Comparison of amorphous Mo and Cr disilicides in hydrogenated amorphous silicon

The general features of Mo and Cr disilicides formed in hydrogenated amorph ous silicon (a-Si:H) have been compared. Following deposition of the chromi um and molybdenum films at room temperature the films were annealed over a range of times and temperatures below 350 degrees C. It was found that in b oth cases stable metal disilicides were formed at the interface of a-Si:H w ith the metals. TEM measurements confirmed that the silicides were amorphou s. In both cases the amorphous silicide was only a few nanometers thick wit h the square of the thickness proportional to the annealing time. In the ca se of Mo a much thinner silicide layer was formed. The density derived from the thickness and metal surface density was close to the value for crystal line CrSi2 and MoSi2 for all films formed in the range of temperatures used . The activation energies for the formation process for CrSi2 and MoSi2 wer e approximate to 0.55 eV and approximate to 0.4 eV and their specific resis tivities were approximate to 600 mu Omega cm and approximate to 1000 mu Ome ga cm, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.