Determination of Helium presence in the mask/wafer gap of X-ray lithography steppers

This paper describes a technique to determine the presence and uniformity of Helium in the mask/wafer gap of x-ray lithography steppers by utilizing the oxygen sensitive resist polychlorostyrene (PSC). Results obtained at the IBM Advanced Lithography Facility using a SUSS stepper and the HELIOS superconducting synchrotron storage ring are presented. © 1995 Elsevier Science B.V. All rights reserved.