Characterization of energy levels related to impurities in epitaxial 4H-SiC ion implanted p +n junctions

• Published in: Diamond and related materials Vol. 16; no. 1; pp. 6 - 11
• Main Authors: Menichelli, David, Scaringella, Monica, Moscatelli, Francesco, Bruzzi, Mara, Nipoti, Roberta
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2007; Elsevier
• Subjects: 29.40.Wk Solid-state detectors; 61.72.Ji Point defects: vacancies, interstitials, color centers, etc. and defect clusters; 71.55.Ht Other nonmetals (impurity and defect levels); 81.05.Hd Material science: other semiconductors; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Defect characterization; Defects and impurities in crystals; microstructure; Detectors; Electron states; Exact sciences and technology; Implantation; Impurity and defect levels; Physical radiation effects, radiation damage; Physics; Silicon carbide (SiC); Structure of solids and liquids; crystallography; Defect characterization; 81.05.Hd Material science: other semiconductors; 29.40.Wk Solid-state detectors; 71.55.Ht Other nonmetals (impurity and defect levels); Detectors; 61.72.Ji Point defects: vacancies, interstitials, color centers, etc. and defect clusters; Implantation; Silicon carbide (SiC); Crystal growth; Temperature dependence; Radiation effects; Ion implantation; Epitaxial layers; Energy levels; Semiconductor materials; Thermostimulated conduction; etc. and defect clusters; Silicon carbide (SiC); Implantation; Defect characterization; Detectors; interstitials; Silicon carbides; color centers; Non oxide ceramics; Energy gap; Boron; 29.40.Wk Solid-state detectors; 71.55.Ht Other nonmetals (impurity and defect levels); 81.05.Hd Material science: other semiconductors; 61.72.Ji Point defects: vacancies; p n junctions; Nitrogen additions; Impurity states; Deep energy levels
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2006.03.008

The distribution of energy levels within the bandgap of epitaxial 4H-SiC p +/n junctions was studied. The junction was obtained by Al ion implantation on a nitrogen doped n-type epitaxial substrate. Thermally stimulated currents/capacitance (TSC/TSCAP) as well as current/capacitance deep level transient spectroscopy (I- and C-DLTS) were carried out over a wide temperature range (20–400 K). The two TSC/DLTS peaks associated with N-doping were detected for the first time and their trap signatures determined. Two hole traps relating to deep and shallow boron confirm that a boron contamination occurred during crystal growth. A negligible concentration of the Z 1/2 level, which is usually the dominant level produced by irradiation of ion implant, was measured. The concentrations of all observed traps were significantly lower than nitrogen one, which determines the doping. This evidence supports the high quality of the processed junctions, making these devices particularly attractive for future use in particle detection as well as in optoelectronic applications.