr to 10 -7 Torr.

[0028] Furthermore, it also includes the step of shutting off the purging device before starting the cryogenic condensation pump.

[0029] The present invention has the following beneficial effects:

[0030] By integrating multiple process cavities onto a single vacuum transfer cavity, wafer processing efficiency can be improved.

[0031] Furthermore, by configuring the cavity with positive pressure relative to the chemical vapor deposition cavity and negative pressure relative to the non-chemical vapor deposition cavity, the contamination of the wafer by adverse gases is minimized, thereby improving the efficiency and safety of wafer transfer.

[0032] Furthermore, the adoption of standard process flows has improved wafer processing efficiency.

[0033] This invention performs excellently in the deposition process of copper seed layers, improving process safety while ensuring efficiency. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the structure of a vacuum transmission cavity according to an embodiment of the present invention.

[0035] Figure 2 This is a schematic diagram of the structure of a process platform according to an embodiment of the present invention. Detailed Implementation

[0036] The vacuum transmission cavity, process platform, and control method proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, only for the purpose of conveniently and clearly illustrating the embodiments of this invention. Please refer to the drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0037] As described in the background section, in semiconductor chip manufacturing, wafers need to be transferred between multiple process chambers to perform epitaxial processes. Chemical vapor deposition (CVD) chambers require the introduction of reactive gases and generate exhaust gases after the process. If these exhaust gases and reactive gases flow into other process chambers, they can contaminate the reaction environment of those chambers, especially affecting the growth process of copper seed layers. Copper seed layers are deposited using physical vapor deposition (PVD) chambers, which are particularly sensitive to the process gases and exhaust gases generated during CVD.

[0038] To ensure the continuity and efficiency of wafer transfer between process cavities, different process cavities are connected by a common transfer cavity, and a robotic arm is used to move wafers between the transfer cavity and each process cavity. This places high demands on the cleanliness of the common transfer cavity. To isolate the gases in the chemical vapor deposition (CVD) cavity, this invention provides a vacuum transfer cavity that can transfer wafers between multiple process cavities, particularly between CVD and non-CVD cavities, and reduces the impact of exhaust gases and CVD process gases on the non-CVD cavity during wafer transfer.

[0039] Please see Figure 1 The diagram illustrates a schematic structure of a vacuum transfer cavity according to an embodiment of the present invention. The vacuum transfer cavity includes a cavity body 11, a vacuum pumping device 12, and a purging device 13. The cavity body 11 has multiple interfaces 101 for connecting to process cavities. Valves can be installed between the interfaces 101 and each process cavity to control the on / off state. The processes performed between the process cavities can be the same or different. A robotic arm for handling wafers can be installed within the cavity body 11 to transfer wafers between the various process cavities. In other examples, the robotic arm can also handle wafers transferred from other vacuum transfer cavities, as will be described in the examples below.

[0040] The cavity 11 is mainly enclosed by walls, which are connected to the vacuum pumping device 12 and the purging device 13. The process chamber includes a chemical vapor deposition (CVD) chamber 21 and a non-CVD chamber 22. As mentioned above, the CVD chamber 21 uses process gases during the process, and these process gases react to produce exhaust gases. To prevent the process gases and exhaust gases in the CVD chamber 21 from contaminating the vacuum transfer chamber, the purging device 13 provides purging gas to the cavity 11 to maintain a positive pressure in the cavity 11 relative to the CVD chamber 21, thus preventing the process gases and exhaust gases from flowing into the cavity 11. Specifically, when it is necessary to connect the CVD chamber 21, the purging device 13 is first activated to supply gas to the cavity 11 until the pressure inside the cavity 11 is greater than that in the CVD chamber 21, at which point the valve connecting the two is opened. During valve opening, the purging device 13 continuously supplies air to maintain positive pressure between the cavity 11 and the chemical vapor deposition chamber 21, preventing process gases and exhaust gases from entering the cavity 11. This reduces most of the gas contamination from the chemical vapor deposition chamber 21. Compared to traditional methods—requiring multiple cleaning processes of the chemical vapor deposition chamber before connecting it to the vacuum transfer chamber—the vacuum transfer chamber provided by this invention can reduce or even eliminate the need for multiple cleaning processes of the chemical vapor deposition chamber, thus significantly improving production efficiency.

