Drytek poly-etch using Freon-22

Len Booth booth at snf.stanford.edu
Fri May 23 15:36:53 PDT 2003


Drytek users -
        As you know by now, the F-115 is gone, and
has been replaced by F-22.
        Jim McVittie & Henry have done characterization
of the F-22 in the poly etch process.  The contact 
cleanup process is not working yet - additional process
changes are being developed by Jim McVittie this weekend.
Do NOT use the contact cleanup etch in the Dryteks
until Jim has finished developing a new process.

        Those of you using poly-etch recipes which now are
using F-22, a temporary multiplier must be factored into
the dial setting that you must now use for the F-22 (MFC-3).

MFC-3   flowing F-115   @ max setpoint 240= real flow of 240sccm

MFC-3   flowing F-22    @ max setpoint 240= real flow of 110sccm

        Therefore those of you using F-22 in MFC-3 should 
expect the setpoint range to be from 0 to 240 on the dial,
which will corespond to 0 to 110 sccm of F-22 measured flow
on the digital readout.

Examples for setting using F-22 in MFC-3:

	dial setting	digital flow	real F-22
			readout		Flow sccm
	240		238		110
	120		119		 55
	060		062		 27
	044		044		 20
	030		031		 13

        By next week we hope to correct the old recipe spec
information.
                        Len



More information about the drytek2 mailing list