A control method for a liquid pressurization system for semiconductor etching

Abstract

The present invention discloses a control method for a liquid pressurization system for semiconductor etching. The liquid pressurization system is applied to replacement during semiconductor manufacturing process. The control method comprises: a host computer provides operation target commands required by the liquid pressurization system according to different semiconductor processes; monitors the operation parameters of the liquid pressurization system; determines the error value between the operation target command for the liquid pressurization system and the corresponding operation parameters in the operation parameters of the liquid pressurization system; when the error value is greater than 15%L / Min, uses a PID controller to determine the PID gain of the schedule based on the error value, determines the system control command for the liquid pressurization system based on the modified schedule PID gain, and controls the liquid pressurization system based on the system control command for the liquid pressurization system. The present invention improves the etching quality by adjusting the constant speed of the liquid flow rate.

Description

Technical field:

[0002] The invention relates to the technical field of control of a pressurization system, in particular to a control method of a liquid pressurization system for semiconductor etching. Background technology:

[0004] Etching is a technique that uses chemical reactions or physical impact to remove metal materials. Etching technology can be divided into two categories: wet etching and dry etching. For example, hydrofluoric acid, hydrogen peroxide or ferric chloride etching solution is used to corrode the metal surface, and various patterns, designs, scales, grids, etc. are engraved on its surface. The chemical etching process is to apply protective paint or paraffin to the metal surface to be etched. Then put it into the etching solution, the metal surface layer reacts with the etching solution, and the generated chemical products are dissolved in the etching solution or deposited on the metal surface. Chemical etching is to immerse the metal parts to be etched in an etching solution composed of various chemical components. At room temperature or under heating, after a certain period of reaction, the metal to be etched slowly dissolves, and finally reaches the required etching depth, so that the surface of the metal parts reveals decorative text or patterns with a concave and convex three-dimensional sense. The process of chemical etching is actually the self-dissolution of metal in the chemical solution, that is, the corrosion process.

[0005] During the semiconductor etching process, the coolant needs to maintain two states: 1. constant temperature (error ±0.1°C) to ensure the product yield, 2. stable flow (error ±0.3L / Min) to ensure the cooling area. When the existing boost system adjusts the flow of the coolant, the error value of the liquid flow is large, making it difficult to ensure a constant flow rate of the coolant, which reduces the quality of etching. Summary of the invention:

[0007] The object of the present invention is to provide a control method for a liquid pressurization system for semiconductor etching to solve one or more of the above-mentioned problems in the prior art.

[0008] In order to solve the above technical problems, the innovation of the present invention is that the liquid boosting system is applied to the replacement in the semiconductor manufacturing process, and the control method includes:

[0009] The host computer provides the operation target commands required by the liquid boosting system according to different semiconductor processes;

[0010] Monitor operating parameters of liquid booster systems;

[0011] determining an error value between an operational target command for the liquid pressurization system and a corresponding one of the operating parameters of the liquid pressurization system;

[0012] When the error value is greater than 15% L / Min, the PID controller is used to determine the PID gain of the schedule based on the error value;

[0013] determining a system control command for the liquid boosting system based on the modified scheduled PID gains, and controlling the liquid boosting system based on the system control command for the liquid boosting system;

[0014] The PID gain of the schedule is determined according to the following relationship:

[0015]

[0016] Among them, Kp is the proportional gain, T t is the integration time constant, T D is the differential time constant, u(t) is the output signal of the PID controller, and e(t) is the difference between the given value r(t) and the measured value.

[0017] Furthermore, the above operation target command includes a traffic parameter indicator.

[0018] Furthermore, the output signal of the PID controller is converted into a pulse signal through the proportional valve opening on the liquid pipeline and calculation.

[0019] Furthermore, the calculation of the opening of the proportional valve includes the following steps:

[0020] A. Prioritize determining the interval time t1 between the closing and opening of the proportional valve. Within the interval time t1, the proportional valve should be opened once and closed once at least.

[0021] B. Determine the time t0 when the proportional valve is open. The ratio of time t0 to time t1 is the value calculated by PID.

[0022] Furthermore, the above operating parameters include cooling water flow rate and cooling water flow rate.

[0023] Furthermore, the cooling water flow rate and cooling water flow rate are achieved through a flow meter.

[0024] Furthermore, the power of the above-mentioned liquid boosting system is a magnetic pump, and the magnetic pump is electrically connected to a thermal relay and a contactor.

[0025] Furthermore, the magnetic pump uses a PWM control motor.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a control method for a liquid pressurization system for semiconductor etching. According to the error value, the liquid pressurization system will adjust the KP parameter to correct the deviation in a large proportion, shorten the time to reach the expected value, and control the small changes through integration and differentiation to keep it at the expected temperature. Different process technologies require different constant indicators, which ensures the constant speed of the coolant flow rate, thereby improving the quality of etching. Description of the drawings:

[0029] Figure 1 This is a process diagram of the upper computer adjusting the liquid flow rate of the invention.

[0030] Figure 2 This is a diagram of the control process of the magnetic pump by the host computer of the present invention. Specific implementation method:

[0032] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with embodiments and drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0033] like Figure 1 to Figure 2 In a specific embodiment of the present invention, the liquid pressurization system is applied to the replacement in the semiconductor manufacturing process, and the control method includes:

[0034] The host computer 1 provides the operation target commands required by the liquid boosting system according to different semiconductor processes;

[0035] Monitor operating parameters of liquid booster systems;

[0036] determining an error value between an operational target command for the liquid pressurization system and a corresponding one of the operating parameters of the liquid pressurization system;

[0037] When the error value is greater than 15% L / Min, the PID controller is used to determine the PID gain of the schedule based on the error value;

[0038] determining a system control command for the liquid boosting system based on the modified scheduled PID gains, and controlling the liquid boosting system based on the system control command for the liquid boosting system;

[0039] The PID gain of the schedule is determined according to the following relationship:

[0040]

[0041] Among them, Kp is the proportional gain, T t is the integration time constant, T D is the differential time constant, u(t) is the output signal of the PID controller, and e(t) is the difference between the given value r(t) and the measured value.

