An analytical model for the I-V and C-V characteristics of a non-abrupt n/p-InP epitaxial junction grown by metal organic vapor phase epitaxy

A new approach to analyze the current-voltage (I-V) and 1 MHz capacitance-voltage (C-V) characteristics of a non-abrupt p/n-InP epitaxial junction was developed. The theoretical model took into account the diffusion of shallow-dopant impurities during the fabrication process and also provide a non-destructive way to determine shallow-dopant profiles in p/n-semiconductor epitaxial junctions. Our results suggest that the I-V and C-V characteristics are independent of the diffusion of shallow-dopant impurities in the n-side for a n/p-InP epitaxial junction with a donor impurity concentration N_A=10 ¹⁸ cm^-3. Moreover, for an acceptor impurity concentration is N_D⩾10^-3 N_A, the C-V characteristics can not be analyzed in terms of the Mott-Schottky equation. The verification for our theory was done by comparing the calculated values of the capacitance at 1 MHz and electrical current for a n/p-InP epitaxial junction with those reported in the literature and extracted from the I-V data. Excellent agreement between these values strongly support the validity of our theoretical expression for the I-V and 1 MHz C-V characteristics