A CHARACTERIZATION OF THE P/P+ EPITAXIAL AND SUBSTRATE INTERFACE USING THE PULSED METAL-OXIDE-SEMICONDUCTOR CAPACITANCE-TIME TRANSIENT ANALYSIS

Epitaxial silicon wafers having an epitaxial layer of 110 μm thickness were nucleation annealed at 750 °C for times up to 72 h. This was followed by 16-h growth anneal at 1050 °C. After the annealing sequence, the minority-carrier lifetime of the epitaxial layer was characterized using the pulsed metal-oxide-semiconductor capacitance-time transient analysis. A significant improvement in the generation lifetime of the epitaxial layer of the samples which received the nucleation anneal was observed. In contrast, the nucleation anneal appeared to have no effect on the recombination lifetime. From the experimental results, the electronic defects responsible for the limitation of the recombination lifetime of a thin epitaxial layer were hypothesized to be the complexes of metallic impurity and boron originating in the heavily doped substrate region of the epitaxial wafer.