SBIR Phase II: Nanometer-Level Fidelity in Maskless Lithography

This Small Business Innovation Research (SBIR) Phase II project aims to develop a maskless photolithography system by ensuring that the patterns it writes are free of positional error (i.e., distortion) to the sub-1 nm level. In traditional photolithography, distortion minimization depends on the design and construction of an image-projection lens and on the fidelity of the mask. Measuring 1nm and sub-1nm geometric imperfections is intellectually challenging. In Phase I project, a confocal-metrology-system (CMS) was developed to determine focal spot positions from the phase of periodic signals produced when a master reference grating is scanned through the focal spots. In this Phase II project, corrections will be applied in the pattern-writing software. Errors in the X-Y position of the stage will be determined by comparing readings from a master reference grating with readings from the encoder built into the stage. Once known, systematic errors will be corrected in software through a process known as refracturing. The CMS will enable the systems located at disparate sites to reference a common fiducial, thus achieving identical patterning fidelity. The broader/commercial impacts of this project will be the potential to provide a maskless photolithography tool with high fidelity for low-volume manufacturing of custom electronics and photonics, and for future nanomanufacturing. In comparison to existing electron-beam systems, this maskless photolithography tool will provide higher throughput, non-vacuum processing, large-area continuous patterning, lower cost and freedom from distortion to the sub-1nm level.