Examination of Horizontal Current Bipolar Transistor (HCBT) reliability characteristics

The reliability characteristics of HCBT are examined for the first time by employing reverse emitter-base (EB) and mixed-mode stresses. Three HCBT structures with different n-collector doping profiles and different oxide etching parameters before polysilicon deposition are measured, exhibiting different behavior at each stress test. Due to the specific HCBT structure, the traps generation causing I_B degradation, occurs at different regions, i.e. at EB pn-junction near both the top and the bottom EB oxide for reverse EB stress and only at the bottom EB oxide for mixed-mode stress, as discovered by TCAD simulations. Pre-deposition oxide etching conditions turned out to be critical for I_B degradation after reverse EB stress, whereas the n-collector vertical doping profile mostly impacts the trap generation after the mixed-mode stress. The 1/f noise characteristics also show the highest degradation for HCBT structures with the highest stress damage.