This number apparently refers to only the cost of running the furnace alone I think the author has ignored the pumps, gas handling, etc. The cost of running a LPCVD SiN process will be considerably more than the cost of running an oxidation furnace. Roger Shile -----Original Message----- Dear Members, I am trying to find a cost of ownership "COO" model for LPCVD SiN Mask with SiO2 under-layer deposition. The mask will be used for KOH etching. On the web I found the following: ........ Step Description Machine used Cost per wafer .... 2 Oxidation Furnace $0.43 3 Nitridation Furnace $0.43 .....