280 GHz f/sub T/ InP DHBT with 1.2 /spl mu/m/sup 2/ base-emitter junction area in MBE regrown-emitter technology

We report an InP/InGaAs/InP double heterojunction bipolar transistor (DHBT) with a 0.3 /spl mu/m/spl times/4 /spl mu/m regrown base-emitter junction. The HBT exhibits a 280 GHz current gain cutoff frequency (f/sub /spl tau//) and 148 GHz power gain cutoff frequency (f/sub max/). This DHBT was fabricated in a molecular beam epitaxy (MBE) regrown-emitter technology and has the highest f/sub /spl tau// yet reported for a III-V regrown-emitter HBT. The device has V/sub CE.sat/<0.9 V even at J/sub E/=11 mA //spl mu/m/sup 2/, peak AC current gain h/sub 21/=30, and collector breakdown voltage V/sub CEO/=5 V. In this technology, the area of base-emitter junction has been scaled to as small as 1.2 /spl mu/m/sup 2/ while a larger-area extrinsic emitter contact maintains a low 11 /spl Omega/ emitter access resistance.