Aluminum oxide LPCVD system

摘要

A process and apparatus for Al2O3 CVD on silicon wafers using aluminum tri-isopropoxide in a high-volume production environment is presented. The conditions required to use ATI in a production environment and provide maximum utilization of ATI are first of all delivery of ATI via direct evaporation. The ATI source bottle is pumped out (bypassing substrates) until propene and isopropanol signals are reduced to 1% of process pressure before start of aluminum oxide deposition. Either IR spectroscopy or mass spectrometry can be used to provide a control signal to the microprocessor controller. Heating the supplied tetramer to 120 DEG C. for two hours assures complete conversion to trimer. The ATI is stored at 90 DEG C. to minimize decomposition during idle periods and allow recovery of trimer upon return to 120 DEG C. for two hours. During periods of demand, the ATI is held at 120 DEG C. to minimize decomposition.