JP2013251071A - Signal measurement device, signal measurement method, program, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the state of a chamber which generates a plasma.SOLUTION: A signal measurement device 1 includes: mixers 14, 24 for outputting a signal of frequency equal to the difference of the frequency of two inputs; a local signal source 12 for giving a common local signal input to the mixers 14, 24; an error measurement part 54 for measuring a level difference and a phase difference between the outputs of the mixers 14, 24 when a common correction signal input is given to the mixers 14, 24; an impedance measurement part 62 for measuring output ratios of the mixers 14, 24 when a measured signal input having a common frequency is given to the mixers 14, 24; and an error correction part 56 for correcting measurement results of the impedance measurement part 62 on the basis of the measurement results of the error measurement part 54. A progressive wave given to an electrode 6a in a plasma chamber 6 in which a plasma is generated and a reflected wave which the progressive wave is reflected from the plasma chamber 6 are determined as the measured signal input.

Description

  The present invention relates to measuring conditions in a chamber that generates plasma.

  Conventionally, it is known to generate plasma in a chamber (see, for example, Patent Documents 1 to 4). Further, it is known to measure a high-frequency signal (for example, refer to Patent Document 5) although it is not related to plasma.

JP 2002-33310 A Japanese Patent Laid-Open No. 10-185960 JP 2005-350683 A JP 2002-176034 A JP 2004-151065 A

  An object of the present invention is to measure the state of a chamber that generates plasma.

  A signal measuring apparatus according to the present invention includes a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies, a single local signal source that provides a common local signal input to the plurality of mixers, An error measuring unit for measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers, and a signal under test input having a frequency common to the plurality of mixers. An output ratio measuring unit that measures the ratio of the outputs of the plurality of mixers when given, and an error correcting unit that corrects the measurement result of the output ratio measuring unit based on the measurement result of the error measuring unit. The traveling wave applied to the electrode in the plasma chamber where the plasma is generated and the reflected wave reflected from the plasma chamber are used as the signal to be measured.

  According to the signal measuring apparatus configured as described above, the plurality of mixers output signals having a frequency equal to the difference between the frequencies of the two inputs. A single local signal source provides a common local signal input to the plurality of mixers. The error measuring unit measures a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers. The output ratio measuring unit measures the ratio of the outputs of the plurality of mixers when the signal under measurement having a common frequency is given to the plurality of mixers. The error correction unit corrects the measurement result of the output ratio measurement unit based on the measurement result of the error measurement unit. A traveling wave given to an electrode in a plasma chamber in which plasma is generated and a reflected wave obtained by reflecting the traveling wave from the plasma chamber are used as the signal to be measured.

  A signal measuring apparatus according to the present invention includes a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies, a single local signal source that provides a common local signal input to the plurality of mixers, An error measuring unit for measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers, and a signal under test input having a frequency common to the plurality of mixers. When given, an efficiency measuring unit that measures the efficiency of the signal input under measurement based on the phase difference between the outputs of the plurality of mixers, and the measurement result of the efficiency measuring unit is corrected based on the measurement result of the error measuring unit And an error correction unit configured to input a voltage to be applied to an electrode in a plasma chamber in which plasma is generated and a current flowing through the electrode as the signal to be measured.

  According to the signal measuring apparatus configured as described above, the plurality of mixers output signals having a frequency equal to the difference between the frequencies of the two inputs. A single local signal source provides a common local signal input to the plurality of mixers. The error measuring unit measures a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers. The efficiency measuring unit measures the efficiency of the measured signal input based on the phase difference between the outputs of the plurality of mixers when the measured signal input having a common frequency is given to the plurality of mixers. The error correction unit corrects the measurement result of the efficiency measurement unit based on the measurement result of the error measurement unit. The voltage applied to the electrode in the plasma chamber where plasma is generated and the current flowing through the electrode are used as the signal under measurement input.

  The signal measuring apparatus according to the present invention may include an amplitude measuring unit that measures the amplitudes of the outputs of the plurality of mixers when the measured signal input is given to the plurality of mixers.

  In the signal measuring apparatus according to the present invention, the error measuring unit measures the level difference and the phase difference in association with the frequency of the local signal input, and the error correcting unit is configured to detect the local signal input. Correction may be performed according to the frequency.

  In the signal measuring apparatus according to the present invention, the error correction unit may perform correction based on an interpolation of the measurement result of the error measurement unit with respect to the frequency of the local signal input.

  The signal measuring apparatus according to the present invention is supplied with the local signal input and the intermediate frequency signal input, and outputs a signal having a frequency equal to the sum of the frequencies of the local signal input and the intermediate frequency signal input as the correction signal. A correction signal mixer may be provided.

  The present invention includes a plurality of mixers that output a signal having a frequency equal to a frequency difference between two inputs, a single local signal source that provides a common local signal input to the plurality of mixers, and a frequency that is supplied to the plurality of mixers. An output ratio measuring unit that measures a ratio of outputs of the plurality of mixers when a common signal input to be measured is given, and the plurality of mixers when a common signal input is given to the plurality of mixers There is no level difference or phase difference between the outputs of the mixer, and a traveling wave given to an electrode in the plasma chamber in which plasma is generated and a reflected wave in which the traveling wave is reflected from the plasma chamber are input to the signal under measurement. It is a signal measuring device.

  The present invention includes a plurality of mixers that output a signal having a frequency equal to a frequency difference between two inputs, a single local signal source that provides a common local signal input to the plurality of mixers, and a frequency that is supplied to the plurality of mixers. And an efficiency measuring unit that measures the efficiency of the signal input under measurement based on the phase difference between the outputs of the plurality of mixers when a common signal input under measurement is provided, and a signal common to the plurality of mixers There is no level difference or phase difference between the outputs of the plurality of mixers when an input is given, and a voltage applied to an electrode in a plasma chamber in which plasma is generated and a current flowing through the electrode are measured signal It is a signal measuring device as an input.

