Dust particle control method of multi-piece type loading locking module
By setting baffles on the wafer support, the problem of controlling dust particles on the wafer surface in the existing technology is solved, achieving higher wafer surface quality and process quality, and reducing maintenance and equipment costs.
Patent Information
- Application Number
- CN202511061338.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-11-04
AI Technical Summary
Existing technologies are insufficient to effectively control the number of dust particles on the wafer surface during semiconductor manufacturing processes below the 5nm technology node. Existing methods increase maintenance and equipment costs and are difficult to reliably achieve the dust particle count control requirements.
A baffle is installed on the wafer support, located between two wafers, to ensure that the front side of the wafer always faces the clean back side of the baffle, preventing dust particles from falling from the back side of the wafer to the front side of the wafer below due to airflow disturbance. A multi-plate loading and locking module design is adopted.
It effectively reduces the fall of dust particles on the wafer surface, improves the wafer surface quality, and can be combined with existing technologies to further improve process quality and reduce maintenance and equipment costs.
Smart Images
Figure CN120895455A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of semiconductor manufacturing technology, and specifically relates to a dust particle control method for a multi-chip loading locking module. Background Technology
[0002] As integrated circuit process nodes advance from 28nm to 5nm, the requirements for controlling dust particles in semiconductor manufacturing processes, such as ion implantation, also increase accordingly. For example, the 5nm technology node requires that the total number of particles larger than 26nm on a 300mm diameter wafer surface be less than 10. Existing methods for reducing dust particles include increasing the frequency of cleaning internal equipment components and using gas purging of ion implanter components. However, these methods are difficult to reliably achieve the required dust particle count control and also significantly increase maintenance costs, equipment costs, and operational complexity. Summary of the Invention
[0003] Based on the technical problems existing in the prior art, the present invention provides a dust particle control method for a multi-chip loading locking module, which solves the problem that the prior art is difficult to further control the dust particle situation on the wafer surface, and achieves beneficial technical effects such as improving wafer surface quality simply by improving the working method of the equipment.
[0004] According to the technical solution of the present invention, the present invention provides a dust particle control method for a multi-chip loading and locking module. The semiconductor device in which it is applied has a connected vacuum chamber and a loading and locking module. A first gate valve is provided between the vacuum chamber and the loading and locking module. The loading and locking module can switch between vacuum and atmospheric states. The loading and locking module has a wafer support, which is a multi-layer structure in the vertical direction. Each layer forms a placement position that can support the edge of the wafer. Multiple wafers are placed on the wafer support, and a baffle is provided between every two adjacent wafers. The baffle has at least its lower surface cleaned. During the wafer processing process, the baffle does not participate in any wafer processing action to maintain the cleanliness of the lower surface of the baffle.
[0005] In some embodiments, a baffle is also provided above the uppermost wafer on the wafer carrier, and / or a baffle is also provided below the lowermost wafer on the wafer carrier.
[0006] In some embodiments, each layer of the wafer carrier includes two wafer placement plates disposed opposite each other, with a gap between the two wafer placement plates; wafers and baffles are placed at intervals in the placement positions of the multiple layers in the wafer carrier.
[0007] In some implementations, the baffle is the same size as or similar to the wafer.
[0008] In some implementations, the semiconductor device used is an ion implanter.
[0009] In some embodiments, the vacuum chamber connected to the loading and locking module in the ion implanter includes a transfer module and a process module; the transfer module includes a front robotic arm, a rear robotic arm, and a calibrator, with the front robotic arm being closer to the loading and locking module than the rear robotic arm; the process module includes a scanning robotic arm, the end of which is a scanning electrostatic chuck capable of holding the wafer and performing moving scans.
[0010] In some implementations, the loading and locking module is also connected to a front-end module, which includes a wafer transfer box and an atmospheric transfer robotic arm; a second gate valve is provided between the loading and locking module and the front-end module.
[0011] In some implementations, the wafer processing technology includes the following steps:
[0012] The initial state is that both the first and second gate valves are closed, and the interior of the loading and locking module is in atmospheric condition; the conveying module and process module are always in vacuum condition, and the front-end module is always in atmospheric condition.
