46 results about "Plasma impedance" patented technology

A method and apparatus for controlling a power supply to prevent instabilities due to dynamic loads in RF plasma processing systems, operating at frequencies of from 1 MHz and up, uses a feedforward type of control loop to tightly regulate the power supplied to the dynamic electrical load, such as loads caused by variable and inconsistent plasma impedance. A feedback control loop can also be used in combination with the feedforward loop, but at a slower rate, to help regulate the amount of power provided to the load.

A method and apparatus for controlling a power supply to prevent instabilities due to dynamic loads in RF plasma processing systems, operating at frequencies of from 1 MHz and up, uses a feedforward type of control loop to tightly regulate the power supplied to the dynamic electrical load, such as loads caused by variable and inconsistent plasma impedance. A feedback control loop can also be used in combination with the feedforward loop, but at a slower rate, to help regulate the amount of power provided to the load.

An approach for stabilizing the interactions between a plasma and the generator powering the plasma is provided. Reactive elements disposed between the power generator and plasma operate to modify the apparent impedance characteristics of the plasma such that the trajectory of the plasma load impedance as a function of power is substantially aligned locally with the contours of constant power output in impedance space. In this way, instabilities in the generator and plasma system are avoided because reinforcement or amplification of fluctuations in plasma impedance due to interactions between the generator and the plasma are reduced or eliminated. The reactive elements may be variable in order to align plasma trajectories and generator power contours under a range of process conditions.

The invention provides a plasma processing device and a plasma processing method. In the manner of periodically modulating the power of the high frequency used in the plasma processing, variation of plasma impedance and reflection towards the high frequency power supply are reduced as much as possible, so as to ensure the stability and reproducibility of the plasma and the safety of the high frequency power supply. In the plasma processing device, frequency modulation is carried out on the power of the high frequency (LF) for controlling bias voltage by the characteristics corresponding to the processing, and pulse modulation is synchronously carried out on the frequency (LF frequency) thereof together with the pulse modulation of the LF power, namely, the LF frequency and the LF power have the following synchronous relationship in a period: in the time interval of the period T when the LF power is maintained as a set value P of H level, the LF frequency is also maintained as the set value F of H level, and in the time interval of the period when the LF power is maintained as a set value P of L level, the LF frequency is also maintained as the set value F of L level.

An RF impedance matching network includes an RF input; an RF output configured to operably couple to a plasma chamber; a series electronically variable capacitor (“series EVC”), the series EVC electrically coupled in series between the RF input and the RF output; and a shunt electronically variable capacitor (“shunt EVC”), the shunt EVC electrically coupled in parallel between a ground and one of the RF input and the RF output; a control circuit to control the series variable capacitance and the shunt variable capacitance, wherein the control circuit is configured to determine the variable plasma impedance of the plasma chamber, determine a series capacitance value and a shunt capacitance value, and generate a control signal to alter at least one of the series variable capacitance and the shunt variable capacitance; wherein the alteration is caused by at least one of a plurality of switching circuits.

A reduced impedance chamber for plasma processing leads to operational advantages including a plasma sheath voltage that is substantially independent of plasma impedance over a range of plasma impedances. The design of such a reduced impedance chamber includes a chuck assembly, a counter electrode, and a plasma source. The chuck assembly allows mounting of a workpiece for processing and includes a driven electrode and a ground portion. The plasma source operates to generate a plasma in the chamber from process gas. A wall portion of the plasma source is directly electrically connected to the counter electrode and to the ground portion of the chuck assembly. The counter electrode may include an inject-exhaust plate that is mounted in a position opposed to the chuck assembly and that operates to inject process gas into the chamber and to exhaust effluent.

An approach for stabilizing the interactions between a plasma and the generator powering the plasma is provided. Reactive elements disposed between the power generator and plasma operate to modify the apparent impedance characteristics of the plasma such that the trajectory of the plasma load impedance as a function of power is substantially aligned locally with the contours of constant power output in impedance space. In this way, instabilities in the generator and plasma system are avoided because reinforcement or amplification of fluctuations in plasma impedance due to interactions between the generator and the plasma are reduced or eliminated. The reactive elements may be variable in order to align plasma trajectories and generator power contours under a range of process conditions.