  The present invention relates to a signal measuring apparatus including a plurality of mixers that output a signal having a frequency equal to a difference between frequencies of two inputs, and a single local signal source that provides a common local signal input to the plurality of mixers. A signal measurement method for performing signal measurement processing, wherein when a common correction signal input is given to the plurality of mixers, an error measurement step of measuring a level difference and a phase difference between outputs of the plurality of mixers; An output ratio measuring step for measuring a ratio of outputs of the plurality of mixers when a signal input to be measured having a common frequency is supplied to the plurality of mixers; and the output ratio measuring step based on a measurement result of the error measuring step. An error correction step for correcting the measurement result of the traveling wave, a traveling wave applied to an electrode in the plasma chamber in which plasma is generated, and a reaction wave reflected from the plasma chamber. Wherein the wave is a signal measurement method according to the measured signal input.

  The present invention relates to a signal measuring apparatus including a plurality of mixers that output a signal having a frequency equal to a difference between frequencies of two inputs, and a single local signal source that provides a common local signal input to the plurality of mixers. A signal measurement method for performing signal measurement processing, wherein when a common correction signal input is given to the plurality of mixers, an error measurement step of measuring a level difference and a phase difference between outputs of the plurality of mixers; An efficiency measuring step of measuring the efficiency of the measured signal input based on a phase difference between the outputs of the plurality of mixers when a measured signal input having a common frequency is applied to the plurality of mixers; and measurement of the error measuring step An error correction step of correcting the measurement result of the efficiency measurement step based on the result, and a voltage applied to an electrode in the plasma chamber in which plasma is generated and an electric current flowing through the electrode. Wherein the door is a signal measurement method according to the measured signal input.

  The present invention relates to a signal measuring apparatus including a plurality of mixers that output a signal having a frequency equal to a difference between frequencies of two inputs, and a single local signal source that provides a common local signal input to the plurality of mixers. A program for causing a computer to execute signal measurement processing, wherein the signal measurement processing includes a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers. An error measurement step of measuring the output of the plurality of mixers when a signal under test having a common frequency is applied to the plurality of mixers, and a measurement of the error measurement step An error correction step of correcting the measurement result of the output ratio measurement step based on the result, a traveling wave applied to the electrode in the plasma chamber in which plasma is generated, The row wave and reflected wave reflected from the plasma chamber is a program for the signal to be measured input.

  The present invention relates to a signal measuring apparatus including a plurality of mixers that output a signal having a frequency equal to a difference between frequencies of two inputs, and a single local signal source that provides a common local signal input to the plurality of mixers. A program for causing a computer to execute signal measurement processing, wherein the signal measurement processing includes a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers. And an error measurement step for measuring the efficiency of the measured signal input based on the phase difference of the outputs of the plurality of mixers when the measured signal input having a common frequency is applied to the plurality of mixers. A plasma chamber in which plasma is generated, and an error correction step of correcting the measurement result of the efficiency measurement step based on the measurement result of the error measurement step A voltage applied to the electrodes, and a current flowing through the electrode a program to the measured signal input.

  The present invention relates to a signal measuring apparatus including a plurality of mixers that output a signal having a frequency equal to a difference between frequencies of two inputs, and a single local signal source that provides a common local signal input to the plurality of mixers. A computer-readable recording medium storing a program for causing a computer to execute signal measurement processing, wherein the signal measurement processing is performed when the plurality of mixers are given a common correction signal input. An error measurement step for measuring a level difference and a phase difference between the outputs of the mixers, and an output ratio for measuring a ratio of the outputs of the plurality of mixers when a signal under test having a common frequency is given to the plurality of mixers A plasma is generated, comprising: a measurement process; and an error correction process for correcting the measurement result of the output ratio measurement process based on the measurement result of the error measurement process. That the electrode traveling wave given to the plasma chamber, which is a recording medium in which the traveling wave and the signal to be measured input and reflected reflected wave from the plasma chamber.

  The present invention relates to a signal measuring apparatus including a plurality of mixers that output a signal having a frequency equal to a difference between frequencies of two inputs, and a single local signal source that provides a common local signal input to the plurality of mixers. A computer-readable recording medium storing a program for causing a computer to execute signal measurement processing, wherein the signal measurement processing is performed when the plurality of mixers are given a common correction signal input. An error measuring step for measuring a level difference and a phase difference between the outputs of the mixers, and when a signal under test having a common frequency is given to the plurality of mixers, Based on the measurement result of the efficiency measurement step for measuring the efficiency of the measurement signal input and the error measurement step, error correction for correcting the measurement result of the efficiency measurement step Comprising the steps, and a voltage plasma is applied to the electrodes in the plasma chamber for generating is a current flowing through the electrode a recording medium according to the measured signal input.

It is a functional block diagram which shows the structure of the signal measuring apparatus 1 concerning 1st embodiment of this invention. It is a functional block diagram which shows a structure when a correction signal is given to the signal measuring apparatus 1 concerning 1st embodiment of this invention. It is a figure which shows an example of the measurement of the level difference between the outputs of the several mixers 14 and 24 when a common correction signal input is given to the several mixers 14 and 24. FIG. Output level differences ΔLv1 to _ΔLv3 interpolated with respect to the frequency f _Lo1 of the local signal input when a common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 4A) and output phase difference It is a figure which shows what interpolated ( _{DELTA) P1-} ( _{DELTA) P3} about local signal input frequency _fLo1 (refer _FIG.4 (b)). It is a functional block diagram showing composition when a signal under measurement is given to signal measuring device 1 concerning a first embodiment of the present invention. It is a figure for demonstrating the to-be-measured signal input in 1st embodiment of this invention. It is a functional block diagram which shows the structure of the signal measuring apparatus 1 concerning 2nd embodiment of this invention. It is a functional block diagram which shows a structure when a to-be-measured signal is given to the signal measuring apparatus 1 concerning 2nd embodiment of this invention. It is a figure for demonstrating the to-be-measured signal input in 2nd embodiment of this invention. It is a figure which shows the signal measuring apparatus 1 concerning 3rd embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

First Embodiment FIG. 1 is a functional block diagram showing a configuration of a signal measuring apparatus 1 according to a first embodiment of the present invention. The signal measuring device 1 includes a first terminal 11, a second terminal 21, an output terminal 31, a first local signal source 12, a first mixer 14, a first A / D converter 16, a first level / phase measuring unit 18, Second local signal source 22, second mixer 24, second A / D converter 26, second level / phase measurement unit 28, intermediate frequency signal source 32, correction signal mixer 34, switches 42 and 44, local frequency setting Unit 52, error measurement unit 54, error correction unit 56, and impedance measurement unit (output ratio measurement unit) 62. The signal measuring device 1 is, for example, a spectrum analyzer.

