TWI713080B - Plasma radio frequency adjusting method and plasma processing device - Google Patents

Abstract

The invention discloses a plasma radio frequency adjustment method. The adjustment method is performed by a radio frequency power generator. The radio frequency power generator includes an automatic frequency adjustment device. The radio frequency power generator outputs a pulsed radio frequency signal and a controller A plurality of continuous radio frequency adjustment intervals are set, each radio frequency adjustment interval includes at least one pulsed radio frequency period, the automatic frequency adjustment device performs at least one automatic frequency adjustment in each radio frequency adjustment interval, and each radio frequency adjustment interval includes a beginning Frequency and an end frequency, the start frequency of each radio frequency adjustment interval is the end frequency of the previous radio frequency adjustment interval, and the start frequency of the first radio frequency adjustment interval is the preset frequency. The method of the present invention can quickly adjust the frequency, and can quickly find the radio frequency power corresponding to the minimum reflected power for the pulse radio frequency period.

Description

Plasma radio frequency adjusting method and plasma processing device

The present invention relates to a plasma radio frequency adjustment method and a plasma processing device, and more specifically, to the field of matching adjustment technology for supplying pulsed radio frequency power to a plasma processing device.

In conventional semiconductor processing, plasma processing equipment is widely used to process semiconductor wafers to obtain micro-sized semiconductor components and conductor connections. The common types of plasma equipment include capacitive coupling (CCP) and inductive coupling (ICP) reaction chambers. These equipment generally have two RF power supplies, one of which is used to ionize the reaction gas passing into the reaction chamber to generate plasma. Another RF power supply is used to control the ion energy incident on the wafer surface.

At present, many plasma processing processes need to use pulsed plasma processing technology, that is, the RF power supply during part of the process is not continuous power supply but on-off alternately or high-power-low-power RF alternately. The output power is The waveform is pulsed, so it is called pulsed plasma processing. The pulse frequency of pulsed radio frequency signals is usually greater than 100HZ, and the duty cycle of pulsed signals can be set in the range of 10%-90% as needed. Each turn-on, turn-off, or high-power and low-power switching will cause the impedance in the reaction chamber to change rapidly, and the time of each change is milliseconds or even microseconds. Under this demand, the traditional matching circuit is used due to the reaction time Far from reaching the millisecond level, it is difficult to meet the needs of pulsed plasma processing.

Therefore, based on the above reasons, the industry needs a technology that can meet the high-frequency pulse radio frequency period matching.

In order to solve the above technical problems, the present invention provides a plasma radio frequency adjustment method. The adjustment method is performed by a radio frequency power generator, the radio frequency power generator includes an automatic frequency adjustment device, and the adjustment method includes the following steps: The radio frequency power generator outputs a pulsed radio frequency period; a plurality of continuous radio frequency adjustment intervals are set, each radio frequency adjustment interval includes at least one pulse radio frequency period; the automatic frequency adjustment device performs at least one automatic frequency adjustment in each radio frequency adjustment interval, Each radio frequency adjustment interval includes a start frequency and an end frequency. The start frequency of each radio frequency adjustment interval is the end frequency of the previous radio frequency adjustment interval, and the start frequency of the first radio frequency adjustment interval is a preset frequency.

Further, the start frequency includes a start high-level frequency and a start low-level frequency, and the end frequency includes an end high-level frequency and an end low-level frequency.

Further, the automatic frequency modulation method is: assigning a preset frequency to the radio frequency power generator to obtain the first reflected power correspondingly, and adding the preset frequency to the radio frequency power generator by one step to obtain the second reflected power correspondingly , Compare the first reflected power and the second reflected power, if the second reflected power is greater than the first reflected power, increase the step length in the opposite direction, if the second reflected power is less than the first reflected power, continue to It is assumed that the frequency is increased by two steps to endow the radio frequency power generator, and a smaller reflected power can be obtained by adjusting.

Further, the preset frequency is a frequency capable of ensuring plasma ignition.

Further, the method for obtaining the preset frequency is: setting the RF power source to output a continuous RF power signal, calculating and obtaining the minimum reflected power in the continuous RF output stage, and using the frequency corresponding to the minimum reflected power as the preset frequency.

