Exposure apparatus, a tilting device method for performing a tilted focus test, and a device manufactured accordingly

A method of performing a tilted focus test, comprising:

• providing a target object;
• providing a projection beam of radiation;
• providing a patterning device having a pattern to impart the projection beam with a patterned cross-section;
• projecting the patterned beam of radiation onto the target object, providing the projection beam with a tilt;
• determining a lateral shift of the projected patterned beam;
• and
• determining, from said lateral shift, a defocus of the target object with respect to the projected patterned beam.

A device manufactured according to a method comprising:

• providing a target object;
• providing a projection beam of radiation;
• providing a patterning device having a pattern to impart the projection beam with a patterned cross-section;
• projecting the patterned beam of radiation onto the target object,
• providing the projection beam with a tilt;
• determining a lateral shift of the projected patterned beam;
• and
• determining, from said lateral shift, a defocus of the target object with respect to the projected patterned beam.