Abstract: In one embodiment, an RF impedance matching circuit is disclosed. The matching circuit is coupled between a plasma chamber and an RF source providing an RF signal having a frequency. The matching circuit includes a first electronically variable capacitor having a first variable capacitance and a second electronically variable capacitor having a second variable capacitance. A control circuit determines a first parameter related to the plasma chamber, and then determines, based on the first parameter, a first capacitance value for the first electronically variable capacitor and a second capacitance value for the second electronically variable capacitor. The control circuit then generates a control signal to alter the first variable capacitance and the second variable capacitance accordingly, causing the RF power reflected back to the RF source to decrease while the frequency of the RF source is not altered.

Abstract: In one embodiment, the invention can be an impedance matching network including an input configured to operably couple to a radio frequency (RF) source; an output configured to operably couple to a load; a first variable capacitor; a second variable capacitor; and a third capacitor in series with the second variable capacitor and reducing a voltage on the second variable capacitor.

Abstract: In one embodiment, an RF impedance matching network for a plasma chamber is disclosed. It includes a variable capacitor comprising a plurality of capacitors comprising first coarse capacitors each having a substantially similar first coarse capacitance, second coarse capacitors each having a substantially similar second coarse capacitance, and fine capacitors having different capacitances that increase in value. At least one of the fine capacitors has a capacitance greater than the first coarse capacitance. A control circuit is configured cause a gradual increase in the total capacitance of the variable capacitor by switching in, in a predetermined order, each of the first coarse capacitors, followed by each of the second coarse capacitors, only switching in the fine capacitors whose capacitance is less than a capacitance of a next coarse capacitor of the coarse capacitors predetermined to be switched in next.

Abstract: In one embodiment, the invention can be a variable capacitor that includes a plurality of capacitors operably coupled in parallel, and a plurality of switches coupled in series with corresponding capacitors. The plurality of capacitors can include first capacitors increasing in capacitance, and second capacitors having a substantially similar capacitance. Further, for each first capacitor increasing in capacitance, the change to the total capacitance that is provided by the first capacitor when its corresponding switch is closed can increase by a factor of about two.

Abstract: In one embodiment, a phase detection circuit includes a current signal input to receive a current signal indicative of a current amplitude of an RF signal and a voltage signal input to receive a voltage signal indicative of a voltage amplitude of the RF signal. A high-pass filter and a low-pass filter are each configured to filter one of (i) the current signal from the current signal input or (ii) the voltage signal from the voltage signal input, wherein the high-pass filter and the low-pass filter collectively cause a substantially 90 degree offset between a phase angle of the current signal and a phase angle of the voltage signal. A phase difference circuit receives the filtered current signal and the filtered voltage signal to determine a phase angle difference between the current signal and the voltage signal.

Abstract: In one embodiment, an RF impedance matching network for a plasma chamber is disclosed. The matching network includes an electronically variable capacitor (EVC) comprising discrete capacitors, each discrete capacitor having a corresponding switching circuit for switching in and out the discrete capacitor to alter a total capacitance of the EVC. Each switching circuit comprises at least one switching field-effect transistor (FET) operably coupled to the corresponding discrete capacitor to cause the switching in and out of the discrete capacitor. For each switching circuit, when the switching circuit is switched OFF to switch out the corresponding discrete capacitor, the at least one switching FET receives a bias voltage from a bias voltage source to reduce a capacitance variability of the at least one switching FET.

Abstract: In one embodiment, an RF impedance matching network for a plasma chamber is disclosed. The matching network includes an electronically variable capacitor (EVC) comprising discrete capacitors, each discrete capacitor having a corresponding switching circuit for switching in and out the discrete capacitor to alter a total capacitance of the EVC. Each switching circuit includes a diode operably coupled to the discrete capacitor to cause the switching in and out of the discrete capacitor, and a filter circuit parallel to the diode, the filter comprising a filtering capacitor in series with an inductor.