An RF impedance matching network includes an RF input configured to operably couple to an RF source, the RF source having a fixed RF source impedance; an RF output configured to operably couple to a plasma chamber, the plasma chamber having a variable plasma impedance; a series EVC; a shunt EVC; an RF input sensor; and a control circuit configured to: determine an input impedance; determine the plasma impedance; determine a first capacitance value for the series variable capacitance and a second capacitance value for the shunt variable capacitance, the determination of the first capacitance value and the second capacitance value based on the plasma impedance and the RF source impedance; generate a control signal to alter at least one of the series variable capacitance and the shunt variable capacitance to the first capacitance value and the second capacitance value, respectively.

A method and apparatus for detecting the endpoint in a dry plasma etching system comprising a first electrode (e.g., upper electrode) and a second electrode (e.g., lower electrode) upon which a substrate rests is described. A direct current (DC) voltage is applied between the first electrode and a ring electrode surrounding the second electrode, and the DC current is monitored to determine the endpoint of the etching process. The DC current is affected by the impedance of the plasma, and therefore responds to many variations including, for example, the plasma density, electron / ion flux to exposed surfaces, the electron temperature, etc.

An apparatus (14) for and method of measuring impedance in a capacitively coupled plasma reactor system (10). The apparatus includes a high-frequency RF source (150) in electrical communication with an upper electrode (50). A first high-pass filter (130) is arranged between the upper electrode and the high-frequency RF source, to block low-frequency, high-voltage signals from the electrode RF power source (66) from passing through to the impedance measuring circuit A current-voltage probe (140) is arranged between the high-frequency source and the high-pass filter, and is used to measure the current and voltage of the probe signal with and without the plasma present. An amplifier (250) is electrically connected to the current-voltage probe, and a data acquisition unit (260) is electrically connected to the amplifier. A second high-pass filter (276) is electrically connected to a lower electrode (56) and to ground, so as to complete the isolation of the high-frequency circuit of the impedance measurement apparatus from the low-frequency, high-voltage circuit of the capacitively coupled plasma reactor system. A method of measuring the plasma impedance using the apparatus of the present invention is also disclosed.

A plasma processing apparatus including a chamber having an inner wall with a protective film thereon and a sample stage disposed in the chamber in which plasma is generated by supplying high-frequency wave energy to processing gas to conduct plasma processing for a sample on the sample stage using the plasma. The apparatus includes a control device which determines, based on monitor values of a wafer attracting current monitor (Ip) to monitor a current supplied from a wafer attracting power source, an impedance monitor (Zp) to monitor plasma impedance viewed from a plasma generating power source, and an impedance monitor (Zb) to monitor a plasma impedance viewed from a bias power supply, presence or absence of occurrence of an associated one of abnormal discharge in inner parts, deterioration in insulation of an insulating film of a wafer attracting electrode, and abnormal injection in a gas injection plate.

The invention relates to a device for the regulation of a plasma impedance in a vacuum chamber, wherein at least one electrode is connected to an AC generator. This AC generator is a free-running [oscillator], whose frequency adjusts to the resonance frequency of the load upon which it acts. This load comprises fixed circuit elements and a variable plasma impedance. If the plasma impedance is changed, with it the resonance frequency is also changed. The plasma impedance can thus be varied by acquisition of the resonance frequency and by presetting of a reference frequency value, for example thereby that the voltage, the current, the power or the gas inflow is varied as a function of the difference between resonance frequency and reference frequency value.

An RF impedance matching network includes an RF input; an RF output configured to operably couple to a plasma chamber; a series electronically variable capacitor (“series EVC”), the series EVC electrically coupled in series between the RF input and the RF output; and a shunt electronically variable capacitor (“shunt EVC”), the shunt EVC electrically coupled in parallel between a ground and one of the RF input and the RF output; a control circuit to control the series variable capacitance and the shunt variable capacitance, wherein the control circuit is configured to determine the variable plasma impedance of the plasma chamber, determine a series capacitance value and a shunt capacitance value, and generate a control signal to alter at least one of the series variable capacitance and the shunt variable capacitance; wherein the alteration is caused by at least one of a plurality of switching circuits.

Disclosed is a substrate treating apparatus which comprises a process chamber; an electrode configured to generate plasma from a gas supplied into the process chamber; an RF power supply configured to output an RF power; a transmission line configured to transmit the RF power to the electrode from the RF power supply; an impedance matching unit connected to the transmission line and configured to match plasma impedance; and a controller configured to output a control signal to the impedance matching unit, wherein the impedance matching unit comprises an adjustable capacitor having a plurality of capacitors and a plurality of switches corresponding to the plurality of capacitors, the plurality of switches being switched on / off according to the control signal so that capacitance of the adjustable capacitor is adjusted.

