A New Isolation Technology for Bipolar Devices by Low Pressure Selective Silicon Epitaxy

The selective silicon epitaxy at low pressure provides good selectivity and flatness. Better selectivity and flatness are easily realized with reducing the epitaxial growth pressure [1]. The good flatness affords bird's head- and beak-free silicon surface. With these advantages, Low Pressure Selective Silicon Epitaxial Isolation (LPSEI) technology will be successfully applied to the VLSI fabrication. In addition, the application to the bipolar LSI will realize a self-alignment of the buried collector with the isolation mask, resulting in the higher integration. This paper reports the application of LPSEI to the bipolar device fabrication.