Characterization of SiC Materials and Devices by SIMS

Abstract

AbstractBased on the various implanted standards, we have used SIMS (Secondary Ion Mass Spectrometry) to characterize SiC materials and devices. We develop the SIMS analysis on 2'' and 3'' full SiC wafers using our customized sample load chamber at a Cameca 4f magnetic sector SIMS tool. This feature is particularly useful for the on-line control of the wafer processing. With our special mounting skills, we provide SIMS analyses on small patterned area (say 50 microns × 50 microns or larger) of the tiny or large SiC dies. The detailed comparison between the implanted profiles for the major dopants (such as B, Al, and N) measured by SIMS and the simulated profiles by SRIM code [1] will be discussed. The detection limits for selected elements will also be discussed. In addition, it is well know that nitrogen has a very high ionization potential and zero electronic affinity. Therefore, nitrogen is normally profiled with a Cs+ primary beam and monitored negative molecular ions of (matrix+N)- [such as (Al+N)- in Al [2], (Si+N)- in Si, and (C+N)- in SiC]. However, such negative molecular detection mode cannot be applied to the multi-layers with different matrix elements (such as Al/SiC and Cu/SiC samples). Fortunately, like to detect nitrogen in Cu [3], we have found that using a Cs+ primary ion beam and monitoring (Cs2N)+ molecular ions by Cameca magnetic sector SIMS tools, nitrogen in the multi-layer samples including SiC layer can be detected by the (Cs2N)+ detection model [3,4] with a very low profiling energy (such as 2.5keV).