SiGe HBT Technology Based on a 0.13- $\mu{\rm m}$ Process Featuring an ${f}_{\rm MAX}$ of 325 GHz

A self-aligned SiGe HBT technology achieving a cutoff frequency (f
_T
) of 253 GHz was developed using a selective SiGe epitaxial growth process. Germanium concentration in an i-SiGe layer just under a p
⁺
intrinsic base region was raised to 27.4% to improve f
_T
, and boron concentration in the intrinsic base region reached 2.4 × 10
²⁰
cm
^-3
as a deposition to maintain a breakdown voltage of 1.5 V. A 0.13-μm SiGe BiCMOS technology geometrically advanced from an earlier 0.18-μm version shrinks the emitter width from 0.2 to 0.12 μm to reduce collector-base capacitance and base resistance. It achieves a maximum oscillation frequency (f
_MAX
) of 325 GHz. This technology can be applied to optical and mm wave communication systems.