Germanium nanowire synthesis using a localized heat source and a comparison to synthesis in a uniform temperature environment

摘要

In this work, we compare the synthesis of germanium nanowires (GeNWs) using a highly localized heat source with GeNWs synthesized in a uniform temperature environment. With the exception of thermal environment, identical synthesis parameters were maintained in all experiments. The localized heat source, a suspended silicon microscale heater, enabled site-specific synthesis and thus the direct integration of GeNWs which is presented for the first time. The effect of heat source implementation and local temperature gradients on the resulting nanowires is assessed in terms of resulting nanowire geometry, growth rate, and quality. Overall, we note a reduction in growth rate and elevated kinking levels in locally synthesized nanowires when compared to nanowires synthesized in uniform temperature processes. The taper which typically characterizes GeNWs, however, is significantly reduced. Finally, we explore branching behavior which hints of instabilities in the synthesis process as nanowires grow away from the heat source.