Synchrotron-radiation-stimulated etching of SiO2 thin films with a tungsten nano-pillar mask

A nano-pattern of SiO(2) on a Si (100) surface has been demonstrated by synchrotron-radiation-stimulated etching with a tungsten nano-pillar mask. The reaction gas was a mixture of SF(6) and O(2). The mask was fabricated using a focused ion beam with W(CO)(6) as the source gas. The width and height of the tungsten nano-pillar were approximately 80 nm and 160 nm, respectively. Synchrotron radiation irradiation with flowing SF(6) and O(2) effectively etches the silicon dioxide, and the etching process followed the surface photochemical reaction. The etched surface was very flat, and no undercutting occurred during the etching process.