Mixed Gas Composition for CVD Reactor Cleaning
Publication Date: 2003-Sep-12
The IP.com Prior Art Database
A blend of 2 to 12 % F2 in NF3 has been proposed for in situ CVD reactor cleans. This blend had been shown to give improved "clean" rates downstream from the primary discharge in a plasma clean step. Unfortunately this mixture represents a much more difficult gas handling challenge than either of the two individual constituents. NF3, a strong oxidizer, can be used in a safe, routine manner if the proper safety precautions are followed. On the other hand, molecular fluorine is an extremely reactive chemical and extensive safety measures must be taken for its safe use. The danger occurs when the NF3 is heated, either through chemical reaction or adiabatic compression, to a temperature where free fluorine is generated. The potential problem exists since the free fluorine can act as an initiator if it contacts any incompatible materials, and the NF3 could sustain a fire or an explosion.