[0042] In the present invention, as a preferred solution, the above-mentioned operation target command includes a flow parameter indicator.

[0043] In the present invention, as a preferred solution, the output signal of the PID controller is converted into a pulse signal through the opening of the proportional valve 3 on the liquid pipeline and calculated. The proportional valve 3 receives the instruction of the host computer 1 to adjust the flow rate of the pipeline liquid.

[0044] In the present invention, as a preferred solution, the calculation of the opening of the proportional valve 3 includes the following steps:

[0045] A. Prioritize determining the interval time t1 between the closing and opening of the proportional valve 3. Within the interval time t1, at least one opening state and one closing state of the proportional valve 3 are completed;

[0046] B. Determine the time t0 when the proportional valve 3 is in the open state. The ratio of time t0 to time t1 is the value calculated by PID.

[0047] In the present invention, as a preferred embodiment, the above-mentioned operating parameters include cooling water flow rate and cooling water flow rate.

[0048] In the present invention, as a preferred solution, the above cooling water flow rate and cooling water flow rate are realized by a flow meter 2 , and the flow meter 2 detects the flow rate of the pipeline liquid and feeds back the corresponding data signal to the host computer 1 .

[0049] In the present invention, as a preferred solution, the power of the above-mentioned liquid boosting system is a magnetic pump 6, and the magnetic pump 6 is electrically connected to a thermal relay 5 and a contactor 4. In the process of the liquid boosting system receiving various instructions from the host computer 1 through the contactor 4, the thermal relay 5 plays an overcurrent protection role to prevent the magnetic pump 6 from malfunctioning due to temperature rise due to various reasons.

[0050] In the present invention, as a preferred solution, a PWM control motor is selected for the magnetic pump 6 .

[0051] In the present invention, when the semiconductor process is changed, the liquid pressurization system is started or shut down according to the different processes. The specific principle is as follows: according to the different semiconductor processes, the upper computer 1 will automatically give different flow parameter indicators. Generally, when the error value is 15%L / Min, the flow rate will be adjusted, and the liquid pressurization system will be automatically started to increase the opening of the liquid pipeline proportional valve 3. The internal calculation output pulse will drive the magnetic pump 6 to increase the opening of the liquid pipeline proportional valve 3 to meet the production requirements.

[0052] In the present invention, the liquid boosting system can realize real-time monitoring of the liquid flow rate and judgment of the error value through the flow meter 2. The motor uses a PWM control motor and uses a multi-layer PID algorithm to control the stability of the flow rate and temperature to improve the etching quality.

[0053] In the present invention, in order to ensure the constancy of the flow rate, the liquid-liquid boosting system will adjust the KP parameter according to the error value, correct the deviation in a large proportion, shorten the time to reach the expected value, and control small changes through integration and differentiation to keep it at the expected temperature. Different process technologies require different constant indicators, and the system can support the input of parameter instructions.

[0054] Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A control method for a liquid pressurization system for semiconductor etching, characterized in that: The liquid pressurizing system is applied to the replacement in the semiconductor manufacturing process, and the control method includes: The host computer (1) provides the operation target commands required by the liquid pressurization system according to different semiconductor processes; Monitor operating parameters of liquid booster systems; determining an error value between the operational target command for a liquid pressurization system and a corresponding one of the operational parameters of the liquid pressurization system; When the error value is greater than 15% L / Min, a PID controller is used to determine a PID gain of the schedule based on the error value; determining a system control command for the liquid boosting system based on the modified scheduled PID gains, and controlling the liquid boosting system based on the system control command for the liquid boosting system; The PID gain of the schedule is determined according to the following relationship: Among them, Kp is the proportional gain, T t is the integration time constant, T D is the differential time constant, u(t) is the output signal of the PID controller, and e(t) is the difference between the given value r(t) and the measured value.

2. The control method of a liquid pressurization system for semiconductor etching according to claim 1, characterized in that: The operation target command includes a flow parameter indicator.

3. The control method of a semiconductor etching liquid pressurization system according to claim 1, characterized in that: The output signal of the PID controller is converted into a pulse signal through the opening of a proportional valve (3) on the liquid pipeline and calculation.

4. The control method of a semiconductor etching liquid pressurization system according to claim 3, characterized in that: The calculation of the opening of the proportional valve (3) comprises the following steps: A. determining an interval time t1 between closing and opening of the proportional valve (3), and completing at least one open state and one closed state of the proportional valve (3) within the interval time t1; B. Determine the time t0 when the proportional valve (3) is in the open state. The ratio of the time t0 to the time t1 is the value calculated by PID.

5. The control method of a semiconductor etching liquid pressurization system according to claim 1, characterized in that: The operating parameters include cooling water flow rate and cooling water flow rate.

6. The control method of a semiconductor etching liquid pressurization system according to claim 5, characterized in that: The cooling water flow rate and the cooling water flow rate are achieved through a flow meter (2).

7. The control method of a semiconductor etching liquid pressurization system according to claim 1, characterized in that: The power of the liquid pressurizing system is a magnetic pump (6), and the magnetic pump (6) is electrically connected to a thermal relay (5) and a contactor (4).

8. The control method of a semiconductor etching liquid pressurization system according to claim 7, characterized in that: The magnetic pump (6) uses a PWM control motor.

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