DEEP-LEVEL TRANSIENT SPECTROSCOPY AND ELECTRICAL CHARACTERIZATION OF ION-IMPLANTED P-N-JUNCTIONS INTO UNDOPED INP

Current-voltage, small-signal measurements, and deep-level transient s pectroscopy (DLTS) spectra of p-n junctions made by Mg implantation in to undoped InP are described. The I-V characteristics show that the do minant conduction mechanism at forward bias is recombination in the sp ace-charge zone, whereas a thermally activated tunneling mechanism inv olving a trap at 0.32 eV dominates at reverse bias. Five deep levels l ocated in the upper-half of the band gap were detected in the junction s by DLTS measurements, three of which (at 0.6, 0.45, and 0.425 eV) we re found to appear due to rapid thermal annealing. The origin of the o ther two levels, at 0.31 and 0.285 eV, can be ascribed to implantation damage. Admittance spectroscopy measurements showed the presence of t hree levels at 0.44, 0.415, and 0.30 eV, all in agreement with those f ound by DLTS. The DLTS measurements showed that the concentration of d eep levels decreased after longer annealing times, and that the concen tration of deep levels due to the implantation increased after additio nal P or Si implantations. This explains the influence of annealing ti me and additional implantations on the I-V characteristics of the junc tions. (C) 1995 American Institute of Physics.