Abstract: Provided is an exhaust unit capable of preventing large pressure fluctuations within a process chamber due to atmospheric pressure changes. The exhaust unit includes a main exhaust duct and a supplemental exhaust duct that acts as a partial bypass. A flap is located at a downstream opening between the main exhaust duct and supplemental exhaust duct and controls the amount of bypassed gas flowing from the supplemental exhaust duct to the main exhaust duct. First and second plates of the flap are pivotally coupled to the main exhaust duct adjacent the downstream opening, the first plate colliding with gas flowing through the main exhaust duct and the second plate partially blocking bypassed gas flowing back into the main exhaust duct from the supplemental exhaust duct. When gas is exhausted through the main exhaust line and the supplemental exhaust duct, the flap passively controls the amount by which the supplemental exhaust duct is opened through fluctuations in atmospheric pressure.

Abstract: An air shower head of an exposure device of photolithography equipment is free of chemical substances that could otherwise contaminate a photoresist layer on a semiconductor wafer and degrade the profile of the photoresist pattern. The air shower head is interposed between a lens system of the exposure device and a wafer stage, and has a hole in the middle thereof through which exposure light can pass to a wafer supported on the stage. The air shower head includes an upper frame defining a cavity open at the bottom thereof, and a porous bottom member covering the bottom of the upper frame. The porous member is mechanically secured to bottom ends of both the inner and outer side walls of the upper frame, i.e., without the use of chemical binders, to reduce the ability of the air shower head to serve as a source of contamination.

Abstract: An air shower head of an exposure device of photolithography equipment is free of chemical substances that could otherwise contaminate a photoresist layer on a semiconductor wafer and degrade the profile of the photoresist pattern. The air shower head is interposed between a lens system of the exposure device and a wafer stage, and has a hole in the middle thereof through which exposure light can pass to a wafer supported on the stage. The air shower head includes an upper frame defining a cavity open at the bottom thereof, and a porous bottom member covering the bottom of the upper frame. The porous member is mechanically secured to bottom ends of both the inner and outer side walls of the upper frame, i.e., without the use of chemical binders, to reduce the ability of the air shower head to serve as a source of contamination.