Boron carbide crystals ranging in size from 50 microns to several millimeters have been grown from a copper-boron carbide flux at temperatures from 1500°C to 1750°C. The crystal size increased with growth temperature although copper evaporation limited growth at the higher temperatures. Synchrotron X-ray Laue patterns were indexed according to (001) orientation boron carbide structure, indicating the bulk crystals were single crystalline with {001} growth facets. Raman spectrum of boron carbide indicates an improved crystal quality compared to the source powder, but peaks of crystals grown from 11B -enriched source shifted to the lower energy by 1-4 cm−1 from literature values, possibly due to the boron isotope dependency. Five fold symmetry defects and twin planes were common as observed by optical microscope and scanning electron microscope. Raindrop shape etch pits were formed after defect selective etching in molten potassium hydroxide at 600°C for 6 minutes. Typically, the etch pit density was on the order of 106/cm2.
Quantitative two-dimensional (2D) dopant profiling for 0.25 micron CMOS technology was demonstrated using secondary ion mass-spectrometry (SIMS) and scanning capacitance spectroscopy (SCS). P-well and N-well dopant profiles measured by 2D SIMS are in agreement with TSUPREM4 (TS4) simulations. TS4 was pre-calibrated to the specific technology using 1D SIMS and electrical data. 2D SIMS, TS4 and SCS show agreement on the well boundary location. SCS is an advanced form of scanning capacitance microscopy (SCM) devised for pn-junction delineation. 2D SIMS dopant profiling with lateral resolution of 10 nm (limited by the lithography pixel size) and sensitivity of 1~1 0 '~ cm" was realized on commercial equipment.
\
IntroductionThe goal of this study is to demonstrate capabilities of recently developed two-dimensional (2D) secondary ion mass-spectrometry (SIMS) and scanning capacitance spectroscopy (SCS) techniques for quantitative 2D dopant analysis. SIMS is the only doping characterization technique that directly measures dopant concentration. 2D SIMS was invented by Hill, Dowsett and Cooke (1) and improved lately by using a MoirC pattern design for the test structure (2).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.