A plasma processing apparatus includes a processing chamber configured to perform a plasma processing on a sample, a first radio frequency power supply configured to generate a plasma, a sample stage configured to place the sample thereon, a second radio frequency power supply configured to supply a radio frequency power to the sample stage, a mass flow controller configured to supply a gas into the processing chamber, and a control device configured to change the radio frequency power supplied from the first radio frequency power supply or the second radio frequency power supply based on a change of plasma impedance after a first gas is switched to a second gas.

A signal processing portion obtains the reciprocal of a composite impedance of gap static capacitance and a plasma impedance, obtains composite static capacitance which is the sum of the gap static capacitance and a static capacitance component included in the plasma impedance from an imaginary part of the reciprocal, and obtains a resistance component included in the plasma impedance from a real part of the reciprocal. A gap detection device obtains the static capacitance component by using a model representing the characteristics of the reciprocal of the plasma impedance and the resistance component and obtains the gap static capacitance by subtracting the static capacitance component from the composite static capacitance. The gap detection device obtains a gap from the obtained gap static capacitance. Thus provided is a technique to detect a gap between a nozzle of a laser beam machine for outputting a laser beam and an object to be machined with high accuracy.

A plasma processing system, method, and computer readable medium for measuring plasma impedance. The system includes a chamber configured to contain a plasma and including a chuck within an interior area of the chamber, the chuck including a support surface and a bottom surface, and a first voltage-current probe positioned at a first position located exterior to the chamber and on a radio-frequency transmission line between the chamber and a power source. The system also includes a simulation module connected to the first voltage-current probe and arranged to solve, based on measurements transmitted from the first voltage-current probe, a radio-frequency model of the radio-frequency transmission line between the first position and a second position located within the chamber.

Apparatuses for multi-station semiconductor deposition operations with RF power frequency tuning are disclosed. The RF power frequency may be tuned according to a measured impedance of a plasma during the semiconductor deposition operation. In certain implementations of the apparatuses, a RF power parameter may be adjusted during or prior to the deposition operation. Certain other implementations of the semiconductor deposition operations may include multiple different deposition processes with corresponding different recipes. The recipes may include different RF power parameters for each respective recipe. The respective recipes may adjust the RF power parameter prior to each deposition process. RF power frequency tuning may be utilized during each deposition process.

Methods for determining characteristics of a plasma are provided. In one embodiment, a method for determining characteristics of a plasma includes obtaining metrics of current and voltage information for first and second waveforms coupled to a plasma at different frequencies, determining at least one characteristic of the plasma using the metrics obtained from each different frequency waveform. In another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, and determining at least one characteristic of a plasma using model. In yet another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, measuring current and voltage for waveforms coupled to the plasma and having at least two different frequencies, and determining ion mass of a plasma from model and the measured current and voltage of the waveforms.

The invention provides a plasma etching method, a plasma etching device and an RF source system thereof, wherein the method, the device and the system are used for improving RF power outputting stability. The plasma etching method comprises a plurality of working periods, wherein each period comprises two steps: a first step, applying and keeping a bias power (P) and an RF power (P1); and a secondstep, setting the bias power to zero and simultaneously increasing the RF power (P2). In the period, the frequency of the RF power is unchanged. In a more preferably embodiment, plasma impedance in the period is kept stable.

The invention relates to a method for refining crystal grains in ultra-pure copper or copper alloy. The refining method comprises the steps of: heating an ultra-pure copper or copper alloy blank; andthen sequentially carrying out first equal channel angular pressing and second equal channel angular pressing. According to the method provided by the invention, by adopting the specific equal channelangular pressing process, crystal grains are refined to the specification of below 5mum so as to ensure that a target material has good sputtering performance when being sputtered by adopting the refined ultra-pure copper or copper alloy; and furthermore, by the refining method, when in use, the target material is low in plasma impedance, high in thin film deposition rate and good in thin film thickness uniformity.

Methods for determining characteristics of a plasma are provided. In one embodiment, a method for determining characteristics of a plasma includes obtaining metrics of a plasma at two different frequencies, and determining at least one characteristic of the plasma utilizing the metrics. In another embodiment, a method for determining characteristics of a plasma includes obtaining metrics of current and voltage information for first and second waveforms coupled to a plasma at different frequencies, determining at least one characteristic of the plasma using the metrics obtained from each different frequency waveform. In another embodiment, the method includes providing a plasma impedance model of a plasma as a function of frequency, and determining at least one characteristic of a plasma using model.