  FIG. 2 is a functional block diagram showing a configuration when a correction signal is given to the signal measuring apparatus 1 according to the first embodiment of the present invention. FIG. 5 is a functional block diagram showing a configuration when a signal under measurement is given to the signal measuring apparatus 1 according to the first embodiment of the present invention.

  Referring to FIG. 2, distributor 4 provides a correction signal to first terminal 11 and second terminal 21. The distributor 4 may be built in the signal measuring device 1. Referring to FIG. 5, traveling wave and reflected wave (measurement signal input) are applied to first terminal 11 and second terminal 21, respectively.

  FIG. 6 is a diagram for explaining the signal under measurement input in the first embodiment of the present invention. The signal measuring apparatus 1 according to the first embodiment of the present invention is intended for measurement of a plasma apparatus.

  A traveling wave from the high frequency power source 2 (frequency is, for example, 2.4 GHz) is applied to the electrode 6 a in the plasma chamber 6 through the matcher 4. The matcher 4 is for impedance matching between the high-frequency power source 2 side (impedance is about 50Ω) and the plasma chamber 6 side (impedance is much lower than 50Ω). In the plasma chamber 6, an electrode 6b (grounded) is also arranged. Plasma is generated in the plasma chamber 6. Plasma is generated between the electrodes 6a and 6b. The semiconductor 7 placed on the electrode 6b is processed by plasma. However, abnormal discharge may occur in the plasma chamber 6, and in such a case, the semiconductor 7 is damaged. When abnormal discharge occurs in the plasma chamber 6, harmonics are generated in the traveling wave and the reflected wave, and these are the measurement targets of the signal measuring device 1.

  The signal measuring device 1 receives a traveling wave from a directional coupler 3 disposed between the high-frequency power source 2 and the matcher 4 and a reflected wave in which the traveling wave is reflected from the plasma chamber 6. The traveling wave is given to the first terminal 11 of the signal measuring device 1. The reflected wave is given to the second terminal 21 of the signal measuring device 1. The traveling wave and the reflected wave are input to the signal under measurement. The traveling wave and the reflected wave have the same frequency.

  The first terminal (CH1: channel 1) 11 supplies a traveling wave (see FIG. 5) or a correction signal (see FIG. 2) given from the distributor 4 to the first mixer. The second terminal (CH2: channel 2) 21 supplies the reflected wave (see FIG. 5) or the correction signal (see FIG. 2) given from the distributor 4 to the second mixer 24.

  The output terminal 31 outputs a correction signal. The output terminal 31 is connected to the distributor 4 (see FIG. 2).

  The first mixer 14 outputs a signal having a frequency equal to the difference between the frequencies of two inputs (R input and L input) (I output). However, the R input is supplied from the first terminal 11 and the L input is supplied from the first local signal source 12. R input, L input, and I output mean Radio Frequency input, Local input, and Intermediate Frequency output, respectively.

  The second mixer 24 outputs a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) (I output). However, the R input is supplied from the second terminal 21 and the L input is supplied from the first local signal source 12. The meanings of the R input, the L input, and the I output are the same as those of the first mixer 14.

The first local signal source 12 is a single local signal source that provides a common local signal input to the L inputs of the plurality of mixers 14 and 24 (see FIGS. 2 and 5). Note that the frequency f _{Lo1 of the} local signal is variable, that is, can be swept.

  The first A / D converter 16 receives the I output (analog signal) of the first mixer 14 and converts it into a digital signal. The second A / D converter 26 receives the I output (analog signal) of the second mixer 24 and converts it into a digital signal.

  The first level / phase measurement unit 18 provides the first mixer when a plurality of mixers 14 and 24 are supplied with a signal under measurement (see FIG. 5) having a common frequency or a common correction signal input (see FIG. 2). Measure the level and phase of the 14 outputs. The measurement result of the first mixer 14 is given to the error measurement unit 54 (see FIG. 2) or given to the impedance measurement unit 62 (see FIG. 5).

  Referring to FIG. 5, the first level / phase measuring unit (amplitude measuring unit) 18 measures the amplitude of the output of the first mixer 14 and outputs it to the outside of the signal measuring device 1. For example, the amplitude of the output of the first mixer 14 is displayed.

  The second level / phase measurement unit 28 provides the second mixer when the measured signal input (see FIG. 5) or the common correction signal input (see FIG. 2) having the same frequency is given to the plurality of mixers 14 and 24. Measure the level and phase of the 24 outputs. The measurement result of the second mixer 24 is given to the error measuring unit 54 (see FIG. 2) or given to the impedance measuring unit 62 (see FIG. 5).

  Referring to FIG. 5, the second level / phase measuring unit (amplitude measuring unit) 28 measures the amplitude of the output of the second mixer 24 and outputs it to the outside of the signal measuring apparatus 1. For example, the amplitude of the output of the second mixer 24 is displayed.

  The first level / phase measurement unit 18 and the second level / phase measurement unit 28 are implemented by, for example, a DSP (Digital Signal Processor).

  The second local signal source 22 is a signal source that can be swept (variable in frequency).

