Capacitive coupling plasma processing apparatus
View Patent ↗A capacitive coupling plasma processing apparatus includes a process chamber configured to have a vacuum atmosphere, and a process gas supply section configured to supply a process gas into the chamber. In the chamber, a first electrode and a second electrode are disposed opposite each other. An RF power supply is disposed to supply an RF power to the first or second electrode to form an RF electric field within a plasma generation region between the first and second electrodes, so as to turn the process gas into plasma. The target substrate is supported by a support member between the first and second electrodes such that a process target surface thereof faces the second electrode. A conductive functional surface is disposed in a surrounding region around the plasma generation region and grounded to be coupled with the plasma in a sense of DC to expand the plasma.
1. A capacitive coupling plasma processing apparatus comprising:
a process chamber configured to have a vacuum atmosphere;
a process gas supply section configured to supply a process gas into the chamber;
a first electrode disposed in the chamber;
a second electrode disposed opposite the first electrode in the chamber;
an RF power supply configured to supply an RF power to the first or second electrode to form an RF electric field within a plasma generation region between the first and second electrodes, so as to turn the process gas into plasma by the RF electric field; and
a support member configured to support a target substrate between the first and second electrodes such that a process target surface of the target substrate faces the second electrode;
wherein the plasma generation region and a surrounding region around the plasma generation region inside the chamber are contained by a chamber inner surface comprising a component surface that is conductive and grounded,
a functional surface that is conductive and grounded is disposed in the surrounding region to expand the plasma outside the plasma generation region, and
the functional surface is covered with a first insulator while the component surface is covered with a second insulator, and the first and second insulators differ from each other such that the functional surface is coupled with the plasma in a sense of DC (direct current) while the component surface is not coupled with the plasma in a sense of DC.
2. The apparatus according to claim 1 , wherein the functional surface is disposed substantially concentrically with the target substrate supported by the support member.
3. The apparatus according to claim 1 , wherein the second insulator is thicker than the first insulator.
4. The apparatus according to claim 1 , wherein the functional surface is defined by a surface of a conductive member disposed on one or both of the support member and the chamber.
5. The apparatus according to claim 1 , wherein the functional surface is defined by a surface of a conductive portion of one or both of the support member and the chamber.
6. The apparatus according to claim 1 , wherein an exhaust passage for exhausting gas from the plasma generation region is formed around the support member, and the functional surface faces the exhaust passage.
7. The apparatus according to claim 6 , wherein the functional surface is disposed near a bottom of the chamber inside the exhaust passage.
8. The apparatus according to claim 1 , wherein a ring member is supported by the support member or the chamber to surround the support member, and includes a conductive portion having a surface serving as the functional surface.
9. The apparatus according to claim 8 , wherein the ring member comprises a conductive shield member disposed on a side surface of the support member.
10. The apparatus according to claim 8 , wherein an exhaust passage for exhausting gas from the plasma generation region is formed around the support member, and the ring member comprises a conductive exhaust ring disposed around the support member to partition the exhaust passage and having a hole for allowing gas to pass therethrough.
11. The apparatus according to claim 8 , wherein an exhaust passage for exhausting gas from the plasma generation region is formed around the support member, and the ring member is disposed to define part of an inner surface of the exhaust passage.
12. The apparatus according to claim 1 , wherein the RF power supply is connected to the first electrode.
13. The apparatus according to claim 1 , wherein the first electrode is built in the support member.
14. The apparatus according to claim 1 , wherein the RF power has a frequency of 40 MHz or more.
15. The apparatus according to claim 1 , wherein the functional surface is disposed inside the chamber at a position that is radially outside a focus ring to be disposed around the first electrode.
16. The apparatus according to claim 1 , wherein the first insulator comprises an anodized oxide film of aluminum and the second insulator comprises quartz.
17. The apparatus according to claim 1 , wherein the component surface is coupled with the plasma in a sense of AC (alternating current) or RF (radio frequency).