H2-Enhanced Epitaxial Regrowth of Polycrystalline Silicon through Natural Oxide Layers on Silicon Substrates

Abstract

Poly- to single-crystal Si epitaxial regrowth by H₂ annealing was achieved even in the presence of thick interfacial oxide layers up to 2 nm thick. The epitaxial regrowth took place through anomalous layers after the coalescence of the interfacial oxide layers to oxide precipitates. Twins and stacking faults were also grown at the interfaces when the epitaxial regrowth was initiated on the substrates at numerous openings in clusters of the oxide precipitates. TEM and SIMS analyses confirmed a previously-proposed schematic model of the epitaxial regrowth by H₂ annealing and showed that the anomalous layers were composed of coalesced oxide layers and layers supersaturated with oxygen.