[0041] Please continue reading. Figure 1 Because physical vapor deposition (PVD) devices require a higher vacuum level, typically around 10... - 8 Torr, the vacuum transfer chamber connected to the physical vapor deposition apparatus also needs to maintain a high vacuum level. Therefore, the vacuum pumping device 12 described in this application includes a molecular pump 102 and a cryogenic condensation pump 103. Further, the molecular pump 102 is connected to the chamber 11 via a first valve 104, and the cryogenic condensation pump 103 is connected to the chamber 11 via a second valve 105. The usage differs depending on the vacuum pumping characteristics of the two pumps. The molecular pump 102 reduces the vacuum level by transferring gas outside the pump, while the cryogenic condensation pump 103 reduces the vacuum level by adsorbing gas at low temperature. Since the gas adsorbed at low temperature is not discharged outside the pump, the cryogenic condensation pump 103 is suitable for use under high vacuum conditions. It is configured to be used after the molecular pump 102 is started to reduce the number of times the cryogenic condensation pump 103 needs to be regenerated. In this embodiment, after the purging device 13 is started, there is a large amount of gas in the chamber 11 with a high pressure. First, the molecular pump 102 reduces the vacuum level of the chamber 11 to approximately 10. -5 Torr to 10 -7 The pressure is in the Torr range. The cryogenic condensation pump 103 is then restarted to reduce the vacuum level in chamber 11 to approximately 10. -8Torr to 10 -9 The molecular pump 102 can also be used in series with a dry vacuum pump 106, which can perform rough vacuuming to accelerate the vacuuming efficiency.

[0042] Please see Figure 2 The diagram shows a schematic representation of the structure of a vacuum platform according to the present invention, wherein the vacuum platform includes the vacuum transmission cavity. Figure 2 As shown, the vacuum transfer cavity can be an n-sided cavity, where n is not less than 7. The cavity 11 can have 7 interfaces, connecting to six process cavities 21 and 22 and a buffer cavity 31, respectively. The six process cavities can be chemical vapor deposition cavities 201, 202, and 203, and physical vapor deposition cavities 204, 205, and 206. Depending on the type of process cavity being connected, the cavity 11 can be divided into a first region 107 and a second region 108. The first region 107 is a chemical vapor deposition region, and the second region 108 is a physical vapor deposition region. The first region 107 and the second region 108 are spatially opposite each other. In other examples, the first region 107 and the second region 108 can be discontinuous regions, and their division is mainly based on the type of process cavity connected to the cavity. For ease of explanation, in this example, the first region 107 and the second region 108 are arranged opposite each other. The differences between the two regions in terms of function and environment will be explained below.

[0043] like Figure 2 As shown, in one embodiment, the first region 107 connects three chemical vapor deposition (CVD) chambers 201, 202, and 203. These chambers can be chambers using the same or different processes, such as a cobalt CVD chamber, a ruthenium CVD chamber, and an tantalum nitride atomic layer deposition (ALD) chamber. The second region 108 connects three physical vapor deposition (PVD) chambers 204, 205, and 206. These chambers can be chambers using the same or different processes, such as a tantalum nitride PVA chamber and a copper PVA chamber. The chambers located in the second region 108 are highly sensitive to CVD process gases and exhaust gases. Therefore, during the process, it is necessary to reduce the amount of exhaust gas entering chamber 11, and further reduce the amount of exhaust gas entering the second region 108.

[0044] As can be seen from the above embodiments, in order to suppress the diffusion of process gas and exhaust gas into the second region 108, the purging device 13 is disposed in the second region 108 of the cavity 11, and the molecular pump 102 is disposed in the first region 107 of the cavity 11. When the purging device 13 is activated, an airflow F can be formed from the second region 108 to the first region 107 to prevent process gas and exhaust gas from entering the second region 108.

