Photo-Mask-Based Multi-Beam-Interference Lithography for Wafer-Scale-Integration of Photonic Crystal Devices

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

Objective Conventional lithographic techniques, though highly developed, cannot produce three-dimensional structures in a single step. However, such structures are needed to implement the photonic crystal devices which are envisioned to produce the first truly dense integrated photonic circuits and systems. Multiple Beam Interference Lithography (MBIL) offers a promising technique for the fabrication of photonic crystal devices. However, MBIL, in its present form, is not compatible with 1) microelectronics manufacturing or with 2) integration of multiple circuit elements. The objective of the present research is to overcome these shortcomings by developing a new photo-mask concept that allows the fabrication and integration of a multiplicity of optimized photonic crystal devices, in parallel, across an entire wafer. Intellectual Merit However, the path to achieving such a fabrication breakthrough is impeded by the limited design space for interference patterns that is currently available. The intellectual merit of the present research lies in the dramatic definition and application of an exhaustive set of conditions for primitive-lattice-vector direction equal contrasts, which, for the first time, show the full richness of interference patterns usable with both positive and negative photoresists. These results will affect all applications of interference lithography including the photo-mask implementation of this proposal. Broader Impact The use of MBIL to produce dense integrated photonic circuits and systems will, in turn, enable developments in security (through sensing, uninterruptible communications, control, etc.) and in economic growth (through systems that provide efficient interactive access to a broad range of business, medical, financial, research, and data base information.).