Semiconductor processing equipment and control method thereof

Abstract

The invention discloses semiconductor processing equipment and a control method thereof, and relates to the technical field of semiconductor manufacturing. The semiconductor processing equipment comprises a cavity, an air source and at least one air inlet valve group, the side edge of the cavity is provided with a plurality of air inlet holes which are arranged in a surrounding manner, the air inlet valve group comprises a plurality of air inlet valves which are in one-to-one correspondence with the air inlet holes and are independently controllable, and each air inlet valve can independently control the on-off of an air path of the corresponding air inlet hole. In the operation process of the etching process, part of the air inlet valves and the other air inlet valves in the same air inlet valve group can execute inconsistent opening and closing actions, so that different etching amounts are obtained in all areas in the circumferential direction of the substrate. According to the method, the etching amount can be regulated and controlled according to different areas in the circumferential direction of the substrate, the defect of non-uniform film thickness pre-existing in the substrate is effectively overcome, and the feature morphology uniformity of all the areas of the etched substrate and the semiconductor process yield are improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a semiconductor processing apparatus for an etching process, and a control method for the semiconductor processing apparatus. Background Technology

[0002] In actual production, the aforementioned front-end processes inevitably introduce local defects into the substrate surface. These defects manifest as uneven film thickness distribution, uneven film density distribution, critical dimension (CD) deviations in photolithography patterns, and inconsistent regional characteristics such as uneven spatial distribution of mask patterns throughout the substrate. These defects exhibit localized and differentiated distribution characteristics, which traditional globally uniform etching processes cannot compensate for. Ultimately, this results in substandard uniformity of key parameters on the etched substrate, severely impacting device performance and product yield.

[0003] Traditional semiconductor etching equipment uses a centralized gas supply system. Edge gas supply often uses a uniform gas supply ring and main control valve, which can only achieve uniform adjustment of gas supply parameters throughout the process chamber. Even if multi-channel gas intake control is introduced, its control objective is to ensure uniform etching within the etching process, that is, to keep the amount of etching uniform. It cannot perform differentiated etching control for inherent defects in the substrate before the process. As a result, defects introduced in the previous process cannot be effectively compensated. The uniformity treatment within the etching process actually causes the key parameters of the substrate after the final etching to fail to meet the standards, which seriously affects the electrical performance of the device and the product yield. Summary of the Invention

[0004] To address the aforementioned deficiencies in the prior art, the present invention aims to provide a semiconductor processing device and its control method. By circumferentially arranging independently controllable air intake valves and air intake holes in a one-to-one correspondence, independent on / off control of each air intake point can be achieved. Based on regional characteristic defects introduced by the substrate front-end process, the air intake valves in the same air intake valve group can be controlled to perform differentiated opening and closing actions, thereby achieving differentiated etching treatment of different areas of the substrate, accurately suppressing front-end defects, and improving product yield.

[0005] According to one aspect of the present invention, a semiconductor processing apparatus is provided, comprising a cavity, a gas source, and a controller; the cavity is enclosed to form a process chamber and has an exhaust port communicating with the process chamber; the process chamber is evacuated through the exhaust port to maintain a vacuum environment required for the process; a gas supply ring is provided on the side wall of the cavity, and a plurality of gas inlets are arranged circumferentially around the gas supply ring for supplying gas to the edge of the process chamber; the apparatus further comprises at least one gas inlet valve group, the gas inlet valve group comprising a plurality of independently controllable gas inlet valves, the plurality of gas inlet valves being arranged around the gas supply ring and corresponding one-to-one with the plurality of gas inlet ports. The configuration includes: the intake valve group is connected to the gas source, which supplies process gas; during the process, the intake valve group controls the supply of process gas, and the process chamber carries a substrate processed by the previous process; the controller is configured to: acquire defects with inconsistent characteristics in different areas of the substrate before etching, and, based on the defects, control some intake valves in the same intake valve group to perform inconsistent opening and closing actions with the remaining intake valves, thereby differentially etching the defective areas of the substrate compared to other areas to smooth out the defects.

[0006] For example, the etching process includes an atomic layer etching process, which includes alternating modification and stripping stages; the gas source includes a first gas source and a second gas source, the first gas source being used to supply a first process gas for the modification stage, and the second gas source being used to supply a second process gas for the stripping stage; an intake valve assembly is connected to the first gas source or the second gas source and is used to supply the first process gas or the second process gas.

[0007] For example, the controller is communicatively connected to each of the intake valves and controls the opening and closing timing of each intake valve according to the defect, driving the corresponding intake valve to perform independent opening and closing actions to mitigate the defect.

[0008] For example, the semiconductor processing apparatus includes two sets of inlet valve groups, namely a first inlet valve group and a second inlet valve group; the first inlet valve group is connected to the first gas source and is used to control the supply of the first process gas; the second inlet valve group is connected to the second gas source and is used to control the supply of the second process gas; the first inlet valve group and the second inlet valve group are switched on and off as a whole based on the modification stage and the stripping stage.

[0009] For example, an intake valve in the first intake valve group and an intake valve in the second intake valve group are paired to form an intake valve pair. The intake valve pair is configured to correspond one-to-one with the intake port. The two intake valves in one intake valve pair are connected in parallel to one intake port.

[0010] For example, the air intake includes a first air intake and a second air intake, the first air intake valve group is connected to the first air intake, the second air intake valve group is connected to the second air intake, a plurality of air intake valves in the first air intake valve group are configured to correspond one-to-one with the first air intake, and a plurality of air intake valves in the second air intake valve group are configured to correspond one-to-one with the second air intake.

[0011] For example, the first air inlet and the second air inlet are arranged alternately in the circumferential direction of the air supply ring, and / or the first air inlet and the second air inlet are arranged at intervals in the axial direction of the air supply ring.

[0012] For example, the features of each region include substrate film thickness distribution, substrate density distribution, substrate lithography critical size distribution, or substrate mask spatial distribution.

[0013] For example, the process chamber is equipped with an in-situ detection unit, which is communicatively connected to the controller and is used to detect the characteristics of each region in situ without disrupting the vacuum environment of the process chamber; the controller generates the opening and closing control sequence of the multiple air intake valves based on the characteristics of each region to mitigate the defects.