  The intermediate frequency signal source 32 provides an intermediate frequency signal input to the correction signal mixer 34. The intermediate frequency signal may be a signal similar to the signal under measurement, or may be a pulse, a continuous wave (frequency may be swept), a modulated signal, or noise.

  The correction signal mixer 34 is supplied with a local signal input (L input) and an intermediate frequency signal input (I input). Further, the correction signal mixer 34 outputs a signal having a frequency equal to the sum of the frequencies of the local signal input and the intermediate frequency signal input as a correction signal (R output). The local signal input (L input) is supplied from the first local signal source 12 via the switch 42. The intermediate frequency signal input (I input) is supplied from the intermediate frequency signal source 32. The correction signal is given to the output terminal 31.

  However, R output, L input, and I input mean Radio Frequency output, Local (local) input, and Intermediate Frequency input (intermediate frequency), respectively.

  The switch 42 is a switch for switching whether the first local signal source 12 is connected to the correction signal mixer 34 (see FIG. 2) or not (see FIG. 5).

  The switch 44 is a switch that connects the second mixer 24 to the single local signal source 12 (see FIGS. 2 and 5) or the second local signal source 22.

The local frequency setting unit 52 sets f _Lo1 that is the frequency of the first local signal source 12.

  The error measurement unit 54 outputs the level and phase of the output of the first mixer 14 from the first level / phase measurement unit 18 when a common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 2). Then, the level and phase of the output of the second mixer 24 are received from the second level / phase measurement unit 28.

  Further, the error measurement unit 54 is configured to provide a common correction signal input to the plurality of mixers 14 and 24 based on the measurement results received from the first level / phase measurement unit 18 and the second level / phase measurement unit 28. (See FIG. 2), the level difference and phase difference between the outputs of the plurality of mixers 14, 24 are measured.

The error measuring unit 54 calculates the level difference and phase difference between the outputs of the plurality of mixers 14 and 24 when the common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 2). _Measured in association with frequency f _Lo1 .

  FIG. 3 is a diagram showing an example of the measurement of the level difference and the phase difference between the outputs of the plurality of mixers 14 and 24 when a common correction signal input is given to the plurality of mixers 14 and 24.

The error measurement unit 54 receives from the first level / phase measurement unit 18 the output level of the first mixer 14 (CH1) when the frequency f _Lo1 of the local signal input is f ₁ . In addition, the error measurement unit 54 receives the output level of the second mixer 24 (CH2) from the second level / phase measurement unit 28 when the frequency f _Lo1 of the local signal input is f ₁ . Further, the error measuring unit 54 calculates (ΔLv1) and records the difference (CH2−CH1) between the two output levels. The error measurement unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₁ . The error measurement unit 54 records ΔLv1 in association with f ₁ .

Similarly, the error measurement section 54 calculates the difference between the output levels of both when the frequency f _Lo1 of the local signal input is _{f 2 (CH2-CH1) (} ΔLv2), is recorded. The error measuring unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₂ . Error measuring section 54 records the ΔLv2 in association with f _2.

Further, the error measurement section 54 calculates the difference between the output levels of both when the frequency f _Lo1 of the local signal input is _{f 3 (CH2-CH1) (} ΔLv3), is recorded. The error measuring unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₃ . Error measuring section 54 records the ΔLv3 in association with f _3.

For example, f ₃ −f ₂ = f ₂ −f ₁ and f ₃ > f ₂ > f ₁ .

The error measurement unit 54 receives from the first level / phase measurement unit 18 the output phase of the first mixer 14 (CH1) when the frequency f _Lo1 of the local signal input is f ₁ . Moreover, the error measurement unit 54 receives the output phase of the second mixer 24 (CH2) from the second level / phase measurement unit 28 when the local signal input frequency f _Lo1 is f ₁ . Further, the error measurement unit 54 obtains (ΔP1) and records the difference (CH2−CH1) between the two output phases. The error measurement unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₁ . The error measurement unit 54 records ΔP1 in association with f ₁ .

Similarly, the error measurement section 54 calculates the difference between the output phase when the frequency f _Lo1 of the local signal input is _{f 2 (CH2-CH1) (} ΔP2), is recorded. The error measuring unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₂ . Error measuring section 54 records the ΔP2 in association with f _2.

Further, the error measurement section 54 calculates the difference between the output phase when the frequency f _Lo1 of the local signal input is _{f 3 (CH2-CH1) (} ΔP3), is recorded. The error measuring unit 54 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₃ . Error measuring section 54 records the ΔP3 in association with f _3.

  The impedance measuring unit (output ratio measuring unit) 62 (see FIG. 5) measures the ratio of the outputs of the plurality of mixers 14 and 24 when the measured signals having the same frequency are supplied to the plurality of mixers 14 and 24. To do.

  The impedance measurement unit 62 gives the first measurement result of the output (electric field) of the first mixer 14 (CH1) when the measured signal input having a common frequency is given to the plurality of mixers 14 and 24 (see FIG. 5). The level / phase measurement unit 18 receives the measurement result of the output (electric field) of the second mixer 24 (CH 2) from the second level / phase measurement unit 28.

  Further, the impedance measuring unit 62 measures and outputs the ratio between the output of the first mixer 14 (CH1) and the output of the second mixer 24 (CH2). The output (having amplitude and phase) of the mixer 14 represents a traveling wave, and the output (having amplitude and phase) of the mixer 24 represents a reflected wave. The impedance measuring unit 62 calculates (traveling wave) / (reflected wave), which means that impedance is being measured.

The error correction unit 56 corrects the measurement result of the impedance measurement unit 62 according to the frequency f _Lo1 of the local signal input based on the measurement result of the error measurement unit 54 (see FIG. 5).

