Thermal stability and electrical properties of hydrogenated amorphous carbon film

The thermal stability of a plasma-deposited amorphous carbon film was enhanced by using acetylene heavily diluted with He. The film preserved its hardness even after annealing at ≅590°C in Ar/H2, while a film deposited in similar conditions in an acetylene/Ar mixture softened significantly. The I-V characteristics of n- and p-type Si/amorphous carbon heterojunctions showed a 0.2 eV discrepancy. This is attributed to an offset in the conduction band of the amorphous carbon with respect to Si. © 1994 American Institute of Physics.