High-Frequency Plasma Processing Apparatus

Abstract

This application discloses a High-Frequency plasma processing apparatus comprising a process chamber in which a substrate to be processed is placed, a process-gas introduction line for introducing a process gas into the process chamber, a first HF electrode provided in the process chamber, a first HF power source for applying voltage to the first HF electrode, thereby generating plasma of the process gas. The apparatus further comprises a second HF electrode facing the first HF electrode in the process chamber, interposing discharge space, and a series resonator connecting the second HF electrode and the ground. The frequency of the first HF power source is not lower than 30 MHz. The series resonator is resonant as the distributed constant circuit at the frequency of the first HF power source.

1 - 12 . (canceled) 
   
   
       13 . A substrate processing method, comprising:
 placing a substrate in a process chamber;   introducing an etchant gas into the process chamber through a process gas introduction line;   applying an HF voltage to a first electrode by a first HP power source, thereby generating a plasma in the process chamber;   applying an HF voltage to a second electrode by a second HP power source;   the second electrode facing the first electrode in the process chamber;   providing an inner conductor supporting the second electrode, and an outer conductor surrounding the inner conductor; and   making a resonance in a coaxial resonator including the inner conductor and the outer conductor.   
   
   
       14 . A substrate processing method as claimed in  claim 13 , further comprising grounding the second electrode via the coaxial resonator. 
   
   
       15 . A substrate processing method as claimed in  claim 13 , wherein the resonance is a series resonance. 
   
   
       16 . A substrate processing method as claimed in  claim 13 , further comprising controlling a reactance in the coaxial resonator, thereby establishing the resonance. 
   
   
       17 . A substrate processing method as claimed in  claim 13 , wherein a cavity of the coaxial resonator is located outside the process chamber. 
   
   
       18 . A substrate processing method as claimed in  claim 16 , wherein the coaxial resonator includes a variable capacitor, and further comprising:
 controlling a capacitance of the variable capacitor by a reactance controller, thereby establishing the resonance.   
   
   
       19 . A substrate processing method as claimed in  claim 14 , wherein
 the series resonator has a circuit length from the second electrode to the ground, and   the resonance takes place in the whole circuit length of the coaxial resonator at a frequency of the first HP power source.   
   
   
       20 . A substrate processing method as claimed in  claim 13 , wherein a frequency of the first HP power source is not lower than 30 MHz. 
   
   
       21 . A substrate processing method as claimed in  claim 18 , further comprising:
 measuring a current flowing through the coaxial resonator by an ammeter, and   controlling the capacitance of the variable capacitor by a reactance controller according to a signal from the ammeter, so as to minimize the current flowing through the coaxial resonator.   
   
   
       22 . A substrate processing method as claimed in  claim 21 , wherein the ammeter is a peak-to-peak ammeter to measure width of a positive peak and a negative peak. 
   
   
       23 . A substrate processing method as claimed in  claim 13 , further comprising using the second electrode as a substrate holder for holding the substrate at a required position in the process chamber. 
   
   
       24 . A substrate processing method as claimed in  claim 23 , further comprising
 controlling an ion-bombardment energy onto the substrate by the second HP power source,   wherein a frequency of the second HP power source differs from that of the first HP power source.   
   
   
       25 . A substrate processing method as claimed in  claim 13 , wherein the HF voltage applied to the first electrode by the first HP power source is capable of generating the plasma at a pressure not higher than 10 Pa. 
   
   
       26 . A substrate manufacturing method, comprising:
 placing a substrate in a process chamber;   introducing an etchant gas into the process chamber through a process gas introduction line;   applying an HF voltage to a first electrode by a first HP power source, thereby generating a plasma in the process chamber;   applying an HF voltage to a second electrode by a second HP power source;   the second electrode facing the first electrode in the process chamber;   providing an inner conductor supporting the second electrode, and an outer conductor surrounding the inner conductor; and   making a resonance in a coaxial resonator including the inner conductor and the outer conductor.   
   
   
       27 . A substrate manufacturing method as claimed in  claim 26 , further comprising grounding the second electrode via the coaxial resonator. 
   
   
       28 . A substrate manufacturing method as claimed in  claim 26 , wherein the resonance is a series resonance. 
   
   
       29 . A substrate manufacturing method as claimed in  claim 26 , further comprising controlling a reactance in the coaxial resonator, thereby establishing the resonance. 
   
   
       30 . A substrate manufacturing method as claimed in  claim 26 , wherein a cavity of the coaxial resonator is located outside the process chamber. 
   
   
       31 . A substrate manufacturing method as claimed in  claim 29 , wherein the coaxial resonator includes a variable capacitor, and further comprising
 controlling a capacitance of the variable capacitor by a reactance controller, thereby establishing the resonance.   
   
   
       32 . A substrate manufacturing method as claimed in  claim 27 , wherein
 the series resonator has a circuit length from the second electrode to the ground, and   the resonance takes place in the whole circuit length of the coaxial resonator at a frequency of the first HF power source.   
   
   
       33 . A substrate manufacturing method as claimed in  claim 26 , wherein a frequency of the first HP power source is not lower than 30 MHZ. 
   
   
       34 . A substrate manufacturing method as claimed in  claim 31 , further comprising measuring a current flowing through the coaxial resonator by an ammeter, and controlling the capacitance of the variable capacitor by a reactance controller according to a signal from the ammeter, so as to minimize the current flowing through the coaxial resonator. 
   
   
       35 . A substrate manufacturing method as claimed in  claim 34 , wherein the ammeter is a peak-to-peak ammeter to measure width of a positive peak and a negative peak. 
   
   
       36 . A substrate manufacturing method as claimed in  claim 26 , further comprising using the second electrode as a substrate holder for holding the substrate at a required position in the process chamber. 
   
   
       37 . A substrate manufacturing method as claimed in  claim 36 , further comprising
 controlling an ion-bombardment energy onto the substrate by the second HP power source,   wherein a frequency of the second HP power source differs from that of the first HP power source.   
   
   
       38 . A substrate manufacturing method as claimed in  claim 26 , wherein the HF voltage applied to the first electrode by the first HP power source is capable of generating the plasma at a pressure not higher than 10 Pa.