Patent ID: 7883954
Filing Date: 2011-02-08
Classification: H01L

Abstract:
1. A method for forming a self-aligned bipolar transistor over a silicon substrate having a well region of a first polarity type, the method comprising: defining a bipolar active region and field region in the bipolar region using a first bipolar mask, the active transistor area having an isolation region separating a bipolar region and a CMOS region, wherein defining the bipolar active area includes, depositing a silicon-germanium-type (SiGe-type) base layer of a second polarity type into the bipolar active region and the field area, and forming inside spacers on the SiGe-type base layer within the bipolar active region; forming an emitter region between the inside spacers in the bipolar active region, wherein forming the emitter region includes, defining an extrinsic base region using a second bipolar mask, removing material in the SiGe-type base layer as a function of masking protection provided by the second bipolar mask, implanting a collector region within the CMOS region; and defining at least one contact area for each of the extrinsic base region, the emitter region, and the collector region of the active transistor areas.