Breakdown in Silicon pn Junctions†

Abstract

ABSTRACT Some useful empirical relationships on the variation of effective ionization coefficients associated with the avalanche breakdown phenomena in pn junctions are derived from measurements on silicon alloy junctions, in the range of impurity concentrations of the basic material from 5 × 1013/cm3 to 10l8/cm3. These results show that for electric field strengths from 1.5 × 203 v/ cm to 3 × 105 v /cm the effective ionization coefficient is equal to 18E7; from 3 × 10 7 v/cm to 6 × 105 v/cm it is of the form 2.7 × 10 5 exp–(6.45/E) and for values greater than 6 × 105 v/cm the effective ionization coefficient tends to E 105/5 where in all cases E is measured in units of 105 v/cm. Some discussion is given on the compatibility of calculations of ionization coefficients derived from breakdown measurements and those from multiplication measurements.