System and method for rapidly adjusting pressure of process chamber based on small valve and pump array

Abstract

The invention relates to a system and a method for quickly adjusting the pressure of a process chamber based on a small valve and pump array. The system is provided with a micro baffle, so that accurate and rapid gas flow regulation and control are realized. The system controller compensates the non-uniformity caused by the design limitation of the to-be-processed substrate and the process system by adjusting the current of the motor, thereby ensuring the improvement of the uniformity of the substrate in the semiconductor manufacturing process.

Description

Cross-reference to related applications

[0001] This invention claims priority to U.S. Patent Application No. 18 / 908,690, filed on October 7, 2024. Technical Field

[0002] This invention relates to semiconductor manufacturing equipment, and more particularly to a system that allows for faster adjustment of process chamber pressure during semiconductor manufacturing. Background Technology

[0003] In semiconductor manufacturing, rapidly achieving target chamber pressure is crucial, especially in processes such as atomic layer deposition (ALD) and atomic layer etching (ALE). Existing systems typically rely on a large pump (usually located at the bottom of the process chamber) to remove reaction byproducts and maintain a suitable environment for the chemical reaction. These systems also use a large valve to regulate the chamber pressure. However, this valve operates slowly, often resulting in delays in the chamber pressure stabilization process. As the demands for faster chamber pressure regulation in semiconductor manufacturing processes continue to increase, there is a pressing need for a system that can accelerate this process. Summary of the Invention

[0004] The following is a brief overview of various aspects of the present invention, with further details to be elaborated in specific embodiments. This overview is not intended to limit the scope of the invention, nor does it cover all features of the invention.

[0005] To address the need for faster chamber pressure regulation, this invention proposes a system employing a miniature valve and pump array. This structure significantly reduces the time required for the process chamber to reach the desired steady-state pressure. Unlike traditional systems that rely on large pumps and valves, this invention uses multiple small, fast-response valves (also known as micro-baffles) to regulate gas discharge. These micro-baffles function similarly to camera shutters, but adapted for this novel application.

[0006] Each miniature baffle contains one or more blades that control the flow rate of gas into the corresponding pump. A motor-driven actuator synchronizes the blade movement via a rotary-linear conversion mechanism, optimizing gas discharge efficiency and enabling rapid pressure regulation. The system controller adjusts the motor current to control the blade position based on feedback from a pressure gauge that monitors the chamber pressure in real time. The controller employs Proportional-Integral-Derivative (PID) control to ensure both rapid and stable pressure regulation.

[0007] Furthermore, the system can compensate for substrate non-uniformity caused by earlier process steps or design limitations. In some embodiments, the uniformity engine assesses the amount of adjustment required to counteract the non-uniformity of the substrate to be processed. Subsequently, the system controller adjusts the motor current to change the opening size of the micro-baffle, thereby ensuring improved substrate uniformity during the process.

[0008] In summary, this invention provides a novel solution for the rapid regulation of process chamber pressure by integrating a small valve and pump array with an advanced control system. Attached Figure Description

[0009] To clearly describe the technical solution, the following explanation will refer to the accompanying drawings:

[0010] Figure 1A This illustrates a process chamber with a small array of valves and pumps for rapid pressure regulation.

[0011] Figure 1B : A top view of an array of miniature baffles used as quick-switching valves is shown;

[0012] Figure 2 This diagram illustrates the functional block diagram of the valve and pump array components and their connections within the process chamber.

[0013] Figure 3 A flowchart illustrating the use of a small array of valves and pumps to regulate chamber pressure is shown.

[0014] Figure 4 The diagram illustrates a process for regulating chamber pressure to optimize substrate uniformity by adjusting the motor current used for different valves. Detailed Implementation

[0015] To facilitate a full understanding of the invention, specific embodiments thereof will be described in detail below. While specific details are provided for ease of explanation, any modifications and variations consistent with the technical principles of the invention are considered appropriate. Certain well-known procedures and components are described selectively only to highlight the unique features of the invention.

