Depth Profile Analysis of Phosphorus Implanted SiC Structures

Secondary ion mass spectrometry depth profile analyses were performed on two sets of 4H-SiC(0001) substrate samples implanted with phosphorus. Both sets were processed under the same conditions. We implanted the samples with 100 keV (10¹¹-10¹⁴ cm¯²) phosphorus ions through the thin chemical vapor deposition deposited silicon dioxide stopping mask in order to obtain an ultra-shallow implantation profile. After phosphorus implantation, secondary ion mass spectrometry depth profile analysis was performed on the first set of samples and the second set was subjected to thermal oxidation procedure at 1200°C in order to create a dielectric layer. The aim of the oxidation process was formation of the silicon dioxide layer enriched with phosphorus: the element, which is considered to be suitable for trap density reduction. Ion implantation parameters as well as oxidation and chemical etching procedures were examined for the proper incorporation of phosphorus into the subsurface structure of the silicon oxide. Secondary ion mass spectrometry depth profile analysis was performed with Physical Electronics 06-350E sputter ion gun and QMA-410 Balzers quadrupole mass analyser. The analytical parameters such as: 1.7 keV Ar⁺ ion beam digitally scanned over 3×3 mm² area and ion erosion rate of 1.4 nm/min and sampling rate of 0.3 nm, were suitable for samples oxidized after ion implantation.