Patent ID: 8221581

Claim:
A processing gas supply mechanism that is disposed so as to face opposite a stage inside a processing chamber and supplies a processing gas toward a processing target substrate held on said stage, comprising: a processing gas delivery port through which the processing gas is delivered; a processing gas supply mechanism main unit having formed therein a diffusion chamber through which said processing gas delivered through said processing gas delivery port is diffused; a plate member layered over said processing gas supply mechanism main unit on a side thereof toward said stage and constituted of a material with a coefficient of thermal expansion different from said processing gas supply mechanism main unit; and a plurality of processing gas supply holes through which the processing gas is supplied into said processing chamber from said diffusion chamber, wherein: said processing gas supply holes are each constituted with a gas outlet hole formed at said plate member and a gas injection hole formed at said processing gas supply mechanism main unit; and said gas injection hole is formed so that the processing gas flowing in from said diffusion chamber communicating with a gas injection hole on an upstream side thereof is injected toward said gas outlet hole from an injection opening at a nozzle portion disposed on a downstream side thereof, and a suction flow passage with an upstream side thereof communicating with a boundary of said gas supply mechanism main unit and said plate member and a downstream side thereof connecting to said gas outlet hole is formed around said nozzle portion.