[0014] For example, the in-situ detection unit includes an optical reflectometer, a scattering meter, an elliptic polarimeter, or a critical dimension online detection device.

[0015] For example, the intake valve is fixedly connected to the air supply ring via an air guide block, and the distance from the intake valve to the air intake port communicating with it is the shortest relative to the distance from the intake valve to other air intake ports.

[0016] On the other hand, the present invention provides a control method for a semiconductor processing apparatus, applied to the aforementioned semiconductor processing apparatus, comprising the following steps: acquiring the characteristics of each region of a substrate, recording defects in the characteristics of each region of the substrate that are inconsistent, running the process cavity in the etching process, controlling the opening and closing control sequence of multiple intake valves in the intake valve group based on the characteristics of each region, driving the intake valves to perform independent opening and closing actions, causing some intake valves in an intake valve group to perform inconsistent opening and closing actions with the other intake valves, and differentially etching the defective regions of the substrate with other regions to suppress the defects.

[0017] For example, the opening and closing control timing is implemented by analyzing the region that needs to be corrected in each region of the substrate and placing it within the coordinate range of the substrate. The coordinate range is then matched with the corresponding air intake valve of the air intake hole that controls the air supply area of ​​the coordinate range among the multiple air intake valves. The corresponding air intake valve is then controlled to perform inconsistent opening and closing actions with the other air intake valves in the same air intake valve group to mitigate the defect.

[0018] For example, the inconsistent opening and closing actions include: during the etching process, some of the intake valves in one intake valve group are in the open state while the rest are in the closed state; or during the etching process, the opening duration of some of the intake valves in one intake valve group is different from the opening duration of the rest.

[0019] For example, the etching process includes an atomic layer etching process, which includes alternating modification and stripping stages. The inconsistent opening and closing actions include: within the same atomic layer etching cycle, the opening duration of some intake valves in an intake valve group is different from the opening duration of the other intake valves; or within multiple atomic layer etching cycles, the number of opening cycles of some intake valves in an intake valve group is different from the number of opening cycles of the other intake valves.

[0020] For example, the corresponding region includes a sector, and the corresponding intake valve includes an intake valve whose intake port is directly opposite the sector, and / or an intake valve whose intake port is adjacent to the sector.

[0021] For example, when there is no air intake port directly facing the sector, the corresponding air intake valve is at least two air intake valves connected to the air intake port adjacent to the sector. When the inconsistent opening and closing action is performed, multiple air intake valves in the corresponding air intake valve are alternately opened and closed.

[0022] For example, the etching process includes an atomic layer etching process, which includes a modification stage based on a first process gas and a stripping stage based on a second process gas. The first process gas is supplied to the process chamber by a first inlet valve group, and the second process gas is supplied to the process chamber by a second inlet valve group. Both the first and second inlet valve groups are controlled to supply gas to the process chamber through the side edge of the process chamber.

[0023] For example, the second intake valve assembly and the first intake valve assembly both perform the inconsistent opening and closing actions.

[0024] For example, the atomic layer etching cycle is divided into an initial cycle, an intermediate cycle, and a final cycle according to the cycle execution sequence, and the opening and closing inconsistent operation is performed only in the intermediate cycle.

[0025] This invention utilizes multiple independently controllable air intake valves arranged circumferentially around the air supply ring, each corresponding to a specific air intake port. This enables independent on / off control of each air intake point. Based on local defects introduced by the previous process steps, it can control some air intake valves within the same air intake valve group to perform differentiated opening and closing actions compared to the others. This results in different concentrations of reactive particles in different areas of the substrate during at least a portion of the process time, achieving differentiated control of the etching amount in different areas of the substrate. This mitigates inconsistencies in regional characteristics caused by previous processes and improves product yield. Attached Figure Description

[0026] Figure 1 A schematic diagram of a semiconductor processing device provided by the present invention; Figure 2 A schematic diagram of a dual-inlet semiconductor processing device provided by the present invention; Figure 3 A schematic diagram of another dual-inlet semiconductor processing device provided by the present invention; Figure 4 A schematic diagram of a circumferential arrangement structure with dual-edge air intakes provided by the present invention; Figure 5 A schematic diagram of another circumferential arrangement structure with dual-edge air intakes provided by the present invention; Figure 6 A flowchart illustrating a control method for a semiconductor processing device provided by the present invention; Figure 7 A schematic diagram showing the circumferential arrangement structure of an intake valve assembly provided by the present invention and its correspondence with substrate defects; Figure 8 A schematic diagram of the intake control timing of an intake valve group for the atomic layer etching process provided by the present invention.

[0027] Those skilled in the art should understand that the above drawings are only schematic drawings and are not scaled to actual proportions. The same reference numerals in the drawings are used to refer to the same or similar parts, and their details do not constitute a limitation on the present invention. Detailed Implementation

[0028] The following detailed description of several embodiments of the present invention, in conjunction with the accompanying drawings, will enable those skilled in the art to clearly understand the technical solutions, core principles, and beneficial effects of the present invention. These embodiments are implemented based on the technical solutions of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0029] See Figure 1 According to one aspect of the present invention, a semiconductor processing apparatus is provided for etching a semiconductor substrate 8. The apparatus includes a cavity 1, a gas source 6, and a controller 7.

[0030] For example, the interior of cavity 1 encloses a process cavity 2, and an exhaust port 12 communicating with the process cavity 2 is provided on the bottom or side of cavity 1. Generally, a vacuum module 14 is connected to the exhaust port 12. The vacuum module 14 can continuously evacuate the process cavity 2, maintaining the pressure inside the process cavity 2 stably within the vacuum range required for the etching process. The vacuum module 14 generally consists of a vacuum valve and a vacuum pump. The vacuum valve is connected between the vacuum pump and cavity 1 to control the opening of the vacuum flow channel between process cavity 2 and vacuum pump. Generally, an electrostatic chuck 13 is fixed inside the process cavity 2. The electrostatic chuck 13 is used to fix the substrate 8 to be etched during the etching process by electrostatic adsorption force and can control the temperature of the substrate 8. Optionally, cavity 1 can be made of corrosion-resistant material or have an internal corrosion-resistant coating.

