Paper NS-FrM6
Nanoscale Electron Beam Induced Etching (EBIE)

Friday, October 19, 2007, 9:40 am, Room 616

Traditionally, high-resolution nanomachining utilizes a gallium focused ion beam (FIB) to physically sputter away material or dissociate a precursor material to deposit material. During the process, gallium ions are implanted into the surface of the substrate and leave undesirable effects, such as reduced transmission of clear area repairs in photomasks; otherwise damaging or change the remaining material. The use of electron beam induced processes for high spatial resolution nanopatterning has recently been developed as an alternative to FIB. The electron beam induces the dissociation of a precursor gas to cause a reaction at the surface of the material. This reaction either deposits material or removes material, depending upon the precursor/substrate combination. This presentation focuses on the latter, electron beam induced etching (EBIE) of materials. Electron beam induced etching provides superior spatial resolution and can offer much better etching selectivity compared to FIB. Additionally electrons do not damage the substrate materials because of their relatively small mass compared to gallium ions. This work characterizes the process of high resolution EBIE of various relevant materials. The effects of electron beam parameters such as accelerating voltage, beam current, and the scanning parameters are investigated, as well as the relationship of the beam parameters to the gas parameters such as pressure and injection needle position. Furthermore, various precursor gases were examined, and the effects on spatial resolution, etching rate, and selectivity against other materials are determined. A 3-D Monte Carlo type simulation of the etching process has also been developed and simulation results will be compared to experimental results.