Abstract: In one embodiment, the present disclosure is directed to a method for performing diagnostics on a matching network that utilizes an electronically variable capacitor (EVC). According to the method, all the discrete capacitors of the EVC are switched out. At a first node, a parameter associated with a current flowing between a power supply and one or more of the switches of the discrete capacitors is measured. The method then switches in, one at a time, each discrete capacitor of the EVC. Upon the switching in of each discrete capacitor, the method re-measures the parameter at the first node and determines whether a change to the parameter at the first node is within a predetermined range to determine whether the corresponding switch, driver circuit, or filter of the discrete capacitor most recently switch in has failed.

Abstract: In one embodiment, an RF impedance matching network for a plasma chamber is disclosed. The matching network includes a mechanically variable capacitor (MVC) and a second variable capacitor. A control circuit is configured to carry out a first process for altering the second variable capacitor and the RF source frequency to reduce reflected power. The control circuit is further configured to carry out a second process of, upon determining that the alteration of the RF source frequency has caused the RF source frequency to be outside, at a minimum, or at a maximum of a predetermined frequency range, determining a new MVC configuration to cause the RF source frequency, according to the first process, to be altered to be within or closer to the predetermined frequency range. The new MVC configuration is based on the RF source frequency and the predetermined frequency range.

Abstract: In one embodiment, an RF impedance matching network for a plasma chamber is disclosed. The matching network includes first and second variable capacitors, and a sensor configured to measure a parameter related to the plasma chamber. A control circuit carries out a matching process of determining a parameter-based value based on the measured parameter; inputting the parameter-based value into a match configuration look-up table to determine a match configuration for reducing a reflected power, the match configuration comprising a first variable capacitor configuration, a second variable capacitor configuration, and an RF source frequency; and causing an altering of the first variable capacitor to the first variable capacitor configuration, the second variable capacitor to the second variable capacitor configuration, and the RF source to the RF source frequency.

Abstract: In one embodiment, an RF impedance matching circuit is disclosed. The matching circuit is coupled between a plasma chamber and an RF source providing an RF signal having a frequency. The matching circuit includes a first electronically variable capacitor having a first variable capacitance and a second electronically variable capacitor having a second variable capacitance. A control circuit determines a first parameter related to the plasma chamber, and then determines, based on the first parameter, a first capacitance value for the first electronically variable capacitor and a second capacitance value for the second electronically variable capacitor. The control circuit then generates a control signal to alter the first variable capacitance and the second variable capacitance accordingly, causing the RF power reflected back to the RF source to decrease while the frequency of the RF source is not altered.

Abstract: In one embodiment, an RF impedance matching network for a plasma chamber is disclosed. The matching network includes at least one electronically variable capacitor (EVC), each EVC comprising discrete capacitors each having a corresponding switching circuit. Each switching circuit is configured to switch in and out its corresponding discrete capacitor to alter a total capacitance of the EVC. Each switching circuit include a first diode operably coupled to the discrete capacitor, a capacitor coupled in series with the first diode, and a second diode operably coupled to the discrete capacitor. The second diode parallel to the first diode and the capacitor coupled in series.

Abstract: In one embodiment, the present disclosure is directed to an RF impedance matching network that includes an RF input coupled to an RF source, an RF output coupled to a plasma chamber, and an electronically variable capacitor (EVC). A first control circuit controls the EVC and is separate and distinct from a second control circuit controlling the RF source. To assist in causing an impedance match between the RF source and the plasma chamber, the first control circuit determines, using a match lookup table with a value based on a detected RF parameter, a new EVC configuration for providing a new EVC capacitance. To further cause the impedance match, the second control circuit alters the variable frequency of the RF source, but operates independently from the first control circuit.

