Hi, I am currently working on developing a process that involves Honeywell's Spin-on-Glass (SOG) 512B that is deposited on LPCVD Silicon Nitride wafers. I am using a RIE dry etch to pattern the SOG, and apparently my recipe etches the nitride faster than it does the SOG. The recipe I am using includes CHF3 (40 sccm flow rate), Ar (70 sccm), and CF4 (7sccm). This recipe etches SOG at a rate of 0.20 microns/min, and nitride at 0.5 microns/min. Since my main concern is etching SOG, and I need the nitride for insulation puroposes, I was looking for an alternative RIE etch that would be selective to LPCVD silicon nitride. I really appreciate your help. Thanks, Abdel Moneim Marzouk