Characterization of onset tunneling voltage (Vonset) walkout in high-voltage deep trench isolation on SOI

Deep trench isolation (DTI) with “walkout” onset tunneling voltage (V_onset) can cause serious confusion for performance enhancement and process optimization in technology development. The ordinary breakdown voltage (BV) “walkout” phenomenon occurs when a premature avalanche breakdown injects high energy carriers into an oxide so that subsequent stress may causes an increase in oxide breakdown voltage [1]. However, the increase in the V_onset with multiple I-V sweeps for our DTI structures are of very different origins. This is the first report on the characterization of V_onset “walkout” in HV deep trench isolation (DTI) on SOI.