Rapid Epitaxial Growth of Ion-Implanted Polycrystalline Silicon Films for Bipolar Transistor Emitter Structures and Selective Very Thin Epitaxial Layers
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
Ion implantation into polysilicon-on-silicon can be combined with rapid thermal anneal to form shallow junctions and selective thin epitaxial layers. A limiting factor to the reduction in size, packing density and improved characteristic of high-performance bipolar transistors processed using auto-doped poly emitter is the emitter series resistance. This series resistance is contributed mainly by the poly-material and the poly/single crystal interface. Further, the actual emitter doping profile is critical in determining the emitter efficiency, and, consequently, a delicate balance exists between the emitter series resistance and the emitter efficiency.