Enhanced Depth of Lift-off Pattern Defined with Soft Mold Ultraviolet Nanoimprint by Multi-Layer Masks
WANG Zhi-Hao1**, LIU Wen1**, ZUO Qiang1, WANG Lei2, ZHAO Yan-Li1, XU Zhi-Mou1
1Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic information, Huazhong University of Science and Technology, Wuhan 430074 2State Key Laboratory of Optical Communication Technologies and Networks, Wuhan Research Institute of Posts and Telecommunications, Wuhan 430074
Abstract：The traditional lift-off process can hardly be carried out in ultraviolet nanoimprint defined patterns due to the poor solubility of the ultraviolet resist. Moreover, the depth of lift-off pattern defined by an ultraviolet nanoimprint is limited by that of the soft mold. In this work, a modified nanoimprint process by a multi-layer mask method is introduced to enhance the depth of the final lift-off pattern. Pillar photonic crystal is fabricated from the hole pattern defined by NIL to prove the pattern-reversal capability. On its basis, combining the features of overetching technology and the lateral diffusion phenomenon in the metal depositing process, pillar-shaped photonic crystal stamps with different duty cycles have been fabricated by adjusting the etching time of the lift-off layer. Based on this process, a 50-nm line width metal grating is fabricated from a soft stamp with an aspect ratio as low as 1.
2014, Vol. 31 