[0013] The second valve opens, and the atmospheric conveying robotic arm takes out the corresponding wafer from the wafer conveying box and places it into the loading and locking module as needed;
[0014] The second valve is closed, the loading and locking module is converted to a vacuum state, and then the first valve is opened;
[0015] The robotic arm removes the wafer from the loading and locking module and places it on the calibrator;
[0016] The calibrator rotates to calibrate the wafer;
[0017] The robotic arm then removes the wafer from the calibrator and places it on the scanning electrostatic chuck.
[0018] The scanning electrostatic chuck holds the wafer and performs a scanning motion with the wafer to complete ion implantation;
[0019] The robotic arm removes the implanted wafer from the scanning electrostatic chuck and places it back into the loading and locking module;
[0020] After the wafer has completed ion implantation and been completely returned to the loading and locking module, the first gate valve is closed, the interior of the loading and locking module is converted to atmospheric conditions, and then the second gate valve is opened.
[0021] The atmospheric conveying robotic arm removes the wafer from the loading and locking module and places it back into the corresponding wafer transfer box.
[0022] Compared with the prior art, the beneficial technical effects of the present invention are as follows:
[0023] The dust particle control method of the multi-wafer loading locking module of the present invention adopts the method of inserting a baffle between two wafers. The baffle does not participate in any of the actions required for ion implantation, thus avoiding the generation of dust particles on the back side of the baffle. Therefore, the front side of the wafer is always facing the clean back side of the baffle, eliminating the problem of dust particles on the back side of the wafer falling to the front side of the wafer below due to airflow disturbance in the loading locking module.
[0024] The technical solution of the present invention can be implemented based on the existing loading and locking module, which is simple and effective. The prior art does not take technical measures to reduce dust particles in the loading and locking module. Therefore, the technical solution of the present invention can also be combined with other means of reducing dust particles, which can further improve the process quality. Attached Figure Description
[0025] Figure 1 This is a partial structural diagram of the first gate valve with the locking module installed in the method provided by the present invention in the open state.
[0026] Figure 2 This is a partial structural schematic diagram of an ion implanter using the method provided by the present invention.
[0027] Explanation of reference numerals in the attached figures:
[0028] 1. Loading and locking module; 11. First gate valve; 10. Wafer holder; 2. Wafer; 3. Baffle; 41. Front robotic arm; 42. Rear robotic arm; 43. Calibrator; 51. Scanning robotic arm; 52. Scanning electrostatic chuck; 53. Faraday cup; 6. Ion beam. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0030] It should also be noted that, for ease of description, only the parts relevant to the inventive point are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described herein can be combined with each other.
[0031] It should be noted that the concepts of "first" and "second" mentioned in this invention are only used to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.
[0032] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".
[0033] This invention provides a dust particle control method for a multi-chip loaded locking module, belonging to the field of semiconductor manufacturing technology. It mainly aims to solve the problem that existing technologies are difficult to further control the dust particle situation on the wafer surface, and achieve beneficial technical effects such as improving wafer surface quality simply by improving the equipment working method.
[0034] Studies show that under actual production conditions, the main source of dust particles on wafers is the vacuuming and devastation process of the loadlock module. Common loadlock modules can hold two or more wafers (e.g., 25). Taking ion implanters as an example, they typically use a batch size of 25 wafers, all with their front (process side) facing up. Except for the top wafer, the front sides of the other wafers face the back side of the wafer above them. Large-scale data shows that the top wafer has fewer dust particles than the others and exhibits greater stability. During implantation and other processes, the back side of the wafer must contact multiple robotic arms to transfer the wafer between different working points, be held by an electrostatic chuck, and traverse the ion beam to complete the ion implantation process. These actions generate movement and friction between the back of the wafer and the solid surface, producing fine particles. These fine particles fall onto the surface of the wafer below in the loading and locking module, forming a dust particle problem. In particular, when the loading and locking module is evacuated from the atmosphere to a vacuum, the gas disturbance in the cavity will carry particles from the back of the upper wafer to the front of the lower wafer.
[0035] Therefore, the basic concept of the solution proposed in this invention is to insert a baffle between two wafers to separate them. The front side of the wafer always faces the clean back side of the baffle, thereby effectively eliminating the problem of dust particles on the back side of the wafer falling to the front side of the wafer below due to airflow disturbance in the loading locking module.
