Mechanics Based Approach for Detection and Measurement of Particle Contamination in Proximity Nanofabrication Processes

Abstract

In spite of the great progress made toward addressing the challenge of particle contamination in nanomanufacturing, its deleterious effect on yield is still not negligible. This is particularly true for nanofabrication processes that involve close proximity or contact between two or more surfaces. One such process is JetandFlash Imprint Lithography (JFILâ„¢), which involves the formation of a nanoscale liquid film between a patterned template and a substrate. In this process, the presence of any frontside particle taller than the liquid film thickness, which is typically sub25 nm, can not only disrupt the continuity of this liquid film but also damage the expensive template upon contact. The detection of these particles has typically relied on the use of subwavelength optical techniques such as scatterometry that can suffer from low throughput for nanoscale particles. In this paper, a novel mechanicsbased method has been proposed as an alternative to these techniques. It can provide a nearly 1000 أ— amplification of the particle size, thereby allowing for optical microscopy based detection. This technique has been supported by an experimentally validated multiphysics model which also allows for estimation of the loss in yield and potential contactrelated template damage because of the particle encounter. Also, finer inspection of template damage needs to be carried out over a much smaller area, thereby increasing throughput of the overall process. This technique also has the potential for inline integration, thereby circumventing the need for separate tooling for subwavelength optical inspection of substrates.