Extended-area deposition of homogeneously sized nanoparticles using modified inert gas condensation technique

Abstract

The inert gas condensation (IGC) process was modified to synthesize and directly deposit thin films of homogeneously sized NanoParticles (NPs) over a large surface area. We replaced the single 2 mm hole that is used to extract the nanoparticle beam with a multiple-hole pattern consisting of 25 holes, each 0.31 mm in diameter, arranged as a 5 × 5 array. The resultant deposition covered a larger substrate area of 144 mm2 but the NPs were deposited only on the substrate area in front of the holes, leaving the rest of the area devoid of NPs. Thus in order to achieve deposition over the entire substrate area a single slit gasket was used and the substrate was continuously rotated during the synthesis process using an 8 rpm motor. The slit used was 20 mm long and 0.13 mm wide. A deposition over the entire substrate area of 350 mm2 was achieved using this single slit IGC. Homogeneous NPs of Copper, Silver, Indium Nitride and Aluminum Nitride doped with Erbium, were deposited over (111) p-type Silicon wafer. Field emission scanning electron microscopy study demonstrated uniformity in the size of these NPs. Thus NP deposition area was increased from 1–2 mm2 to 350 mm2 using our modifications to the standard IGC.