For example, the error correction unit 56 acquires from the local frequency setting unit 52 that the frequency f _Lo1 of the local signal input is f ₁ . Further, the error correction unit 56 reads out the output level difference ΔLv 1 and the output phase difference ΔP ₁ associated with f ₁ from the error measurement unit 54. The error correction unit 56 corrects the measurement result of the impedance measurement unit 62 by providing ΔLv1 and ΔP1 to the impedance measurement unit 62. For example, when the impedance measuring unit 62 measures the ratio between the output of the first mixer 14 (CH1) and the output of the second mixer 24 (CH2), the level [dBm] of the output of the second mixer 24 (CH2). And the phase [rad] is reduced by ΔLv1 and ΔP1.

Similar correction is performed when the frequency f _Lo1 of the local signal input is f ₂ or f ₃ .

However, when the frequency f _Lo1 of the local signal input is not any of f ₁ , f ₂ and f ₃ , the measurement result of the impedance measuring unit 62 cannot be corrected by the above method. In such a case, the error correction unit 56 corrects the measurement result of the impedance measurement unit 62 based on the measurement result of the error measurement unit 54 interpolated with respect to the frequency f _Lo1 of the local signal input.

FIG. 4 shows an output level difference ΔLv1 to _ΔLv3 interpolated with respect to the frequency f _Lo1 of the local signal input when a common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 4A) and It is a figure which shows what interpolated the difference (DELTA) P1-ΔP3 of output phase about the frequency fLo1 of local signal input (refer _FIG.4 (b)).

  In FIG. 4, the output level and the output phase are interpolated by a linear function as an example. The result obtained by interpolating the output level and the output phase is recorded in the error measurement unit 54.

The error correction unit 56 _acquires the value of the frequency f _Lo1 of the local signal input from the local frequency setting unit 52. The error correction unit 56 obtains an output level difference and an output phase difference corresponding to this value from the interpolation result (see FIG. 4A and FIG. 4B), and provides the result to the impedance measurement unit 62. Thus, the measurement result of the impedance measuring unit 62 is corrected.

  Next, the operation of the first embodiment of the present invention will be described.

(1) Input of correction signal (see Fig. 2)
First, referring to FIG. 2, a correction signal is given to the signal measuring apparatus 1.

A switch 42 connects the first local signal source 12 to the L input of the correction signal mixer 34. Here, the local frequency setting unit 52 sets the frequency f _Lo1 of the first local signal source 12. Then, the local signal input (L input) is supplied from the first local signal source 12 to the correction signal mixer 34. In addition, an intermediate frequency signal input (I input) is supplied from the intermediate frequency signal source 32 to the correction signal mixer 34.

  Then, a signal having a frequency equal to the sum of the frequencies of the local signal input and the intermediate frequency signal input is output from the correction signal mixer 34 as a correction signal (R output). The correction signal is output from the output terminal 31 and given to the distributor 4. The distributor 4 gives a correction signal to the first terminal 11 and the second terminal 21.

  Here, the switch 44 connects the second mixer 24 to the single local signal source 12.

  The correction signal given to the first terminal (CH1) 11 is given to the R input of the first mixer 14. A local signal input from the local signal source 12 is given to the L input of the first mixer 14. Then, a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) is output from the first mixer 14 (I output). The frequency of the I output is the frequency of the intermediate frequency signal output from the intermediate frequency signal source 32.

  The I output (analog signal) of the first mixer 14 is converted into a digital signal by the first A / D converter 16 and supplied to the first level / phase measurement unit 18. The first level / phase measurement unit 18 measures the level and phase of the output of the first mixer 14, and provides them to the error measurement unit 54.

  The correction signal given to the second terminal (CH2) 21 is given to the R input of the second mixer 24. A local signal input from the local signal source 12 is given to the L input of the second mixer 24. Then, a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) is output from the second mixer 24 (I output). The frequency of the I output is the frequency of the intermediate frequency signal output from the intermediate frequency signal source 32.

  The I output (analog signal) of the second mixer 24 is converted into a digital signal by the second A / D converter 26 and supplied to the second level / phase measurement unit 28. The second level / phase measurement unit 28 measures the level and phase of the output of the second mixer 24, and provides them to the error measurement unit 54.

  The first level / phase measurement unit 18 and the second level / phase measurement unit 28 measure the output level (power level). Since the power is proportional to the square of the amplitude, the amplitude is measured. It can be said that Note that the amplitude of the harmonic in the correction signal can be measured by analyzing the measured amplitude with a spectrum analyzer.

The local frequency setting unit 52 gives the error measurement unit 54 the value of the local signal input frequency f _Lo1 .

  Since the same correction signal is given to both the first mixer 14 and the second mixer 24, the output level and output phase, which are the measurement results of the first level / phase measurement unit 18, and the second level / phase measurement unit 28. Ideally, the output level and the output phase, which are measurement results, are equal.

  However, in reality, the same correction signal is given to both the first mixer 14 and the second mixer 24, but the output level and output phase, which are the measurement results of the first level / phase measurement unit 18, The output level and the output phase which are the measurement results of the second level / phase measurement unit 28 are different. Actually, there is a difference between the electrical length and attenuation of the electrical circuit from the local signal source 12 to the first mixer 14 and the electrical length and attenuation of the electrical circuit from the local signal source 12 to the second mixer 24. It is.

The error measurement unit 54 provides level differences ΔLv1 to ΔLv3 and phase differences ΔP1 to ΔP3 between outputs of the plurality of mixers 14 and 24 when a common correction signal input is given to the plurality of mixers 14 and 24 (see FIG. 2). _Is measured in association with the frequency f _Lo1 of the local signal input (see FIG. 3).

  The level difference between the outputs of the plurality of mixers 14 and 24 is the difference between the output level that is the measurement result of the first level / phase measurement unit 18 and the output level that is the measurement result of the second level / phase measurement unit 28. It is a difference.

  Further, the phase difference between the outputs of the plurality of mixers 14 and 24 is the difference between the output phase that is the measurement result of the first level / phase measurement unit 18 and the output phase that is the measurement result of the second level / phase measurement unit 28. It is a difference.

