ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
An n-type 8° off-axis 〈0001〉 4H-SiC epitaxial wafer was processed. The n-type epilayerhad doping and thickness of, respectively, ~3 × 1015 cm-3 and ~5 μm. p+/n diodes with notterminated junctions were constructed by a selective area implantation process of 9.2 × 1014 cm-2Al+ ions at 400°C. The diodes had areas in the range 2×10-4-1×10-3cm2. The Al depth profile was6×1019 cm-3 high and 164 nm thick. The post implantation annealing process was done in a highpurity Ar ambient at 1600°C for 30 min. The diode current-voltage characteristics were measured inthe temperature range 25-290°C. Statistics of 50-100 measurements per device type were done.The fraction of diodes that could be modeled as abrupt junctions within the frame of the Shockleytheory decreased with increasing area value, but was always 〉 75%. The ideality factor was 〉 2only at temperatures 〉 200°C and bias values 〈 1 V. The leakage current was extremely weak andremained of the order of 10-9 Acm-2 at 70°C and 500 V reverse bias. 4% of the diodes reached thetheoretical voltage breakdown that was 1030 V. The surface roughness of un-implanted andimplanted regions after diode processing was, respectively, 2 nm and 12 nm
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.527-529.815.pdf
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