[0045] In summary, the vacuum transfer cavity provided by this invention can reduce gas contamination from the chemical vapor deposition cavity and reduce the cleaning time of the chemical vapor deposition cavity, thereby improving wafer transfer efficiency.

[0046] The present invention also provides a process platform based on the above-mentioned vacuum transmission cavity, and a control method applied to the process platform.

[0047] Please continue reading. Figure 2 The process platform includes the vacuum transfer chamber 11 and a controller (not shown in the figure). A first interface on the chamber 11 is connected to at least one chemical vapor deposition chamber 21, and a second interface on the chamber 11 is connected to at least one non-chemical vapor deposition chamber 22. The vacuum transfer chamber 11 includes the aforementioned purge device 13 and vacuum pumping device 12. The controller is connected to both the purge device 13 and the vacuum pumping device 12, and is used to control the purge device 13 to create a positive pressure in the chamber relative to the chemical vapor deposition chamber.

[0048] As a preferred embodiment, the vacuum transfer cavity is a heptagonal cavity with seven interfaces on the cavity body 11, located on the seven sides. These seven interfaces connect to six process cavities and two transfer buffer cavities 31. The six process cavities are chemical vapor deposition cavities 201, 202, and 203, and physical vapor deposition cavities 204, 205, and 206. As described in the above embodiment, the chemical vapor deposition cavity 21 generates exhaust gas, which can contaminate the physical vapor deposition cavity 22. Although the chemical vapor deposition cavity 21 and the physical vapor deposition cavity 22 are isolated by the vacuum transfer cavity 11, the exhaust gas still poses a risk of contaminating the vacuum transfer cavity. This is especially true since a wafer with a copper seed layer is placed inside the vacuum transfer cavity. To avoid exhaust gas contamination of the vacuum transfer cavity, the process platform provided by this invention employs the improved vacuum transfer cavity described in the above embodiment and sets up a standard process flow. This process flow can be automatically implemented by the controller.

[0049] Furthermore, the process platform provided by this invention also includes a buffer chamber 31 and a second vacuum transfer chamber 51 connected to the buffer chamber 31. The second vacuum transfer chamber 51 is connected to a loading locking chamber 61, which is connected to the atmosphere via a valve. The second vacuum transfer chamber 61 can adopt a design similar to the vacuum transfer chamber 11 provided by this invention, and is equipped with corresponding purging and vacuuming devices, which will not be described in detail here. The cross-section of the second vacuum transfer chamber 61 can be set to hexagonal, for connecting chambers including, but not limited to, chemical vapor deposition chambers, physical vapor deposition chambers, and pretreatment chambers.

[0050] In addition, the present invention also provides a control method for the process platform, which can be automatically executed by the controller and includes the following steps:

[0051] Before connecting cavity 11 to chemical vapor deposition cavity 21, purge device 13 is activated to ensure that cavity 11 maintains positive pressure relative to chemical vapor deposition cavity 21 during the connection process. Specifically, the pressure values ​​within chemical vapor deposition cavity 21 and cavity 11 can be obtained through a vacuum detection system on the process platform. Purge device 13 is activated until the pressure value within cavity 11 is greater than that within the chemical vapor deposition cavity 21 to be connected. Then, the corresponding valve is opened to connect cavity 11 to the chemical vapor deposition cavity 21. After connection, wafer transfer can proceed.

[0052] Before the cavity 11 is connected to the non-chemical vapor deposition cavity 22, the vacuum pumping device 12 is activated to ensure that the vacuum transfer cavity reaches a suitable vacuum level, for example, 10. -8 After the torsion is applied, the corresponding valve is opened to connect chamber 11 with the non-chemical vapor deposition chamber 22. Once connected, wafer transfer can be performed.

[0053] It should be noted that an inert gas, such as argon, is introduced into the cavity 11 through the purging device 13. To start the vacuum pump, the molecular pump 102 must first be started and the valve 104 opened to extract the gas from the cavity 11, bringing the cavity 11 to a predetermined vacuum level, which can be 10⁻⁶. -5 Torr to 10 -7 Torr, then start the cryogenic condensation pump 103 and open valve 105 to further evacuate the cavity 11.

