One embodiment of the invention provides a system for reducing incidental exposure caused by phase shifting during fabrication of a semiconductor chip. The system operates by identifying a problem area of likely incidental exposure in close proximity to an existing phase shifter on a phase shifting mask,...http://www.google.com.au/patents/US20020142231?utm_source=gb-gplus-sharePatent US20020142231 - Method and apparatus for reducing incidental exposure by using a phase shifter with a variable regulator