[0031] A gas supply ring 10 is fixed on the side wall of the cavity 1. The gas supply ring 10 can be integrally or separately arranged with the cavity 1, and it is arranged around the circumference of the process cavity 2. Generally, to avoid edge deviation, the gas supply ring 10 is arranged coaxially with the substrate 8. The gas supply ring 10 has a plurality of circumferentially spaced air inlets 3 for supplying edge gas to the interior of the process cavity 2. After the process gas enters the process cavity 2 through the air inlets 3, it diffuses towards the central region of the substrate 8. At this time, plasma excitation can be superimposed to achieve etching treatment on the surface of the substrate 8.

[0032] The semiconductor processing equipment also includes at least one set of inlet valve groups 4, which contains multiple independently controllable inlet valves 5. Preferably, the inlet valves 5 are diaphragm valves, such as ALD valves, to provide extremely fast switching response and excellent sealing performance. Multiple inlet valves 5 are fixedly arranged circumferentially around the gas supply ring 10, and each inlet valve 5 in one set of inlet valve groups 4 is correspondingly set to one inlet port 3, realizing independent on / off control of a single valve to a single port. The inlet end of the inlet valve group 4 is connected to a gas source 6, and each set of inlet valve groups 4 corresponds to one gas source 6, used to control the supply of a process gas to the process chamber 2. It can be understood that the description of a process gas is used to distinguish the gases supplied by different inlet valve groups; different inlet valve groups supply different gases.

[0033] For example, gas source 6 can be any component or its main connecting pipeline that can provide process gas, such as a gas distribution box, main gas supply pipeline, or gas source cylinder.

[0034] For example, the controller 7 can be a programmable logic controller (PLC), which can have built-in process control algorithms and timing generation modules. The controller 7 can establish independent communication connections with all functional components such as the air inlet valve 5, air source 6, vacuum module 14, and electrostatic chuck 13, and can realize automated control of the entire etching process.

[0035] The controller 7 is configured to: acquire feature data of each region of the substrate 8 to be etched before or during the initial stage of the etching process, and analyze the defect data of inconsistent features in each region of the substrate 8; during the etching process, based on the defect data, control some of the intake valves in the same intake valve group 4 to perform inconsistent opening and closing actions with the other intake valves, so as to differentiate the processing of each region of the substrate 8 and suppress defects.

[0036] Before or during the initial stage of the etching process, characteristic data of each region of the substrate 8 to be etched are acquired, and defect data showing inconsistencies in characteristics across the entire substrate 8 are analyzed. During the etching process, based on this defect data, a timing sequence for the opening and closing of each intake valve 5 is generated, and a drive signal is sent to the corresponding intake valve 5 according to this timing sequence. This controls some intake valves 5 within the same intake valve group 4 to perform inconsistent opening and closing actions with the others, thereby introducing differentiated doses of process gas into different regions of the substrate 8. This results in differentiated etching treatment for each region of the substrate 8, ultimately mitigating defects introduced by the previous process. Individual valve control improves control precision.

[0037] The exhaust port 12 continuously evacuates the vacuum, preventing the reactive particles in the process gas or plasma in the process chamber 2 from spreading over the substrate 8 for a long time. Instead, they are quickly drawn away by the exhaust port 12. Combined with the opening and closing of the differentiated air intake valve 5, it makes it difficult for reactive particles in a single air intake direction to completely spread and cover the entire substrate 8. This allows the reactive particles above the substrate 8 to form a differentiated distribution, enabling differentiated treatment of different areas of the substrate 8 to suppress defects.

[0038] In one embodiment, the intake valves 5 within the same intake valve group 4 can be grouped into a regulating group and a regular group. Each group is controlled uniformly, with the regulating group performing inconsistent opening and closing actions relative to the regular group. This allows for differentiated introduction of process gases into different areas of the substrate 8, resulting in differentiated etching treatment for each area of ​​the substrate 8 and ultimately mitigating defects introduced by previous processes. Group control reduces the complexity of control signals, improves the consistency of control response for each group of valves, and reduces inter-valve control delay.

[0039] For example, the characteristics of each region of substrate 8 include substrate film thickness distribution, substrate film density distribution, substrate photolithography critical size distribution, or substrate mask spatial distribution, etc., covering the types of defects that exist in front-end CMP, deposition, photolithography and other processes, so that this equipment can adapt to the defect compensation needs of various front-end processes.

[0040] For example, such as Figure 2 , Figure 3As shown, to improve the response speed and control accuracy of the intake valve 5, each intake valve 5 is fixedly connected to the air supply ring 10 via an air guide block 11. The air guide block 11 can be made of the same material as the air supply ring 10 and has an internal air guide channel. One end of the air guide channel is sealed to the outlet end of the intake valve 5, and the other end of the air guide channel is sealed to the intake end of the corresponding air inlet 3.

[0041] In one embodiment, the air path distance from the outlet end of the intake valve 5 to the air inlet 3 connected to it is the shortest, and this distance is less than the distance from the intake valve 5 to any other air inlet 3 on the air supply ring 10.

[0042] This design shortens the gas path length from a single intake valve 5 to the intake port 3 connected to it, significantly reducing the dead volume of the gas path, improving the gas path response speed of the opening and closing action of the intake valve 5, ensuring the timing accuracy of differentiated control, and is especially suitable for the short pulse and fast response gas supply requirements of atomic layer etching process. At the same time, it reduces the gas residue in the gas path, effectively avoiding the problem that residual gas still escapes into the process chamber 2 after some intake valves 5 are closed, which would weaken the differentiated effect of differentiated intake, and avoids cross-contamination of gases in different process stages.

[0043] In one embodiment, the etching process is an atomic layer etching process, which mainly consists of alternating modification and stripping stages. Generally, the modification stage uses plasma of a first process gas to chemically modify the surface of the film to be etched, forming a modified layer that is easy to remove; the stripping stage uses plasma of a second process gas to remove the modified layer from the surface of the substrate 8. A single modification stage and a single stripping stage constitute a complete atomic layer etching cycle, and etching to a preset thickness is achieved through multiple cycles.

