Patent ID: 7678225

Claim:
A plasma processing apparatus for a semiconductor process, comprising: an airtight process chamber; a supply system configured to supply a process gas into the process chamber; an exhaust system configured to vacuum-exhaust the process chamber; an exciting mechanism configured to excite the process gas to turn into plasma; a worktable disposed in the process chamber and having a main mount surface to support a target substrate having a target surface extending in a horizontal direction; and a focus ring disposed to surround the target substrate in order to cause the plasma to focus toward the target surface, wherein the focus ring comprises a ring main body consisting essentially of a material selected from the group consisting of quartz, and ceramic of Al 2 O 3 or SiC, and an adjustment member fitted in the ring main body and consisting essentially of a material selected from the group consisting of silicon, aluminum surfaced with alumina, silicon carbide, and carbon, the ring main body and the adjustment member are positioned relative to one another and the target surface to set a peak of density of the plasma at a position outside an outer edge of the target substrate so as to provide a more uniform density of the plasma on the target substrate, the ring main body provides an inner region configured to surround the target substrate, and having a surface extending substantially in the horizontal direction to surround the target substrate and consisting essentially of a dielectric on a side to be exposed to the plasma, the adjustment member provides a middle region surrounding the inner region, and having a surface extending substantially in the horizontal direction to surround the target substrate and consisting essentially of an electric conductor that is continuous in a horizontal angular direction on a side to be exposed to the plasma, and the ring main body also provides an outer region surrounding the middle region, and having a surface extending substantially in the horizontal direction to surround the target substrate and consisting essentially of a dielectric on a side to be exposed to the plasma, and wherein the ring main body further includes an inner extending step consisting essentially of a dielectric and being disposed on an inner side of the inner region to extend below and spaced apart from the target substrate.