Uniform delivery of silicon nanoparticles on device quality substrates using spin coating from isopropyl alcohol colloids

Silicon nanoparticles, of predominately 2.9 nm in size, in isopropyl alcohol are spin coated directly on device quality silicon-dioxide layers across 150 mm substrates. Atomic force microscopy (AFM) is used to image the nanoparticle distributions and low levels of agglomeration with apparently regular internanoparticle distances are observed. AFM depth profiling of the nanoparticle size is in agreement with independent high resolution transmission electron microscopy measurements. Hartree-Fock based atomistic simulations confirm the possible formation of Si nanoparticle/isopropanol complexes with a calculated electrostatic binding energy of 30 meV, which is slightly larger than the room temperature thermal agitation energy. The low levels of agglomeration can be explained in terms of such complexes that may regulate the internanoparticle and nanoparticle-solvent interactions.