Fabrication of Tunable Duty Cycle Metal Wire Nanograting by Oblique Sputtering

A method to fabricate metal wire nanogratings of tunable duty cycle (0.5
_~
0.9 and even larger) without using e-beam lithography (EBL) is demonstrated. This provides a low cost technology to realize subwavelength metal slit arrays. The fabrication processes and the details of accurately controlling the grating shape are disclosed. The transmission properties of the metal wire nanograting with different duty cycles are discussed. The technique to make multiple layer metal wire grating using oblique deposition is also proposed.