Demcon focal has the capabilities to design, deliver and qualify one of the most demanding precision optical assemblies: the lithography lens. Demcon uses state-of-the-art alignment tooling (Opticentric) and cleanroom facilities to achieve diffraction limited imaging for a large field of view. We designed a lithography lens with high NA and large field of view that is capable of imaging semiconductor structures on wafers to produce processors, LEDs, MEMS, USB memory, etc.

Project specifics
● Magnification 5x (0.2x)
● Telecentric on image side
● FOV 22mm x 22 mm
● Diffraction limited
– CD < 0.4um (NA> 0.5)
– High CD uniformity (<2%)
● Useable DOF ~ 1 um
● Distortion < 100nm (maximum over field)
● Magnification needs to be adjustable using back-focus
– Order of magnitude 10 ppm
● Minimize magnification and focus errors due to short term temperature fluctuations within +/-0.1 degree
● Magnification change and focus due to pressure change is compensated using focus and back-focus only