[0016] For ease of understanding of this specification, the following terms are defined as follows:

[0017] Process Chamber: A closed environment used to perform semiconductor manufacturing processes (such as etching or deposition).

[0018] Chuck: A structure within a process chamber used to hold a substrate (such as a silicon wafer) during the process. It can be a vacuum chuck or an electrostatic chuck.

[0019] Mass Flow Controller (MFC): A device that regulates the flow rate of gas entering a process chamber.

[0020] Vacuum valve: A valve that controls the discharge of gas from a process chamber by positioning a moving part. It is usually used in conjunction with a vacuum pump to maintain or regulate the chamber pressure.

[0021] Gas Distribution Unit: This unit is used to distribute process gases to the process chambers. Depending on design requirements, this unit can be an ejector or a shower head.

[0022] Gas Conduction Aperture: Its aperture is controlled by a micro-baffle to determine the flow rate of gas through the chamber pressure control system.

[0023] Manometer: A pressure measuring device used to monitor the pressure inside a process chamber.

[0024] Steady-state pressure: The target pressure specified by the process formulation, which is the pressure condition for stable operation of the chamber.

[0025] Micro Shutter: A device with one or more movable blades used to control gas conduction orifices, regulating gas flow in a manner similar to a camera shutter mechanism.

[0026] Blades of the Micro Shutter: Movable components that control gas flow and chamber pressure by adjusting the size of the gas conduction orifice.

[0027] Shutter Actuator: A mechanism that drives the movement of blades inside a miniature baffle, usually driven by a motor.

[0028] Rotation-to-Linear Conversion Mechanism: A mechanism that converts the rotary motion of a motor into linear motion in order to precisely control the baffle driver.

[0029] PID control: A control algorithm that adjusts system parameters (such as motor current) to achieve the expected set value based on the current and historical deviations of the chamber pressure.

[0030] System Controller: A control system that manages the operation of the chamber (including motor current, actuator movement, and gas flow regulation) based on pressure gauge feedback.

[0031] Process Recipe: A predefined set of operating instructions (such as gas flow rate, pressure, and execution time) used to control semiconductor manufacturing processes.

[0032] Substrate: The material processed within the cavity, typically a silicon wafer.

[0033] Array of Valves and Pumps: A configuration of multiple small valves and pumps used within a chamber for rapid regulation of gas flow and chamber pressure.

[0034] Motor Currents: The current applied to the motor that controls the micro-baffles, used to adjust the blade position and control the gas flow.

[0035] Uniformity Engine: A subsystem or software module within the system controller designed to compensate for non-uniformity in the substrate or process design by adjusting the motor current to improve substrate uniformity.

[0036] Nonuniformity: Deviations in substrate or process conditions that may affect the uniformity of semiconductor processes can be corrected by the system controller.

[0037] Figure 1A A schematic diagram of Embodiment 100 is shown, illustrating a process chamber 101. The chamber structure 102 encloses a vacuum environment suitable for semiconductor processes. A gas distribution unit 104 is connected to a gas box 106 via multiple mass flow controllers (not shown). In one embodiment, the gas distribution unit 104 employs a showerhead structure; in another embodiment, it employs an ejector structure. The chamber 101 also includes a chuck 108 (which may be a vacuum chuck or an electrostatic chuck) for supporting a substrate 110 during the process. The substrate size may vary, but it is typically a silicon wafer.

[0038] In a conventional process chamber, a large pump located at the bottom of the chamber expels reaction byproducts and gases through an exhaust line. A large vacuum valve, used in conjunction with this pump, maintains a stable pressure within chamber 101 suitable for the chemical reaction. A pressure gauge 115 monitors the chamber pressure and adjusts the valve when a deviation is detected; this correction process typically takes hundreds of milliseconds.

[0039] Achieving the chamber pressure specified in the process recipe using large pumps, large valves, and PID control typically takes tens to hundreds of milliseconds. However, advanced processes such as ALD and ALE require much faster pressure regulation speeds.

