Oriented growth of location-controlled Si crystal grains by Ni nano-imprint and excimer laser annealing

A new method of controlling the location and orientation of Si crystal grains by combining metal (Ni) nano-imprint and excimer laser annealing (ELA) using a double-layered Si thin-film structure was successfully demonstrated. Ni nano-imprint at the surface of the first amorphous Si (a-Si) film (25 nm thick) was performed to create {111}-oriented Si-crystal nuclei that act as the seed for the subsequent crystallization using ELA. The annealing that induces the formation of nuclei at the imprinted sites was carried out at temperatures below 450°C to meet the requirement of low-temperature process. After the removal of Ni or Ni-silicide, the second a-Si film (75 nm thick) was deposited. XeCl-laser-based ELA of the sample resulted in the formation of approximately 2 μm sized Si crystal grains at controlled positions. Electron backscattering pattern (EBSP) analysis showed that the surface-normal orientation of all the location-controlled grains distributed less than 10° from 〈111〉 crystal axis.