Patent ID: 7712435

Claim:
A plasma processing apparatus comprising: a reaction chamber; two electrodes provided inside the reaction chamber for generating a plasma therebetween, wherein one of the electrodes is a showerhead comprised of a top plate, a shower plate, and a space formed between the top plate and the shower plate, said top plate having at least one gas inlet pore for introducing a gas into the space therethrough, said shower plate having multiple holes for introducing the gas included inside the space into the reaction chamber therethrough; and a gas inlet pipe coupled to the gas inlet pore for introducing the gas into the space, said gas inlet pipe being insulated from the gas inlet pore at a boundary between the gas inlet pipe and the top plate, wherein an insulation member is placed inside the gas inlet pipe upstream of the boundary and inside the gas inlet pore downstream of the boundary, wherein the gas inlet pipe is grounded whereas the top plate having the gas inlet pore has a potential voltage such as would generate an arc discharge between the top plate at the gas inlet pore and the gas inlet pipe without the insulation member, and wherein the insulation member covers an area continuously from a portion of the inside of the gas inlet pipe, through the boundary, to a portion of the inside of the gas inlet pore so as to suppress generation of an arc discharge between the gas inlet pipe and the top plate at the gas inlet pore.