In this letter we report for the first time the fabrication of bulk‐quality bipolar transistors in low‐temperature (Tdep=800 °C) epitaxial silicon. The epitaxial layers were deposited by an ultra‐low pressure chemical vapor deposition technique utilizing aninsitupredeposition argon sputter clean. The critical parameter affecting the quality of the epitaxial films is the deposition temperature. The junction leakage current decreases by two orders of magnitude, the ideality factor improves from 1.36 to 1.04, and the minority‐carrier lifetime increases from 1.3 to 46 &mgr;s as the deposition temperature is increased from 750 to 800 °C. Analysis of the base‐emitter and base‐collector junction characteristics indicates that bipolar transistors fabricated in epitaxial films deposited at 800 °C have characteristicsatleastas good as control fabricated in bulk silicon.