Process and method for in-situ dry cleaning of thin film deposition reactors and thin film layers

A method for cleaning reaction product deposits from interior surfaces of a chemical reactor chamber or from a substrate within said chemical reactor chamber, comprising the steps of:

• heating said reactor chamber to an elevated temperature of at least 100° C.;
• introducing an etchant gas into said reactor chamber, said etchant gas being of the general formula AOmXn, wherein:
• A is selected from the group consisting of C, N, and S;
• O is oxygen;
• X is a halogen;
• and
• the subscripts m and n are greater than zero;
• activating said etchant gas either before or after said introduction;
• allowing an etching reaction to proceed between said activated etchant gas and said reaction product deposits to remove said reaction product deposits without substantial re-deposition of etching reaction products within said reactor chamber;
• and
• evacuating said activated etchant gas together with substantially all products of said etching reaction;
• wherein pressure within said reactor chamber is between 20 mBar and 1000 mBar during said etching reaction.