[0036] Specifically, please refer to Figure 1 The present invention discloses a dust particle control method for a multi-chip loading locking module, wherein the semiconductor device in which it is applied has interconnected vacuum cavities. Figure 1 (not shown) and loading locking module 1, a first gate valve 11 is provided between the vacuum chamber and the loading locking module 1. Figure 1In the open state, the first valve 11 can be closed to seal the vacuum chamber and the loading locking module 1. The first valve is more specifically, for example, a slit valve. The loading locking module 1 can switch between vacuum and atmospheric conditions. Specifically, the loading locking module 1 is equipped with a vacuum pump, vacuum gauge, etc.
[0037] The loading and locking module 1 contains a wafer support 10, which is a multi-layered structure in the vertical direction. Each layer forms a placement position that supports the edge of the wafer. Multiple wafers 2 are placed on the wafer support 10. As a supplementary explanation, the portion of the placement position corresponding to the middle of the wafer 2 is empty, allowing a robotic arm to extend and move up and down to complete the action of picking up and placing the wafer 2. Furthermore, since the layers of the wafer support 10 are vertically connected, there is a problem in the prior art where dust particles from the bottom surface of the upper wafer fall onto the surface of the lower wafer.
[0038] In this invention, a baffle 3 is provided between at least every two adjacent wafers 2. The lower surface of the baffle 3 is cleaned to ensure that there are no dust particles or very few dust particles on the lower surface of the baffle 3. For example, the baffle 3 is cleaned before being placed in an unloaded loading and locking module 1, and then the wafer 2 is placed in during the process. During the wafer processing, the baffle 3 does not participate in any actions of the wafer processing process to keep the lower surface of the baffle 3 clean. The lower surface of the baffle 3 will not generate dust particles due to contact and friction with the robotic arm, so no dust particles (or only a very small number of dust particles) will fall onto the wafer 2 below. Dust particles present on the lower surface of the upper wafer 2 will fall onto the upper surface of the baffle 3, and the baffle 3 forms a shielding and protection for the lower wafer 2.
[0039] As a supplementary explanation, the statement that the baffle 3 does not participate in any wafer processing action means that the baffle 3 does not undergo the same processing as the wafer 2, for example, the baffle 3 remains stationary; or alternatively, the baffle 3 may perform other actions, such as cleaning itself, but it must be ensured that the dust particle condition on the lower surface of the baffle 3 meets the requirements after it is placed back into the wafer holder 10, and that a baffle that meets the requirements is present adjacent to the wafer above the wafer when the processed wafer is placed back into the wafer holder 10.
[0040] Preferably, a baffle 3 is also provided above the uppermost wafer on the wafer support 10, and / or a baffle 3 is also provided below the lowermost wafer on the wafer support 10. Providing a baffle 3 at the uppermost position further prevents dust particles present on the inner top wall of the loading locking module 1 from falling onto the uppermost wafer; and cleaning the baffle 3 and ensuring a higher level of cleanliness is easier than cleaning the inner top wall of the loading locking module 1. Providing a baffle 3 at the lowermost position further catches falling dust particles, helping to maintain the cleanliness of the inner bottom wall of the loading locking module 1 and simplifying the maintenance and cleaning process of the loading locking module 1 cavity itself.
[0041] In some embodiments, each layer of the wafer support 10 includes two wafer placement plates arranged opposite each other, with a gap between the two wafer placement plates. This gap allows a robotic arm to pass through to perform wafer placement actions. Wafers 2 and baffles 3 are placed at intervals in the multiple placement positions of the wafer support 10. This wafer support 10 structure is a relatively common existing structure. The present invention essentially uses an existing (or similar) loading and locking module, only changing its working method. Originally, each placement position held one wafer; the present invention changes this to placing wafers and baffles interspersed, with wafers placed in half (or nearly half) of the placement positions, and baffles placed in the other half (or nearly half). The size of the baffles 3 is, for example, the same as or similar to the size of the wafers 2. The baffles 3 are, for example, made of the same material as the wafers or are graphite sheets, etc.