[0044] Correspondingly, the gas source 6 includes a first gas source 61 and a second gas source 62. The first gas source 61 is used to store and supply the first process gas required for the modification stage, and the second gas source 62 is used to store and supply the second process gas required for the stripping stage. A single set of inlet valve group 4 is connected to one of the first gas source 61 or the second gas source 62, that is, a set of inlet valve group 4 is used to control the supply of the first process gas or to control the supply of the second process gas, so as to achieve complete separation of the gas path and control logic of the two process gases.

[0045] In one embodiment, the intake valve assembly 4 is an edge intake valve assembly connected to a first air source 61 or a second air source 62, and also includes a center intake valve 15 connected to another air source. For example, ... Figure 2As shown, the intake valve assembly 4 is connected to the first gas source 61, and the central intake valve 15 is located in the middle of the cover plate 16 at the top of the cavity 1 and is connected to the second gas source 62. The intake valve assembly 4 and the central intake valve 15 are alternately switched on and off to match the two-stage process gas supply of ALE. The cover plate 16 can be a dielectric window or an upper electrode. When the cover plate 16 is a dielectric window, an RF coil is also provided above the cover plate 16, which is electrically connected to the RF source to excite plasma in the process cavity 2. When the cover plate 16 is an upper electrode, the cover plate is a conductor and can be grounded or electrically connected to the RF source to form capacitively coupled plasma in the process cavity 2.

[0046] In one embodiment, such as Figure 3 As shown, two independent intake valve groups 4 are provided, namely the first intake valve group 41 and the second intake valve group 42. The intake end of the first intake valve group 41 is connected to the first gas source 61, and all its intake valves 5 are used to independently control the supply of the first process gas to the corresponding intake port 3; the intake end of the second intake valve group 42 is connected to the second gas source 62, and all its intake valves 5 are used to independently control the supply of the second process gas to the corresponding intake port 3. In the entire process of atomic layer etching, the controller 7 controls the first intake valve group 41 and the second intake valve group 42 to perform overall alternating on / off switching based on the modification stage and the stripping stage: that is, in the modification stage, the controller 7 controls all the intake valves 5 of the second intake valve group 42 to remain closed, and the intake valves 5 of the first intake valve group 41 are in a controllable open state; in the stripping stage, the controller 7 controls all the intake valves 5 of the first intake valve group 41 to remain closed, and the intake valves 5 of the second intake valve group 42 are in a controllable open state. This design ensures complete isolation of process gases during the modification and stripping stages, avoiding particulate contamination and reduced etching precision caused by gas cross-reaction. At the same time, through the overall alternating on / off control logic, it guarantees the basic timing requirements and process stability of the ALE process's self-limiting reaction.

[0047] See Figure 4 In one embodiment, an intake valve 5 in the first intake valve group 41 and an intake valve 5 in the second intake valve group 42 are paired to form an intake valve pair. Multiple intake valve pairs are evenly arranged around the circumference of the air supply ring 10, and each intake valve pair corresponds one-to-one with an air inlet 3. Specifically, the outlet ends of the two intake valves 5 in the same intake valve pair can be directly connected or connected to the same air inlet 3 through parallel air guiding channels in the air guiding block 11. That is, the same air inlet 3 can be used to supply the first process gas through the corresponding intake valve 5 of the first intake valve group 41, or the second process gas through the corresponding intake valve 5 of the second intake valve group 42. This design ensures the consistency of the position or phase angle of the two independent circumferential air supply of the process gas, avoids the problem of misalignment of the circumferential air supply position caused by the split-hole design, and improves the accuracy of air supply control in each circumferential area and the consistency of air supply control in the two stages of ALE.

[0048] See Figure 5 In one embodiment, the air inlet 3 on the gas supply ring 10 is divided into a first air inlet 31 and a second air inlet 32, which are independent of each other. The first air inlet 31 is connected to the first air inlet valve group 41, and the second air inlet 32 ​​is connected to the second air inlet valve group 42. Multiple air inlet valves 5 in the first air inlet valve group 41 are configured one-to-one with multiple first air inlets 31, and each air inlet valve 5 controls the on / off state of the first process gas corresponding to one first air inlet 31. Similarly, multiple air inlet valves 5 in the second air inlet valve group 42 are configured one-to-one with multiple second air inlets 32, and each air inlet valve 5 controls the on / off state of the second process gas corresponding to one second air inlet 32. This design achieves complete physical isolation between the air inlet channels of the first and second process gases, preventing premature contact between the two gases within the air inlet channels and avoiding mutual interference between the two gas paths, thus improving the accuracy and stability of gas flow control.

[0049] For example, the first air inlet 31 and the second air inlet 32 ​​can be arranged in any one of the following two ways, or a combination of the two ways: The first type is a circumferential alternating arrangement, that is, along the circumferential direction of the air supply ring 10, the first air inlet 31 and the second air inlet 32 ​​are arranged alternately in sequence, and the two adjacent air inlets are the first air inlet 31 and the second air inlet 32 ​​respectively. The spacing between all the first air inlets 31 in the circumferential direction is consistent with the spacing between all the second air inlets 32, so as to ensure the uniform distribution of the two gas in the circumferential direction and avoid the occurrence of air supply blind spots. The second type is axially spaced arrangement: along the axial direction of the air supply ring 10, two independent air inlet hole layers are set, one of which is the first air inlet hole 31 and the other is the second air inlet hole 32. The two air inlet holes maintain a preset interval distance in the axial direction, and can be arranged in a one-to-one correspondence or staggered arrangement in the circumferential direction. The air inlet height of the two gas paths can be flexibly adjusted to adapt to different process flow field design requirements.

