Abstract: We have discovered that exposure of a photoresist on a photomask substrate to a vacuum after the photoresist has been exposed to imaging radiation results in improved critical dimension uniformity of the developed photoresist. Exposure of the imaged photoresist to vacuum is performed for a period of time sufficient to allow pattern critical dimensions to reach equilibrium across the photoresist. The vacuum treatment process of the invention is typically performed prior to the performance of a post-exposure bake process and prior to development of the photoresist. We have also discovered that exposure of a photoresist on a photomask substrate to a vacuum after the photoresist has been developed results in an improvement in the line edge roughness of pattern openings that have been formed through the photoresist layer thickness.

Abstract: An electric guitar has an electromagnetic resonating unit (3) which is arranged to resonate the strings (2) of the guitar, either individually or together. The resonance of each string is picked up by a pick-up unit (4), and the frequency of resonation of the string is detected and compared with a desired value. A tension adjusting unit (5) adjusts the tension in each string (2) until the frequency of resonance of the string correponds to the desired frequency, in order to tune the guitar to a desired tuning pattern. A control panel (6) on the body (1) of the guitar displays optional tuning patterns which may be selected by a user. Automatic tuning of the guitar may be achieved, without requiring the strings to be plucked manually.