PLASMA PROCESSING APPARATUS
There is provided a plasma processing apparatus enabling uniform plasma processing over the entire surface of a sample, without causing abnormal discharge even when the electromagnetic field strength is strong as in the case of the inductive coupling method. The plasma processing apparatus includes a process chamber, a first dielectric vacuum window, an inductive coil, a radio-frequency power supply, a gas supply unit, and a sample holder. The gas supply unit includes a second dielectric gas guide plate and a third dielectric island member. The second dielectric gas guide plate is located near below the vacuum window, and has a gas inlet port in the center. The third dielectric island member is provided in a gap between the vacuum window and the gas guide plate. The dielectric constant of the third dielectric is higher than the dielectric constant of the first and second dielectrics.
1 . A plasma processing apparatus comprising:
a process chamber for plasma processing an object to be processed;
a first dielectric vacuum window for vacuum sealing the top of the process chamber;
an inductive coil provided above the vacuum window;
a radio-frequency power supply for supplying radio-frequency power to the inductive coil;
a gas supply unit for supplying gas into the process chamber; and
a sample holder on which the object to be processed is placed in the process chamber,
wherein the gas supply unit is located near below the vacuum window,
wherein the gas supply unit includes a second dielectric gas guide plate having a gas inlet port in the center thereof, and a third dielectric island member provided in a gap between the vacuum window and the gas guide plate,
wherein the dielectric constant of the third dielectric is higher than the dielectric constant of the first and second dielectrics,
wherein the gas transmitted to a gas flow path formed by the gap and the member, is supplied into the process chamber through the gas inlet port located in the center of the gas guide plate.
2 . The plasma processing apparatus according to claim 1 ,
wherein the member is formed by thermally spraying or depositing insulating material or by attaching insulating sheet.
3 . The plasma processing apparatus according to claim 1 ,
wherein the gas inlet port has a plurality of gas inlet holes.
4 . The plasma processing apparatus according to claim 1 ,
wherein the planar shape of the island member is rectangular or a fan-like shape.
5 . The plasma processing apparatus according to claim 1 ,
wherein when it is assumed that the distance of the member is W and the height of the gas flow path is H, the ratio W/H is 2.5 or less.
6 . The plasma processing apparatus according to claim 1 ,
wherein the inside of the member is formed with a conductor.
7 . The plasma processing apparatus according to claim 1 ,
wherein the island member is provided in the vicinity of the inductive coil.
8 . A plasma processing apparatus comprising:
a process chamber for plasma processing an object to be processed;
a first dielectric vacuum window for vacuum sealing the top of the process chamber;
an inductive coil provided above the vacuum window;
a radio-frequency power supply for supplying radio-frequency power to the inductive coil;
a gas supply unit for supplying gas into the process chamber; and
a sample holder on which the object to be processed is placed in the process chamber,
wherein the gas supply unit is located near below the vacuum window,
wherein the gas supply unit includes a second dielectric gas guide plate having a gas inlet port in the center thereof, and a conductor island member provided in a gap between the vacuum window and the gas guide plate,
wherein the gas transmitted to a gas flow path formed by the gap and the member is supplied into the process chamber through the gas inlet port located in the center of the gas guide plate.
9 . The plasma processing apparatus according to claim 8 ,
wherein the conductor is corrosion resistant to the gas.
10 . The plasma processing apparatus according to claim 8 ,
wherein the gas inlet port has a plurality of gas inlet holes.
11 . The plasma processing apparatus according to claim 8 ,
wherein the planar shape of the island member is rectangular or a fan-like shape.
12 . The plasma processing apparatus according to claim 8 ,
wherein the island member is located just below the inductive coil.