Gallium Assisted PECVD Synthesis of Silicon Nanowires

Within the here presented experiments, we researched the gallium assisted growth of silicon nanowires. For previous deposition of the small gallium droplet-like islands, two different modifications of MW-PECVD were tested. First experiments were performed by standard liquid delivery of the Ga containing chemical. In current experiments, the chemical is transported by vapor draw out of a heat able precursor container and pulsed into a carrier gas flow. In both cases a pure organometallic precursor, trimethylgallium was used as gallium source. The results of both delivery methods were compared. As substrates differently treated <111> and <100> oriented p-doped silicon wafers were used. For the subsequently silicon super saturation similarly MW-PECVD was used as growth method. Silane acted as silicon source. Argon and hydrogen worked as plasma enhanced gases. Differences in the growth of the wires due to the change in Ga deposition and the different treatment of the substrates were analyzed