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:
We investigate the effect of surface orientation and off-angle for Al-implanted 4H-SiCsamples after high temperature annealing. The samples are obtained from a 4H-SiC (0001) substrate8° off-angled (Si-face 8°off), and (000-1) substrates 8° (C-face 8°off), 4° (C-face 4°off) and lessthan 1° off-angled (C-face ~1°off). An n-type epitaxial layer is deposited on all substrates. Multipleimplantations of Al+ (30~200keV) are carried out at 600°C. The total dose is 8.6 × 1015 cm-2. TheAl-implanted samples are annealed in Ar ambient at 1580°C, 1700°C and 1800°C for 30s using thehybrid super rapid thermal annealing (HS-RTA) equipment.In this study, sheet resistance (Rs), free carrier concentration (Ns), Hall mobility (μ) androot-mean square roughness (Rrms) are used to evaluate the Al-implanted samples after hightemperature annealing. Rs for all Al-implanted samples after annealing at 1800°C for 30s is around18k[removed info]/[removed info]. Rrms for the Al-implanted C-face samples after annealing at 1800°C increases withincreasing off-angle. Rrms for the Al-implanted Si-face 8°off sample after annealing increases withannealing temperature. Rrms for the C-face ~1°off Al-implanted sample after annealing at 1800°C islower than that for the Si-face 8°off Al-implanted sample after annealing at 1700°C, moreover Rsfor the C-face ~1°off sample after annealing at 1800°C is about 10% of that for the Si-face 8°offAl-implanted sample after annealing at 1700°C. It is shown that the C-face ~1°off sample is usefulto fabricate a p+ region with low Rs and low Rrms. If C-face 4H-SiC is used to fabricate devices,devices made on C-face 4H-SiC with low off angle are expected to decrease any problems causedby increase of surface roughness after high temperature annealing (~1800°C)
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.527-529.835.pdf
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