The error measuring unit 54 interpolates the output level differences ΔLv1 to ΔLv3 with respect to the local signal input frequency f _Lo1 (see FIG. 4A) and the output phase differences ΔP1 to ΔP3 with respect to the local signal input frequency f _Lo1 . The interpolated one (see FIG. 4B) is obtained and recorded.

(2) Input signal under measurement (see Fig. 5)
Next, referring to FIG. 5, a signal under measurement is given to the signal measuring device 1.

  First, referring to FIG. 6, the directional coupler 3 is connected to the first terminal 11 and the second terminal 21. Then, measured signals (traveling waves and reflected waves) are applied to the first terminal 11 and the second terminal 21, respectively.

  Here, the switch 44 connects the second mixer 24 to the single local signal source 12.

  The signal under measurement (traveling wave) given to the first terminal (CH 1) 11 is given to the R input of the first mixer 14. A local signal input from the local signal source 12 is given to the L input of the first mixer 14. Then, a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) is output from the first mixer 14 (I output).

  The I output (analog signal) of the first mixer 14 is converted into a digital signal by the first A / D converter 16 and supplied to the first level / phase measurement unit 18. The first level / phase measurement unit 18 measures the amplitude and phase of the output of the first mixer 14 and outputs the result to the impedance measurement unit 62. The first level / phase measurement unit 18 measures the output level (power level), but it can be said that the power is proportional to the square of the amplitude, and therefore measures the amplitude. In addition, the amplitude of the harmonic in the signal under measurement (traveling wave) can be measured by analyzing the measured amplitude by FFT and extracting the harmonic component.

  The signal under measurement (reflected wave) given to the second terminal (CH 2) 21 is given to the R input of the second mixer 24. A local signal input from the local signal source 12 is given to the L input of the second mixer 24. Then, a signal having a frequency equal to the difference between the frequencies of the two inputs (R input and L input) is output from the second mixer 24 (I output).

  The I output (analog signal) of the second mixer 24 is converted into a digital signal by the second A / D converter 26 and supplied to the second level / phase measurement unit 28. The second level / phase measurement unit 28 measures the amplitude and phase of the output of the second mixer 24 and outputs the result to the impedance measurement unit 62. The second level / phase measurement unit 28 measures the output level (power level), but the power is proportional to the square of the amplitude, and thus can be said to measure the amplitude. In addition, the amplitude of the harmonic in the signal under measurement (reflected wave) can be measured by analyzing the measured amplitude by FFT and extracting the harmonic component.

Further, the error correction unit 56 _acquires the value of the frequency f _Lo1 of the local signal input from the local frequency setting unit 52. Further, the error correction unit 56 reads out from the error measurement unit 54 the difference in output level and the difference in output phase corresponding to the value of the frequency f _Lo1 of the local signal input.

If the value of the frequency f _Lo1 of the local signal input is any one of f ₁ , f _2, and f ₃ , the error correction unit 56 is one of the actual measurement values ΔLv1 to ΔLv3 of the error measurement unit 54 and ΔP1 to ΔP3. Any one (see FIG. 3) may be read.

When the frequency f _Lo1 of the local signal input is not any of f ₁ , f ₂ and f ₃ , the error correction unit 56 calculates the difference in output level and output phase corresponding to the frequency f _Lo1 of the local signal input. From the interpolation result recorded in the error measurement unit 54 (see FIGS. 4A and 4B).

  The error correcting unit 56 gives the read output level difference and output phase difference to the impedance measuring unit 62. Then, the impedance measuring unit 62 corrects the measurement result (impedance = (transmitted wave) / (reflected wave)) of the impedance measuring unit 62 according to the value given from the error correcting unit 56.

  Thereby, there is a difference between the electrical length and attenuation of the electrical circuit from the local signal source 12 to the first mixer 14 and the electrical length and attenuation of the electrical circuit from the local signal source 12 to the second mixer 24. An error between the measurement results of the first level / phase measurement unit 18 and the second level / phase measurement unit 28 can be corrected.

  However, if there is no level difference or phase difference between the outputs of the first mixer 14 and the second mixer 24 when a common signal input is given to both the first mixer 14 and the second mixer 24, error correction is performed. Correction by the unit 56 is unnecessary.

  According to the first embodiment of the present invention, impedance = (transmitted wave) / (reflected wave) can be derived.

  In addition, the output of a single local signal source 12 is used as a local signal in the signal measuring apparatus 1 having a plurality of channels (CH1, CH2). For this reason, since the phase fluctuation of the local signal in each channel is common, the phase mismatch of the local signal can be reduced.

Furthermore, there is a difference between the electrical length and attenuation of the electrical circuit from the local signal source 12 to the first mixer 14 and the electrical length and attenuation of the electrical circuit from the local signal source 12 to the second mixer 24. The error between the measurement results of the first level / phase measurement unit 18 and the second level / phase measurement unit 28 is recorded in the error measurement unit 54 in association with the value of the frequency f _Lo1 of the local signal input. The error is corrected by the error correction unit 56 and supplied to the impedance measurement unit 62 to correct the measurement result.

Second Embodiment The signal measuring apparatus 1 according to the second embodiment is different from the first embodiment in that an efficiency measuring unit 64 is provided instead of the impedance measuring unit (output ratio measuring unit) 62.

  FIG. 7 is a functional block diagram showing the configuration of the signal measuring apparatus 1 according to the second embodiment of the present invention. The signal measuring device 1 includes a first terminal 11, a second terminal 21, an output terminal 31, a first local signal source 12, a first mixer 14, a first A / D converter 16, a first level / phase measuring unit 18, Second local signal source 22, second mixer 24, second A / D converter 26, second level / phase measurement unit 28, intermediate frequency signal source 32, correction signal mixer 34, switches 42 and 44, local frequency setting Unit 52, error measurement unit 54, error correction unit 56, and efficiency measurement unit 64. The signal measuring device 1 is, for example, a spectrum analyzer.

