The present invention provides a bipolar transistor located on a semiconductor wafer substrate. The bipolar transistor may comprise a collector located in the semiconductor wafer substrate, a base located in the collector, and an emitter located on the base and in contact with at least a portion of the base, wherein the emitter has a low K layer located therein. The low K layer may be, for example, located proximate a side of the emitter, or it may be located proximate opposing sides of the emitter. In all embodiments, however, the low K layer does not interfere with the proper functioning of the bipolar transistor, and substantially reduces the emitter-base capacitance typically associated with conventional bipolar transistors.