Electronic device manufacturing apparatus and method for manufacturing electronic device

Abstract

An electronic device manufacturing apparatus includes: a reaction chamber including a wall having a ground potential level; a reaction gas inlet for introducing a reaction gas into the reaction chamber; a high frequency power generator for generating a high frequency voltage for exciting the reaction gas into plasma state or dissociated state; a cathode electrode connected to the high frequency power generator; and a floating capacitance formed between a potential level of the cathode electrode and the ground potential level. An impedance adjusting capacitor is inserted so as to be in series with the floating capacitance. The impedance adjusting capacitor has a capacitance value less than that of the floating capacitance.

1. An electronic device manufacturing apparatus comprising:
 a reaction chamber including a wall having a ground potential level;  
 a reaction gas inlet for introducing a reaction gas into the reaction chamber;  
 a high frequency power generator for generating a high frequency voltage for exciting the reaction gas into plasma state or dissociated state; and  
 a cathode electrode connected to the high frequency power generator; wherein  
 a floating capacitance is defined between a potential level of the cathode electrode and the ground potential level,  
 and further including an impedance adjusting capacitor positioned in series with the floating capacitance to suppress parallel resonance that occurs between the floating capacitance and a capacitance an inductance component formed between the cathode electrode and an anode electrode,  
 the impedance adjusting capacitor having a capacitance value less than that of the floating capacitance.  
 
     
     
       2. An electronic device manufacturing apparatus according to  claim 1 ,
 wherein the cathode electrode includes an upper cathode electrode and a lower cathode electrode, the apparatus further comprises a DC blocking capacitance element connected in series between the high frequency power generator and the lower cathode electrode, and  
 the impedance adjusting capacitor is inserted between the upper and lower cathode electrodes.  
 
     
     
       3. An electronic device manufacturing apparatus according to  claim 2 , wherein the impedance adjusting capacitor insulates for a DC voltage the upper cathode electrode from the DC blocking capacitance element. 
     
     
       4. An electronic device manufacturing apparatus according to  claim 1 , wherein the impedance adjusting capacitor is inserted at such a location that the impedance adjusting capacitor is equivalently in series with the floating capacitance at a frequency of the high frequency power generator. 
     
     
       5. An electronic device manufacturing apparatus according to  claim 1 , wherein the impedance adjusting capacitor is formed so as to insulate for a DC voltage the cathode electrode from the high frequency power generator. 
     
     
       6. An electronic device manufacturing apparatus according to  claim 1 , wherein the impedance adjusting capacitor is formed of a dielectric which is provided on the cathode electrode. 
     
     
       7. An electronic device manufacturing apparatus according to  claim 1 , wherein, when capacitance of the impedance adjusting capacitor and the floating capacitance are connected in series with each other, a total capacitance C is set so as to satisfy Expression (1) below:
   C·≦1/{L G ·(2π·f) 2 }  (1)  
 where L G  denotes a magnitude of an inductance component equivalently existing between the cathode electrode and a location which opposes an electrode surface of the cathode electrode and which has a ground potential,  
 π denotes pi (ratio of the circumference of a circle to the diameter), and  
 f denotes the frequency of the high frequency voltage used for excitation.  
 
     
     
       8. An electronic device manufacturing apparatus according to  claim 1 , wherein the reaction gas is one of a material gas for depositing a thin film semiconductor and an etching gas for processing a semiconductor device. 
     
     
       9. An electronic device manufacturing apparatus according to  claim 1 , wherein: the cathode electrode is designed so as to satisfy Expression (4) below:
   D≧( 1/16)·λ  (4)  
 where D denotes a maximum length of a surface of the cathode electrode, and 
 λ denotes a wavelength of the high frequency voltage for excitation.  
 
 
     
     
       10. An electronic device manufacturing apparatus according to  claim 1 , wherein the cathode electrode is designed so as to satisfy Expression (5) below:
   D≧(⅛)·λ  (5)  
 where D denotes a maximum length of a surface of the cathode electrode, and 
 λ denotes a wavelength of the high frequency voltage for excitation.  
 
 
     
     
       11. An electronic device manufacturing apparatus according to  claim 1 , wherein the reaction chamber is designed so as to satisfy Expression (6) below:
   D o ≦(½)·λ  (6)  
 where D o  denotes a maximum length provided in the reaction chamber parallel to a surface of the cathode electrode, and 
 λ denotes a wavelength of the high frequency voltage for excitation.  
 
 
     
     
       12. An electronic device manufacturing apparatus according to  claim 1 , wherein a high frequency condition of the high frequency power generator is set to be continuous discharge in a high frequency VHF range. 
     