Further, each radio frequency adjustment interval includes at least two pulse radio frequency periods, and the automatic frequency adjustment device performs multiple automatic frequency adjustments in each pulse radio frequency period. The automatic frequency adjustment device has the same start frequency and end frequency in different pulse radio frequency periods of the same radio frequency adjustment interval.

Further, the automatic frequency adjustment device has the same start frequency and different end frequencies in different pulse radio frequency periods of the same radio frequency adjustment interval.

Further, the time of the radio frequency adjustment interval is set by a controller.

Further, the controller reads the ending frequency of the automatic frequency adjustment device and assigns the ending frequency to the automatic frequency adjustment device as the start frequency of the next radio frequency adjustment interval.

Further, the controller sets a reflected power threshold, and when the reflected power found by the automatic frequency adjustment device is lower than the reflected power threshold, the frequency modulation process stops.

Further, the duration of the radio frequency adjustment interval is greater than or equal to 1 millisecond.

Preferably, the duration of the radio frequency adjustment interval is 10 milliseconds.

Preferably, the duration of the radio frequency adjustment interval is 50 milliseconds.

Preferably, the duration of the radio frequency adjustment interval is 100 milliseconds.

Preferably, the duration of the radio frequency adjustment interval is 150 milliseconds.

Preferably, the duration of the radio frequency adjustment interval is 200 milliseconds.

Further, the frequency modulation time of the automatic frequency modulation device is greater than or equal to 0.1 microseconds.

Preferably, the frequency modulation time of the automatic frequency modulation device is 1 microsecond.

Preferably, the frequency modulation time of the automatic frequency modulation device is 5 microseconds.

Preferably, the frequency modulation time of the automatic frequency modulation device is 10 microseconds.

Preferably, the frequency modulation time of the automatic frequency modulation device is 20 microseconds.

Preferably, the frequency modulation time of the automatic frequency modulation device is 30 microseconds.

Further, the pulse signal is high-low level, and the low level is greater than or equal to zero.

The method of the present invention can realize the frequency modulation matching of the radio frequency power generator whose pulse frequency of the pulse radio frequency period is greater than 100 Hz.

The method of the present invention can realize the frequency modulation matching of the radio frequency power generator whose pulse frequency of the pulse radio frequency period is greater than 5000 Hz.

Further, the present invention discloses a plasma processing device, which includes:

A plasma processing chamber; used to accommodate and process wafers;

A radio frequency power generator applied to the plasma processing chamber for generating or regulating plasma;

A controller acting on the radio frequency power generator for controlling the duration of a radio frequency adjustment interval;

The radio frequency power generator outputs a pulsed radio frequency period; each of the radio frequency adjustment intervals includes at least one pulsed radio frequency period;

The radio frequency power generator includes an automatic frequency adjustment device; the automatic frequency adjustment device performs at least one automatic frequency adjustment in each pulse radio frequency period, and each radio frequency adjustment interval includes a start frequency and an end frequency. The start frequency of the interval is the end frequency of the previous radio frequency adjustment interval, and the start frequency of the first radio frequency adjustment interval is the preset frequency.

Further, the start frequency includes a start high-level frequency and a start low-level frequency, and the end frequency includes an end high-level frequency and an end low-level frequency.

Further, the preset frequency is a first preset frequency, the preset frequency includes a high-level preset frequency and a low-level preset frequency, and the high-level preset frequency is a continuous radio frequency power generator. The frequency corresponding to the minimum reflected power during high power output, and the low-level preset frequency is the frequency corresponding to the minimum reflected power of the radio frequency power generator during continuous low power output.

Further, the preset frequency is given to the automatic frequency adjustment device through the controller.

Further, the processing device includes a second radio frequency power generator, and the second radio frequency power generator outputs a second pulsed radio frequency signal.

Further, the second radio frequency power generator includes a second automatic frequency adjustment device; the second automatic frequency adjustment device performs at least one automatic frequency adjustment in each radio frequency adjustment interval, and each radio frequency adjustment interval includes a start Frequency and an end frequency, the start frequency of each radio frequency adjustment interval is the end frequency of the previous radio frequency adjustment interval, and the start frequency of the first radio frequency adjustment interval is the second preset frequency.

Preferably, the frequency modulation time of the automatic frequency modulation device is greater than or equal to 0.1 microseconds.

Preferably, the controller controls the duration of the radio frequency adjustment interval to be greater than or equal to 1 millisecond.