[0042] In other embodiments, the loading locking module and / or wafer holder are specially designed based on the structural concept of the present invention, and the baffle 3 is a detachable or non-detachable configuration, that is, a novel loading locking module is used to separate the wafers individually.
[0043] Please see Figure 2In a specific embodiment, the semiconductor equipment used in the method of the present invention is an ion implanter. Further, in the ion implanter, the vacuum chamber connected to the loading and locking module 1 includes a transfer module and a process module. The transfer module and the process module have a single, integral vacuum chamber, or correspond to two interconnected vacuum chambers, or have multiple interconnected vacuum chambers; in this embodiment, the loading and locking module 1, the transfer module, and the process module each have a vacuum chamber, and the vacuum chambers of the transfer module and the process module are sequentially connected, with an optional openable and closable valve between the two vacuum chambers. The transfer module includes a front robotic arm 41, a rear robotic arm 42, and an aligner 43, with the front robotic arm 41 being closer to the loading and locking module 1 than the rear robotic arm 42. The process module includes a scanning robotic arm 51, the end of which is a scanning electrostatic chuck 52 capable of holding the wafer 2 and performing moving scanning.
[0044] As a supplementary explanation, the calibrator 43 is approximately located near the centerline between the front robotic arm 41 and the rear robotic arm 42, so that the movement range of the front robotic arm 41 and the rear robotic arm 42 covers the calibrator 43 and is beneficial to the overall spatial layout. The scanning electrostatic chuck 52 has a wafer pick-and-place working state and a wafer scanning working state. In the embodiment, in the wafer pick-and-place working state, the scanning electrostatic chuck 52 is laid flat, located below the ion beam 6 with a horizontal strip cross-section, and approximately located near the centerline between the front robotic arm 41 and the rear robotic arm 42, within the movement range of the front robotic arm 41 and the rear robotic arm 42; in the wafer scanning working state, the scanning electrostatic chuck 52 is flipped to a vertical position and moves in the up-down direction so that the wafer repeatedly passes through the ion beam 6 to achieve scanning implantation. The ion beam 6 is output by the ion beam forming module, and the vacuum chamber has a Faraday cup 53 on the side opposite to the output of the ion beam forming module to receive the ion beam 6.
[0045] Furthermore, the load locking module 1 is also connected to a front-end module (EFEM), which includes a wafer transfer cassette (FOUP) and an atmospheric transfer robotic arm. More specifically, for example, an ion implanter is typically equipped with a front-end module containing four wafer cassette stages (LoadPorts), each designed to accept a standard 25-wafer transfer cassette. A second gate valve is provided between the load locking module 1 and the front-end module. It should be noted that other specific technical aspects related to the ion implanter are not the focus of this invention; existing technologies or any other feasible solutions can be adopted.
[0046] Furthermore, in the ion implanter based on the embodiments of the present invention, the wafer processing process, i.e., the ion implantation process, includes the following steps:
[0047] The initial state is that the first valve 11 and the second valve are both closed, and the interior of the loading and locking module 1 is in an atmospheric state; the conveying module and the process module are always in a vacuum state, and the front-end module is always in an atmospheric state.
[0048] The second valve opens, and the atmospheric conveying robotic arm takes out the corresponding wafer from the wafer conveying box and places it into the loading and locking module 1 as needed;
[0049] The second valve is closed, the internal state of the loading locking module 1 is converted to a vacuum state (vacuuming, establishing the required high vacuum), and then the first valve 11 is opened;
[0050] The front robotic arm 41 removes the wafer from the loading and locking module 1 and places it on the calibrator 43;
[0051] The calibrator 43 rotates to calibrate the wafer;
[0052] The robotic arm 42 then removes the wafer from the calibrator 43 and places it on the scanning electrostatic chuck 52.
[0053] The electrostatic chuck 52 holds the wafer and performs a scanning motion with the wafer to complete ion implantation;
[0054] The front robotic arm 41 takes the implanted wafer from the scanning electrostatic chuck 52 and puts it back into the loading and locking module 1;
[0055] After the wafer is implanted with ions and completely returned to the loading and locking module 1, the first gate valve 11 is closed, the interior of the loading and locking module 1 is converted to atmospheric state (vacuum breaking), and then the second gate valve is opened.
