Left: Principle sketch of SBIL setup with two mirrors. Right: Simulation of SBIL in x-direction with different disturbances. The first scenario shows a perfect scan without disturbances. The second scenario shows the case in which the fringes in the exposure pattern move up and down alternately due to phase fluctuations and generate curved paths. In the next scenario, the angle of incidence drifts during scanning. This changes the period of the fringe during the exposure. In the last scenario, the fringe pattern is rotated to the scan direction, thus leads to poor dose contrast during exposure.