SiGe HBT Profiles With Enhanced Inverse-Mode Operation and Their Impact on Single-Event Transients

The doping profile of silicon-germanium heterojunction bipolar transistors (SiGe HBTs) is modified to enhance inverse-mode (IM) device operation. Device improvements are presented in this paper, along with the impact the alterations have on the radiation effects response. This investigation represents the first published occurrence of a radiation-hardening-by-process approach in a SiGe HBT technology. Results show that improving IM performance can degrade the radiation tolerance of the structure. Total ionizing dose and single-event transient (SET) results are provided along with an analysis that utilizes TCAD simulation. An additional profile modification using an implanted vertical superjunction is included in this paper to expand upon how nonradiation specific device modifications can impact SETs.