Plasma processing method and apparatus

Abstract

Plasma is generated in the interior of a vacuum chamber to process a high melting metal film formed on a substrate, while supplying gas into the vacuum chamber and simultaneously exhausting the interior of the vacuum chamber to control to a specified pressure, by supplying a high-frequency power of a 30 MHz to 3 GHz frequency to an antenna provided within the vacuum chamber in opposition to the substrate placed on a substrate electrode within the vacuum chamber, by supplying a high-frequency power of a 100 kHz to 20 MHz frequency different from the above frequency to the antenna.

What is claimed is:  
     
         1 . A plasma processing method for generating plasma in a vacuum vessel, by supplying a high-frequency power of a 30 MHz to 3 GHz frequency to an antenna provided within the vacuum vessel in opposition to a substrate placed on a substrate electrode within the vacuum vessel while interior of the vacuum vessel is controlled to a specified pressure by supplying gas into the vacuum vessel and simultaneously exhausting the interior of the vacuum vessel, and thus processing a high melting metal film formed on the substrate, 
 the method comprising: 
 additionally supplying a high-frequency power of a 100 kHz to 20 MHz frequency different from the above frequency to the antenna to process the substrate.  
   
     
     
         2 . The plasma processing method according to  claim 1 , wherein the high melting metal film is a film containing at least one element selected from among iridium, rhodium, ruthenium, platinum, gold, copper, rhenium, bismuth, strontium, barium, zirconium, lead, and niobium.  
     
     
         3 . The plasma processing method according to  claim 1 , wherein the substrate is processed with temperature of the antenna controlled by giving a flow of a refrigerant to the antenna while heat conduction between the antenna and an antenna cover is ensured by an electrically conductive sheet which is disposed between the antenna and the antenna cover and whose surface parallel to the substrate is larger in surface area than that of the antenna, and further the substrate is processed while a self-bias voltage is generated up to an end portion of the cover by additionally supplying the high-frequency power of the 100 kHz to 20 MHz frequency different from the above frequency to the antenna.  
     
     
         4 . The plasma processing method according to  claim 3 , wherein the plasma processing is an etching process of the high melting metal film formed on the substrate.  
     
     
         5 . The plasma processing method according to  claim 4 , wherein the high melting metal film is a film containing at least one element selected from among iridium, rhodium, ruthenium, platinum, gold, copper, rhenium, bismuth, strontium, barium, zirconium, lead, and niobium.  
     
     
         6 . A plasma processing apparatus comprising: 
 a vacuum vessel;    a gas supply unit for supplying gas into the vacuum vessel;    an exhausting unit for exhausting interior of the vacuum vessel;    a pressure-regulating valve for controlling the interior of the vacuum vessel to a specified pressure;    a substrate electrode for placing thereon a substrate within the vacuum vessel;    an antenna provided in opposition to the substrate electrode and covered with an insulating antenna cover;    a first high-frequency power supply capable of supplying a high-frequency power of a 30 MHz to 3 GHz frequency to the antenna;    a second high-frequency power supply capable of additionally supplying a high-frequency power of a 100 kHz to 20 MHz frequency different from the above frequency to the antenna;    a refrigerant supply unit for making a refrigerant flow to the antenna; and    an electrically conductive sheet whose surface parallel to the substrate is larger than that of the antenna and which is provided between the antenna and the antenna cover.    
     
     
         7 . The plasma processing apparatus according to  claim 6 , wherein the antenna cover is made of quartz glass.  
     
     
         8 . The plasma processing apparatus according to  claim 6 , wherein the antenna cover is made of insulative silicon.  
     
     
         9 . The plasma processing apparatus according to  claim 6 , wherein the antenna cover is 1 mm to 10 mm thick.  
     
     
         10 . The plasma processing apparatus according to  claim 6 , wherein the electrically conductive sheet is made of a material having a resistivity of not more than 10 Ω·m.  
     
     
         11 . The plasma processing apparatus according to  claim 6 , wherein the electrically conductive sheet is 0.03 mm to 3 mm thick.  
     
     
         12 . A plasma processing method for generating inductive-coupling type plasma in a vacuum vessel by placing a substrate on a substrate electrode within the vacuum vessel, supplying a first high-frequency power of a 1 MHz to 60 MHz frequency to a feeding point which is one end of a coil provided in opposition to the substrate electrode while interior of the vacuum vessel is controlled to a specified pressure by supplying gas into the vacuum vessel and simultaneously exhausting the interior of the vacuum vessel, and thus processing the substrate or a film formed on the substrate, 
 the method comprising: 
 while supplying a second high-frequency power of a frequency lower than that of the first high-frequency power to the coil with the other end of the coil grounded via a capacitor, processing the substrate.  
   
     
     
         13 . A plasma processing method for generating inductive-coupling type plasma in a vacuum vessel by placing a substrate on a substrate electrode within the vacuum vessel, supplying a first high-frequency power of a 1 MHz to 60 MHz frequency to a feeding point which is one end of a coil provided in opposition to the substrate electrode while interior of the vacuum vessel is controlled to a specified pressure by supplying gas into the vacuum vessel and simultaneously exhausting the interior of the vacuum vessel, and thus processing the substrate or a film formed on the substrate, 
 the method comprising: 
 while supplying a second high-frequency power of a frequency lower than that of the first high-frequency power to an electrode provided at a vacancy of the coil, processing the substrate.  
   
     
     
         14 . The plasma processing method according to  claim 12 , wherein the plasma processing is an etching process of a high melting metal film formed on the substrate.  
     
     
         15 . The plasma processing method according to  claim 14 , wherein the high melting metal film is a film containing at least one element selected from among iridium, rhodium, ruthenium, platinum, gold, copper, rhenium, bismuth, strontium, barium, zirconium, lead, and niobium.  
     
     
         16 . A plasma processing apparatus comprising: 
 a vacuum vessel;    a gas supply unit for supplying gas into the vacuum vessel;    an exhausting unit for exhausting interior of the vacuum vessel;    a pressure-regulating valve for controlling the interior of the vacuum vessel to a specified pressure;    a substrate electrode for placing thereon a substrate within the vacuum vessel;    a coil provided in opposition to the substrate electrode and having one end grounded via a capacitor;    a first high-frequency power supply for supplying a first high-frequency power of a 1 MHz to 60 MHz frequency to a feeding point which is the other end of the coil; and    a second high-frequency power supply for supplying a second high-frequency power of a frequency lower than that of the first high-frequency power to the coil.    
     
     
         17 . A plasma processing apparatus comprising: 
 a vacuum vessel;    a gas supply unit for supplying gas into the vacuum vessel;    an exhausting unit for exhausting interior of the vacuum vessel;    a pressure-regulating valve for controlling the interior of the vacuum vessel to a specified pressure;    a substrate electrode for placing thereon a substrate within the vacuum vessel;    a coil provided in opposition to the substrate electrode;    a first high-frequency power supply for supplying a first high-frequency power of a 1 MHz to 60 MHz frequency to a feeding point which is one end of the coil; and    a second high-frequency power supply for supplying a second high-frequency power of a frequency lower than that of the first high-frequency power to an electrode provided at a vacancy of the coil.