High frequency power supply device and high frequency power supplying method

Abstract

A high frequency power supply device and power supplying method are disclosed, which can rapidly and accurately control power used for generation of plasmas. The device includes a first high frequency power supply, providing power at frequency f 1 , and a second high frequency power supply providing power at frequency f 2 (f 1 >f 2 ). The first power supply includes: a first high frequency oscillator, which excites the high frequency power at the first frequency and has a variable frequency; a first power amplification block, which amplifies the power of the high frequency oscillator; a heterodyne detection block, which performs heterodyne detection of a reflected wave; and a first control block, which receives a signal after detection of the heterodyne detection block and a traveling wave signal, and controls an oscillating frequency of the first high frequency oscillating block and an output of the first power amplification block.

1 . A high frequency power supply device, at least comprising a first high frequency power supply block, which supplies a plasma processing chamber with a high frequency power at a first frequency, and a second high frequency power supply block, which supplies the plasma processing chamber with a high frequency power at a second frequency below the first frequency, wherein:
 the first high frequency power supply block comprises:   a first high frequency oscillating block, which excites the high frequency power at the first frequency and has a variable frequency;   a first power amplification block, which receives an output of the first high frequency oscillating block and amplifies the power thereof;   a first directivity coupler, which receives a reflected wave from the plasma processing chamber and a traveling wave from the first power amplification block;   a first reflected wave heterodyne detection block, which performs heterodyne detection of a reflected wave signal from the first directivity coupler; and   a first control block, which receives a signal after detection of the first reflected wave heterodyne detection block and a traveling wave signal from the first directivity coupler, and controls an oscillating frequency of the first high frequency oscillating block and an output level of the first power amplification block.   
   
   
       2 . The high frequency power supply device according to  claim 1 , wherein:
 the first high frequency power supply block comprises a first traveling wave heterodyne detection block, which performs heterodyne detection of a traveling wave signal from the first directivity coupler; and,   the first control block receives a heterodyne detection signal of the traveling wave signal.   
   
   
       3 . The high frequency power supply device according to  claim 1 , wherein:
 the second high frequency power supply block comprises:   a second high frequency oscillating block, which excites the high frequency power at the second frequency and has a variable frequency;   a second power amplification block, which receives an output of the second high frequency oscillating block and amplifies the power thereof;   a second directivity coupler, which receives a reflected wave from the plasma processing chamber and a traveling wave from the second power amplification block;   a second reflected wave detection block, which detects a reflected wave signal from the second directivity coupler; and   a second control block, which receives a signal after detection of the second reflected wave detection block and a traveling wave signal from the second directivity coupler, and controls an oscillating frequency of the second high frequency oscillating block and an output of the second power amplification block.   
   
   
       4 . The high frequency power supply device according to  claim 3 , wherein:
 the first high frequency power supply block comprises a first traveling wave heterodyne detection block, which performs heterodyne detection of a traveling wave signal from the first directivity coupler;   the first control block receives a heterodyne detection signal of the traveling wave signal;   the second reflected wave detection block is a second reflected wave heterodyne detection block, which performs heterodyne detection of the reflected wave signal; and   the second control block receives a signal after detection of the second reflected wave heterodyne detection block and controls the oscillating frequency of the second high frequency oscillating block and the output of the second power amplification block.   
   
   
       5 . The high frequency power supply device according to  claim 4 , wherein:
 the second high frequency power supply block comprises a second traveling wave heterodyne detection block, which performs heterodyne detection of a traveling wave signal from the second directivity coupler;   the second control block receives a heterodyne detection signal of the traveling wave signal.   
   
   
       6 . The high frequency power supply device according to  claim 5 , further comprising one or more high frequency power supply blocks, which supply the plasma processing chamber with high frequency power and output high frequency power at a frequency different from the first and second frequencies. 
   
