NUMERICAL-SIMULATION OF AVALANCHE BREAKDOWN WITHIN INP-INGAAS SAGCM STANDOFF AVALANCHE PHOTODIODES

The breakdown location within a planar InP/In0.53Ga0.47As (InGaAs) sep arate absorption, grading, charge sheet, and multiplication (SAGCM) av alanche photodiode (APD), using the standoff breakdown suppression des ign to replace guard rings, depends on the two-dimensional (2-D) geome try of the Zn diffused well, Since the geometry of this p(+) diffusion is dependent upon the surface etch, the effects of varying the etch d epth (t(standoff)) and length of the sloped etch edge (w(slope)) are s tudied using a two-dimensional drift-diffusion simulator, It is determ ined that the etch depth brackets a region where center breakdown domi nance is possible, To ensure center breakdown within this region it is concluded that there is a maximum value that the slope of the etch wa lls must not exceed.