System and method for lithography process monitoring and control

A system to collect image data which is representative of an aerial image of a mask that is projected, by an optical system, on a wafer plane of lithographic equipment, the system comprising:

• an image sensor unit, disposed on the moveable platform, to collect data which is representative of the aerial image of the mask, the image sensor unit includes:
• a substrate adapted to be disposed on a platform of the lithographic equipment;
• a sensor array, disposed on or in, or integrated into the substrate, wherein the sensor array is capable of being located in the wafer plane, the sensor array includes:
• a plurality of sensor cells wherein each sensor cell includes an active area to sense light of a predetermined wavelength that is incident thereon;
• and
• a film, disposed over the active areas of the plurality of sensor cells and including a material that impedes passage of light of the predetermined wavelength, wherein the film includes a plurality of apertures which are arranged such that an aperture of the plurality of apertures overlies an associated active area of a corresponding sensor cell to expose a portion of the associated active area and wherein light of the predetermined wavelength is capable of being sensed by the portion of the active area that is exposed by the associated aperture.

An image sensor unit, for use with photolithographic equipment, the image sensor unit comprising:

• a substrate adapted to be disposed on a platform of the lithographic equipment;
• a sensor array, disposed on or in, or integrated into the substrate, the sensor array including:
• a plurality of sensor cells wherein each sensor cell includes an active area to sense light of a predetermined wavelength that is incident thereon;
• and
• a film, disposed over the active areas of the plurality of sensor cells and comprised of a material that impedes passage of light of the predetermined wavelength, wherein the film includes a plurality of apertures which are arranged such that an aperture of the plurality of apertures overlies an active area of a corresponding sensor cell to expose a portion of the active area and wherein light of the predetermined wavelength is capable of being sensed by the portion of the active area that is exposed by the corresponding aperture.