Embodiments described herein relate to apparatus and methods for substantially reducing an occurrence of radio frequency (RF) coupling through a chucking electrode. The chucking electrode is disposed in an electrostatic chuck positioned on a substrate support. The substrate support is coupled to a process chamber body. An RF source is used to generate a plasma in a process volume adjacent to the substrate support. An impedance matching circuit is disposed between the RF source and the chucking electrode is disposed in the electrostatic chuck. An electrostatic chuck filter is coupled between the chucking electrode and the chucking power source.

A plasma generation device provided by the present invention comprises a dielectric window, an induction coil surrounding the dielectric window and an impedance matching device, and also comprises a Faraday shielding member arranged between the dielectric window and the induction coil. The present invention also provides a semiconductor processing device. According to the plasma generation device provided by the present invention, the current transmission on the surface of the induction coil is not influenced by the plasma state perturbation any more, so that at work, the plasma generation device provided by the present invention does not generate the phenomena that the plasma quenches, the impedance matching device is matched again, etc., and accordingly, the plasma impedance matching can be realized rapidly, and further the etching morphology of a semiconductor substrate during a Bosch etching technical process is controlled more easily, and the repeatability of the Bosch process is improved.

A plasma processing apparatus, including a processing; a first radio frequency power source; a sample stage on which the sample is placed; a second radio frequency power; and a control device configured to control, when the second radio frequency power source is controlled based on a change in a plasma impedance, which is generated when a first gas that is a gas for a first step is switched to a second gas that is a gas for a second step, such that the second radio frequency power is changed from a value of the second radio frequency power in the first step to a value of the second radio frequency power in the second step, and a supply time of the first gas such that a supply time of the second radio frequency power in the first step is substantially equal to a time of the first step.

A signal processing portion obtains the reciprocal of a composite impedance of gap static capacitance and a plasma impedance, obtains composite static capacitance which is the sum of the gap static capacitance and a static capacitance component included in the plasma impedance from an imaginary part of the reciprocal, and obtains a resistance component included in the plasma impedance from a real part of the reciprocal. A gap detection device obtains the static capacitance component by using a model representing the characteristics of the reciprocal of the plasma impedance and the resistance component and obtains the gap static capacitance by subtracting the static capacitance component from the composite static capacitance. The gap detection device obtains a gap from the obtained gap static capacitance. Thus provided is a technique to detect a gap between a nozzle of a laser beam machine for outputting a laser beam and an object to be machined with high accuracy.

The invention relates to a method and a device for measuring impedance and power of plasma. The method comprises the following steps: acquiring a voltage waveform and a current waveform; acquiring a voltage amplitude and a voltage phase according to the voltage waveform; acquiring a current amplitude and a current phase according to the current waveform; performing phase difference calibration according to the voltage phase and the current phase to obtain a V-I phase difference; and calculating the impedance and power of the plasma according to the voltage waveform, the current waveform, the voltage amplitude, the current amplitude and the V-I phase difference. Aiming at the problems in the prior art, pulse modulation is carried out on a pulse radio frequency power supply, and the evolution process of radio frequency power and plasma impedance along with time is further obtained by prolonging the pulse turn-off time and calibrating the V-I phase difference; when the plasma is stable, stable-state (continuous wave-driven) plasma can absorb power.

The present invention provides an impedance matching network for a plasma reactor, which comprises at least one inductor and at least one variable capacitor unit, wherein the variable capacitor unit comprises at least one variable vacuum capacitor; the variable vacuum capacitor comprises two parallel electrode plates; an annular piezoelectric ceramic plate is arranged between the two electrode plates; the annular piezoelectric ceramic plate is connected with a driving power supply; and an arc-shaped electrode plate is arranged in the hollow region of the annular piezoelectric ceramic plate. The variable vacuum capacitor in the impedance matching network described in the present invention uses the inverse piezoelectric effect of piezoelectric ceramic material; when alternating driving voltage is applied to piezoelectric ceramics, the piezoelectric ceramics can rapidly generate telescopic motion along a voltage loading direction, so that the distance of the arc-shaped electrode plate relative to the other electrode plate is changed; accordingly, the capacitance value of the variable vacuum capacitor is rapidly changed to realize that the size of the variable vacuum capacitor can be regulated within microsecond magnitude; and the need that plasma impedance is rapidly changed with the output of a radio frequency power source is satisfied.