Study of the correlation between the cutting edge current breakdown and the simulated lateral electrical field boundary in high resistivity silicon detectors with multi-guard ring structure

High resistivity silicon detectors with multi-guard ring structure (MGRS), after being subjected to laser cutting to various distances (L, from 10 μm to 1000 μm) from the outer most guard ring, have been used to investigate the effect of cutting edge current breakdown (CECB). The bias on the outer most guard ring at which CECB starts, or the edge breakdown voltage V_b, increases monotonically with L. This result has been compared to the simulated lateral depletion depth (W_L) from the outer most guard ring as a function of bias voltage V with very good correlation. For a given bias V, CECB occurs if W_L is larger than L, suggesting that current injects as soon as electrical field reaches the cutting edge