An improved approach to fabricate distributed feedback laser based on nanoimprint lithography

摘要

The soft-stamp nanoimprint lithography (NIL) has been widely used to improve the quality and uniformity of the large area substrate. However, the soft-stamp easily deforms due to the high pressure during the manufacture process with subsequently leading to the duplicated pattern distortion. In this paper, an optimized NIL process named by High Pressure Difference (HPD) NIL is proposed to fabricate the distributed feedback (DFB) laser, in which a pressure variation with a high contrast and low absolute value during the process instead of the fixed high pressure is introduced to ameliorate the imprinting quality. Meanwhile, the multi-layer mask is employed to remove the residual resist, and effectively improve the overgrowth quality of the grating and the laser performance.