KCHARACTERIZATION OF POLYCRYSTALLINE SILICON SINGLE-CRYSTAL SILICON INTERFACES AND CORRELATION TO BIPOLAR-TRANSISTOR DEVICE DATA

Depth-resolved secondary-ion mass spectrometry (SIMS) and high-resolution transmission electron microscopy were used to study the composition and structure of the arsenic-doped polycrystalline silicon (polysilicon)-single-crystal silicon interface. This interface remains intact during an 880-degrees-C anneal, with no alignment of the polysilicon occurring. When the interfacial oxide varies from a thin, discontinuous film, to a continuous layer, SIMS analysis is able to quantify differences in the interfacial oxygen content. This interfacial oxygen, expressed as oxygen atoms/cm2, is found to correlate to polysilicon emitter bipolar transistor device current gain.