[0040] Example 100 proposes an innovative solution that uses an array configuration of small valves 112 and pumps 114 to accelerate the steady-state regulation of chamber pressure, while achieving finer control to improve substrate uniformity.

[0041] Figure 1B A top view of a small valve array including micro-baffles 116 is shown. This embodiment features 12 micro-baffles, but the number can be adjusted as needed. These micro-baffles, similar to camera shutters, function as quick-switching valves in conjunction with the pump. Each micro-baffle includes one or more blades 118 that regulate the flow rate of gas into the pump by changing the overall position of the blades, thereby controlling the size of the gas conduction orifice 120. The movement of the blades is coordinated by an actuator, which is driven by a motor via a rotary-linear conversion mechanism.

[0042] The use of miniature valves and pumps makes the manufacturing process more feasible. Miniature pumps can be produced through additive manufacturing or 3D printing technology, while miniature baffles inspired by camera technology provide an efficient and economical solution for integrating these valves and pumps into the system.

[0043] Figure 2 A functional block diagram showing the connections of the components of the small valve and pump array in process chamber 101 is illustrated. System 200 consists of a small valve and pump array labeled "A" to "N". Each unit includes an actuator 202 (AN), which powers a motor 204 (AN), which is connected to a rotary-linear conversion mechanism 206 (AN). For example, for valve "A", actuator 202A controls the motor speed by adjusting the current applied to motor 204A, thereby affecting the rotary-linear conversion mechanism 206A, baffle actuator 208A, and the orifice size of baffle 210A.

[0044] System controller 211 manages the current distribution of motor 204A via driver 202A. The stability of the chamber pressure depends on two key factors: (1) the gas flow rate from gas distribution unit 104; and (2) the gas pumping rate (affected by the baffle orifice size and pump displacement). Pressure gauge 115 measures the chamber pressure at set intervals. If a deviation between the chamber pressure and the target value is detected, system controller 211 activates PID controller 214 for correction.

[0045] The miniature valve and pump array also provides an innovative solution for improving the uniformity of substrate 110. In conventional semiconductor manufacturing, substrates may exhibit non-uniformity due to accumulated deviations from multiple processes, making it often necessary to correct these non-uniformities in subsequent process steps. An optional uniformity engine 216 is used to determine the amount of non-uniformity compensation required for the current process. Upon receiving this input, the system controller 211 adjusts the current applied to different motors, thereby improving the uniformity of the processed substrate.

[0046] In some embodiments, the uniformity engine 216 includes a software module that may contain digital twin models of the process system and associated processes. The uniformity engine 216 can use these digital twin models to perform simulations and calculate the motor current required to compensate for substrate non-uniformity (which may be caused by one or more earlier process steps). In other embodiments, the uniformity engine 216 can simulate non-uniformity caused by design constraints of the process system 100 and determine solutions to correct these design-related deviations by adjusting the motor current. The uniformity engine 216 may be integrated within the system controller 211, in which case it may include firmware and hardware components to accelerate the calculation and application of the motor current.

[0047] Figure 3 A flowchart of process 300 is provided, detailing the process of regulating chamber pressure using a small array of valves and pumps. In step 302, power is supplied to each motor 204 to position the blades of baffle 210 appropriately. In step 304, process gas is introduced into the chamber through gas distribution unit 104. In step 306, pressure gauge 115 measures the chamber pressure; if a deviation between the measured pressure and the target value is detected in step 308, then in step 310, system controller 211 iteratively adjusts the motor current using PID controller 214 to achieve the desired pressure.

[0048] Figure 4 A flowchart of process 400 is shown, which optimizes substrate uniformity by applying different motor currents to different valves. The process begins at step 402: the uniformity engine 216 provides input to the system controller 211 to calculate the appropriate current for each motor 204. In step 404, the calculated current is applied to the motors 204, positioning the baffle blades 210 accordingly. In step 406, process gas is introduced into the chamber. In step 408, the pressure gauge 115 measures the chamber pressure. If a deviation from the target value is detected in step 410, the system controller 211 iteratively adjusts the motor current using a PID controller 214 in step 412 to accelerate the pressure stabilization process.

