Method and apparatus for projection printing

An apparatus for printing highly accurate patterns, e.g. in microlithography, including:

• an image object,
• a workpiece,
• an illuminator illuminating the object and having an illuminator aperture function, an optical projection system having in the projection pupil a pupil function and forming a partially coherent image on the workpiece,
• where said projection aperture function has a continuous or semi-continuous variation with the pupil coordinate.

A method for printing highly accurate patterns, e.g. in microlithography, comprising the steps of

• providing an image object,
• providing a workpiece,
• providing an illuminator illuminating the object and having an illuminator aperture function,
• further providing an optical projection system having in the projection pupil a pupil function and forming a partially coherent image on the workpiece,
• where the projection aperture function and the pupil function are chosen to provide good fidelity for a set of different feature types.

A method for design of an illuminator aperture and a matching pupil functions in a partially coherent projection system, including:

• providing a simulator for the partially coherent image,
• providing a description of the optical system,
• providing restrictions on the optical system,
• further performing an optimization of the image fidelity by modifying said two functions.

A method for printing a microlithographic pattern with improved fidelity and resolution, including:

• providing an illuminator aperture function,
• providing a pupil function,
• said functions being chosen to give essentially flat CD linearity for at least two and preferably a least three feature types above a linewidth essentially equal to said interaction length
• further applying OPC corrections for at least one neighboring edge within said interaction length.