Further, the controller controls the duration of the multiple continuous radio frequency adjustment intervals to be the same or different.

Further, the pulsed radio frequency signal further includes a third-level power state, and the third-level power is between the high-level power and the low-level power. The frequency matching method of the third level power is the same as the frequency matching method of the high-level power state and the low-level power state.

The invention discloses a plasma radio frequency adjustment method and a plasma processing device. The automatic frequency adjustment device provided in the radio frequency power generator is used to define a radio frequency adjustment interval through a controller to cooperate with the automatic frequency adjustment device. In the case of the RF power generator, the pulse output frequency of the RF power generator can be quickly adjusted. Because the frequency of the automatic frequency modulation device does not need to be adjusted by the mechanical hardware, the frequency modulation time can be reduced to 0.1 microseconds, so that the minimum reflected power can be quickly found The corresponding frequency. The frequency modulation method of the present invention has a particularly obvious effect on high-frequency pulse signals.

The radio frequency matching adjustment method disclosed in the present invention is suitable for any plasma processing device that requires fast radio frequency matching, such as a plasma etching processing device, and the common plasma etching processing device includes a capacitive coupling plasma processing device and an inductive coupling The plasma processing device, for ease of description, the following describes the present invention in detail with reference to the drawings and taking a capacitively coupled plasma processing device as an example.

Figure 1 discloses a capacitively coupled plasma processing device, which includes a reaction chamber 100, a susceptor 22 is included in the reaction chamber, and a lower electrode is included in the susceptor. Above the lower electrode includes a wafer fixing device to be processed such as an electrostatic chuck 21, and the wafer 20 is fixed on the upper surface of the electrostatic chuck 21. An edge ring 10 is also included around the electrostatic chuck and the wafer. A gas shower head 11 is also included in the reaction chamber 100 opposite to the base. The gas shower head is connected to a gas source 110 for uniformly supplying gas into the reaction chamber. The gas shower head simultaneously acts as an upper electrode and forms a capacitive coupling with the lower electrode in the base. A first radio frequency power generator 30 is electrically connected to the lower electrode through the matcher 1. Optionally, the plasma processing apparatus further includes a second radio frequency power generator 40 that is electrically connected to the lower electrode through the matcher 2. The first radio frequency power generator 30 and the second radio frequency power generator 40 can output continuous radio frequency signals, or can output pulse radio frequency cycles. Each RF power generator has a predetermined frequency value. Since the impedance of the plasma changes with the changes of the plasma pressure, RF power, plasma concentration and other parameters, it is necessary to continuously adjust the RF power generator The output frequency to obtain the minimum reflected power.

When the RF power generator outputs a continuous and stable RF signal, if other parameters in the reaction cavity do not change, the matcher will perform RF matching on the continuous RF signal within a certain period of time to obtain the RF frequency corresponding to the minimum reflected power, and In the stable manufacturing process, the RF power generator is instructed to output the RF frequency corresponding to the minimum reflected power.

When the RF power generator outputs a pulsed RF signal, the RF power applied to the reaction chamber is switched from low level to high level or on-off state. At this time, the plasma environment in the reaction chamber will change accordingly. The RF frequency that produces the least reflected power will also change constantly. In particular, when the pulse frequency of the pulse signal is greater than 100 Hz, the matcher cannot switch quickly due to hardware conditions (such as a mechanically driven variable capacitance or variable inductance), and cannot match the switching of the pulse signal.

In the present invention, the radio frequency power generator includes an automatic frequency modulation device, which can perform multiple frequency modulation on the pulsed radio frequency signal in each pulse radio frequency cycle to find the radio frequency frequency corresponding to the minimum reflected power. In addition, the present invention further includes a controller 50 that outputs a radio frequency adjustment interval signal, and each radio frequency adjustment interval has a duration of T and includes at least one pulsed radio frequency period.

