Fabricating insertion structures for metallic wire grid polarizers by nanoimprint and CMP process

Abstract

This paper proposed an efficient process, with high throughput, for manufacturing stable insertion structures inside PMMA substrates through only three steps, i.e., nanoimprint, metal deposition and chemical mechanical polishing (CMP). The insertion structures with potential applications in metallic wire grid polarizers possesses the advantages of being able to avoid the embedded nanostructure from damage due to contamination or stresses during packaging process or transportation. Furthermore, this architecture offers a flatly finished surface to facilitate subsequent processes, such as sealing and packaging in backlight module for LCD. In this paper, the Al wire gratings of the insertion structure with 100nm in linewidth, 240nm in pitch and 235nm in height were successfully replicated into the PMMA substrate of 1cm2. AFM and FE-SEM were utilized to observe the imprinted surface, and the results indicated that the embedded nanostructure underneath a flatly finished surface was obtained. In addition, the extinction ratio of the fabricated device is over 171.8 with high transmittance of 91.6% at a wavelength of 650nm of incident light.