Planarized self-aligned double-polysilicon bipolar technology

The combination of self-aligned double-polysilicon bipolar technology with the trench isolation technique and planarized field oxide and polysilicon regions results in a high-performance bipolar VLSI process, planarized at all mask levels. The planarization approach simplifies photolithography. It also eliminates deformation and discontinuities of polysilicon lines over severe topography and problems with polysilicon residue after RIE steps. A SWAMI process is used to define and isolate both polysilicon layers.<
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