Abstract: In one embodiment, a semiconductor processing tool includes a plasma chamber and an impedance matching circuit. The matching circuit includes a first electronically variable capacitor having a first variable capacitance, a second electronically variable capacitor having a second variable capacitance, and a control circuit. The control circuit is configured to determine a variable impedance of the plasma chamber, determine a first capacitance value for the first electronically variable capacitor and a second capacitance value for the second electronically variable capacitor, and generate a control signal to alter at least one of the first variable capacitance and the second variable capacitance to the first capacitance value and the second capacitance value, respectively. An elapsed time between determining the variable impedance of the plasma chamber to when RF power reflected back to the RF source decreases is less than about 150 ?sec.

Abstract: A control circuit for a impedance matching circuit having first and second capacitor arrays receives as input one or more RF parameters of the impedance matching circuit, and in response thereto: determines a first match configuration for the first capacitor array and a second match configuration for the second capacitor array to create an impedance match between a fixed RF source impedance and a variable RF load impedance, the first match configuration and the second match configuration being determined from one or more look-up tables and based upon the detected one or more RF parameters; and alters at least one of the first array configuration and the second array configuration to the first match configuration and the second match configuration, respectively, by controlling the on and off states of (a) each discrete capacitor of the first capacitor array and (b) each discrete capacitor of the second capacitor array.

Abstract: In one embodiment, a radio frequency (RF) impedance matching network includes electronically variable capacitors (EVCs), each EVC including discrete capacitors operably coupled in parallel. The discrete capacitors include fine capacitors each having a capacitance value substantially similar to a fine capacitance value, and coarse capacitors each having a capacitance value substantially similar to a coarse capacitance value. The increase of the variable total capacitance of each EVC is achieved by switching in more of the coarse capacitors or more of the fine capacitors than are already switched in without switching out a coarse capacitor that is already switched in.

Abstract: In one embodiment, an RF impedance matching network for a plasma chamber is disclosed. It includes a variable capacitor comprising a plurality of capacitors comprising first coarse capacitors each having a substantially similar first coarse capacitance, second coarse capacitors each having a substantially similar second coarse capacitance, and fine capacitors having different capacitances that increase in value. At least one of the fine capacitors has a capacitance greater than the first coarse capacitance. A control circuit is configured cause a gradual increase in the total capacitance of the variable capacitor by switching in, in a predetermined order, each of the first coarse capacitors, followed by each of the second coarse capacitors, only switching in the fine capacitors whose capacitance is less than a capacitance of a next coarse capacitor of the coarse capacitors predetermined to be switched in next.

Abstract: In one embodiment, a semiconductor processing tool includes a plasma chamber and an impedance matching circuit. The matching circuit includes a first electronically variable capacitor having a first variable capacitance, a second electronically variable capacitor having a second variable capacitance, and a control circuit. The control circuit is configured to determine a variable impedance of the plasma chamber, determine a first capacitance value for the first electronically variable capacitor and a second capacitance value for the second electronically variable capacitor, and generate a control signal to alter at least one of the first variable capacitance and the second variable capacitance to the first capacitance value and the second capacitance value, respectively. An elapsed time between determining the variable impedance of the plasma chamber to when RF power reflected back to the RF source decreases is less than about 150 ?sec.

Abstract: In one embodiment, the invention may be an impedance matching network including an input configured to operably couple to a radio frequency source, an output configured to operably couple to a load, and a first variable capacitor. The matching network may further include an inductor formed from a heat pipe that is wound in a three-dimensional shape. A first heat sink may be coupled adjacent to a first end of the heat pipe, and a second heat sink may be coupled adjacent to a second, opposite end of the heat pipe.

Abstract: In one embodiment, a radio frequency (RF) impedance matching network includes electronically variable capacitors (EVCs), each EVC including discrete capacitors operably coupled in parallel. The discrete capacitors include fine capacitors each having a capacitance value substantially similar to a fine capacitance value, and coarse capacitors each having a capacitance value substantially similar to a coarse capacitance value. The increase of the variable total capacitance of each EVC is achieved by switching in more of the coarse capacitors or more of the fine capacitors than are already switched in without switching out a coarse capacitor that is already switched in.