If you are using a normal exposure to define a square the corners get exposed from both sides and the corners start to disappear. Controlled over exposure can create a circle or close to it. Bill Moffat. -----Original Message----- From: mems-talk-bounces+bmoffat=yieldengineering.com@memsnet.org [mailto:mems-talk-bounces+bmoffat=yieldengineering.com@memsnet.org] On Behalf Of Yingnan Wang Sent: Tuesday, August 03, 2010 7:03 AM To: mems-talk@memsnet.org Subject: Re: [mems-talk] lithography fin etch to define silicon NW Hi Chen, I think you can round the corners by annealing the silicon NW in hydrogen. BR, YN WANG