Hydrogen in crystalline silicon: A deep donor?

An analysis of the hydrogen concentration profiles obtained from secondary ion mass spectrometry in boron-doped silicon points to a deep donor hydrogen state located ∼0.1 eV above the Fermi level for intrinsic material. The theoretical model takes into account both neutral and ionized hydrogen diffusion, the latter enhanced by a built-in electric field associated with the hydrogen doping gradient. The activation energies for the two diffusion processes are ∼1.2 and ∼0.8 eV, respectively. A formerly reported discrepancy between low- and high-temperature results is lifted.