The influence of growth conditions on carrier lifetime in 4H-SiC epilayers
2013 (English)In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 381, 43-50 p.Article in journal (Refereed) Published
4H-SiC homoepitaxial layers have been grown in a horizontal hot-wall CVD (chemical vapor deposition) reactor and the measured carrier lifetimes have been correlated to the CVD growth conditions. Two different generations of reactors were compared, resulting in measured carrier lifetimes in two different orders of magnitude, from a few hundreds of ns to a few ms. The variations in measured carrier lifetime were correlated to deep level concentrations of the Z(1/2) center and the D-1 center, seen by photoluminescence. Decreasing the growth temperature clearly prolonged the carrier life time and showed lower Z(1/2) concentrations, where as lowering the growth rate only showed a small improvement of the carrier lifetime and no obvious tendencyin Z(1/2) defect concentrations, indicating that Z(1/2) is not the only defect limiting the carrier lifetime. Increasing the C/Si ratio resulted in decreasing Z(1/2) concentrations, indicating the carbon vacancy nature of the defect. However, carrier lifetime measurements showed maximum values for a C/Si ratio of 1 but otherwise an increasing tendency for increasing C/Si ratios. The reactor giving higher carrier lifetimes, correspondingly also showed lower Z(1/2) concentrations indicating the lifetime limiting property of Z(1/2). Furthermore, the D-1 defect intensity increased with growth temperature and decreased with increasing C/Si ratio, similar to the Z(1/2) concentration.
Place, publisher, year, edition, pages
Elsevier , 2013. Vol. 381, 43-50 p.
Atomic force microscopy, Characterization, Chemical vapor deposition processes, Hot-wall epitaxy, Semiconducting materials, Bipolar transistors
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-98658DOI: 10.1016/j.jcrysgro.2013.06.037ISI: 000324303500009OAI: oai:DiVA.org:liu-98658DiVA: diva2:655277
Funding Agencies|Swedish Research Council (VR)||Advanced Functional Materials (AFM)||Swedish Foundation for Strategic Research (SSF)||2013-10-102013-10-102016-05-19