   
       7 . The high frequency power supply device according to  claim 6 , wherein:
 at least one of the one or more high frequency power supply blocks comprises: a heterodyne detection block, which performs heterodyne detection of at least a reflected wave signal of a reflected wave signal and a traveling wave signal; and a control block, which receives the reflected wave signal after detection of the heterodyne detection block and controls an oscillating frequency and an output of the high frequency power supply block.   
   
   
       8 . A high frequency power supplying method for supplying a plasma processing chamber at least with a first high frequency power at a first frequency and a second high frequency power at a second frequency below the first frequency, wherein the method comprises:
 a process of amplifying the first high frequency power in a first high frequency power supply block, and amplifying the second high frequency power in a second high frequency power supply block, and supplying to the plasma processing chamber;   a process of performing, in the first high frequency power supply block, heterodyne detection of a reflected wave from the plasma processing chamber;   a process of receiving a reflected wave signal after the heterodyne detection and a traveling wave signal of the first high frequency power, and controlling an oscillating frequency and a power amplification of the first high frequency power supply block;   a process of detecting, in the second high frequency power supply block, a reflected wave from the plasma processing chamber and a traveling wave of the second high frequency power; and   a process of receiving a reflected wave signal and a traveling wave signal after the detection, and controlling an oscillating frequency and a power amplification of the second high frequency power supply block.   
   
   
       9 . An RF power supply system for use with plasma chamber, comprising:
 a variable frequency oscillator providing high RF frequency signal;   a power amplifier receiving and amplifying the high RF frequency signal;   a heterodyne detector receiving a reflected signal from the plasma chamber and generating a modulated signal corresponding to reflected power included within the reflected signal;   a controller receiving the modulated signal and providing a frequency control signal to control the output of the variable frequency oscillator and an amplification control signal to control the output of the power amplifier.   
   
   
       10 . The RF power supply system of  claim 9 , further comprising:
 a second frequency oscillator providing a low RF frequency signal;   a second power amplifier receiving and amplifying the low RF frequency signal.   
   
   
       11 . The RF power supply system of  claim 10 , further comprising an impedance matching circuit for coupling at least one of the high RF frequency signal and low RF frequency signal to the plasma chamber. 
   
   
       12 . The RF power supply system of  claim 11 , wherein the second frequency oscillator comprises a second variable frequency oscillator, and wherein the system further comprises:
 a second heterodyne detector receiving the reflected signal from the plasma chamber and generating a second modulated signal corresponding to reflected power included within the reflected signal; and   a second controller receiving the second modulated signal and providing a second frequency control signal to control the output of the second variable frequency oscillator.   
   
   
       13 . A plasma chamber for processing a substrate, comprising:
 a vacuum chamber;   an RF power applicator for coupling RF energy into the vacuum chamber;   an RF power supply system coupled to the RF power applicator, the RF power supply system comprising:
 a variable frequency oscillator providing high RF frequency signal; 
 a power amplifier receiving and amplifying the high RF frequency signal; 
 a heterodyne detector receiving a reflected signal from the plasma chamber and generating a modulated signal corresponding to reflected power included within the reflected signal; 
 a controller receiving the modulated signal and providing a frequency control signal to control the output of the variable frequency oscillator and an amplification control signal to control the output of the power amplifier. 
   
   
   
       14 . The plasma chamber of  claim 13 , further comprising:
 a second frequency oscillator providing a low RF frequency signal;   a second power amplifier receiving and amplifying the low RF frequency signal.   
   
   
       15 . The plasma chamber of  claim 14 , further comprising an impedance matching circuit for coupling at least one of the high RF frequency signal and low RF frequency signal to the plasma chamber. 
   
   
       16 . The plasma chamber of  claim 15 , wherein the second frequency oscillator comprises a second variable frequency oscillator, and wherein the system further comprises:
 a second heterodyne detector receiving the reflected signal from the plasma chamber and generating a second modulated signal corresponding to reflected power included within the reflected signal; and   a second controller receiving the second modulated signal and providing a second frequency control signal to control the output of the second variable frequency oscillator.