As shown in Figures 2-4, Figure 2 shows a pulsed radio frequency signal emitted by the radio frequency power generator. A radio frequency adjustment interval T can include multiple pulse radio frequency cycles. In the same process, the radio frequency adjustment The duration of the interval T may be the same or different. Generally, in order to reduce the calculation amount of the controller 50, radio frequency adjustment intervals with the same time are used in the same manufacturing process. Figure 3 shows a schematic diagram of frequency adjustment of an automatic frequency modulation device. In each pulse radio frequency cycle, the automatic frequency modulation device performs multiple automatic frequency modulation steps. The automatic frequency modulation method is specifically: the controller first grants the RF power generator A preset frequency corresponds to obtaining the first reflected power, the preset frequency is increased by one step to the radio frequency power generator, the second reflected power is obtained correspondingly, and the first reflected power is compared with the second reflected power. If the reflected power is greater than the first reflected power, increase the step length in the opposite direction. If the second reflected power is less than the first reflected power, continue to increase the preset frequency by two steps to the radio frequency power generator, and continue to obtain Less reflected power. The frequency adjustment time of the automatic frequency adjustment device is the time required to obtain a reflected power for each step length. The automatic frequency adjustment time can be set to be greater than or equal to 0.1 microseconds, preferably 0.1 microseconds, 1 microseconds, 5 microseconds, 10 microseconds , 15 microseconds, 20 microseconds or 30 microseconds, etc.

During the frequency adjustment process of the automatic frequency adjustment device, due to the continuous changes of the plasma environment in the reaction chamber, the radio frequency adjustment of each pulse radio frequency cycle is not completely the same in the same radio frequency adjustment interval. This means that even if the same start frequency is assigned to each pulse radio frequency period, the end frequency of each pulse radio frequency period is not necessarily the same. If the pulse radio frequency cycle time is long enough and the frequency modulation time of the automatic frequency modulation device is short enough, and the minimum reflected power can be found in one pulse radio frequency cycle, different pulse radio frequency cycles in the same radio frequency adjustment interval may also have the same end frequency. In order to ensure the continuity of radio frequency adjustment, the end frequency of the last pulse radio frequency period of a radio frequency adjustment interval is usually selected as the end frequency of the entire radio frequency adjustment interval.

The automatic frequency modulation device includes a start frequency and an end frequency in a radio frequency adjustment interval, and is limited by the duration of a radio frequency adjustment interval. It is difficult for the automatic frequency adjustment device to find the frequency corresponding to the minimum reflected power in a radio frequency adjustment interval. Therefore, It is necessary to perform frequency modulation in multiple continuous radio frequency adjustment intervals. The method of frequency modulation is to assign a preset frequency f ₀ to the radio frequency power generator as the start frequency in the first radio frequency adjustment interval, and assign the end frequency f _{1 of the} first radio frequency adjustment interval to the radio frequency power generator as the second frequency. The starting frequency of the radio frequency adjustment interval, and so on, until the frequency corresponding to the minimum reflected power is obtained. During the frequency modulation process, the controller sets a reflected power threshold. When the reflected power found by the automatic frequency modulation device is less than the reflected power threshold, the assigned frequency modulation process ends. When the impedance or condition changes in the reaction chamber cause the reflected power to be higher than the threshold, the assignment frequency modulation process restarts.

Since a pulsed radio frequency signal includes a high level and a low level, the start frequency includes a start high level frequency and a start low level frequency, and the end frequency includes an end high level frequency and an end low level frequency. Flat frequency. According to the frequency modulation method described above, the end high-level frequency of the previous radio frequency adjustment interval is used as the start high-level frequency of the next radio frequency adjustment interval, and the end low-level frequency of the previous radio frequency adjustment interval is taken as the next radio frequency adjustment interval. Start low frequency. In combination with the diagram shown in Figure 3, it is specifically to determine the starting high-level frequency f ₀ (h) and the starting low-level frequency f ₀ (l) of the first radio frequency adjustment interval, and each pulse radio frequency period of the first radio frequency adjustment interval The internal repetition starts from the starting high level frequency f ₀ (h) and the starting low level frequency f ₀ (l) to find the frequency corresponding to the minimum reflected power, and the frequency f corresponding to the smaller reflected power is obtained at the end of the first radio frequency adjustment interval ₁ (h) and f ₁ (l). Due to the limited duration of the RF adjustment interval, the smaller reflected power obtained at the end of the first RF adjustment interval may not be the minimum reflected power. Therefore, in the second RF adjustment interval, The automatic frequency modulation device continues to perform automatic frequency modulation. At this time, the frequencies f ₁ (h) and f ₁ (l) corresponding to the smaller reflected power obtained at the end of the previous radio frequency adjustment interval are used as the starting high-level frequency and the starting low-level frequency , And at the end of the second radio frequency adjustment interval, the end high-level frequency f ₂ (h) and end low-level frequency f ₂ (l) are obtained, and continue to be the start high-level frequency and start low-level frequency of the subsequent radio frequency adjustment interval. Flat frequency.

