Sub-nm Near-Surface Activation Profiling for Highly Doped Si and Ge Using Differential Hall Effect Metrology (DHEM)

We present Differential Hall Effect Metrology (DHEM) data for very highly phosphorus-doped (~1x1021cm-3) epitaxial Si thin films grown on counter doped Si substrates. Carrier concentration and mobility depth profiles obtained by DHEM showed process conditions suitable for the highest dopant activation and established certain trends for the variation of mobility through the layers. Data was also collected from n-doped Ge epi layers. Reduction of dopant activation in a sample capped by alumina during processing was found to be due to compensating effect of Al diffusing into the film during annealing. Presented data demonstrates the value of DHEM technique for characterization of near-surface dopant activation, especially in low resistance ohmic contact development efforts.