Mounting table and plasma processing apparatus

A wafer stage for use in a plasma processing apparatus, the wafer stage comprising:

• a conductive base having first and second base through-holes;
• a first insulating spacer disposed in the first base through-hole, the first insulating spacer having a first spacer through-hole,
• a second insulating spacer disposed in the second base through-hole, the second insulating spacer having a second spacer through-hole,
• an electrostatic chuck disposed on the conductive base, the electrostatic chuck having first and second chuck through-holes, the first chuck through-hole being in communication with the first spacer through-hole, the second chuck through-hole being in communication with the second spacer through-hole, each of the first and second chuck through-holes being defined by a vertical wall;
• a fixed pin disposed in the first spacer through-hole and the first chuck through-hole, a first gap is defined between the fixed pin and the first chuck through-hole, a second gap is defined between the fixed pin and the first spacer through-hole, the first gap is greater than the second gap;
• and
• a lifter pin disposed in the second spacer through-hole and the second chuck through-hole, a third gap is defined between the lifter pin and the second chuck through-hole, a fourth gap is defined between the lifter pin and the second spacer through-hole, the third gap is greater than the fourth gap.

A wafer stage for use in a plasma processing apparatus, the wafer stage comprising:

• a base having a first through-hole;
• an electrostatic chuck disposed on the base, the electrostatic chuck having a second through-hole in communication with the first through-hole, the second through-hole being defined by a vertical wall;
• and
• a pin disposed in the first through-hole and the second through hole, a first gap is defined between the pin and the first through-hole, a second gap is defined between the pin and the second through-hole, the second gap is greater than the first gap.