IPC Definitions - January 01, 2012

G03F 1/54 - Definition fr

Definition statement

This group covers:

Subject matter of main group G03F 1/00 in which the radiation modifying products have an absorber (e.g., of opaque material) which functions to absorb incident radiation.

(1) Note. The absorber can be a particular opaque material that is chemically defined (e.g., tantalum (Ta), gold (Au), chromium (Cr), carbon (C), molybdenum silicide (MoSi)). Alternatively, the absorber can have a specific pattern (e.g., an unresolvable grid pattern leading to a grey tone mask, a gradient mask), a particular thickness (e.g., making the absorber region semi-transparent to provide only 20% transmittance for incident radiation at a target wavelength for imaging), or a given internal structure (e.g., multilayer absorber, ion implanted opaque layer to change an optical property for absorbing more incident radiation).

(2) Note. Excluded from this subgroup are attenuating phase shift masks (PSMs) having PS regions created by sufficiently reducing the thickness of a normally opaque absorber layer material, such as a thin layer of chromium (Cr) often called "leaky chrome".