Plasma processing method and apparatus

Abstract

A plasma processing method is arranged to supply a predetermined process gas into a plasma generation space in which a target substrate is placed, and turn the process gas into plasma. The substrate is subjected to a predetermined plasma process by this plasma. The spatial distribution of density of the plasma and the spatial distribution of density of radicals in the plasma are controlled independently of each other relative to the substrate by a facing portion opposite the substrate to form a predetermined process state over the entire target surface of the substrate.

1 . A plasma processing method comprising: 
 supplying a predetermined process gas into a plasma generation space in which a target substrate is placed, and turning the process gas into plasma; and    subjecting the substrate to a predetermined plasma process by the plasma,    wherein spatial distribution of density of the plasma and spatial distribution of density of radicals in the plasma relative to the substrate are controlled independently of each other by a set of first and second RF discharge regions and a set of first and second process gas delivery regions, respectively, to form a predetermined process state over an entire target surface of the substrate, and    wherein the set of first and second RF discharge regions and the set of first and second process gas delivery regions are disposed in layouts independently of each other.    
     
     
         2 . The method according to  claim 1 , wherein a facing portion opposite the substrate is divided into two regions as the first and second RF discharge regions on a peripheral side and a central side, respectively, in a radial direction relative to a center through which a vertical line extending from a center of the substrate passes; and 
 the second RF discharge region on the facing portion is divided into two regions as the first and second process gas delivery regions on a peripheral side and a central side, respectively, in the radial direction.    
     
     
         3 . The method according to  claim 2 , wherein the first RF discharge region is disposed radially outside an outer peripheral edge of the substrate.  
     
     
         4 . The method according to  claim 1 , wherein an RF output from a single RF power supply is divided at a predetermined ratio, and thereby discharged from the first RF discharge region and the second RF discharge region.  
     
     
         5 . The method according to  claim 1 , wherein a process gas supplied from a single process gas supply source is divided at a predetermined ratio, and thereby delivered from the first process gas delivery region and the second process gas delivery region.  
     
     
         6 . The method according to  claim 5 , wherein the process gas is delivered from the first and second process gas delivery regions at deferent flow rates per unit area.  
     
     
         7 . The method according to  claim 1 , wherein the process gas is a mixture gas of a plurality of gases, the plurality of gases are delivered from the first process gas delivery region at a first gas mixture ratio, and the plurality of gases are delivered from the second process gas delivery region at a second gas mixture ratio different from the first gas mixture ratio.  
     
     
         8 . A plasma processing method comprising: 
 exposing a target substrate to plasma of a predetermined process gas; and    subjecting the substrate to a predetermined plasma process by the plasma,    wherein spatial distribution of density of the plasma and spatial distribution of density of radicals in the plasma are controlled independently of each other relative to the substrate to form a predetermined process state over an entire target surface of the substrate, and    wherein processing rates at respective positions on the target surface of the substrate are mainly controlled in accordance with the plasma density spatial distribution, and one or both of processing selectivity and processing shapes at respective positions on the target surface are mainly controlled in accordance with the radical density spatial distribution.    
     
     
         9 . The method according to  claim 1 , wherein the first and second RF discharge regions comprise an RF electrode to be supplied with an RF.  
     
     
         10 . A plasma processing apparatus arranged to turn a process gas into plasma in a plasma generation space within a process container configured to have a vacuum atmosphere therein, and subject a target substrate placed within the plasma generation space to a predetermined plasma process, the apparatus comprising: 
 a plasma density control section configured to control spatial distribution of density of the plasma relative to the substrate; and    a radical density control section configured to control spatial distribution of density of radicals in the plasma relative to the substrate independently of the plasma density spatial distribution,    wherein the plasma density control section comprises a set of first and second RF discharge regions configured to control the plasma density spatial distribution,    the radical density control section comprises a set of first and second process gas delivery regions configured to control the radical density spatial distribution, and    the set of first and second RF discharge regions and the set of first and second process gas delivery regions are disposed in layouts independently of each other.    
     
     
         11 . The apparatus according to  claim 10 , wherein a facing portion opposite the substrate and in contact with the plasma generation space is divided into two regions as the first and second RF discharge regions on a peripheral side and a central side, respectively, in a radial direction relative to a center through which a vertical line extending from a center of the substrate passes; and 
 the second RF discharge region on the facing portion is divided into two regions as the first and second process gas delivery regions on a peripheral side and a central side, respectively, in the radial direction.    
     
     
         12 . The apparatus according to  claim 11 , wherein the first RF discharge region is disposed radially outside an outer peripheral edge of the substrate.  
     
     
         13 . The apparatus according to  claim 10 , wherein the process gas is a mixture gas of a plurality of gases, the plurality of gases are delivered from the first process gas delivery region at a first gas mixture ratio, and the plurality of gases are delivered from the second process gas delivery region at a second gas mixture ratio different from the first gas mixture ratio.  
     
     
         14 . The apparatus according to  claim 10 , wherein an RF power is discharged toward the plasma space from the first and second RF discharge regions at a predetermined ratio; and 
 the process gas is delivered toward the plasma space from the first and second process gas delivery regions at a predetermined ratio.    
     
     
         15 . The apparatus according to  claim 14 , wherein the plasma density control section comprises an RF distributor configured to divide and transmit an RF with a constant frequency, output from an RF power supply, at a predetermined ratio to the first and second RF discharge regions; and 
 the radical density control section comprises a process gas distributor configured to divide and supply the process gas, output from a process gas supply source, at a predetermined ratio to the first and second process gas delivery regions.    
     
     
         16 . The apparatus according to  claim 15 , wherein the RF distributor includes an impedance control section configured to variably control one or both of an impedance of a first feed circuit from the RF power supply to the first RF discharge region, and an impedance of a second feed circuit from the RF power supply to the second RF discharge region.  
     
     
         17 . The apparatus according to  claim 10 , wherein the first and second RF discharge regions respectively comprise first and second electrodes electrically insulated from each other.  
     
     
         18 . The apparatus according to  claim 17 , wherein the first and second process gas delivery regions include a number of process gas delivery holes formed on the second electrode.