Arsenic emitter high-performance transistor

Silicon n-p-n transistors with gain-bandwidth, fT, of 13 GHz and current gain β of 280 have been fabricated by using arsenic capsule diffusion to produce the emitter region. Devices have been fabricated With the same epitaxial and diffusion processes up to emitter diffusion, and then emitter regions were formed by either arsenic or phosphorus diffusion. For the same mask geometry, devices with an arsenic emitter showed 60% improvement over those with a phosphorus emitter in fTand β under the condition of similar intrinsic base sheet resistance, which is a measure of total impurity in the active base region under the emitter. For comparable base width, arsenic-emitter devices show much higher collector punch-through voltage. Experimental data on a comparison between various dc and ac characteristics and circuit speed with these two types of devices will be presented as will data on various emitter geometries with arsenic emitter diffusion.