To protect the fabricated SiNPs from possible damage, a thick resist was applied before the deep reactive ion etching procedure (DRIE, Deep RIE Versaline DSE). PR1-12000A1 resist was applied and spincoated at 300 rpm for 10 s and 3000 rpm for 40s, then baked at 120°C for 3 min. The etch mask was exposed to 480mJ/cm 2 divided into 5 short and consecutive exposures. Following exposure, the die was placed in RD6 developer for 8 minutes under constant rotation. BOE solution was used to remove the oxide layer from the unprotected silicon area. The substrate was then placed in the DRIE and etched for 150 loops. The die was separated into individual devices using the dicing saw and placed in warm NMP to remove the remaining resist.