VERTICAL DIFFUSION FURNACE WITH PARTICLE COUNTING FUNCTION

摘要

PURPOSE: A vertical diffusion furnace with a particle counting function is provided to take necessary actions like a cleaning process without performing a deposition process when plenty of particles more than a reference value are detected by measuring the number of the particles generated in the vertical diffusion furnace before the deposition process. CONSTITUTION: A deposition process regarding a wafer is performed in an inner tube(130). An outer tube(140) seals the inner tube and is installed in the outside of the inner tube. The inner tube and the outer tube are mounted on a flange(160). A gas spray unit supplies source gas and process gas to the inner tube. The gas spray unit is inserted through a spray pipe insertion hole formed in a side of the flange. A pump(180) absorbs the gas of the inner tube. A heater(150) heats the wafer. A particle counter(185) measures the number of the particles in the gas absorbed by the pump to reduce the pressure of the inner tube before a deposition process. The particle counter(185) compares the number of the particles with a predetermined reference value.