Novel Top-Down Wafer-Scale Fabrication of Single Crystal Silicon Nanowires

Abstract

A new low-cost, top-down nanowire fabrication technology is presented not requiring nanolithography and suitable for any conventional microtechnology cleanroom facility. This novel wafer-scale process technology uses a combination of angled thin-film deposition and etching of a metal layer in a precisely defined cavity with a single micrometer-scale photolithography step. Electrically functional silicon and metallic nanowires with lengths up to several millimeters, lateral widths of 100 nm, and thicknesses 20 nm have been realized and tested. Device characterization includes a general description of device operation, electrochemical biasing, and sensitivity for sensor applications followed by electrical measurements showing linear i-v characteristics with specific contact resistivity rhoc approximately 4 x 10-4 ohm's cm2 and electrochemical behavior of the oxidized silicon nanowires is described with the site-binding model.

Top-Down Processed SOI Nanowire Devices for Biomedical Applications

“…We varied the nanowire designs in lengths (10,20, or 40 µm) since longer wires were reported to have advantages compared to shorter ones. By tuning the wet etching times we achieved very small wires having a bottom width of only 70 nm (with lengths up to 40 µm), while maintaining very smooth surfaces compared to other fabrication methods (34). A detailed description of the first (35) and the second process run (36) was published previously.…”

“…In all related works, different methods for SiNW fabrication are described (14)(15)(16)(28)(29)(30)(31)(32)(33)(34)(35). The fabrication processes can be divided into two categories: the "bottom-up" approach that is usually based on the vapor-liquid-solid growth method (VLS) with metal precursers (mostly Au) and the "top-down" approach that is based on advanced lithography techniques.…”

Electrothermal phenomena in zinc oxide nanowires and contacts

“…Electrothermal transport data for relevant materials are examined to assess the impact of relative heating on an array of nanowire devices proposed for energy conversion applications. Figure 4.2 shows the relative heating versus specific contact resistivity for silicon [36,[44][45][46][47][48], gallium nitride [38,[49][50][51][52], and zinc oxide [2,[53][54][55]. Using data reported by previous studies, the relative heat generation rate is determined assuming typical metal-nanowire contact length, nanowire length, and device current of 1 µm, 10 µm, and 1 µA, respectively.…”

Realization of an Antireflection Nanopore Array for Black Si Solar Energy Utilization

“…Sub-ten-nanometer pattern generation commonly utilizes electron beam lithography, which is time-consuming and expensive [14,15]. Another popular Si nanofabrication technology is standard RIE, which is aided by advanced lithography techniques, [16,17] such as photolithography, nanosphere lithography, and nanoimprint lithography.…”