[0050] In one embodiment, to achieve closed-loop precise control of the etching process, an in-situ detection unit 9 is also provided at the top of the process chamber 2. The in-situ detection unit 9 can be fixed to the top of the chamber 1 through a vacuum sealing flange. Its detection end can detect the surface of the substrate 8 in the process chamber 2 through the observation window or transparent dielectric window on the top wall of the chamber 1. The in-situ detection unit 9 establishes a real-time high-speed communication connection with the controller 7. Before the etching process is executed, or during the interval of the atomic layer etching cycle, the in-situ detection unit 9 can perform a full-area scan detection of the features of each region on the surface of the substrate 8 without disrupting the vacuum environment of the process chamber 2, and transmit the detected feature distribution data to the controller 7 in real time. After receiving the detection data, the controller 7 analyzes the defect data of the substrate 8 in real time, and updates and generates the opening and closing control sequence of each air inlet valve 5 based on the defect data in real time. The timing sequence is executed in the subsequent etching process to suppress defects. This design enables online detection and closed-loop feedback control without disrupting the vacuum environment, avoiding the risks of process interruption, reduced production efficiency, and environmental pollution caused by vacuum-breaking detection. At the same time, the control strategy can be dynamically adjusted based on real-time detection results, further improving the accuracy and timeliness of defect compensation.

[0051] For example, the in-situ detection unit 9 can be any one or a combination of an optical reflectometer, a scattering meter, an ellipsometer, or a critical dimension online detection device. The optical reflectometer, scattering meter, and ellipsometer are used to detect features such as film thickness and film density on the surface of the substrate 8, while the critical dimension online detection device is used to detect features such as the critical dimensions of the photolithographic pattern on the surface of the substrate 8 and the spatial distribution of the mask pattern. All of these devices are mature non-contact detection equipment in the semiconductor manufacturing field, and can be integrated without significant modifications to the structure of the cavity 1. Their detection accuracy meets the detection requirements of advanced process nodes.

[0052] According to another aspect of the present invention, a control method for a semiconductor processing apparatus is provided, the method being applied to the aforementioned semiconductor processing apparatus, the flowchart of which is shown below. Figure 6 As shown, the characteristics of each region of the substrate 8 are obtained, the defects of inconsistent characteristics in each region of the substrate 8 are recorded, and the process chamber 2 is run in the etching process to process the substrate 8. Based on the characteristics of each region, the opening and closing control timing of multiple air intake valves 5 in the air intake valve group 4 is controlled, and the air intake valves 5 are driven to perform independent opening and closing actions, so that some air intake valves 5 in one air intake valve group 4 perform inconsistent opening and closing actions with the other air intake valves 5, so as to suppress defects.

[0053] Optionally, the characteristics of each region of the substrate 8 to be etched are first obtained, and the defects of inconsistent characteristics in each region of the substrate 8 are recorded. The substrate 8 is then transferred to the process cavity 2. After the process environment preparation is completed, the process cavity 2 is run in the etching process.

[0054] For example, feature data of each region of substrate 8 can be obtained in two ways: one is through the in-situ detection unit 9 built into the process chamber 2, which obtains the data in situ without disrupting the vacuum environment; the other is through the machine inspection in the previous process, and then transmitting the detection data to the controller 7. The controller 7 compares the acquired feature data of each region with the target standard value preset by the process, and analyzes the deviation between the feature data of each region in the entire substrate 8 and the target value, that is, the defect data of inconsistent feature data in each region.

[0055] Before, after, or simultaneously with acquiring the characteristics of each region of the substrate 8 to be etched, the controller 7 uses a vacuum robot to transfer the substrate 8 to the electrostatic chuck 13 in the process chamber 2, completing the adsorption and fixation of the substrate 8, vacuum extraction of the process chamber 2, temperature stabilization and other process environment preparations, and then starts the etching process.

[0056] Subsequently, based on the characteristics of each region of the substrate 8, the opening and closing control timing of multiple intake valves 5 in the intake valve group 4 is controlled, and the intake valves 5 are driven to perform independent opening and closing actions, so that some intake valves 5 in the same intake valve group 4 perform inconsistent opening and closing actions with the other intake valves 5, in order to suppress defects.

[0057] Preferably, multiple air inlet valves 5 are connected one-to-one with multiple air inlet holes 3 arranged around the side edge of the process chamber 2, so as to independently control the gas flow of each air inlet hole 3.

[0058] For example, such as Figure 7 As shown, one generation and execution process of the opening and closing control timing is as follows: The controller 7 first analyzes the feature data of each region of the substrate 8, locates the region 81 that needs to be etched and corrected, and determines the coordinate range of the region 81 that needs to be corrected in the substrate plane. The coordinates can be based on Cartesian coordinates or polar coordinates. Then, the coordinate range is spatially matched with the gas supply area of ​​multiple gas inlets 3 to determine the gas inlet 3 that controls the gas supply area corresponding to the coordinate range. The gas inlet valve 5 corresponding to the gas inlet 3 is further matched as the corresponding gas inlet valve 51 that needs to be differentially controlled. After that, the controller 7 controls the corresponding gas inlet valve 51 and the other gas inlet valves 52 in the same gas inlet valve group 4 to perform inconsistent opening and closing actions, and differentially introduce process gas into the region that needs to be corrected to realize the control of the etching amount in the region, so as to suppress the defects introduced by the previous process.

[0059] In one embodiment, to improve the matching degree between the defect location and the air inlet valve, the air inlet valve and the corresponding air supply area of ​​the substrate are calibrated in advance, a one-to-one mapping relationship between the coordinate range of the air inlet valve and the air supply area is established, and the mapping relationship is stored in the storage module of the controller 7. The calibration can be performed using any one of static geometric calibration and dynamic process calibration, or a combination of both methods to improve calibration accuracy.

[0060] In one implementation method, a static geometric calibration method can be used, and the specific implementation process is as follows: First, establish a unified coordinate system. With the center of substrate 8 as the origin and the notch positioning edge of substrate 8 as the reference direction with a polar angle of 0°, establish a substrate planar polar coordinate system, where the polar angle θ is the circumferential angle and the polar radius r is the radial distance from the center of the substrate.

[0061] Next, complete the circumferential region division of the substrate. See [link / reference] Figure 7 The effective process area of ​​substrate 8 is divided into N independent sectors along the circumference. The number of sectors N can be equal to the number of intake valves 5 in the same intake valve group 4. The circumferential angle range of each sector is 360° / N. Preferably, the circumferential boundary of adjacent sectors coincides with the angle bisector of the circumferential centerline of two adjacent intake valves 5 to avoid errors in determining blind spots or overlapping areas of gas supply coverage. For example, when intake valve group 4 contains 24 circumferentially uniformly arranged intake valves 5, substrate 8 is divided into 24 sectors of 15° each.

