<title>Step-and-scan and step-and-repeat: a technology comparison</title>

Silicon Photonics Circuit Design: Methods, Tools and Challenges

“…But the layout of a circuit can be optimized to make this correlation as robust as possible. This device matching problem is also known in analog electronics design, and it is addressed at the layout level by – Positioning devices as close together as possible : this helps to keep the layer thicknesses and local pattern densities similar. – Maintaining the same orientation : As high‐end optical lithography uses a step‐and‐scan system rather than a step‐and‐repeat, there is a small but intrinsic anisotropy in the projection system. By orienting components along the same axis, the mismatch is minimized. – Using so‐called Manhattan geometries : Orienting as many device facets along the X and Y direction brings two benefits: In crystalline silicon, this corresponds to crystal planes, which can give rise to a more uniform etch quality.…”

“…This device matching problem is also known in analog electronics design, and it is addressed at the layout level by -Positioning devices as close together as possible: this helps to keep the layer thicknesses and local pattern densities similar. -Maintaining the same orientation: As high-end optical lithography uses a step-and-scan system rather than a step-andrepeat, [160] there is a small but intrinsic anisotropy in the projection system. By orienting components along the same axis, the mismatch is minimized.…”

Optical lithography—a historical perspective

“…The last evolution in optical exposure systems was the transition to step and scan systems (also commonly called 'scanners') [1]. Here the complexity of the optics was further reduced by only projecting one slit of the mask onto the wafer and scanning wafer and reticle in a synchronized way to complete the total mask image.…”

A real-time exposure dose control algorithm for DUV excimer lasers

“…In the process of scan exposure, the die goes through an illuminated slit at a constant velocity to get a number of pulses or a burst of energy. Consequently, the exposure dose is the accumulated energy of all pulses in the burst [9]. Apparently, pulse-to-pulse energy fluctuation, especially energy overshot, influences dose accuracy and dose uniformity significantly, although several pulses may smooth this effect -the more pulses in a burst, the better the smoothness that can be achieved in theory.…”