Research On Fabrication Of Nano-array Patterns By Multi-beam Holographic Lithography

This paper is based on the theories of interference of light, holographic lithography and fringe locking technology. In this paper, the nanoscale graphic array has been firstly designed through the theoretical analysis, and then the periodic grating, hole array and dot array are successfully prepared in the photoresist by establishing a system of multiple beam holographic lithography. Both of periodic arrays have the period of 528 nm.And then high resolution, large field of view, fine nanoscale array pattern are prepared by wet etching and dry etching technique.The periodic array is fabricated on GaAs substrate. The single exposure for grating in holographic lithography is adopted to optimized exposure time of 40 s.The double exposure for hole array in holographic lithography is adopted to optimized exposure time of 60 s, and the optimal time of dot array is 90 s. Wet etching solution with 1:1:10 volume ratio of H3PO4,H2O2 and H2 O is adopted to etch the grating for 20 s, and to etch the hole array and dot array for 30 s.Images of scanning electron microscopy(SEM) show that the grating the hole array and dot array has a period of 528 nm, etching depth of grating is 85 nm, and the etching depth of hole array is 124 nm, with perfect surface morphology, good fringe continuity and uniformity.Finally, based on the technologies mentioned above, Periodic dot array would be optimized with the help of image reverse process, meanwhile, the precision of periodic dot array would be improved as well. The etching depth of dot array is 124 nm, the diameter of the dot structure is 340 nm.