Extended Data Fig. 1: Fabrication Workflow.
From: Optical control of resonances in temporally symmetry-broken metasurfaces
(a) The 115 nm crystalline silicon (c-Si) film on Al2O3 is first coated with a 40 nm layer of Cr via sputtering, followed by spin-coating with 125 nm of electron beam lithography (EBL) resist. (b) The resist is exposed in an EBL machine and developed using a two-step process. (c) The patterned resist serves as a mask for anisotropic etching of the Cr film using reactive ion etching (RIE). (d) During the liftoff the remaining resist is chemically removed. (e) The Cr layer is then used as a hard mask to etch down the 115 nm c-Si film. (f) The remaining Cr is chemically wet-etched. (g) Finally, the c-Si film is encapsulated in spin-on-glass (resembling SiO2) with approximately 1000 nm height.