[0062] Subsequently, a basic correspondence is established. All intake valves 5 are sequentially numbered along the direction of increasing polar angle. A one-to-one correspondence is established between the intake valve 5 numbered n and the nth sector with a polar angle range of [(n-1)×360° / N, n×360° / N]. The basic air supply area of ​​this intake valve 5 is determined to be the corresponding nth sector.

[0063] Finally, the radial range calibration is completed. The radial range of the gas supply area corresponding to each gas inlet valve 5 can be determined based on the installation height of the gas supply ring 10, the injection angle of the gas inlet 3, and the flow field simulation results of the process cavity 2. Optionally, for the gas inlet valve 5 with edge gas supply, when its gas supply area cannot cover the defects in the center area of ​​the substrate, full coverage can be achieved by the coordinated gas supply of multiple adjacent circumferential gas inlet valves 5.

[0064] In another alternative implementation, a dynamic process calibration method can be used to eliminate flow field errors caused by geometric calibration and improve calibration accuracy. The specific implementation process is as follows: First, a thin film of uniform thickness to be etched is deposited on the substrate 8. The substrate 8 is then transferred into the process cavity 2 and fixed by an electrostatic chuck 13. The process cavity 2 is then stabilized to the vacuum environment, temperature and other process parameters required for the etching process.

[0065] Next, each individual air inlet valve 5 is opened sequentially to introduce a preset amount of etching process gas. After completing a single etching, the substrate 8 is removed, and the etching amount distribution over the entire substrate 8 is detected by a film thickness detection device. The area where the etching amount is greater than a preset threshold after the air inlet valve 5 is opened is determined to be the effective gas supply area of ​​the air inlet valve 5.

[0066] Subsequently, the above steps are repeated to complete the calibration of the effective air supply area of ​​all intake valves 5, establish a one-to-one mapping relationship between each intake valve 5 and the corresponding effective air supply area coordinate range, and store it in the controller 7.

[0067] In one embodiment, to better match the differential control of the circumferential intake valve, the global plane of substrate 8 can be divided circumferentially into multiple independent sectors based on the corresponding region requiring correction, such as... Figure 7 As shown, each sector corresponds to a circumferential region of the substrate 8. The corresponding intake valve for that sector includes: the intake port 3 connected to the intake valve 5 is directly opposite the intake valve 5 of the sector, and / or the intake port 3 connected to the intake valve 5 is adjacent to the intake valve 5 of the sector.

[0068] When a sector requiring correction lacks a directly opposite air inlet 3, the controller 7 identifies at least two adjacent air inlet valves 5 on either side of the sector as the corresponding air inlet valves. During inconsistent opening and closing actions, the controller 7 controls these multiple adjacent corresponding air inlet valves to alternately open and close. That is, within the same process stage, multiple corresponding air inlet valves open and close sequentially according to a preset time sequence, alternately supplying process gas to the sector. This design enables consistent and controllable differential gas supply to sectors without a directly opposite air inlet, avoiding uneven regional gas supply caused by a single adjacent air inlet valve, ensuring the uniformity of etching within the sector, and preventing interference with the etching process of adjacent sectors.

[0069] In one embodiment, after the controller 7 completes defect identification, it can obtain the corresponding intake valve 51 for defect compensation through the following steps: The first step is defect region localization. The controller 7 compares the acquired feature values ​​of each region of the substrate 8 with preset process target values, and determines the region where the feature value deviation exceeds the preset allowable range as defect region 81. The polar coordinate range (θ) corresponding to defect region 81 is recorded. start ,θ end ,r start ,r end ).

[0070] The second step is candidate intake valve screening. The controller 7 traverses the calibrated air supply area of ​​all intake valves 5 and screens out intake valves 5 whose air supply area and defect area 81 have spatial overlap as candidate intake valves.

[0071] The third step is to determine the corresponding intake valve. The controller 7 calculates the percentage overlap between the air supply area and the defective area 81 of each candidate intake valve, and determines the candidate intake valve 51 whose overlap percentage is greater than a preset threshold. Preferably, the preset threshold is not less than 50% to ensure the matching degree between the air supply area and the defective area 81 of the corresponding intake valve 51.

[0072] For the defective area 81 without a direct air supply area, the controller 7 determines at least two adjacent air inlet valves 5 on both sides of the defective area 81 as corresponding air inlet valves 51. Through a coordinated control method of alternating opening and closing or synchronous opening, the controller achieves uniform air supply coverage of the defective area 81, avoiding the problem of uneven etching caused by air supply from a single air inlet valve.

[0073] In some embodiments, inconsistent opening and closing actions within the same intake valve group 4 are performed such that, within the same process stage of the etching process, some intake valves 5 within the same intake valve group 4 are continuously open, while the remaining intake valves 5 are continuously closed. This is suitable for scenarios where defects are concentrated and a significant adjustment of the etching amount is required.

[0074] In some embodiments, inconsistent opening and closing actions within the same intake valve group 4 are performed such that all intake valves 5 within the same intake valve group 4 are opened during the same process stage of the etching process, but the opening duration of some intake valves 5 is different from that of the others. By adjusting the opening duration, the total gas dose introduced into the corresponding area is controlled, thereby achieving fine-tuning of the etching amount. This is suitable for scenarios that require minor correction of defects.

[0075] In some embodiments, the etching process is an atomic layer etching process, and correspondingly, inconsistent opening and closing actions are implemented as duration differences within a single cycle and / or number differences within multiple cycles.

[0076] The time difference within a single cycle is implemented by the fact that within the same process stage of the same atomic layer etching cycle, the opening time of some intake valves 5 in the same intake valve group 4 is different from that of the other intake valves 5. By adjusting the opening time within a single cycle, atomic-level fine-tuning of the etching amount in the corresponding area within a single cycle can be achieved.

[0077] The multi-cycle differential operation is implemented by having some intake valves 5 in the same intake valve group 4 only open in some cycles, while the remaining intake valves 5 open in all cycles. This makes the number of cycles in which some intake valves 5 open different from the number of cycles in which the remaining intake valves 5 open, thereby adjusting the total etching amount in the corresponding area.