Claims

1. A process chamber for semiconductor manufacturing, characterized in that, include: The cavity structure is configured to maintain a vacuum environment; A gas distribution unit, located within the cavity structure, is used to introduce gas; A valve array, wherein each valve comprises a miniature baffle with one or more blades, and the overall position of the blades controls the pumping rate of gas entering the associated pump. and The system controller is configured to compare the chamber pressure measured by the pressure gauge with the target value specified in the process recipe, and to adjust the blade position by regulating the current applied to the motors connected to the micro baffles.

2. The process chamber according to claim 1, wherein, The position of the blade is determined by a baffle driver, which is connected to a motor via a rotary-linear conversion mechanism.

3. The process chamber according to claim 2, wherein, The overall position of the blades determines the size of the baffle orifice, which in turn determines the gas pumping speed.

4. The process chamber according to claim 1, wherein, The system controller employs PID control to achieve steady-state chamber pressure.

5. The process chamber according to claim 1, wherein, The system controller also includes a uniformity engine configured to assess the amount of non-uniformity compensation required for the current process. The system controller adjusts the motor current based on the input of the uniformity engine to optimize substrate uniformity.

6. The process chamber according to claim 1, wherein, The pumps associated with the micro-baffles are manufactured using additive manufacturing or 3D printing techniques.

7. The process chamber according to claim 1, wherein, Each pump and its associated valves are integrated into a single structure.

8. A method for regulating chamber pressure in a semiconductor manufacturing process, characterized in that, The method includes: Maintaining a vacuum environment within the cavity structure; Process gas is introduced through the gas distribution unit; The gas extraction rate is controlled by adjusting the position of one or more blades of the miniature baffles in the valve array. The chamber pressure measured by the pressure gauge is compared with the target value, and the current applied to the motors connected to the miniature baffle is adjusted accordingly; and The position of the blades of the micro baffle is adjusted by the system controller until the measured pressure matches the target value.

9. The method according to claim 8, wherein, The method also includes a driver connected to a motor via a rotary-linear conversion mechanism to achieve synchronous adjustment of the blade position.

10. The method according to claim 8, wherein, The method also includes using the system controller and PID control to stabilize the chamber pressure.

11. The method according to claim 8, wherein, The method further includes determining the amount of non-uniformity compensation required for the current process through a uniformity engine, wherein the system controller adjusts the motor current according to the input of the uniformity engine to achieve substrate uniformity optimization.

12. The method according to claim 11, wherein, The uniformity engine utilizes data from the substrate to be processed.

13. A method for achieving substrate uniformity within a semiconductor manufacturing process chamber, characterized in that, The method includes: Maintaining a vacuum environment within the cavity structure; Place the substrate on the chuck inside the cavity structure; Gas is introduced into the cavity structure through the gas distribution unit; The non-uniformity of a substrate is evaluated using a uniformity engine. Based on the non-uniformity identified in the assessment, the gas extraction rate is controlled by adjusting the position of one or more blades of the micro-baffles in the valve array; and The system controller adjusts the current applied to the motors connected to the micro-baffles based on the input from the uniformity engine to compensate for the non-uniformity obtained from the evaluation.

14. The method according to claim 13, wherein, The method also includes a driver connected to a motor via a rotary-linear conversion mechanism to achieve synchronous adjustment of the blade position.

15. The method according to claim 13, wherein, The non-uniformity identified in the assessment is due to process deviations accumulated in previous process steps of the substrate.

16. The method according to claim 13, wherein, The method also includes compensating for non-uniformity caused by limitations in the process system design.

17. The method according to claim 13, wherein, The uniformity engine includes software modules.

18. The method according to claim 17, wherein, The software module includes a digital twin model of the process system and related processes.

19. The method according to claim 13, wherein, The gas distribution unit introduces gas in the form of a shower head or jet injector.

20. The method according to claim 13, wherein, The method also includes using a system controller and PID control to achieve steady-state chamber pressure during the non-uniformity compensation process.

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