  Hereinafter, the same parts as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  FIG. 9 is a diagram for explaining a signal under measurement input according to the second embodiment of the present invention. The signal measuring apparatus 1 according to the second embodiment of the present invention is intended for measurement of a plasma apparatus. Portions similar to those in FIG. 6 are assigned the same numbers as in FIG.

  The signal measuring apparatus 1 receives a voltage V applied to an electrode 6a in the plasma chamber 6 from a VI probe 5 disposed between the matcher 4 and the plasma chamber 6, and a current I flowing through the electrode 6a. The voltage V is applied to the first terminal 11 of the signal measuring device 1. The current I is given to the second terminal 21 of the signal measuring device 1. The voltage V and the current I are the signal under measurement input. Voltage V and current I have the same frequency.

  FIG. 8 is a functional block diagram showing a configuration when a signal under measurement is given to the signal measuring apparatus 1 according to the second embodiment of the present invention.

  The first terminal (CH1: channel 1) 11 supplies the voltage V (see FIG. 8) or the correction signal (see FIG. 2) given from the distributor 4 to the first mixer 14. The second terminal (CH2: channel 2) 21 supplies a current I (see FIG. 8) or a correction signal (see FIG. 2) given from the distributor 4 to the second mixer 24.

  The efficiency measuring unit 64 (see FIG. 8), when the measured signal input having a common frequency is applied to the plurality of mixers 14 and 24, the phase difference between the outputs (voltage V and current I) of the plurality of mixers 14 and 24. Is used to measure the efficiency of the signal under test input (voltage V, current I).

  The efficiency of the signal under test input (voltage V, current I) is also called power factor. If the phase difference between the outputs of the plurality of mixers 14 and 24 is φ, cos φ is obtained.

  The efficiency measurement unit 64 outputs the measurement result of the output of the first mixer 14 (CH1) when the measured signal input having a common frequency is given to the plurality of mixers 14 and 24 (see FIG. 5). The measurement result is received from the measurement unit 18 and the measurement result of the output of the second mixer 24 (CH 2) is received from the second level / phase measurement unit 28.

  Furthermore, the efficiency measuring unit 64 measures the output of the first mixer 14 (CH1), the output of the second mixer 24 (CH2), and the phase difference φ, and outputs the efficiency (power factor) cos φ.

  Next, the operation of the second embodiment of the present invention is the same as the operation of the first embodiment, except that the impedance measurement unit (output ratio measurement unit) 62 is replaced with the efficiency measurement unit 64, and the description will be made. Is omitted.

  According to the second embodiment of the present invention, the efficiency (power factor) between the voltage V applied to the electrode 6a in the plasma chamber 6 and the current I flowing through the electrode 6a can be derived. Other effects are the same as those of the first embodiment.

Third Embodiment The third embodiment of the present invention is a combination of the first embodiment (see FIG. 6) and the second embodiment (see FIG. 9).

  FIG. 10 is a diagram showing a signal measuring apparatus 1 according to the third embodiment of the present invention. A directional coupler 3 and a VI probe 5 are arranged before and after the matcher 4, and the signal measuring device 1 is connected to each.

  Moreover, said embodiment is realizable as follows. A computer equipped with a CPU, a hard disk, and a medium (floppy (registered trademark) disk, CD-ROM, etc.) reader is added to each of the above-described parts, for example, the first level / phase measurement unit 18, the second level / phase measurement unit 28, A medium recording a program for realizing the error measurement unit 54, the error correction unit 56, the impedance measurement unit 62, and the efficiency measurement unit 64 is read and installed on the hard disk. Such a method can also realize the above functions.

DESCRIPTION OF SYMBOLS 1 Signal measuring device 4 Divider 6 Plasma chamber 6a, 6b Electrode 7 Semiconductor 11 1st terminal 21 2nd terminal 31 Output terminal 12 (single) 1st local signal source 14 1st mixer 16 1st A / D converter 18 First Level / Phase Measurement Unit 22 Second Local Signal Source 24 Second Mixer 26 Second A / D Converter 28 Second Level / Phase Measurement Unit 32 Intermediate Frequency Signal Source 34 Correction Signal Mixer 42, 44 Switch 52 Local Frequency setting unit 54 Error measurement unit 56 Error correction unit 62 Impedance measurement unit (output ratio measurement unit)
64 Efficiency measurement unit
f _Lo1 local signal input frequency ΔLv1 to ΔLv3 Level difference between the outputs of the plurality of mixers 14 and 24 ΔP1 to ΔP3 Phase difference between the outputs of the plurality of mixers 14 and 24

Claims (14)