[0078] It is understandable that in atomic layer etching, if the modifying gas or stripping gas is not supplied in a certain cycle, the modification stage or stripping stage of that cycle cannot be carried out, and there will be no etching behavior in the entire cycle. Therefore, when some of the intake valves 5 in the same intake valve group 4 only perform the opening action in some cycles, while the remaining intake valves 5 perform the opening action in all cycles, the number of atomic layers etched in the substrate 8 region corresponding to some intake valves 5 will be less than the number of atomic layers etched in the substrate 8 region corresponding to the remaining intake valves 5. Ideally, this difference can be determined by controlling the number of differentiated cycles, that is, by controlling the number of differentiated cycles, the difference between the number of atomic layers etched in the area to be corrected of the substrate 8 and other regions can be precisely controlled, thereby achieving precise control of the characteristics of each region of the substrate 8 to suppress the defects of inconsistent characteristics of each region of the substrate 8.

[0079] For example, in the atomic layer etching process, the first process gas is supplied to the process chamber 2 by the first inlet valve group 41, and the second process gas is supplied to the process chamber 2 by the second inlet valve group 42. The controller 7 controls the first inlet valve group 41 and the second inlet valve group 42 to supply gas to the process chamber 2 through the side edge of the process chamber 2.

[0080] In one embodiment, the controller 7 controls the second intake valve group 42 and the first intake valve group 41 to perform inconsistent opening and closing actions. That is, in the modification stage, the first intake valve group 41 is used to differentiate the degree of modification in different regions of the substrate 8; in the peeling stage, the second intake valve group 42 is used to differentiate the amount of peeling in the substrate 8 corresponding to the modification stage. The two work together to achieve a more accurate defect compensation effect.

[0081] In one embodiment, the controller 7 calculates the differentiated control parameters of the corresponding intake valve 51 based on the degree of defect deviation, thereby achieving precise control of the etching amount. The specific process is as follows: First, the defect deviation is calculated. Controller 7 calculates the characteristic deviation Δ of the defect region 81. For example, when the defect is due to excessive film thickness, Δ = actual film thickness of the defect region - target film thickness of the process, which means that the defect region needs to be additionally etched.

[0082] Secondly, the etching amount benchmark is determined. The memory module of the controller 7 contains pre-stored etching amount benchmark data that has been calibrated through process testing: the unit etching amount d0 of a single air intake valve 5 within a standard opening duration and a single atomic layer etching cycle, corresponding to the air supply area.

[0083] Subsequently, the control parameter conversion is completed. Based on the required additional etching amount Δ, the controller 7 calculates the differentiated control parameters corresponding to the intake valve 51, which can be done using either of the following two methods: The first type is single-cycle duration differential control: the opening duration of the corresponding intake valve 51 is t=t0×(1+Δ / d0), and the other intake valves 52 in the same intake valve group 4 keep the standard opening duration t0 unchanged. By adjusting the opening duration in a single cycle, the etching amount in a single cycle can be finely adjusted.

[0084] The second type is multi-cycle differential control: the number of opening cycles of the corresponding intake valve 51 is C=C0×(1+Δ / d0), and the other intake valves 52 in the same intake valve group 4 keep the standard number of cycles C0 unchanged, where C0 is the total number of etching cycles. By adjusting the number of opening cycles, the total etching amount can be precisely controlled.

[0085] Finally, the control timing is generated. Based on the calculated control parameters, the controller 7 generates the opening and closing control timing for each intake valve 5, driving the corresponding intake valve to perform differentiated opening and closing actions to complete defect compensation.

[0086] See Figure 8 To ensure the overall stability of the atomic layer etching (ALE) process, all etching cycles can be divided into initial, intermediate, and final cycles according to their order. Inconsistent opening and closing of the inlet valve 5 is only implemented in the intermediate cycle. The initial cycle stabilizes the process environment and ensures a smooth start to the etching reaction, while the final cycle completes the etching process. Implementing differentiated control only in the intermediate cycle, where the process is stable, maintains the overall stability and consistency of the ALE process while ensuring defect compensation, thus preventing the differentiated control from affecting the stability of the initial and final stages of the process.

[0087] For example, the 500 atomic-layer etching cycles are divided into initial cycles (first 50 cycles), intermediate cycles (cycles 51-450), and final cycles (cycles 451-500). Differential control is only implemented in the intermediate cycles. In the 400 cycles of the intermediate cycles, the corresponding intake valve for the corresponding sector can be opened throughout the entire cycle, while the remaining intake valves are opened only in 200 cycles. Ultimately, the total number of cycles in which the corresponding intake valve for that sector is opened is 50 + 400 + 50 = 500, corresponding to an etching depth of 50 nm. The total number of cycles in which the remaining intake valves are opened is 50 + 200 + 50 = 300, corresponding to an etching depth of 30 nm. This means that when the defect is a film thickness smaller than other areas, the remaining intake valves can be opened throughout the entire cycle, while the corresponding intake valve is opened only in 200 cycles. This is to mitigate film thickness unevenness defects and meet the uniformity requirements of the process nodes.

[0088] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A semiconductor processing apparatus, comprising a cavity, a gas source, and a controller. The cavity is enclosed to form a process chamber and is provided with an exhaust port. The process chamber is evacuated through the exhaust port to maintain the vacuum environment required for the process. The cavity sidewall is provided with an air supply ring, and the air supply ring has multiple air inlets arranged circumferentially around it for supplying air to the edge of the process cavity. Its characteristic is... It also includes at least one intake valve group, which includes multiple independently controllable intake valves, the multiple intake valves being arranged in a ring around the air supply ring and corresponding one-to-one with the multiple air intake holes; The intake valve assembly is connected to the gas source, which is used to supply process gas. During the process, an intake valve assembly is used to control the supply of a process gas, and the process chamber carries a substrate. The controller is configured to: The method involves obtaining defects in different regions of the substrate before etching, and controlling some of the intake valves in the same intake valve group to perform inconsistent opening and closing actions based on these defects during the etching process. This differentiates the etching of the defective regions of the substrate from other regions to mitigate the defects.

