IPC Definitions - January 01, 2012

G03F 1/62 - Definition fr

Definition statement

This group covers:

Subject matter of main group G03F 1/00 in which the pellicles, per se, or the pellicles in combination with radiation modifying products, provide protection for a patterned mask by excluding foreign matter (e.g., solid particles of dust) that would otherwise degrade proper imaging from the patterned mask (e.g., pellicle assembly having membrane on support frame).

Note. In this subgroup, the pellicle often includes a thin transparent layer (such as a transparent flexible membrane) attached to a rigid frame to hold the thin transparent layer at a specified distance away from the mask pattern so that foreign matter collecting on the outside of the pellicle will not be in the range of focus during imaging, in order to avoid degradation of the resulting imaged pattern produced from the mask. Alternatively, the pellicle can be a hard self-supporting layer, having a specified thickness and transparency, that is formed on the patterned mask. In either case, the pellicle still protects the mask, to which the pellicle is attached, from dust adhering on the mask pattern that would otherwise occur during imaging of the mask without any benefit of the pellicle.