초록 ▼

The present hot switching method and impedance matching circuit extends the tuning range of matching circuits to include increased power levels. The hot switching method and circuit includes coupling a controlled impedance network between an RF generator output and a plasma chamber input for matchin

The present hot switching method and impedance matching circuit extends the tuning range of matching circuits to include increased power levels. The hot switching method and circuit includes coupling a controlled impedance network between an RF generator output and a plasma chamber input for matching impedances. The controlled impedance network includes an RF switch for switching a predetermined impedance. A device performance characteristic of the RF switch is determined. RF power is applied from the RF generator through the controlled impedance network to the plasma chamber. A signal characteristic of the impedance match is measured. The RF switch is controlled based upon the measured signal characteristic such that the impedance match is driven towards a predetermined matching range. The RF switch is switched any speed based upon the device performance characteristic.

대표청구항 ▼

The present hot switching method and impedance matching circuit extends the tuning range of matching circuits to include increased power levels. The hot switching method and circuit includes coupling a controlled impedance network between an RF generator output and a plasma chamber input for matchin

The present hot switching method and impedance matching circuit extends the tuning range of matching circuits to include increased power levels. The hot switching method and circuit includes coupling a controlled impedance network between an RF generator output and a plasma chamber input for matching impedances. The controlled impedance network includes an RF switch for switching a predetermined impedance. A device performance characteristic of the RF switch is determined. RF power is applied from the RF generator through the controlled impedance network to the plasma chamber. A signal characteristic of the impedance match is measured. The RF switch is controlled based upon the measured signal characteristic such that the impedance match is driven towards a predetermined matching range. The RF switch is switched any speed based upon the device performance characteristic. determined length, operating the phase-locked loop with a feedback frequency division ratio set to an initial value selected to control the conduction time of the charge pump to place an amount of charge on the loop filter during the first period sufficient to produce a control voltage for controlling the voltage-controlled oscillator to output an output signal substantially at the desired output frequency, wherein the initial value is determined based on the overall capacitance of the loop filter, the amplitude of the current output by the charge pump and the gain of the voltage-controlled oscillator; and subsequently operating the phase-locked loop with a feedback frequency division ratio set to a proper value for locking the output frequency to the desired frequency. 5. A method according to claim 4, wherein the first period is determined by counting a first predetermined number of comparison periods of the phase comparator. 6. A method according to claim 5, wherein said comparison periods are counted by counting reset pulses of the phase comparator. 7. A method according to claim 5, wherein the first predetermined number is one. 8. A method according to claim 7, wherein the conduction time of the charge pump is controlled by operating the phase-locked loop with a feedback frequency value set to an initial value N' given by the equation where N1is the original value of the output frequency division ratio before change of the output frequency, dF0is the desired change in output frequency, Ctis the overall capacitance of the loop filter, Kvcois the gain of the voltage-controlled oscillator, Kpdis the amplitude of the current output by the charge pump and tcompis the comparison period of the comparison frequency signal. 9. A method according to claim 5, wherein the first predetermined number is a plural number. 10. A method of according to claim 1, wherein the second period is determined by counting a second predetermined number of comparison periods of the phase comparator. 11. A method according to claim 10, wherein said comparison periods are counted by counting the reset pulses of the phase comparator. 12. A method of operating a phase-locked loop comprising: a charge pump; a phase comparator for controlling the charge pump to conduct for a time equal to the phase difference between a comparison frequency signal and feedback signal; a loop filter for filtering the output of the charge pump to output a control voltage; a voltage-controlled oscillator for outputting an output signal having a frequency controlled by the control voltage output from the loop filter; and a feedback loop for feeding back the output signal to the phase comparator as said feedback signal and including a feedback frequency divider for frequency dividing the output signal on the feedback loop, the method comprising changing the frequency of the output signal by: for a first period having a predetermined length, operating the phase-locked loop with a feedback frequency division ratio set to an initial value selected to control the conduction time of the charge pump to place an amount of charge on the loop filter during the first period sufficient to produce a control voltage for controlling the voltage-controlled oscillator to output an output signal substantially at the desired output frequency: and subsequently operating the phase-locked loop with a feedback frequency division ratio set to a proper value for locking the output frequency to the desired frequency, wherein the proper value and the initial value of the feedback frequency division ratio are stored in a main register and a shadow register, respectively, and the feedback frequency divider is set with the initial value from the shadow register during the first period and with the proper value from the main register subsequent a second period. 13. A phase-locked loop comprising: a charge p ump; a phase comparator for controlling the charge pump to conduct for a time equal to the phase difference between a comparison frequency signal and feedback signal; a loop filter for filtering the output of the charge pump to output a control voltage; a voltage-controlled oscillator for outputting an output signal having a frequency controlled by the control voltage output from the loop filter; and a feedback loop for feeding back the output signal to the phase comparator as said feedback signal and including a feedback frequency divider for frequency dividing the output signal on the feedback loop; wherein the phase-locked loop further comprises means for changing the frequency of the output signal to a desired frequency, comprising: means for controlling the conduction time of the charge pump during a first period having a predetermined length to place an amount of charge on the loop filter during the first period sufficient to produce a control voltage for controlling the voltage controlled oscillator to output an output signal substantially at the desired output frequency; means for setting the feedback frequency division ratio to a proper value such that subsequent operation of the phase-locked loop locks the output frequency to the desired frequency; and means for opening the feedback loop at the end of the first period for a second period to allow the control voltage output from the loop filter to settle and subsequently closing the feedback loop. 14. A phase-locked loop according to claim 13, wherein the charge pump has a predetermined output amplitude. 15. A phase-locked loop according to claim 13, wherein dynamics of the loop filter are maintained constant. 16. A phase-locked loop according to claim 13, wherein the means for opening and closing the feedback loop comprises means for enabling and disabling the charge pump. 17. A phase locked loop comprising: a charge pump; a phase comparator for controlling the charge pump to conduct for a time equal to the phase difference between a comparison frequency signal and feedback signal; a loop filter for filtering the output of the charge pump to output a control voltage; a voltage-controlled oscillator for outputting an output signal having a frequency controlled by the control voltage output from the loop filter; and a feedback loop for feeding back the output signal to the phase comparator as said feedback signal and including a feedback frequency divider for frequency dividing the output signal on the feedback loop, wherein the phase-locked loop further comprises means for changing the frequency of the output signal to a desired frequency, comprising: means for setting the feedback frequency division ratio to an initial value during a first period having a predetermined length, the initial value being selected to control the conduction time of the charge pump to place an amount of charge on the loop filter during the first period sufficient to produce a control voltage for controlling the voltage-controlled oscillator to output an output signal substantially at the desired output frequency; and means for setting the feedback frequency division ratio to a proper value such that subsequent operation of the phase-locked loop locks the output frequency to the desired frequency, wherein said means for setting the feedback frequency division ratio includes a shadow register for storing the initial value controlled to supply the initial value to the feedback frequency divider during the first period. 18. A phase-locked loop according to claim 13, wherein the means for controlling is selectively operable during the first period either to perform said control of the conduction time of the charge pump by setting the feedback frequency division ratio to the initial value or to set the feedback frequency division ratio to said proper value. 19. A phase-locked loop comprising: a charge pump; a phase comparator for controlling the charge pump to