Method and apparatus for thin films formation by CVD

摘要

A method and apparatus for ramping down the deposition pressure in a SACVD process. The present invention also provides a method and apparatus for subsequently ramping up the pressure for a PECVD process in such a manner as to prevent unwanted reactions which could form a weak interlayer interface. In particular, the deposition pressure in the SACVD process is ramped down by stopping the flow of the silicon containing gas (preferably TEOS) and/or the carrier gas (preferably helium), while diluting the flow of ozone with oxygen. A ramp down of the pressure starts at the same time. The diluting of the ozone with oxygen limits reactions with undesired reactants at the end of a process. <IMAGE>