Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr, 20, 01069, Dresden, Germany.
Nanoscale Res Lett. 2009 Sep 3;4(12):1463-8. doi: 10.1007/s11671-009-9421-8.
The effect of illumination on the hydrofluoric acid etching of AlAs sacrificial layers with systematically varied thicknesses in order to release and roll up InGaAs/GaAs bilayers was studied. For thicknesses of AlAs below 10 nm, there were two etching regimes for the area under illumination: one at low illumination intensities, in which the etching and releasing proceeds as expected and one at higher intensities in which the etching and any releasing are completely suppressed. The "etch suppression" area is well defined by the illumination spot, a feature that can be used to create heterogeneously etched regions with a high degree of control, shown here on patterned samples. Together with the studied self-limitation effect, the technique offers a way to determine the position of rolled-up micro- and nanotubes independently from the predefined lithographic pattern.
研究了系统改变厚度的 AlAs 牺牲层在氢氟酸中的各向异性刻蚀，以释放和卷起 InGaAs/GaAs 双层结构。对于厚度低于 10nm 的 AlAs，有两种光照区域的刻蚀模式：一种是在低光照强度下，刻蚀和释放按预期进行；另一种是在更高强度下，刻蚀和任何释放都被完全抑制。“刻蚀抑制”区域由光照光斑清晰定义，这一特性可用于创建具有高度可控性的非均匀刻蚀区域，如图中所示的图案化样品。结合研究中的自限制效应，该技术提供了一种独立于预定义光刻图案确定卷起微纳管位置的方法。
