Patent ID: 8525300

Claim:
An apparatus, comprising: a bipolar junction transistor (BJT) device that includes: a collector disposed in a substrate, the collector including: a first doped element and a second doped element disposed over the first doped element, wherein the first and second doped elements each have a first doping polarity, and wherein the second doped element has a greater doping concentration level than the first doped element; a base disposed in the substrate and adjacent to the collector, the base including: a third doped element having a second doping polarity different from the first doping polarity, wherein a p-n junction is formed between the third doped element and one of the first and second doped elements; and an emitter disposed over the base, the emitter including a fourth doped element having the first doping polarity, wherein the fourth doped element has a greater doping concentration level than the third doped element.