Theory of dislocations in diamond and silicon and their interaction with hydrogen

Dislocations in semiconductors can be strongly affected by a hydrogen plasm a; core states may be passivated and mobility changed. For example, in sili con the activation barrier For dislocation motion drops by 1.0 eV upon expo sure to H plasma for one hour at 470-540 degreesC. If such an effect were t o be found in diamond, a simple scaling argument would yield an activation energy of 1.9 eV. Here, density functional calculations have been applied t o the 90 degrees partial dislocation in diamond which confirm this predicti on. They also show that, energetically, the soliton model for motion of the 90 degrees partial is as viable as the strained-bond model.