Si/SiGe resonant interband tunnel diode with f_r0 20.2 GHz and peak current density 218 kA/cm² for K-band mixed-signal applications

This letter presents the room-temperature high-frequency operation of Si/SiGe-based resonant interband tunnel diodes that were fabricated by low-temperature molecular beam epitaxy. The resulting devices show a resistive cutoff frequency f_r0 of 20.2 GHz with a peak current density of 218 kA/cm², a speed index of 35.9 mV/ps, and a peak-to-valley current ratio of 1.47. A specific contact resistivity of 5.3×10^-7 Ω·cm² extracted from RF measurements was achieved by Ni silicidation through a P δ-doped quantum well by rapid thermal sintering at 430°C for 30 s. The resulting devices are very good candidates for RF high-power mixed-signal applications. The device structures presented here are compatible with a standard complementary metal-oxide-semiconductor or heterojunction bipolar transistor process.