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3D Depth Profile Reconstruction of Segregated Impurities Using Secondary Ion Mass Spectrometry
Published on: April 29, 2020
Depth profiling of ion implanted materials with skewed doping distributions using Fourier transform infrared
1Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, Greece. katsidis@materials.uoc.gr
Applied Optics
|January 12, 2008
Summary
This study extends optical analysis methods to simulate complex doping profiles in silicon. Infrared reflectance spectra reveal sensitivities to doping distribution moments, validating the new simulation approach for ion-implanted semiconductors.
Area of Science:
- Materials Science
- Optical Physics
- Semiconductor Device Fabrication
Background:
- The transfer-matrix method is a standard technique for optical analysis of multilayer structures.
- Simulating complex doping profiles, such as those resulting from ion implantation, is crucial for semiconductor device modeling.
- Previous methods may not adequately capture the asymmetry and multi-moment characteristics of annealed implantation profiles.
Purpose of the Study:
- To extend the general transfer-matrix method for optical analysis to simulate asymmetric implantation doping profiles.
- To investigate the sensitivity of infrared reflectance spectra to variations in the moments of free carrier distributions.
- To validate the simulation method using experimental data from arsenic-implanted silicon.
Main Methods:
- Extension of the transfer-matrix method to incorporate four-moment distributions for doping profiles.
- Analysis of infrared reflectance spectra to assess sensitivity to Pearson free carrier distribution moments.
- Experimental implantation of 1.5 MeV and 2.5 MeV arsenic ions into p-type silicon, followed by annealing at 1100°C.
- Comparison of simulated profiles with experimental data, including Rutherford backscattering analysis.
Main Results:
- Demonstrated sensitivity of infrared reflectance spectra to the first four moments of a Pearson free carrier distribution.
- Experimental data from annealed arsenic-implanted silicon suggest the necessity of using two joined Pearson IV distribution segments.
- A twin peak feature observed in the 1.5 MeV implantation case was confirmed by Rutherford backscattering analysis.
Conclusions:
- The extended transfer-matrix method effectively simulates asymmetric doping profiles using multi-moment distributions.
- The study highlights the importance of accurately modeling annealed doping profiles for optical analysis of semiconductors.
- The findings support the use of advanced distribution models for precise simulation of ion-implanted silicon.
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