A plurality of mixers that output a signal having a frequency equal to the difference between the frequencies of the two inputs;
A single local signal source providing a common local signal input to the plurality of mixers;
An error measuring unit for measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
An output ratio measuring unit for measuring a ratio of outputs of the plurality of mixers when a signal under test input having a common frequency is given to the plurality of mixers;
Based on the measurement result of the error measurement unit, an error correction unit for correcting the measurement result of the output ratio measurement unit,
With
A traveling wave given to an electrode in a plasma chamber in which plasma is generated and a reflected wave reflected from the plasma chamber by the traveling wave is used as the signal to be measured;
Signal measuring device. A plurality of mixers that output a signal having a frequency equal to the difference between the frequencies of the two inputs;
A single local signal source providing a common local signal input to the plurality of mixers;
An error measuring unit for measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
An efficiency measuring unit that measures the efficiency of the signal under test input based on the phase difference of the outputs of the plurality of mixers when the signal under test input having a common frequency is given to the plurality of mixers;
Based on the measurement result of the error measurement unit, an error correction unit for correcting the measurement result of the efficiency measurement unit;
With
The voltage applied to the electrode in the plasma chamber where the plasma is generated and the current flowing through the electrode are used as the signal to be measured.
Signal measuring device. The signal measuring device according to claim 1 or 2,
A signal measuring apparatus comprising an amplitude measuring unit that measures amplitudes of the outputs of the plurality of mixers when the signals to be measured are supplied to the plurality of mixers. The signal measuring device according to claim 1 or 2,
The error measurement unit measures the level difference and the phase difference in association with the frequency of the local signal input;
The error correction unit performs correction according to the frequency of the local signal input.
Signal measuring device. The signal measuring device according to claim 4,
The error correction unit performs correction based on an interpolation of the measurement result of the error measurement unit with respect to the frequency of the local signal input.
Signal measuring device. The signal measuring device according to claim 1 or 2,
A correction signal mixer which is provided with the local signal input and the intermediate frequency signal input and outputs a signal having a frequency equal to the sum of the frequencies of the local signal input and the intermediate frequency signal input as the correction signal;
A signal measuring device. A plurality of mixers that output a signal having a frequency equal to the difference between the frequencies of the two inputs;
A single local signal source providing a common local signal input to the plurality of mixers;
An output ratio measuring unit for measuring a ratio of outputs of the plurality of mixers when a signal input to be measured having a common frequency is given to the plurality of mixers;
With
When a common signal input is given to the plurality of mixers, there is no level difference and phase difference between the outputs of the plurality of mixers,
A traveling wave given to an electrode in a plasma chamber in which plasma is generated and a reflected wave reflected from the plasma chamber by the traveling wave is used as the signal to be measured;
Signal measuring device. A plurality of mixers that output a signal having a frequency equal to the difference between the frequencies of the two inputs;
A single local signal source providing a common local signal input to the plurality of mixers;
An efficiency measuring unit that measures the efficiency of the signal under test input based on the phase difference of the outputs of the plurality of mixers when the signal under test input having a common frequency is given to the plurality of mixers;
With
When a common signal input is given to the plurality of mixers, there is no level difference and phase difference between the outputs of the plurality of mixers,
The voltage applied to the electrode in the plasma chamber where the plasma is generated and the current flowing through the electrode are used as the signal to be measured.
Signal measuring device. A signal measurement process in a signal measurement apparatus comprising: a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies; and a single local signal source that provides a common local signal input to the plurality of mixers. A signal measurement method to perform,
An error measuring step of measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
An output ratio measuring step for measuring a ratio of outputs of the plurality of mixers when a signal under test having a common frequency is given to the plurality of mixers;
Based on the measurement result of the error measurement step, an error correction step of correcting the measurement result of the output ratio measurement step,
With
A traveling wave given to an electrode in a plasma chamber in which plasma is generated and a reflected wave reflected from the plasma chamber by the traveling wave is used as the signal to be measured;
Signal measurement method. A signal measurement process in a signal measurement apparatus comprising: a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies; and a single local signal source that provides a common local signal input to the plurality of mixers. A signal measurement method to perform,
An error measuring step of measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
An efficiency measuring step of measuring the efficiency of the signal under test input based on the phase difference of the outputs of the plurality of mixers when the signal under test input having a common frequency is given to the plurality of mixers;
Based on the measurement result of the error measurement step, an error correction step of correcting the measurement result of the efficiency measurement step;
With
The voltage applied to the electrode in the plasma chamber where the plasma is generated and the current flowing through the electrode are used as the signal to be measured.
Signal measurement method. A signal measurement process in a signal measurement apparatus comprising: a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies; and a single local signal source that provides a common local signal input to the plurality of mixers. A program for causing a computer to execute,
The signal measurement process includes:
An error measuring step of measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
An output ratio measuring step for measuring a ratio of outputs of the plurality of mixers when a signal under test having a common frequency is given to the plurality of mixers;
Based on the measurement result of the error measurement step, an error correction step of correcting the measurement result of the output ratio measurement step,
With
A traveling wave given to an electrode in a plasma chamber in which plasma is generated and a reflected wave reflected from the plasma chamber by the traveling wave is used as the signal to be measured;
program. A signal measurement process in a signal measurement apparatus comprising: a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies; and a single local signal source that provides a common local signal input to the plurality of mixers. A program for causing a computer to execute,
The signal measurement process includes:
An error measuring step of measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
An efficiency measuring step of measuring the efficiency of the signal under test input based on the phase difference of the outputs of the plurality of mixers when the signal under test input having a common frequency is given to the plurality of mixers;
Based on the measurement result of the error measurement step, an error correction step of correcting the measurement result of the efficiency measurement step;
With
The voltage applied to the electrode in the plasma chamber where the plasma is generated and the current flowing through the electrode are used as the signal to be measured.
program. A signal measurement process in a signal measurement apparatus comprising: a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies; and a single local signal source that provides a common local signal input to the plurality of mixers. A computer-readable recording medium storing a program to be executed by a computer,
The signal measurement process includes:
An error measuring step of measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
An output ratio measuring step for measuring a ratio of outputs of the plurality of mixers when a signal under test having a common frequency is given to the plurality of mixers;
Based on the measurement result of the error measurement step, an error correction step of correcting the measurement result of the output ratio measurement step,
With
A traveling wave given to an electrode in a plasma chamber in which plasma is generated and a reflected wave reflected from the plasma chamber by the traveling wave is used as the signal to be measured;
recoding media. A signal measurement process in a signal measurement apparatus comprising: a plurality of mixers that output a signal having a frequency equal to a difference between two input frequencies; and a single local signal source that provides a common local signal input to the plurality of mixers. A computer-readable recording medium storing a program to be executed by a computer,
The signal measurement process includes:
An error measuring step of measuring a level difference and a phase difference between outputs of the plurality of mixers when a common correction signal input is given to the plurality of mixers;
An efficiency measuring step of measuring the efficiency of the signal under test input based on the phase difference of the outputs of the plurality of mixers when the signal under test input having a common frequency is given to the plurality of mixers;
Based on the measurement result of the error measurement step, an error correction step of correcting the measurement result of the efficiency measurement step;
With
The voltage applied to the electrode in the plasma chamber where the plasma is generated and the current flowing through the electrode are used as the signal to be measured.
recoding media.

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