[0056] The atmospheric conveying robotic arm removes the wafer from the loading and locking module 1 and places it back into the corresponding wafer transfer box.
[0057] In summary, the dust particle control method of the multi-wafer loading locking module of the present invention employs a baffle inserted between two wafers. The baffle does not participate in any actions required for ion implantation, thus preventing dust particles from being generated on the back side of the baffle. Therefore, the front side of the wafer always faces the clean back side of the baffle, eliminating the problem of dust particles falling from the back side of the wafer to the front side of the wafer below due to airflow disturbances in the loading locking module. Furthermore, the solution of the present invention can be implemented based on existing loading locking modules, making it simple and effective. Existing technologies do not employ technical means to reduce dust particles in the loading locking module; therefore, the solution of the present invention can be combined with other dust particle reduction methods to further improve process quality.
[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for controlling dust particles using a multi-plate loading and locking module, characterized in that, The semiconductor device used has a connected vacuum chamber and a loading locking module. A first gate valve is located between the vacuum chamber and the loading locking module. The loading locking module can switch between vacuum and atmospheric conditions. The loading locking module has a wafer support, which is a multi-layered structure in the vertical direction. Each layer forms a placement position that can support the edge of the wafer. Multiple wafers are placed on the wafer support, and a baffle is provided between every two adjacent wafers. The baffle has at least a cleaned lower surface. During the wafer processing, the baffle does not participate in any of the wafer processing actions in order to keep the lower surface of the baffle clean.
2. The dust particle control method of the multi-plate loading and locking module according to claim 1, characterized in that, A baffle is also provided above the topmost wafer on the wafer carrier, and / or a baffle is also provided below the bottommost wafer on the wafer carrier.
3. The dust particle control method of the multi-plate loading and locking module according to claim 1, characterized in that, Each layer of the wafer support includes two wafer placement plates arranged opposite each other, with a gap between the two wafer placement plates; wafers and baffles are placed at intervals in the multi-layer placement positions of the wafer support.
4. The dust particle control method of the multi-plate loading and locking module according to claim 3, characterized in that, The baffle is the same size as or similar to the wafer.
5. The dust particle control method for a multi-plate loading and locking module according to any one of claims 1-4, characterized in that, The semiconductor equipment used is an ion implanter.
6. The dust particle control method of the multi-plate loading and locking module according to claim 5, characterized in that, In the ion implanter, the vacuum chamber connected to the loading and locking module includes a transfer module and a process module; the transfer module includes a front robotic arm, a rear robotic arm, and a calibrator, with the front robotic arm being closer to the loading and locking module than the rear robotic arm; the process module includes a scanning robotic arm, the end of which is a scanning electrostatic chuck capable of holding the wafer and performing moving scans.
7. The dust particle control method of the multi-plate loading and locking module according to claim 6, characterized in that, The loading and locking module is also connected to a front-end module, which contains a wafer transfer box and an atmospheric transfer robotic arm; a second gate valve is located between the loading and locking module and the front-end module.
8. The dust particle control method of the multi-plate loading and locking module according to claim 7, characterized in that, The wafer processing technology includes the following steps: The initial state is that both the first and second gate valves are closed, and the interior of the loading and locking module is in atmospheric condition; the conveying module and process module are always in vacuum condition, and the front-end module is always in atmospheric condition. The second valve opens, and the atmospheric conveying robotic arm takes out the corresponding wafer from the wafer conveying box and places it into the loading and locking module as needed; The second valve is closed, the loading and locking module is converted to a vacuum state, and then the first valve is opened; The robotic arm removes the wafer from the loading and locking module and places it on the calibrator; The calibrator rotates to calibrate the wafer; The robotic arm then removes the wafer from the calibrator and places it on the scanning electrostatic chuck. The scanning electrostatic chuck holds the wafer and performs a scanning motion with the wafer to complete ion implantation; The robotic arm removes the implanted wafer from the scanning electrostatic chuck and places it back into the loading and locking module; After the wafer has completed ion implantation and been completely returned to the loading and locking module, the first gate valve is closed, the interior of the loading and locking module is converted to atmospheric conditions, and then the second gate valve is opened. The atmospheric conveying robotic arm removes the wafer from the loading and locking module and places it back into the corresponding wafer transfer box.