Near-surface lateral vacancy migration in O +-implanted SiC studied by positron re-emission microscopy

• Published in: Applied surface science Vol. 149; no. 1; pp. 135 - 139
• Main Authors: Burrows, C.P, Knights, A.P, Coleman, P.G
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-08-1999; Elsevier Science
• Subjects: Composition; defects and impurities; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Defects and impurities in crystals; microstructure; Exact sciences and technology; Microscopy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other interactions of matter with particles and radiation; Physics; Point defects (vacancies, interstitials, color centers, etc.) and defect clusters; Positron; Positron annihilation; Silicon carbide; Solid surfaces and solid-solid interfaces; Structure of solids and liquids; crystallography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Vacancies; 79.20.Mb; PLM; 07.78.+s; 61.72.Ji; Vacancies; Silicon carbide; IL; Microscopy; SG; OE; 78.70.Bj; Positron; Ion implantation; Inorganic compounds; Semiconductor materials; Surface defect; Migration; Positrons; Silicon carbides; Experimental study
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/S0169-4332(99)00188-9

The areal distribution of near-surface defects created by the implantation of O
+ ions into 6H–SiC through chemically-deposited masks has been studied by reflection-geometry positron re-emission microscopy (PRM). PRM images were obtained for ion doses of 1×10
13 and 1×10
14 cm
−2. The ratios of re-emitted positron intensities from unmasked and masked regions of the two samples were measured to be 78(3)% and 45(3)%, respectively. These results are consistent with the trapping of thermalised positrons prior to reaching the exit surface; the sharpness of images obtained from the low fluence sample is also consistent with work-function, rather than epithermal, emission from the sample. Removal of the instrumental resolution function from the image from the higher fluence sample shows evidence of lateral subsurface vacancy migration characterised by a broadening function of 44(5) μm F.W.H.M.