There are many ways to determine the starting frequency of the first radio frequency adjustment interval, and any frequency at which the plasma can be ignited can be used as the starting frequency. In a common embodiment, since the RF power generator usually outputs pulsed RF power after outputting continuous RF power for a certain period of time, when adjusting the frequency corresponding to the minimum reflected power of the pulsed RF power, the start of the first RF adjustment interval The frequency may be the frequency corresponding to the minimum reflected power in the continuous RF output stage, and the frequency is given to the RF power generator by the controller 50.

Since the RF power source can include a high-level power state and a low-level power state, a method to determine the starting frequency of the high-level power state is to set the RF power generator to output a continuous high-level power state and obtain the corresponding minimum reflected power Frequency, a method for determining the starting frequency of the low-level power state is to set the RF power generator to output a continuous low-level power state and obtain the frequency corresponding to the minimum reflected power.

Using the above frequency modulation method, the output frequency of the RF power generator can be quickly adjusted without changing the matcher. Since the frequency change of the automatic frequency modulation device does not require the adjustment of mechanical hardware, the frequency modulation time can be reduced to 0.1 microseconds For a 100 Hz pulse signal, assuming that the duty cycle of the pulse signal is 50%, the automatic frequency modulation device can adjust the frequency 50,000 times in a pulse radio frequency cycle, and the frequency corresponding to the minimum reflected power can be quickly found.

The frequency modulation method of the present invention has a particularly obvious effect on high-frequency pulse signals. When the pulse frequency of the pulsed radio frequency signal reaches 5000 Hz, the high and low level switching rate of the radio frequency signal is very rapid, and the duration of each pulse radio frequency cycle is only 200 Microseconds, assuming that the frequency modulation time of the automatic frequency modulation device is 10 microseconds each time, the duty cycle of the pulse signal is 50%, and the automatic frequency modulation device can perform 10 microseconds on the high-level frequency and the low-level frequency in each pulse radio frequency cycle. For the second frequency search, set the duration of the radio frequency adjustment interval to 10 milliseconds, and the automatic frequency modulation device can perform 1000 radio frequency adjustments within 1 second, so the radio frequency power corresponding to the minimum reflected power can be quickly found.

The controller 50 can control the duration of each radio frequency adjustment interval. The smaller the duration, the shorter the time for the radio frequency power generator to adjust to find the minimum reflected power, which is more conducive to the stable and accurate progress of the plasma treatment process. What needs to be considered is that the smaller the duration of the radio frequency adjustment interval means the larger the data that the controller needs to process and the faster the speed. Therefore, it needs to be comprehensively considered according to the accuracy requirements of the plasma processing process. Preferably, the duration of the radio frequency regulation interval is greater than or equal to 1 millisecond, and the duration of the commonly used radio frequency regulation interval is one of the following durations: 10 milliseconds, 50 milliseconds, 100 milliseconds, 150 milliseconds, 200 milliseconds, 250 milliseconds, 300 milliseconds Wait.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as limiting the present invention. After those skilled in the art have read the above content, various modifications and alternatives to the present invention will be obvious. Therefore, the scope of protection of the present invention should be limited by the scope of the attached patent application.

1, 2‧‧‧Matcher 10‧‧‧Edge ring 100‧‧‧Reaction chamber 11‧‧‧Gas shower head 110‧‧‧Air source 20‧‧‧Chip 21‧‧‧Electrostatic chuck 22‧‧‧ Base 30‧‧‧First RF power generator 40‧‧‧Second RF power generator 50‧‧‧Controller

By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the present invention will become more apparent: Figure 1 shows a schematic structural diagram of a plasma processing apparatus; Figure 2 A schematic diagram showing the pulse signal output by the RF power generator; Figure 3 shows a schematic diagram of the automatic frequency modulation device performing frequency modulation; Figure 4 shows a schematic diagram of the reflected power curve corresponding to the frequency modulation of the automatic frequency modulation device.

