Self-organized laser functionalization (SOLF) is an advanced manufacturing technique that creates self-organized micro- and nano-scale structures on the surface of objects via scanning with ultrashort laser pulses. SOLF structures can enhance surface properties for a wide variety of applications including two-phase heat transfer, microfluidics, catalysis, and radiative heat transfer. While the influence of the laser parameters on the final structure morphology is well understood, a relatively underexplored aspect of SOLF is the position of the structures relative to the unprocessed surface and the amount of material removed. Gaining an understanding of the position of the microstructures and of the amount of material removed is critical for many applications and helps reveal some of the fundamental mechanisms underlying the microstructure formation. In this work, we explore the recession of SOLF microstructures and corresponding volumetric material removal over a large range of laser parameters. A sweeping parameter study is performed on silicon to identify the range of laser parameters that produce structures. Scanning electron microscopy is used to classify the microstructures. Laser scanning confocal microscopy (LSCM) is used to measure the size of the produced structures and determine their position relative to the original unprocessed silicon surface. The volumetric material removed is also calculated based on the LSCM data. Trends in the microstructure heights and recession are identified over an extremely large laser parameter space. These trends give insight into fundamental structure formation dynamics and provide greater control over the final surface features for future applications.
Keywords
- Self-Organized Laser Functionalization
- Silicon Processing
- Surface Processing