[0054] Furthermore, the control method also includes the step of shutting off the purging device 13 before starting the cryogenic condensation pump 103.

[0055] In other embodiments, a possible method is to clean the cavity by means of a purge device 13 and a vacuum device 12 (molecular pump 102 and / or dry vacuum pump 106) after disconnecting the cavity 11 from the chemical vapor deposition cavity 21 and before connecting the non-chemical vapor deposition cavity 22. That is, the purge device 13 and the vacuum device 12 are turned on simultaneously, or the purge device 13 and the vacuum device 12 are turned on alternately, and then the purge device 13 is turned off, and the molecular pump 102 and the cryogenic condensation pump 103 are turned on in sequence.

[0056] In summary, this invention solves the problem of exhaust gas contamination in chemical vapor deposition (CVD) chambers by improving the vacuum transfer cavity, and enables efficient wafer transfer between various process cavities. By setting a stable process flow and automatically running process steps, efficient and safe wafer transfer between process cavities is achieved. Furthermore, by integrating CVD and non-CVD cavities into the improved vacuum transfer cavity, wafer processing efficiency is improved, particularly for copper seed layer processing, which shows a significant improvement.

[0057] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A vacuum transmission cavity, characterized in that, include: The cavity includes multiple interfaces, at least some of which are used to connect to the chemical vapor deposition cavity; A purging device, connected to the cavity, is used to provide purging gas to create positive pressure in the chemical vapor deposition cavity. A vacuum pumping device connected to the cavity.

2. The vacuum transmission cavity as described in claim 1, characterized in that, The vacuum pumping device includes a molecular pump and a cryogenic condensation pump.

3. The vacuum transmission cavity as described in claim 2, characterized in that, The vacuum pumping device also includes a first valve and a second valve. The molecular pump is connected to the cavity through the first valve, and the cryogenic condensation pump is connected to the cavity through the second valve.

4. The vacuum transmission cavity as described in claim 2, characterized in that, The molecular pump is connected to the first region of the cavity.

5. The vacuum transmission cavity as described in claim 1, characterized in that, The purging device is connected to the second region of the cavity.

6. The vacuum transmission cavity as described in claim 1, characterized in that, The cavity has n interfaces, and n is not less than 7.

7. The vacuum transmission cavity as described in claim 1, characterized in that, The purging device is connected to an inert gas source.

8. A process platform, characterized in that, Includes a vacuum transport cavity as described in any one of claims 1 to 7, wherein a first portion of the cavity is connected to at least one chemical vapor deposition cavity. The second part of the cavity is connected to at least one non-chemical vapor deposition cavity; The controller is used to control the purging device to create positive pressure in the chemical vapor deposition chamber.

9. The process platform as described in claim 8, characterized in that, The non-chemical vapor deposition chamber is a physical vapor deposition chamber.

10. The process platform as described in claim 9, characterized in that, The physical vapor deposition chamber is used to deposit thin films containing metal elements.

11. The process platform as described in claim 10, characterized in that, The metallic element is copper.

12. The process platform as described in claim 8, characterized in that, It also includes a buffer cavity and a second vacuum transmission cavity connected to the buffer cavity, the second vacuum transmission cavity being connected to the loading locking cavity.

13. A control method, characterized in that, For the process platform as described in any one of claims 8 to 12, comprising: Before connecting the cavity to the chemical vapor deposition chamber, start the purging device to ensure that the cavity forms a positive pressure relative to the chemical vapor deposition chamber during the connection process.

14. The control method as described in claim 13, characterized in that, Starting the vacuum system involves: first starting the molecular pump to bring the cavity to the predetermined vacuum level, and then starting the cryogenic condensation pump.

15. The control method as described in claim 14, characterized in that, The predetermined vacuum level is 10. -5 Torr to 10 - 7 Torr.

16. The control method as described in claim 14, characterized in that, It also includes the step of shutting off the purging device before starting the cryogenic condensation pump.

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