On what basis do you make these suggestions? Do you have first hand experience? Thanks, James Jie Zou wrote: > Try first less bias. then less RF power. then less SF6. > > On Tue, May 19, 2009 at 6:11 AM, shimul sahawrote: > >> Hello, >> >> I am using BOSCH process for deep dry etching of silicon. The gases are SF6, O2 during etching cycles and C4F8 during deposition cycles.. At present I am getting slightly negative sidewall, but I want a positive sidewall. Can you please provide any hint, probably changing gas ratio (incerase or decrease any of the gas content) or power to get a positive sidewall in etching. Any suggestions will be greatly helpful for me. Thanking you in advance. >> >> Best regards, >> Shimul -- Dr. James Paul Grant Postdoctoral Research Associate Microsystems Technology Group 76 Oakfield Avenue Room 3 University of Glasgow Glasgow Scotland G12 8LS Telephone: +44(0)141 330 3374