On Approximate Estimation of Emitters Injection Ability Limit in p-i-n Structures

The classical theory of p-i-n rectifiers operation at high current densities [8] is generalized to the case of incomplete dopants ionization and bandgap narrowing in heavily doped regions. An impact of the following effects on the emitters injection coefficients in 4H-SiC p-i-n structures is shown. The limiting values of minority carriers' charges, which can be stored in heavily doped emitters of drift step recovery diodes, are estimated. A comparative analysis of Si and 4H-SiC p-i-n structures behavior has been carried out. The results of theoretical study are in reasonable agreement with the results of computer simulation in Synopsys Sentaurus TCAD software.