RET simulations for SLM-based maskless lithography

In this paper, we have preformed some simulations of reticle enhancement techniques (RET) for SLM-based maskless lithography. Our results show that, on the one hand, increased slope and larger process window can be simultaneously obtained by overtilting some mirrors around the printed structure; On the other hand, fully making use of the grayscaling generated by tilting a mirror across it, a maskless tool can use the same OPC model as a mask-based scanner, such as gray level serifs, sub-resolution scatter bars, transmittance controlled mask, and so on. The results also imply that optical maskless lithography (OML) provides the ability in attaining high resolution comparable to the mask-based lithography.