Plasma processing apparatus and plasma processing methdo

Abstract

In one embodiment, a plasma processing apparatus includes: a chamber; an introducing part; a counter electrode; a high-frequency power source; and a plurality of low-frequency power sources. A substrate electrode is disposed in the chamber, a substrate is directly or indirectly placed on the substrate electrode, and the substrate electrode has a plurality of electrode element groups. The introducing part introduces process gas into the chamber. The high-frequency power source outputs a high-frequency voltage for ionizing the process gas to generate plasma. The plurality of low-frequency power sources apply a plurality of low-frequency voltages of 20 MHz or less with mutually different phases for introducing ions from the plasma, to each of the plurality of electrode element groups.

1 .- 20 . (canceled) 
     
     
         21 . A plasma processing apparatus comprising:
 a chamber;   an introducing part configured to introduce process gas into the chamber;   a high-frequency power source configured to output a high-frequency voltage for ionizing the process gas to generate plasma;   a substrate electrode disposed in the chamber and comprising a plurality of first electrode elements to a plurality of second electrode elements, each of the first electrode elements and each of the second electrode elements being alternately arranged;   a substrate holder configured to hold a substrate between the substrate electrode and the plasma;   a first and a second low-frequency power source configured to apply a first and a second low-frequency voltage of 20 MHz or less respectively to the first electrode elements and the second electrode elements to introduce ions in the plasma to the substrate, the first and second voltages having phases different from each other; and   a rotator configured to rotate the substrate relatively to the substrate electrode; and   a controller configured to control the rotator to rotate the substrate while the ions in the plasma are introduced to the substrate.   
     
     
         22 . The apparatus according to  claim 21 ,
 wherein each of the first and second electrode elements has a column shape.   
     
     
         23 . The apparatus according to  claim 21 ,
 wherein the phase differences is approximately π/2 or −π/2.   
     
     
         24 . The apparatus according to  claim 21 ,
 wherein the substrate electrode further comprises a plurality of third electrode elements having a column shape with an axis in parallel to the axes of the first and second electrode elements and to the main surface of the substrate, each of the first electrode elements to each of the third electrode elements are sequentially arranged,   wherein the apparatus comprises the third low-frequency power source to apply a third low-frequency voltage of 20 MHz or less to the third electrode elements, the first to the third low-frequency voltage have phases different from each other,   wherein phase differences between the low-frequency voltages applied to adjacent electrode element are approximately 2π/3 or −2π/3.   
     
     
         25 . The apparatus according to  claim 21 ,
 wherein the substrate electrode further comprises a plurality of fourth electrode elements having a column shape with an axis in parallel to the axes of the first to third electrode elements and to the main surface of the substrate, each of the first electrode elements to each of fourth third electrode elements are sequentially arranged,   wherein the apparatus comprises the fourth low-frequency power source to apply a fourth low-frequency voltage of 20 MHz or less to the third electrode elements, the first to the fourth low-frequency voltage have phases different from each other,   wherein phases of the first to fourth low-frequency voltages are 0, +π/2, −π, and +3π/2, or 0, −π/2, −π, and −3π/2, respectively.   
     
     
         26 . The apparatus according to  claim 21 ,
 wherein intervals between adjacent electrode elements are 5 mm or less.   
     
     
         27 . The apparatus according to  claim 21 ,
 wherein the first and second electrode elements have axes along a direction in parallel to the substrate.   
     
     
         28 . The apparatus according to  claim 27 , further comprising:
 a second substrate electrode comprising a plurality of electrode elements having axes along a second direction different from the direction; and   a switch configured to select the substrate electrode or the second substrate electrode and apply the low-frequency voltages to the selected substrate electrode.   
     
     
         29 . The apparatus according to  claim 21 , further comprising
 a phase adjuster configured to shift phases of the low-frequency voltages in accordance with a progress of a plasma processing process.   
     
     
         30 . The apparatus according to  claim 21 ,
 wherein the substrate holder comprises:   an attraction electrode disposed between the substrate and the substrate electrode, and comprising a plurality of openings, and   a direct-current power source configured to apply a direct-current voltage to the attraction electrode to make the attraction electrode attract the substrate.   
     
     
         31 . The apparatus according to  claim 30 ,
 wherein a width of each of the plurality of openings is not less than 2 mm nor more than 5 mm.   
     
     
         32 . The apparatus according to  claim 30 , further comprising
 a cooling medium supply configured to supply a cooling medium to cool the substrate through the openings.   
     
     
         33 . The apparatus according to  claim 21 ,
 wherein the high-frequency power source applies the high-frequency voltage of 40 MHz or more to the substrate electrode.   
     
     
         34 . The apparatus according to  claim 21 , further comprising
 an induction coil to which the high-frequency voltage is applied.   
     
     
         35 . The apparatus according to  claim 21 , further comprising
 a counter electrode to which the high-frequency voltage is applied.   
     
     
         36 . A plasma processing method, comprising:
 placing a substrate directly or indirectly on a substrate electrode in a chamber, the substrate electrode comprising a plurality of first electrode elements to a plurality of second electrode elements, each of the first electrode elements and each of the second electrode elements being sequentially arranged;   introducing process gas into the chamber;   ionizing the process gas in the chamber to generate plasma on the side of the substrate opposite from the substrate electrode;   applying a first and a second low-frequency voltage of 20 MHz or less respectively to the first electrode elements and the second electrode elements to introduce ions in the plasma to the substrate, the first and second voltages having phases different from each other; and   rotating the substrate relatively to the substrate electrode while the ions in the plasma are introduced to the substrate.