On Miller´s approximation in Silicon plane junctions

A comparison is made between the avalanche multiplication functions of n⁺-p and p⁺-n junctions, taking into account the carrier generation in the space-charge region. Results for one-sided and for Gauss-diffused p⁺-n and n⁺-p junctions are given. The avalanche multiplication factorMcan be approximated by Miller´s relationship with exponentnbetween 7 and 3 for bulk impurity concentrations between 10¹³and 10¹⁷cm^-3for one-sided p⁺-n junctions, whereas this relationship does not apply for one-sided n⁺-p junctions; also, p⁺-n junctions exhibit harder breakdown characteristics than their n⁺-p counterparts. Gauss-diffused junctions of both p⁺-n and n⁺-p types do not observe Miller´s relationship; however, p⁺-n junctions still maintain harder breakdown characteristics than n⁺-p junctions.