Buffer Layer Assisted Laser Patterning of Metals on Surfaces

Abstract

A new method is presented for a single pulse laser patterning of metallic thin films. This process is used to form submicron, variable width metallic wires. By employing laser desorption of a physisorbed buffer gas, a grating of gold has been patterned on a Ru(100) substrate under UHV conditions. Upon annealing, the physisorbed layer desorbs and the patterned metallic clusters softly land and strongly attach to the substrate. This versatile technique can be employed with practically any metallic element or molecular species.

Patterning thin metallic film via laser structured weakly bound template

“…The details of the experimental setup were described elsewhere [7,8,10]. The method is schematically shown in Fig.…”

“…A thin metallic layer of gold is then deposited (thermal evaporation, see Ref. [8]) on top of the structured buffer layer at a rate of 0.3 nm/min, as determined in situ by a quartz microbalance. The ablated Xe grating troughs are then filled-up with a smooth layer of metal (gold, 7 ± 2 nm thick), strongly attached to the substrate below.…”

“…2. The laser power used for both the Xe grating formation (1.7-2.2 MW/cm 2 or 0.017-0.022 J/cm 2 ) and the second pulse (3-6 MW/cm 2 or 0.03-0.06 J/cm 2 ) are well below surface damage threshold [7,8,13].…”

“…It is therefore possible to utilize laser ablation of weakly adsorbed buffer layers for the removal and patterning of metallic film deposited on top. This overcomes LITD limitations, and has enabled the patterning of metallic films and clusters on surfaces [7][8][9], and the in situ investigation of clusters surface diffusion [10]. Patterning Xe in the form of monolayer grating as a template for hydrogen sticking to silicon was reported earlier by Williams et al [11].…”

Semiconductor and insulator nanostructures: challenges and opportunities

“…Among others, buffer-layer-assisted-growth (BLAG) [14] or laser-patterning (BLALP) [15], deposition on surfaces pre-patterned by laser interference [16] or focused ion beams (FIB) [17,18] represent other high-resolution and possibly low-cost patterning methods. Deposition through a miniature shadowmask (nanostencil) [19] was lately also proposed as a flexible method to grow directly patterned nanostructures in a single step [20].…”