A novel high voltage bipolar technology featuring trench-isolated base

Abstract

In this paper, we present a novel bipolar technology featuring the trench-isolated base. When employed for a conventional 2 /spl mu/m process, the trench isolation reduces both the surface leakage and current gain of the parasitic lateral pnp transistor by at least one order, which results in the improvement of the punchthrough-induced breakdown behavior by almost a factor of two. The depletion capacitance is also diminished by about 60% thanks to the decrease of the effective base-collector junction area, suggesting that the trench isolation is a viable approach even for high frequency as well as for high voltage applications.