PLASMA PROCESSING APPARATUS AND METHOD

Abstract

In a plasma processing apparatus in which a radio-frequency power from a radio-frequency power source is supplied to at least one of an upper electrode and a lower electrode disposed to vertically face each other in a process vessel, to thereby generate, in the process vessel, plasma with which a substrate is processed, a chemical component emitting member which is caused to emit a chemical component necessary for processing the substrate into the process vessel by entrance of ions in the plasma generated in the process vessel is provided in the process vessel in an exposed state, and an impedance varying circuit varying impedance on the chemical component emitting member side of the plasma generated in the process vessel to frequency of the radio-frequency power source is connected to the chemical component emitting member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical cross-sectional view showing a schematic construction of a plasma etching apparatus according to an embodiment of the present invention;

FIG. 2 is a circuitry diagram of an impedance varying part;

FIG. 3( a) and FIG. 3(b) are views to explain a case where of a hole is formed in a semiconductor wafer by etching, FIG. 3(a) showing a state where etching with high anisotropy is performed and FIG. 3(b) showing a state where the hole has a bowing shape;

FIG. 4 is a circuit diagram showing a modified example of an impedance varying circuit;

FIG. 5 is a vertical cross-sectional view showing a schematic construction of a plasma etching apparatus according to an embodiment where a focus ring serves as a chemical component emitting member;

FIG. 6 is a vertical cross-sectional view showing a schematic construction of a plasma etching apparatus according to an embodiment where a chemical component emitting member is disposed around plasma generated in a process vessel;

FIG. 7 is a graph showing etching rate in center and peripheral edge portions of a semiconductor wafer; and

FIG. 8 is a vertical cross-sectional view showing a schematic construction of a plasma etching apparatus according to an embodiment including sensors detecting emission intensity (radical density) of plasma in the center and peripheral edge portions of the semiconductor wafer.

Claims

1. A plasma processing apparatus in which a radio-frequency power from a radio-frequency power source is supplied to at least one of an upper electrode and a lower electrode disposed to vertically face each other in a process vessel, to thereby generate, in the process vessel, plasma with which a substrate is processed, wherein a chemical component emitting member which is caused to emit a chemical component necessary for processing the substrate into the process vessel by entrance of ions in the plasma generated in the process vessel is provided in the process vessel in an exposed state, andwherein an impedance varying circuit varying impedance on said chemical component emitting member side of the plasma generated in the process vessel to frequency of the radio-frequency power source is connected to said chemical component emitting member.

2. The plasma processing apparatus according to claim 1, wherein said chemical component emitting member is disposed on a lower surface of the upper electrode.

3. The plasma processing apparatus according to claim 1, wherein said chemical component emitting member is a focus ring provided around a periphery of the lower electrode.

4. The plasma processing apparatus according to claim 1, wherein said chemical component emitting member is disposed around the plasma generated in the process vessel.

5. The plasma processing apparatus according to claim 1, wherein the chemical component necessary for processing the substrate is oxygen.

6. The plasma processing apparatus according to claim 5, wherein said chemical component emitting member is made of SiO2.

7. The plasma processing apparatus according to claim 1, wherein the chemical component necessary for processing the substrate is fluorine.

8. The plasma processing apparatus according to claim 7, wherein said chemical component emitting member is made of fluorocarbon resin.

9. A plasma processing method in which a radio-frequency power from a radio-frequency power source is supplied to at least one of an upper electrode and a lower electrode disposed to vertically face each other in a process vessel, to thereby generate, in the process vessel, plasma with which a substrate is processed, wherein a chemical component emitting member which is caused to emit a chemical component necessary for processing the substrate into the process vessel by entrance of ions in the plasma generated in the process vessel is disposed in the process vessel in an exposed state, andwherein impedance on said chemical component emitting member side of the plasma generated in the process vessel to frequency of the radio-frequency power source is varied, thereby controlling an emission amount of the component necessary for processing the substrate emitted into the process vessel from said chemical component emitting member.

10. The plasma processing method according to claim 9, wherein the chemical component necessary for processing the substrate is oxygen.

11. The plasma processing method according to claim 10, wherein said chemical component emitting member is made of SiO2.

12. The plasma processing method according to claim 9, wherein the chemical component necessary for processing the substrate is fluorine.

13. The plasma processing method according to claim 12, wherein said chemical component emitting member is made of fluorocarbon resin.