Torsten: Your point is well made. I too gain some insight from the problems and questions that arise from this exchange. I also agree that many of the questions could be answered the old fashion way by researching what is already available particularly via the internet. I am still available to anyone who might have questions relating to wafer processing with emphasis on plasma etching of all types and materials relating to MEMS and other devices. My phone number is 602-206-6154 and is available to anyone with a serious question. Bob Henderson