Figure 6.

X-ray energy-dispersive spectroscopy (EDS) area scan for chemical composition of O, Si, Cr. (a) A film of 40 nm Cr was coated on Si substrate before laser exposure. Edge between Si and Cr coating was determined by a cover glass rim during e-beam evaporation. (b) A Cr–Si alloyed ring at pulse energy of $E_p=1.1\pm 0.1$ nJ (on sample); $\lambda =515$ nm wavelength, objective lens of $NA=0.9$. Cr was washed out after the laser exposure by Cr-etch; surface around the ring is Si.