In-situ phosphorus-doped polysilicon emitters deposited on monocrystalline silicon substrates at a temperature of 627 °C and subjected to no additional high-temperature annealing are shown to be capable of giving Gummel numbers G<inf>E</inf>in excess of 10<sup>15</sup> scm<sup>-4</sup>. Polysilicon emitters formed in this way have been used to produce superbeta transistors with performance comparable to the record levels recently reported for MIS emitter devices. In particular, commonemitter current gains β in excess of 30 000 have been obtained at low vcbvalues. Copyright