Simultaneous formation of poly-poly capacitor, MOS transistor and bipolar transistor on substrate used in production of integrated circuits comprises using polycrystalline silicon to form electrodes

摘要

The simultaneous formation of a poly-poly capacitor, a MOS transistor and a bipolar transistor on a substrate (10) comprises applying and structuring a first layer made from polycrystalline silicon on the substrate to form a first plate electrode of the capacitor and an electrode of the MOS transistor; and applying and structuring a second layer made from a polycrystalline silicon on the substrate to form a second plate electrode of the capacitor and an electrode of the bipolar transistor. The second polycrystalline layer is made from SiGe-polycrystalline silicon. An Independent claim is also included for the production of a poly-poly capacitor. Preferred Features: The electrode of the MOS transistor comprises a polycrystalline gate (20) formed on a gate oxide (22). The gate oxide is formed on the surface of the substrate and the substrate has source and drain regions (14) below the polycrystalline gate.