1, 2‧‧‧matcher

10‧‧‧Edge Ring

100‧‧‧Reaction chamber

11‧‧‧Gas sprinkler

110‧‧‧Air source

20‧‧‧chip

21‧‧‧Electrostatic chuck

22‧‧‧Pedestal

30‧‧‧The first RF power generator

40‧‧‧Second RF Power Generator

50‧‧‧controller

Claims (36)

A plasma radio frequency adjustment method. The plasma radio frequency adjustment method is performed by a radio frequency power generator. The radio frequency power generator includes an automatic frequency adjustment device. The plasma radio frequency adjustment method includes the following steps: The radio frequency power generator outputs a pulse Radio frequency signal; set a plurality of continuous radio frequency adjustment intervals, each radio frequency adjustment interval includes at least one pulsed radio frequency period; the automatic frequency adjustment device performs at least one automatic frequency adjustment in each radio frequency adjustment interval, and each radio frequency adjustment interval includes one A start frequency and an end frequency, the start frequency of each radio frequency adjustment interval is the end frequency of the previous radio frequency adjustment interval, and the start frequency of the first radio frequency adjustment interval is the preset frequency. As described in the first item of the scope of patent application, the plasma radio frequency adjustment method, wherein the start frequency includes a start high level frequency and a start low level frequency, and the end frequency includes an end high level frequency and an end low level frequency. Flat frequency. For the plasma radio frequency adjustment method described in item 1 of the scope of patent application, the automatic frequency adjustment method is: assigning the radio frequency power generator the preset frequency, correspondingly obtaining the first reflected power, and increasing the preset frequency by one step The RF power generator is assigned to obtain the second reflected power correspondingly, and the first reflected power is compared with the second reflected power. If the second reflected power is greater than the first reflected power, the step length is increased in the opposite direction. If the second reflected power is less than the first reflected power, then continue to increase the preset frequency by two steps to give the radio frequency power generator, and adjust to obtain a smaller reflected power. In the plasma radio frequency adjustment method described in item 3 of the scope of patent application, the preset frequency is a frequency that can ensure plasma ignition. For example, in the plasma radio frequency adjustment method described in item 3 of the scope of patent application, the method for obtaining the preset frequency is: setting the radio frequency power source to output a continuous radio frequency power signal, and calculating the minimum reflected power in the continuous radio frequency output stage, and the minimum The frequency corresponding to the reflected power is used as the preset frequency. As described in the first item of the scope of patent application, the plasma radio frequency adjustment method, wherein each radio frequency adjustment interval includes at least two pulsed radio frequency periods, and the automatic frequency adjustment device performs multiple automatic frequency adjustments in each pulsed radio frequency period. The plasma radio frequency adjustment method described in item 6 of the scope of patent application, wherein the automatic frequency adjustment device has the same start frequency and the same end frequency in different pulse radio frequency periods of the same radio frequency adjustment interval. The plasma radio frequency adjustment method as described in item 6 of the scope of patent application, wherein the automatic frequency adjustment device has the same start frequency and different end frequencies in different pulse radio frequency periods of the same radio frequency adjustment interval. As described in the first item of the scope of patent application, the plasma radio frequency adjustment method, wherein the time of the radio frequency adjustment interval is set by a controller. The plasma radio frequency adjustment method according to item 9 of the scope of patent application, wherein the controller reads the end frequency of the automatic frequency adjustment device and assigns the end frequency as the start frequency of the next radio frequency adjustment interval to the automatic frequency adjustment Device. The plasma radio frequency adjustment method as described in item 9 of the scope of patent application, wherein the controller sets a reflected power threshold, and when the reflected power found by the automatic frequency adjustment device is lower than the reflected power threshold, the frequency modulation process stops. According to the plasma radio frequency adjustment method described in item 1 of the scope of patent application, the duration of the radio frequency adjustment interval is greater than or equal to 1 millisecond. The plasma radio frequency adjustment method described in item 12 of the scope of patent application, wherein the duration of the radio frequency adjustment interval is 10 milliseconds. For the plasma radio frequency adjustment method described in item 12 of the scope of patent application, the duration of the radio frequency adjustment interval is 50 milliseconds. The plasma radio frequency adjustment method described in item 12 of the scope of patent application, wherein the duration of the radio frequency adjustment interval is 100 milliseconds. The plasma radio frequency adjustment method described in item 12 of the scope of patent application, wherein the duration of the radio frequency adjustment interval is 150 milliseconds. The plasma radio frequency adjustment method described in item 12 of the scope of patent application, wherein the duration of the