Intrinsic to Extrinsic Base Link
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
In those poly base processes where either the pre-emitter or post-emitter intrinsic base is define by the emitter opening, it is difficult to link this intrinsic base to the extrinsic base defined by polysilicon contacts to monocrystalline silicon. The process here disclosed is designed to produce the required link irrespective of the space between the emitter opening and polysilicon base contacts while also providing for an increase in the emitter-to-base breakdown voltage. The polybase structure shown in Fig. 1 is established following definition of the emitter opening 4 in the polysilicon 3 which overlays the silicon wafer prior to sidewall formation processing. Silicon nitride 1 and silicon oxide 2 layers are also shown for reference. 1.