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Oxygen Impurities and Defects in Epitaxial Layer SiC and SiC Wafer Characterized by Room and Low Temperatures FTIRSiC as a highly promising semiconducting material has received increasing attention in the last decade. The impurities such as oxygen and hydrogen have a great effect in electronic properties of semiconducting materials. In this study, the FTIR spectra were measured at room temperature (25 C) and low temperature (-70 C) for an n-type SiC substrate, a p-type epitaxial layer SiC, and patterned Ta on a p-type epitaxial layer SiC sample. The oxygen related IR peaks were measured for all three samples at room and low temperatures. The peak at 1105 cm(exp -1) is the result of a substitutional carbon and a interstitial oxygen in SiC. The concentration of the impurity oxygen increases in the SiC epitaxial layer during the CVD and electron beam processes. For the n-type SiC substrate, this peak does not appear. The peak at 905 cm(exp -1) exists in the IR spectra only for two epitaxial layer on p-type SiC substrate samples. This peak is related to oxygen vacancy centers in SiC, which are introduced in the CVD epitaxial growth process. At low temperature, the peak at 1105 cm(exp -1) shifts down and the peak at 905 cm(exp -1) shifts up for the epitaxial layer SiC samples. It can be explained that, at low temperatures, the stress increases due to the distorted bonds. The study shows that FTIR is a very effective method to evaluate low concentration impurities in SiC.
Document ID
20000032221
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Lu, W. J.
(Fisk Univ. Nashville, TN United States)
Collins, W. E.
(Fisk Univ. Nashville, TN United States)
Shi, D. T.
(Fisk Univ. Nashville, TN United States)
Tung, Y. S.
(Fisk Univ. Nashville, TN United States)
Larkin, D. J.
(NASA Lewis Research Center Cleveland, OH United States)
Date Acquired
August 19, 2013
Publication Date
February 22, 1998
Publication Information
Publication: NASA University Research Centers Technical Advances in Aeronautics, Space Sciences and Technology, Earth Systems Sciences, Global Hydrology, and Education
Volume: s 2 and 3
Subject Category
Solid-State Physics
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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