Photoresist suck-back device in manufacturing system for semiconductor devices

A photoresist suck-back device for preventing the accumulation of photoresist inside a photoresist spray line, the device comprising:

• a pneumatic drive;
• a photoresist supply line;
• a photoresist spray line in selective fluid communication with said photoresist supply line, said photoresist spray line having a photoresist-confronting inner sidewall;
• a suck-back valve for sucking back a portion of photoresist within said photoresist spray line, said suck-back valve being coupled with said photoresist spray line, said suck-back valve comprising:
• a diaphragm having a photoresist-confronting inner surface;
• a chamber substantially sealed by said diaphragm, said diaphragm defining a wall of said chamber and being movable therein to vary the volume of said chamber;
• and
• a piston coupled with said diaphragm, said piston further being coupled with said pneumatic drive to vary the volume of said chamber by movement of said diaphragm therein,
• said suck-back valve being mounted adjacent said photoresist spray line with said diaphragm forming a substantially contiguous sidewall of said photoresist spray line in a flush relationship therewith,
• said device further comprising:
• a valve coupled with said pneumatic drive, said valve being positioned between said photoresist supply line and said photoresist spray line, said valve when open permitting photoresist to flow from said photoresist supply line into said photoresist spray line and said valve when closed preventing such flow of photoresist from said photoresist supply line to said photoresist spray line, said closing of said supply line activating said piston to reduce said volume of said chamber thereby to form a concavity in the region of said diaphragm for holding the portion of photoresist.

A method of sucking back photoresist in a photoresist spray line having a sidewall, the method comprising:

• providing a suction chamber in communication with the photoresist spray line;
• separating the suction chamber from the photoresist spray line with a diaphragm, said diaphragm having a fluid-confronting surface that forms a generally planar region of the sidewall of the spray line that is flush therewith;
• increasing pressure in the suction chamber when photoresist is allowed to flow in the photoresist spray line;
• and
• decreasing the pressure in the suction chamber when the flow of photoresist in the photoresist spray line is halted.