Amorphous Si1-xCx layers were deposited, by means of low-pressure chemical vapor techniques, onto Si substrates. These layers exhibited a wide optical band-gap and an atomically sharp interface, and were combined with P-doped polycrystalline layers so as to form a 2-layer emitter structure. It was found that the addition of PH3 during growth markedly changed the structural properties of the layers. The P distribution, and the stability during annealing of these materials, were studied by annealing the specimens (N2, 800 to 900C). At higher temperatures, P diffused (table 155) in the amorphous Si1-xCx, and accumulated at the Si1-xCx/Si interface. The presence of P also promoted the formation of nanocrystalline -SiC crystals. The latter crystals greatly enhanced the diffusion of P in the Si1-xCx.

M.J.J.Theunissen, A.M.C.Martens, J.B.Clegg, P.C.Zalm, D.E.W.Vandenhoudt: Journal of the Electrochemical Society, 1995, 142[1], 226-31

Table 155

Diffusivities of P in Si0.55C0.45