Abstract: A method and system for measuring stray light for use in an exposure apparatus uses an image sensor to be disposed at a wafer level in the exposure apparatus. The stray light is measured by preparing a reference pattern and a measuring pattern on a reticle. The reference pattern includes a light shielding region having first open regions for transmitting light to a center of an active region of the image sensor. The measuring pattern includes a light shielding region having second open regions for transmitting light to a periphery of the active region. A first intensity of light reaching the active region after being filtered by the reference pattern and a second intensity of light reaching the image sensor after being filtered by the measuring pattern are measured. The intensity of the stray light is evaluated by a difference between the first and second light intensities.

Abstract: A method and system for measuring stray light for use in an exposure apparatus uses an image sensor to be disposed at a wafer level in the exposure apparatus. The stray light is measured by preparing a reference pattern and a measuring pattern on a reticle. The reference pattern includes a light shielding region having first open regions for transmitting light to a center of an active region of the image sensor. The measuring pattern includes a light shielding region having second open regions for transmitting light to a periphery of the active region. A first intensity of light reaching the active region after being filtered by the reference pattern and a second intensity of light reaching the image sensor after being filtered by the measuring pattern are measured. The intensity of the stray light is evaluated by a difference between the first and second light intensities.

Abstract: A stencil mask includes a membrane forming thin layer having membrane areas and a border area that limits the membrane areas. The membrane areas have a plurality of pattern areas which include an aperture through which particle beams can permeate and non-pattern areas interposed between the pattern areas. A main strut supports the membrane areas and is formed on the border area of the membrane forming thin layer. An auxiliary strut is formed in the non-pattern areas inside the membrane pattern area such that the auxiliary strut divides the membrane areas into plural divided membrane areas. The auxiliary strut supports the divided membrane areas.

Abstract: A photomask is useful in measuring the aberration of an optical lens. The photomask includes a transparent substrate, a first opaque pattern formed on a first surface of the transparent substrate and defining a plurality of apertures that expose the first surface, and a second opaque pattern formed on the second surface of the transparent substrate. The photomask is placed in an exposure apparatus between a light source of the exposure apparatus and an optical lens whose aberration is to be measured. A photoresist layer on a wafer is exposed through the photomask and the pupil of the optical lens to form a first pattern on the wafer corresponding to the second opaque pattern of the photomask. The aberration of the pupil of the optical lens is evaluated based on the relative location at which the first pattern is formed on the wafer.