Shower head, plasma processing apparatus and plasma processing method

摘要

A shower head includes a gas injection plate and a gas supply unit. The gas supply unit has a first gas supply path provided in a region along the axis and a second gas supply path provided in a region surrounding the region where the first gas supply path is provided. The first gas supply path has a first gas diffusion space connected to a first gas line of the gas supply unit, second gas lines, a second gas diffusion space, third gas lines and a third gas diffusion space which are connected in that order. The second gas supply path has a fourth gas diffusion space connected to a fourth gas line of the gas supply unit, fifth gas lines, a fifth gas diffusion space, sixth gas lines, and a sixth gas diffusion space which are connected in that order.

主权项

1. A shower head for a plasma processing apparatus, comprising:
a gas injection plate including an upper plate portion and a lower plate portion, the gas injection plate having a first region and a second region coaxially surrounding the first region about an axis, the axis being passing through a center of the gas injection plate in a vertical direction; and a gas supply unit provided on the gas injection plate, the gas supply unit including a first gas supply path and a second gas supply path arranged coaxially about the axis, wherein the first gas supply path is provided in a region along the axis to supply a processing gas to a plurality of first gas injection holes formed in the first region of the gas injection plate; the second gas supply path is provided in a region surrounding the region where the first gas supply path is provided to supply a processing gas to a plurality of second gas injection holes formed in the second region of the gas injection plate; the first gas supply path has a first gas line, a first gas diffusion space, a plurality of second gas lines, a second gas diffusion space, a plurality of third gas lines, and a third gas diffusion space which are connected in that order, the third gas diffusion space being connected to the first gas injection holes; and the second gas supply path has a fourth gas line, a fourth gas diffusion space, a plurality of fifth gas lines, a fifth gas diffusion space, a plurality of sixth gas lines, and a sixth gas diffusion space which are connected in that order, the sixth gas diffusion space being connected to the second gas injection holes; wherein the second gas lines are arranged in a circumferential direction about the axis and have conductances lower than conductances of the first gas diffusion space and the second gas diffusion space; the third gas lines are arranged in the circumferential direction and have conductances lower than conductances of the second gas diffusion space and the third gas diffusion space; the fifth gas lines are arranged in the circumferential direction and have conductances lower than conductances of the fourth gas diffusion space and the fifth gas diffusion space; and the sixth gas lines are arranged in the circumferential direction and have conductances lower than conductances of the fifth gas diffusion space and the sixth gas diffusion space, wherein the gas supply unit further includes an upper member formed of a first member having a plurality of through holes and a second member having a plurality of through holes, a recess and a groove, and the first member and the second member is connected as a single unit by diffusion bonding, such that the upper member defines the fourth gas diffusion space, the first gas line, fourth gas line, and a part of the first gas diffusion space; wherein the gas supply unit further includes an intermediate member defining the remaining part of the first gas diffusion space, the second gas lines, the fifth gas lines, and a part of the second gas diffusion space; and wherein the gas supply unit further includes a lower member defining the remaining part of the second gas diffusion space and the fifth gas diffusion space at a surface side facing the intermediate member and defining the third gas diffusion space and the sixth gas diffusion space at a surface side facing the gas injection plate, wherein the upper member, the intermediate member, and the lower member are laminated such that the first gas diffusion space to the sixth gas diffusion space and the first gas line to the sixth gas line are formed, wherein a position where the first gas line is connected to the first gas diffusion space is spaced apart from the axis and a position where the fourth gas line is connected to the fourth gas diffusion space is spaced apart from the axis, wherein the gas injection plate further includes a third region extending to coaxially surround the second region; the gas supply unit further includes a third gas supply path arranged coaxially about the axis to supply a processing gas to a plurality of gas injection holes formed in the third region of the gas injection plate, the third gas supply path including a seventh gas diffusion space connected to a seventh gas line of the gas supply unit, a plurality of eighth gas lines, an eighth gas diffusion space, a plurality of ninth gas lines, and a ninth gas diffusion space which are connected in that order; the eighth gas lines are arranged in the circumferential direction and have conductances lower than the conductances of the seventh gas diffusion space and the eighth gas diffusion space; the ninth gas lines are arranged in the circumferential direction and have conductances lower than the conductances of the eighth gas diffusion space and the ninth gas diffusion space; and the seventh gas line has a first flow path extending along the axis and a plurality of second flow paths branched from the first flow path, the second flow paths extending in a radial direction about the axis and arranged in the circumferential direction, wherein volumes of the first gas supply path to the third gas supply path are substantially identical to each other.