TESCAN ANALYTICS R&D program 2022: Acquisition of EDR technology for our ToF-SIMS

TESCAN ANALYTICS has been offering characterization analyses by ToF-SIMS since the beginning. Having added a liquid nitrogen module allowing the cooling of the sample before or during the analysis in order to preserve the vacuum sensitive molecules on the sample surface, our ToF-SIMS continues to grow.

One of the recurrent analytical problems encountered in ToF-SIMS is the semi-quantification of elements chemical concentrations whose intensity reaches the saturation level of the detector.

This is the case, for example, for alkalis in inorganic glasses or silicon in electronic components.
One way to solve this problem is to reduce the intensity of the primary ions to avoid saturation of the detector. However, this solution is accompanied by a loss of sensitivity on trace elements, which is one of the strong points of the ToF-SIMS technique. This compromise is therefore not an analytically acceptable option.
To solve this problem, a new technology patented and marketed by IONTOF, a manufacturer of innovative instruments for surface analysis of materials, extends by a factor of 100 the dynamic range of counting secondary ions while maintaining a linear response of the detection system: EDR technology for 'Extended Dynamic Range'. 

As part of its 2022 R&D program, TESCAN ANALYTICS has invested several hundred thousand euros to acquire this technology. EDR was successfully implemented this summer on our ToF-SIMS spectrometer and our team of experts is currently developing new analysis methodologies.

Taking as an example the analysis of a Silicon Wafer with and without EDR (see figure 1):

• without EDR, the silicon profile is in the saturation zone, its intensity is thus underestimated which induces a loss of information.
• with EDR, the saturation zone has been pushed back for silicon, its profile is no longer saturated and those of other ions like SiO+ remain unchanged.

The results of the analyses obtained by ToF-SIMS equipped with EDR (surface and depth profiles) will be compared with the results of XPS analyses, acquired on the same samples, in order to develop methods of semi-quantification of the concentrations of the elements of the glass, in extreme surface and depth.
Glass samples of different compositions and having undergone various surface treatments will be analyzed. These methodologies will be transposed to other materials (semiconductors, thermoconductors, ceramics, polymers...).