Pulsed Electron Beam Annealing Induced Deep Level Defects in Virgin Silicon

Abstract

ABSTRACTDLTS has been used to investigate deep level defects induced by Pulsed Electron Beam Annealing (PEBA) in virgin (100) boron doped silicon. Various PEBA conditions were selected resulting in different molten layer thicknesses, melt front velocities and thermal gradient distributions. Discrete hole traps distributed in the regrowth layer were observed in all the annealed samples. The activation energies and thermal signatures of these levels do not correspond to already known defects except for one level which has been assigned to the carbon interstitial substitutional pair. Carbon contamination during irradiation is the most probable explanation for the creation of this defect. Other discrete hole trap levels are likely to be generated by quenching of the molten layer as far as their profiles do not extend beyond the regrowth layer. Moreover, a broad band of levels, characteristic of extended defects, has been observed only on the samples which have suffererd the highest thermal stresses. This band of levels might be related to the generation of dislocation networks as recently observed by means of T.E.M. on the same PEBA processed samples.