| CPC H01J 37/32633 (2013.01) [H01J 37/32642 (2013.01); H01J 2237/334 (2013.01)] | 11 Claims |
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1. A plasma baffle, comprising:
a lower ring;
an upper ring outside the lower ring in a plan view and extending vertically; and
an intermediate ring that extends from the lower ring to the upper ring to form an acute angle with respect to a horizontal direction,
wherein the lower ring includes:
a lower central hole that vertically penetrates a center of the lower ring; and
a plurality of lower slits outside the lower central hole and vertically penetrating the lower ring,
wherein the intermediate ring provides an intermediate slit that connects an inner lateral surface of the intermediate ring to an outer lateral surface of the intermediate ring,
wherein the plurality of lower slits and the intermediate slit are spaced apart from each other, and
wherein an area ratio of the plurality of lower slits to the lower ring is equal to or greater than about 59%.
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