Polycrystalline silicon produced by Ni–silicide mediated crystallization of amorphous silicon in an electric field

Crystallization of amorphous silicon (a-Si) by Ni–silicide mediated crystallization (SMC) has been studied in an electric field with Ni area density between 3.3×1013 and 5.7×1014 atoms/cm2 on the a-Si. The needlelike crystallites of ∼1000 A in width and several micron length grow in the 〈111〉 directions with the 〈011〉 normal to the film surface when Ni area density was between 5.1×1013 and 2.9×1014 atoms/cm2. However, dendritic crystallites have been found in the a-Si matrix without complete crystallization of the a-Si when the Ni area density was 3.3×1013 atoms/cm2. The field-effect mobility of the thin-film transistor using the SMC poly-Si was 60–112 cm2/V s when the average Ni bulk density in the poly-Si was around 3.0×1018 atoms/cm3, and it decreases with increasing Ni density.