Control method and control device of stepping motor, matcher and plasma processing device

Abstract

The invention provides a control method and a control device of a stepping motor, a matcher and a plasma processing device. The control method includes: acquiring the algorithm rotation direction of a current control period of the stepping motor; acquiring preset control period dimensions and the algorithm rotation direction of a historical control period based on the preset control period dimensions; and acquiring the actual rotation direction of the stepping motor according to the algorithm rotation direction of the current control period, the algorithm rotation direction of the historical control period and the preset control period dimensions, and adopting the actual rotation direction to control the stepping motor to rotate. The control method can reduce forward rotation and reverse rotation switching times of the stepping motor, accordingly reduces phenomena of step throw and step out of the stepping motor, and service life of the stepping motor is prolonged.

Description

technical field [0001] The invention belongs to the field of plasma processing equipment, and relates to a matching device for matching the nonlinear load impedance of a plasma chamber with the output impedance of a radio frequency power supply, in particular to a control method and device for a stepping motor, a matching device and a matching device including The matcher's plasma processing equipment. Background technique [0002] Plasma is formed by the ionization of material atoms into ions and free electrons, presents a highly excited unstable state, and has good conductivity, and can be captured, moved or accelerated by a magnetic field. Therefore, plasma is widely used in processing processes such as etching, deposition, welding and spraying. [0003] The RF (radio frequency) plasma generator is a device that supplies RF power to the plasma chamber through a radio frequency power supply to ionize the gas in the chamber and generate plasma. In the process of etching a...

AI Technical Summary

Problems solved by technology

However, in the actual process, the nonlinear load in the plasma chamber is very unstable, and using the actual action direction signal obtained by the matching control algorithm to control the stepper motor often leads to frequent forward / reverse switching of the stepper motor, such as figure 2 middle t 2 -t 6 period

Moreover, the rotor of the stepper motor and the load have inertial inertia, so the following problems inevitably exist in the operation of the stepper motor: First, when the stepper motor is switching between forward and reverse, it needs to overcome the previous inertia, so often Lost steps occur, especially when the stepping motor has a large rotational torque, the lost steps are more serious

This will affect the matching accuracy of the matcher, resulting in larger reflected power on the RF transmission line

Second, the stepper motor is prone to delay when it starts instantaneously, and it is prone to overshoot when it stops. When the pulse frequency of the stepper motor is large, the delay and overshoot will cause the stepping motor to lose its step

Third, the frequent forward and reverse switching of the stepping motor reduces its service life, which in turn affects the service life of the matching device

In addition, due to the low accuracy of the sensor and the interference of the external environment, the input from the sensor to the controller is often inaccurate, causing the controller to give a wrong direction signal, which will reduce the matching accuracy of the matcher, resulting in The reflection power is higher

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