     
       13. An electronic device manufacturing apparatus according to  claim 1 , wherein a high frequency condition of the high frequency power generator is set to be pulse discharge in a high frequency VHF range. 
     
     
       14. An electronic device manufacturing apparatus comprising:
 a reaction chamber including a wall having a ground potential level;  
 a reaction gas inlet for introducing a reaction gas into the reaction chamber;  
 a high frequency power generator for generating a high frequency power for exciting the reaction gas into plasma state or dissociated state; and  
 a cathode electrode connected to the high frequency power generator; wherein  
 a floating capacitance is defined between a potential level of the cathode electrode and the ground potential level,  
 and further wherein an impedance adjusting inductor is positioned in parallel with the floating capacitance such that said impedance adjusting inductor suppresses parallel resonance that occurs between the floating capacitance and a capacitance an inductance component formed between the cathode electrode and an anode electrode.  
 
     
     
       15. An electronic device manufacturing apparatus according to  claim 14 , wherein the inductance component L C  of the impedance adjusting inductor is set so as to satisfy Expression (2) below:
   L C ≧1/{(2·π·f) 2 ·C F }  (2).  
 
     
     
       16. An electronic device manufacturing apparatus according to  claim 15 , wherein the reaction chamber is designed so as to satisfy Expression (6) below:
   D o ≦(½)·λ  (6)  
 where D o  changes a maximum length provided in the reaction chamber parallel to a surface of the cathode electrode, and 
 λ denotes a wavelength of the high frequency voltage.  
 
 
     
     
       17. An electronic device manufacturing apparatus according to  claim 14 , wherein the inductance component L C  of the impedance adjusting inductor is set so as to satisfy Expression (3) below:
   L C <1/{(2·π·f) 2 ·C F }  (3).  
 
     
     
       18. An electronic device manufacturing apparatus according to  claim 17 , wherein the reaction chamber is designed so as to satisfy Expression (7) below:
   D o ≧(½)·λ  (7)  
 where D o  denotes a maximum length provided in the reaction chamber parallel to a surface of the cathode electrode, and 
 λ denotes a wavelength of the high frequency voltage for excitation.  
 
 
     
     
       19. An electronic device manufacturing apparatus according to  claim 14 , wherein: the cathode electrode is designed so as to satisfy Expression (4) below:
   D≧( 1/16)·λ  (4)  
 where D denotes a maximum length of a surface of the cathode electrode, and 
 λ denotes a wavelength of the high frequency voltage for excitation.  
 
 
     
     
       20. An electronic device manufacturing apparatus according to  claim 14 , wherein the cathode electrode is designed so as to satisfy Expression (5) below:
   D≧(⅛)·λ  (5)  
 where D denotes a maximum length of a surface of the cathode electrode, and 
 λ denotes a wavelength of the high frequency voltage for excitation.  
 
 
     
     
       21. An electronic device manufacturing apparatus according to  claim 14 , wherein the impedance adjusting inductor is inserted at such a location that the impedance adjusting capacitor can be considered to be equivalently in parallel to the floating capacitance C F  at a frequency of the high frequency power generator. 
     
     
       22. An electronic device manufacturing apparatus according to  claim 14 , wherein the impedance adjusting inductor short-circuits for a DC voltage the cathode electrode to a portion of the reaction chamber having the ground potential level. 
     
     
       23. An electronic device manufacturing apparatus according to  claim 14 , wherein an electrode-side dielectric is provided beside the cathode electrode, and the cathode electrode and the electrode-side dielectric form a bottom wall of the reaction chamber. 
     
     
       24. An electronic device manufacturing apparatus according to  claim 14 , wherein
 the cathode electrode is formed in a cylindrical shape,  
 the anode electrode is provided inside the cathode electrode,  
 an electrode-side dielectric is provided at an end of the cathode electrode, and  
 the cathode electrode and the electrode-side dielectric form a wall of the reaction chamber.  
 
     
     
       25. An electronic device manufacturing apparatus according to  claim 14 , comprising an impedance adjusting capacitor inserted so as to be in series with the floating capacitance,
 wherein the impedance adjusting capacitor has a capacitance value less than that of the floating capacitance C F .  
 
     
     
       26. An electronic device manufacturing apparatus according to  claim 14 , wherein a high frequency condition of the high frequency power generator is set to be continuous discharge in a high frequency VHF range. 
     
     
       27. An electronic device manufacturing apparatus according to  claim 14 , wherein a high frequency condition of the high frequency power generator is set to be pulse discharge in a high frequency VHF range. 
     
     
       28. An electronic device manufacturing apparatus according to  claim 14 , wherein the reaction gas is one of a material gas for depositing a thin film semiconductor and an etching gas for processing a semiconductor device.