Arsenic-Doped High-Resistivity-Silicon Epitaxial Layers for Integrating Low-Capacitance Diodes.

An arsenic doping technique for depositing up to 40-μm-thick high-resistivity layers is presented for fabricating diodes with low RC constants that can be integrated in closely-packed configurations. The doping of the as-grown epi-layers is controlled down to 5 × 10 cm, a value that is solely limited by the cleanness of the epitaxial reactor chamber. To ensure such a low doping concentration, first an As-doped Si seed layer is grown with a concentration of 10 to 10 cm, after which the dopant gas arsine is turned off and a thick lightly-doped epi-layer is deposited.