radio frequency adjustment interval is 200 milliseconds. According to the plasma radio frequency adjustment method described in item 1 of the scope of patent application, the frequency adjustment time of the automatic frequency adjustment device is greater than or equal to 0.1 microseconds. The plasma radio frequency adjustment method described in item 18 of the scope of patent application, wherein the frequency adjustment time of the automatic frequency adjustment device is 1 microsecond. The plasma radio frequency adjustment method described in item 18 of the scope of patent application, wherein the frequency adjustment time of the automatic frequency adjustment device is 5 microseconds. The plasma radio frequency adjustment method described in item 18 of the scope of patent application, wherein the frequency adjustment time of the automatic frequency adjustment device is 10 microseconds. The plasma radio frequency adjustment method described in item 18 of the scope of patent application, wherein the frequency adjustment time of the automatic frequency adjustment device is 20 microseconds. The plasma radio frequency adjustment method described in item 18 of the scope of patent application, wherein the frequency adjustment time of the automatic frequency adjustment device is 30 microseconds. According to the plasma radio frequency adjustment method described in item 1 of the patent application, the pulsed radio frequency signal includes high-level power and low-level power, and the low-level power is greater than or equal to zero. According to the plasma radio frequency adjustment method described in claim 24, the pulsed radio frequency signal further includes a third level power state, and the third level power is between the high level power and the low level power between. As described in the first item of the scope of patent application, the plasma radio frequency adjustment method, wherein the pulse frequency of the pulse radio frequency period is greater than 100 Hz. According to the plasma radio frequency adjustment method described in item 1 of the scope of patent application, the pulse frequency of the pulse radio frequency period is greater than 5000 Hz. A plasma processing device, comprising: a plasma processing chamber for accommodating and processing wafers; a radio frequency power generator applied to the plasma processing chamber for generating or regulating plasma; a controller, which functions The radio frequency power generator is used to control the duration of a radio frequency adjustment interval; the radio frequency power generator outputs a pulsed radio frequency signal, and each radio frequency adjustment interval includes at least one pulse radio frequency period; the radio frequency power generator includes an automatic frequency modulation The automatic frequency adjustment device performs at least one automatic frequency adjustment in each pulse radio frequency cycle, each radio frequency adjustment interval includes a start frequency and an end frequency, and the start frequency of each radio frequency adjustment interval is the previous radio frequency adjustment The end frequency of the interval and the first start frequency of the radio frequency adjustment interval are preset frequencies. The plasma processing device described in item 28 of the scope of patent application, wherein the start frequency includes a start high-level frequency and a start low-level frequency, and the end frequency includes an end high-level frequency and an end low-level frequency frequency. For the plasma processing device described in item 28 of the scope of patent application, the preset frequency includes a high-level preset frequency and a low-level preset frequency, and the high-level preset frequency means that the radio frequency power generator is continuously The frequency corresponding to the minimum reflected power during high-power output, and the low-level preset frequency is the frequency corresponding to the minimum reflected power of the RF power generator during continuous low-power output. The plasma processing device described in item 28 of the scope of patent application, wherein the preset frequency is given to the automatic frequency modulation device by the controller. The plasma processing device according to the 28th patent application, wherein the plasma processing device includes a second radio frequency power generator, and the second radio frequency power generator outputs a second pulsed radio frequency signal. For example, the plasma processing device described in item 28 of the scope of patent application, wherein the second radio frequency power generator includes a second automatic frequency adjustment device, and the second automatic frequency adjustment device performs at least one automatic frequency adjustment in each radio frequency adjustment interval. Each of the radio frequency adjustment intervals includes the start frequency and the end frequency, the start frequency of each radio frequency adjustment interval is the end frequency of the previous radio frequency adjustment interval, and the start frequency of the first radio frequency adjustment interval is the first 2. Preset frequency. For the plasma processing device described in item 28 of the scope of patent application, the frequency modulation time of the automatic frequency modulation device is greater than or equal to 0.1 microseconds. The plasma processing device described in item 28 of the scope of patent application, wherein the controller controls the duration of the radio frequency adjustment interval to be greater than or equal to 1 millisecond. For the plasma processing device described in item 28 of the scope of patent application, the controller controls a plurality of consecutive radio frequency adjustment intervals with the same or different durations.

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