2. The semiconductor processing apparatus as described in claim 1, characterized in that, The etching process includes an atomic layer etching process, which includes an alternating modification stage and a stripping stage. The gas source includes a first gas source and a second gas source. The first gas source is used to supply the first process gas for the modification stage, and the second gas source is used to supply the second process gas for the stripping stage. The intake valve assembly is connected to the first gas source or the second gas source and is used to supply the first process gas or the second process gas.

3. The semiconductor processing apparatus as described in claim 1, characterized in that, The controller is communicatively connected to each of the intake valves and controls the opening and closing timing of each intake valve according to the defect, driving the corresponding intake valve to perform independent opening and closing actions to mitigate the defect.

4. The semiconductor processing apparatus as described in claim 2, characterized in that, The semiconductor processing equipment includes two sets of intake valve groups, namely a first intake valve group and a second intake valve group. The first intake valve assembly is connected to the first gas source and is used to control the supply of the first process gas. The second intake valve assembly is connected to the second gas source and is used to control the supply of the second process gas. The first intake valve group and the second intake valve group are switched on and off alternately based on the modification stage and the stripping stage.

5. The semiconductor processing apparatus as described in claim 4, characterized in that, An intake valve in the first intake valve group and an intake valve in the second intake valve group are paired to form an intake valve pair. The intake valve pair is configured to correspond one-to-one with the intake port. The two intake valves in one intake valve pair are connected in parallel to one intake port.

6. The semiconductor processing apparatus as described in claim 4, characterized in that, The air intake includes a first air intake and a second air intake. The first air intake valve group is connected to the first air intake, and the second air intake valve group is connected to the second air intake. Multiple air intake valves in the first air intake valve group are configured to correspond one-to-one with the first air intake, and multiple air intake valves in the second air intake valve group are configured to correspond one-to-one with the second air intake.

7. The semiconductor processing apparatus as claimed in claim 6, characterized in that, The first air inlet and the second air inlet are alternately arranged circumferentially on the air supply ring, and / or The first air inlet and the second air inlet are arranged at an axial interval on the air supply ring.

8. The semiconductor processing apparatus as claimed in claim 1, characterized in that, The characteristics of each region include substrate film thickness distribution, substrate density distribution, substrate lithography critical size distribution, or substrate mask spatial distribution.

9. The semiconductor processing apparatus as claimed in claim 8, characterized in that, The process chamber is equipped with an in-situ detection unit, which is communicatively connected to the controller. The in-situ detection unit is used to detect the characteristics of each region in situ without disrupting the vacuum environment of the process chamber. The controller generates the opening and closing control sequence of the multiple air intake valves based on the characteristics of each region to mitigate the defects.

10. The semiconductor processing apparatus as claimed in claim 9, characterized in that, The in-situ detection unit includes an optical reflectometer, a scattering meter, an elliptic polarimeter, or a key dimension online detection device.

11. The semiconductor processing apparatus as claimed in claim 1, characterized in that, The intake valve is fixedly connected to the air supply ring via an air guide block, and, The distance from the intake valve to the intake port connected to it is the shortest relative to the distance from the intake valve to other intake ports.

12. A control method for a semiconductor processing apparatus, applied to the semiconductor processing apparatus as described in any one of claims 1 to 11, characterized in that, The characteristics of each region of the substrate are acquired, and defects with inconsistent characteristics in each region of the substrate are recorded, so that the process cavity can operate during the etching process. Based on the characteristics of each region, the opening and closing control timing of multiple intake valves in the intake valve group is controlled, and the intake valves are driven to perform independent opening and closing actions, so that some intake valves in one intake valve group perform inconsistent opening and closing actions with the others, thereby differentiating the etching of the defect area of ​​the substrate from other areas to smooth out the defects.

13. The control method as described in claim 12, characterized in that, The opening and closing control timing is implemented by analyzing the region that needs to be corrected in each region of the substrate and placing it within the coordinate range of the substrate. The coordinate range is then matched with the corresponding air intake valve of the air intake hole that controls the air supply area of ​​the coordinate range among the multiple air intake valves. The corresponding air intake valve is controlled to perform inconsistent opening and closing actions with the other air intake valves in the same air intake valve group in order to mitigate the defect.

14. The control method as described in claim 12, characterized in that, The inconsistent opening and closing actions include: During the etching process, some of the intake valves in the intake valve group are in the open state, while the remaining intake valves are in the closed state; or During the etching process, the opening duration of some intake valves in one of the intake valve groups is different from that of the other intake valves.

15. The control method as described in claim 12, characterized in that, The etching process includes atomic layer etching, which includes alternating modification and stripping stages. The inconsistent opening and closing actions include: Within the same atomic layer etching cycle, the opening duration of some intake valves in one intake valve group differs from the opening duration of the remaining intake valves; or Within multiple atomic layer etching cycles, the number of opening cycles of some intake valves in an intake valve group differs from the number of opening cycles of the other intake valves.

16. The control method as described in claim 13, characterized in that, The corresponding region includes a sector, and the corresponding intake valve includes an intake valve whose intake port is directly opposite the sector, and / or an intake valve whose intake port is adjacent to the sector.

17. The control method as described in claim 16, characterized in that, When there is no air intake port directly facing the sector, the corresponding air intake valve is at least two air intake valves connected to the air intake port that are adjacent to the sector. When the inconsistent opening and closing action is performed, multiple air intake valves in the corresponding air intake valve are alternately opened and closed.

18. The control method as described in claim 13, characterized in that, The etching process includes an atomic layer etching process, which includes a modification stage based on a first process gas and a stripping stage based on a second process gas. The first process gas is supplied to the process chamber by a first inlet valve group, and the second process gas is supplied to the process chamber by a second inlet valve group. Both the first and second inlet valve groups are controlled to supply gas to the process chamber through the side edge of the process chamber.

19. The control method as described in claim 18, characterized in that, The second intake valve group and the first intake valve group both perform inconsistent opening and closing actions.

20. The control method as described in claim 15, characterized in that, The atomic layer etching cycle is divided into an initial cycle, an intermediate cycle, and a final cycle according to the cycle sequence, and the opening and closing inconsistent operation is only performed in the intermediate cycle.

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